xref: /openbmc/linux/drivers/usb/core/hub.c (revision e2f1cf25)
1 /*
2  * USB hub driver.
3  *
4  * (C) Copyright 1999 Linus Torvalds
5  * (C) Copyright 1999 Johannes Erdfelt
6  * (C) Copyright 1999 Gregory P. Smith
7  * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
8  *
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/completion.h>
16 #include <linux/sched.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
19 #include <linux/ioctl.h>
20 #include <linux/usb.h>
21 #include <linux/usbdevice_fs.h>
22 #include <linux/usb/hcd.h>
23 #include <linux/usb/otg.h>
24 #include <linux/usb/quirks.h>
25 #include <linux/workqueue.h>
26 #include <linux/mutex.h>
27 #include <linux/random.h>
28 #include <linux/pm_qos.h>
29 
30 #include <asm/uaccess.h>
31 #include <asm/byteorder.h>
32 
33 #include "hub.h"
34 #include "otg_whitelist.h"
35 
36 #define USB_VENDOR_GENESYS_LOGIC		0x05e3
37 #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND	0x01
38 
39 /* Protect struct usb_device->state and ->children members
40  * Note: Both are also protected by ->dev.sem, except that ->state can
41  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
42 static DEFINE_SPINLOCK(device_state_lock);
43 
44 /* workqueue to process hub events */
45 static struct workqueue_struct *hub_wq;
46 static void hub_event(struct work_struct *work);
47 
48 /* synchronize hub-port add/remove and peering operations */
49 DEFINE_MUTEX(usb_port_peer_mutex);
50 
51 /* cycle leds on hubs that aren't blinking for attention */
52 static bool blinkenlights = 0;
53 module_param (blinkenlights, bool, S_IRUGO);
54 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
55 
56 /*
57  * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
58  * 10 seconds to send reply for the initial 64-byte descriptor request.
59  */
60 /* define initial 64-byte descriptor request timeout in milliseconds */
61 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
62 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
63 MODULE_PARM_DESC(initial_descriptor_timeout,
64 		"initial 64-byte descriptor request timeout in milliseconds "
65 		"(default 5000 - 5.0 seconds)");
66 
67 /*
68  * As of 2.6.10 we introduce a new USB device initialization scheme which
69  * closely resembles the way Windows works.  Hopefully it will be compatible
70  * with a wider range of devices than the old scheme.  However some previously
71  * working devices may start giving rise to "device not accepting address"
72  * errors; if that happens the user can try the old scheme by adjusting the
73  * following module parameters.
74  *
75  * For maximum flexibility there are two boolean parameters to control the
76  * hub driver's behavior.  On the first initialization attempt, if the
77  * "old_scheme_first" parameter is set then the old scheme will be used,
78  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
79  * is set, then the driver will make another attempt, using the other scheme.
80  */
81 static bool old_scheme_first = 0;
82 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
83 MODULE_PARM_DESC(old_scheme_first,
84 		 "start with the old device initialization scheme");
85 
86 static bool use_both_schemes = 1;
87 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
88 MODULE_PARM_DESC(use_both_schemes,
89 		"try the other device initialization scheme if the "
90 		"first one fails");
91 
92 /* Mutual exclusion for EHCI CF initialization.  This interferes with
93  * port reset on some companion controllers.
94  */
95 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
96 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
97 
98 #define HUB_DEBOUNCE_TIMEOUT	2000
99 #define HUB_DEBOUNCE_STEP	  25
100 #define HUB_DEBOUNCE_STABLE	 100
101 
102 static void hub_release(struct kref *kref);
103 static int usb_reset_and_verify_device(struct usb_device *udev);
104 
105 static inline char *portspeed(struct usb_hub *hub, int portstatus)
106 {
107 	if (hub_is_superspeed(hub->hdev))
108 		return "5.0 Gb/s";
109 	if (portstatus & USB_PORT_STAT_HIGH_SPEED)
110 		return "480 Mb/s";
111 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
112 		return "1.5 Mb/s";
113 	else
114 		return "12 Mb/s";
115 }
116 
117 /* Note that hdev or one of its children must be locked! */
118 struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
119 {
120 	if (!hdev || !hdev->actconfig || !hdev->maxchild)
121 		return NULL;
122 	return usb_get_intfdata(hdev->actconfig->interface[0]);
123 }
124 
125 int usb_device_supports_lpm(struct usb_device *udev)
126 {
127 	/* USB 2.1 (and greater) devices indicate LPM support through
128 	 * their USB 2.0 Extended Capabilities BOS descriptor.
129 	 */
130 	if (udev->speed == USB_SPEED_HIGH || udev->speed == USB_SPEED_FULL) {
131 		if (udev->bos->ext_cap &&
132 			(USB_LPM_SUPPORT &
133 			 le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
134 			return 1;
135 		return 0;
136 	}
137 
138 	/*
139 	 * According to the USB 3.0 spec, all USB 3.0 devices must support LPM.
140 	 * However, there are some that don't, and they set the U1/U2 exit
141 	 * latencies to zero.
142 	 */
143 	if (!udev->bos->ss_cap) {
144 		dev_info(&udev->dev, "No LPM exit latency info found, disabling LPM.\n");
145 		return 0;
146 	}
147 
148 	if (udev->bos->ss_cap->bU1devExitLat == 0 &&
149 			udev->bos->ss_cap->bU2DevExitLat == 0) {
150 		if (udev->parent)
151 			dev_info(&udev->dev, "LPM exit latency is zeroed, disabling LPM.\n");
152 		else
153 			dev_info(&udev->dev, "We don't know the algorithms for LPM for this host, disabling LPM.\n");
154 		return 0;
155 	}
156 
157 	if (!udev->parent || udev->parent->lpm_capable)
158 		return 1;
159 	return 0;
160 }
161 
162 /*
163  * Set the Maximum Exit Latency (MEL) for the host to initiate a transition from
164  * either U1 or U2.
165  */
166 static void usb_set_lpm_mel(struct usb_device *udev,
167 		struct usb3_lpm_parameters *udev_lpm_params,
168 		unsigned int udev_exit_latency,
169 		struct usb_hub *hub,
170 		struct usb3_lpm_parameters *hub_lpm_params,
171 		unsigned int hub_exit_latency)
172 {
173 	unsigned int total_mel;
174 	unsigned int device_mel;
175 	unsigned int hub_mel;
176 
177 	/*
178 	 * Calculate the time it takes to transition all links from the roothub
179 	 * to the parent hub into U0.  The parent hub must then decode the
180 	 * packet (hub header decode latency) to figure out which port it was
181 	 * bound for.
182 	 *
183 	 * The Hub Header decode latency is expressed in 0.1us intervals (0x1
184 	 * means 0.1us).  Multiply that by 100 to get nanoseconds.
185 	 */
186 	total_mel = hub_lpm_params->mel +
187 		(hub->descriptor->u.ss.bHubHdrDecLat * 100);
188 
189 	/*
190 	 * How long will it take to transition the downstream hub's port into
191 	 * U0?  The greater of either the hub exit latency or the device exit
192 	 * latency.
193 	 *
194 	 * The BOS U1/U2 exit latencies are expressed in 1us intervals.
195 	 * Multiply that by 1000 to get nanoseconds.
196 	 */
197 	device_mel = udev_exit_latency * 1000;
198 	hub_mel = hub_exit_latency * 1000;
199 	if (device_mel > hub_mel)
200 		total_mel += device_mel;
201 	else
202 		total_mel += hub_mel;
203 
204 	udev_lpm_params->mel = total_mel;
205 }
206 
207 /*
208  * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
209  * a transition from either U1 or U2.
210  */
211 static void usb_set_lpm_pel(struct usb_device *udev,
212 		struct usb3_lpm_parameters *udev_lpm_params,
213 		unsigned int udev_exit_latency,
214 		struct usb_hub *hub,
215 		struct usb3_lpm_parameters *hub_lpm_params,
216 		unsigned int hub_exit_latency,
217 		unsigned int port_to_port_exit_latency)
218 {
219 	unsigned int first_link_pel;
220 	unsigned int hub_pel;
221 
222 	/*
223 	 * First, the device sends an LFPS to transition the link between the
224 	 * device and the parent hub into U0.  The exit latency is the bigger of
225 	 * the device exit latency or the hub exit latency.
226 	 */
227 	if (udev_exit_latency > hub_exit_latency)
228 		first_link_pel = udev_exit_latency * 1000;
229 	else
230 		first_link_pel = hub_exit_latency * 1000;
231 
232 	/*
233 	 * When the hub starts to receive the LFPS, there is a slight delay for
234 	 * it to figure out that one of the ports is sending an LFPS.  Then it
235 	 * will forward the LFPS to its upstream link.  The exit latency is the
236 	 * delay, plus the PEL that we calculated for this hub.
237 	 */
238 	hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;
239 
240 	/*
241 	 * According to figure C-7 in the USB 3.0 spec, the PEL for this device
242 	 * is the greater of the two exit latencies.
243 	 */
244 	if (first_link_pel > hub_pel)
245 		udev_lpm_params->pel = first_link_pel;
246 	else
247 		udev_lpm_params->pel = hub_pel;
248 }
249 
250 /*
251  * Set the System Exit Latency (SEL) to indicate the total worst-case time from
252  * when a device initiates a transition to U0, until when it will receive the
253  * first packet from the host controller.
254  *
255  * Section C.1.5.1 describes the four components to this:
256  *  - t1: device PEL
257  *  - t2: time for the ERDY to make it from the device to the host.
258  *  - t3: a host-specific delay to process the ERDY.
259  *  - t4: time for the packet to make it from the host to the device.
260  *
261  * t3 is specific to both the xHCI host and the platform the host is integrated
262  * into.  The Intel HW folks have said it's negligible, FIXME if a different
263  * vendor says otherwise.
264  */
265 static void usb_set_lpm_sel(struct usb_device *udev,
266 		struct usb3_lpm_parameters *udev_lpm_params)
267 {
268 	struct usb_device *parent;
269 	unsigned int num_hubs;
270 	unsigned int total_sel;
271 
272 	/* t1 = device PEL */
273 	total_sel = udev_lpm_params->pel;
274 	/* How many external hubs are in between the device & the root port. */
275 	for (parent = udev->parent, num_hubs = 0; parent->parent;
276 			parent = parent->parent)
277 		num_hubs++;
278 	/* t2 = 2.1us + 250ns * (num_hubs - 1) */
279 	if (num_hubs > 0)
280 		total_sel += 2100 + 250 * (num_hubs - 1);
281 
282 	/* t4 = 250ns * num_hubs */
283 	total_sel += 250 * num_hubs;
284 
285 	udev_lpm_params->sel = total_sel;
286 }
287 
288 static void usb_set_lpm_parameters(struct usb_device *udev)
289 {
290 	struct usb_hub *hub;
291 	unsigned int port_to_port_delay;
292 	unsigned int udev_u1_del;
293 	unsigned int udev_u2_del;
294 	unsigned int hub_u1_del;
295 	unsigned int hub_u2_del;
296 
297 	if (!udev->lpm_capable || udev->speed != USB_SPEED_SUPER)
298 		return;
299 
300 	hub = usb_hub_to_struct_hub(udev->parent);
301 	/* It doesn't take time to transition the roothub into U0, since it
302 	 * doesn't have an upstream link.
303 	 */
304 	if (!hub)
305 		return;
306 
307 	udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
308 	udev_u2_del = le16_to_cpu(udev->bos->ss_cap->bU2DevExitLat);
309 	hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
310 	hub_u2_del = le16_to_cpu(udev->parent->bos->ss_cap->bU2DevExitLat);
311 
312 	usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
313 			hub, &udev->parent->u1_params, hub_u1_del);
314 
315 	usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
316 			hub, &udev->parent->u2_params, hub_u2_del);
317 
318 	/*
319 	 * Appendix C, section C.2.2.2, says that there is a slight delay from
320 	 * when the parent hub notices the downstream port is trying to
321 	 * transition to U0 to when the hub initiates a U0 transition on its
322 	 * upstream port.  The section says the delays are tPort2PortU1EL and
323 	 * tPort2PortU2EL, but it doesn't define what they are.
324 	 *
325 	 * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
326 	 * about the same delays.  Use the maximum delay calculations from those
327 	 * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
328 	 * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
329 	 * assume the device exit latencies they are talking about are the hub
330 	 * exit latencies.
331 	 *
332 	 * What do we do if the U2 exit latency is less than the U1 exit
333 	 * latency?  It's possible, although not likely...
334 	 */
335 	port_to_port_delay = 1;
336 
337 	usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
338 			hub, &udev->parent->u1_params, hub_u1_del,
339 			port_to_port_delay);
340 
341 	if (hub_u2_del > hub_u1_del)
342 		port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
343 	else
344 		port_to_port_delay = 1 + hub_u1_del;
345 
346 	usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
347 			hub, &udev->parent->u2_params, hub_u2_del,
348 			port_to_port_delay);
349 
350 	/* Now that we've got PEL, calculate SEL. */
351 	usb_set_lpm_sel(udev, &udev->u1_params);
352 	usb_set_lpm_sel(udev, &udev->u2_params);
353 }
354 
355 /* USB 2.0 spec Section 11.24.4.5 */
356 static int get_hub_descriptor(struct usb_device *hdev, void *data)
357 {
358 	int i, ret, size;
359 	unsigned dtype;
360 
361 	if (hub_is_superspeed(hdev)) {
362 		dtype = USB_DT_SS_HUB;
363 		size = USB_DT_SS_HUB_SIZE;
364 	} else {
365 		dtype = USB_DT_HUB;
366 		size = sizeof(struct usb_hub_descriptor);
367 	}
368 
369 	for (i = 0; i < 3; i++) {
370 		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
371 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
372 			dtype << 8, 0, data, size,
373 			USB_CTRL_GET_TIMEOUT);
374 		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
375 			return ret;
376 	}
377 	return -EINVAL;
378 }
379 
380 /*
381  * USB 2.0 spec Section 11.24.2.1
382  */
383 static int clear_hub_feature(struct usb_device *hdev, int feature)
384 {
385 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
386 		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
387 }
388 
389 /*
390  * USB 2.0 spec Section 11.24.2.2
391  */
392 int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
393 {
394 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
395 		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
396 		NULL, 0, 1000);
397 }
398 
399 /*
400  * USB 2.0 spec Section 11.24.2.13
401  */
402 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
403 {
404 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
405 		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
406 		NULL, 0, 1000);
407 }
408 
409 static char *to_led_name(int selector)
410 {
411 	switch (selector) {
412 	case HUB_LED_AMBER:
413 		return "amber";
414 	case HUB_LED_GREEN:
415 		return "green";
416 	case HUB_LED_OFF:
417 		return "off";
418 	case HUB_LED_AUTO:
419 		return "auto";
420 	default:
421 		return "??";
422 	}
423 }
424 
425 /*
426  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
427  * for info about using port indicators
428  */
429 static void set_port_led(struct usb_hub *hub, int port1, int selector)
430 {
431 	struct usb_port *port_dev = hub->ports[port1 - 1];
432 	int status;
433 
434 	status = set_port_feature(hub->hdev, (selector << 8) | port1,
435 			USB_PORT_FEAT_INDICATOR);
436 	dev_dbg(&port_dev->dev, "indicator %s status %d\n",
437 		to_led_name(selector), status);
438 }
439 
440 #define	LED_CYCLE_PERIOD	((2*HZ)/3)
441 
442 static void led_work (struct work_struct *work)
443 {
444 	struct usb_hub		*hub =
445 		container_of(work, struct usb_hub, leds.work);
446 	struct usb_device	*hdev = hub->hdev;
447 	unsigned		i;
448 	unsigned		changed = 0;
449 	int			cursor = -1;
450 
451 	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
452 		return;
453 
454 	for (i = 0; i < hdev->maxchild; i++) {
455 		unsigned	selector, mode;
456 
457 		/* 30%-50% duty cycle */
458 
459 		switch (hub->indicator[i]) {
460 		/* cycle marker */
461 		case INDICATOR_CYCLE:
462 			cursor = i;
463 			selector = HUB_LED_AUTO;
464 			mode = INDICATOR_AUTO;
465 			break;
466 		/* blinking green = sw attention */
467 		case INDICATOR_GREEN_BLINK:
468 			selector = HUB_LED_GREEN;
469 			mode = INDICATOR_GREEN_BLINK_OFF;
470 			break;
471 		case INDICATOR_GREEN_BLINK_OFF:
472 			selector = HUB_LED_OFF;
473 			mode = INDICATOR_GREEN_BLINK;
474 			break;
475 		/* blinking amber = hw attention */
476 		case INDICATOR_AMBER_BLINK:
477 			selector = HUB_LED_AMBER;
478 			mode = INDICATOR_AMBER_BLINK_OFF;
479 			break;
480 		case INDICATOR_AMBER_BLINK_OFF:
481 			selector = HUB_LED_OFF;
482 			mode = INDICATOR_AMBER_BLINK;
483 			break;
484 		/* blink green/amber = reserved */
485 		case INDICATOR_ALT_BLINK:
486 			selector = HUB_LED_GREEN;
487 			mode = INDICATOR_ALT_BLINK_OFF;
488 			break;
489 		case INDICATOR_ALT_BLINK_OFF:
490 			selector = HUB_LED_AMBER;
491 			mode = INDICATOR_ALT_BLINK;
492 			break;
493 		default:
494 			continue;
495 		}
496 		if (selector != HUB_LED_AUTO)
497 			changed = 1;
498 		set_port_led(hub, i + 1, selector);
499 		hub->indicator[i] = mode;
500 	}
501 	if (!changed && blinkenlights) {
502 		cursor++;
503 		cursor %= hdev->maxchild;
504 		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
505 		hub->indicator[cursor] = INDICATOR_CYCLE;
506 		changed++;
507 	}
508 	if (changed)
509 		queue_delayed_work(system_power_efficient_wq,
510 				&hub->leds, LED_CYCLE_PERIOD);
511 }
512 
513 /* use a short timeout for hub/port status fetches */
514 #define	USB_STS_TIMEOUT		1000
515 #define	USB_STS_RETRIES		5
516 
517 /*
518  * USB 2.0 spec Section 11.24.2.6
519  */
520 static int get_hub_status(struct usb_device *hdev,
521 		struct usb_hub_status *data)
522 {
523 	int i, status = -ETIMEDOUT;
524 
525 	for (i = 0; i < USB_STS_RETRIES &&
526 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
527 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
528 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
529 			data, sizeof(*data), USB_STS_TIMEOUT);
530 	}
531 	return status;
532 }
533 
534 /*
535  * USB 2.0 spec Section 11.24.2.7
536  */
537 static int get_port_status(struct usb_device *hdev, int port1,
538 		struct usb_port_status *data)
539 {
540 	int i, status = -ETIMEDOUT;
541 
542 	for (i = 0; i < USB_STS_RETRIES &&
543 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
544 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
545 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
546 			data, sizeof(*data), USB_STS_TIMEOUT);
547 	}
548 	return status;
549 }
550 
551 static int hub_port_status(struct usb_hub *hub, int port1,
552 		u16 *status, u16 *change)
553 {
554 	int ret;
555 
556 	mutex_lock(&hub->status_mutex);
557 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
558 	if (ret < 4) {
559 		if (ret != -ENODEV)
560 			dev_err(hub->intfdev,
561 				"%s failed (err = %d)\n", __func__, ret);
562 		if (ret >= 0)
563 			ret = -EIO;
564 	} else {
565 		*status = le16_to_cpu(hub->status->port.wPortStatus);
566 		*change = le16_to_cpu(hub->status->port.wPortChange);
567 
568 		ret = 0;
569 	}
570 	mutex_unlock(&hub->status_mutex);
571 	return ret;
572 }
573 
574 static void kick_hub_wq(struct usb_hub *hub)
575 {
576 	struct usb_interface *intf;
577 
578 	if (hub->disconnected || work_pending(&hub->events))
579 		return;
580 
581 	/*
582 	 * Suppress autosuspend until the event is proceed.
583 	 *
584 	 * Be careful and make sure that the symmetric operation is
585 	 * always called. We are here only when there is no pending
586 	 * work for this hub. Therefore put the interface either when
587 	 * the new work is called or when it is canceled.
588 	 */
589 	intf = to_usb_interface(hub->intfdev);
590 	usb_autopm_get_interface_no_resume(intf);
591 	kref_get(&hub->kref);
592 
593 	if (queue_work(hub_wq, &hub->events))
594 		return;
595 
596 	/* the work has already been scheduled */
597 	usb_autopm_put_interface_async(intf);
598 	kref_put(&hub->kref, hub_release);
599 }
600 
601 void usb_kick_hub_wq(struct usb_device *hdev)
602 {
603 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
604 
605 	if (hub)
606 		kick_hub_wq(hub);
607 }
608 
609 /*
610  * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
611  * Notification, which indicates it had initiated remote wakeup.
612  *
613  * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
614  * device initiates resume, so the USB core will not receive notice of the
615  * resume through the normal hub interrupt URB.
616  */
617 void usb_wakeup_notification(struct usb_device *hdev,
618 		unsigned int portnum)
619 {
620 	struct usb_hub *hub;
621 
622 	if (!hdev)
623 		return;
624 
625 	hub = usb_hub_to_struct_hub(hdev);
626 	if (hub) {
627 		set_bit(portnum, hub->wakeup_bits);
628 		kick_hub_wq(hub);
629 	}
630 }
631 EXPORT_SYMBOL_GPL(usb_wakeup_notification);
632 
633 /* completion function, fires on port status changes and various faults */
634 static void hub_irq(struct urb *urb)
635 {
636 	struct usb_hub *hub = urb->context;
637 	int status = urb->status;
638 	unsigned i;
639 	unsigned long bits;
640 
641 	switch (status) {
642 	case -ENOENT:		/* synchronous unlink */
643 	case -ECONNRESET:	/* async unlink */
644 	case -ESHUTDOWN:	/* hardware going away */
645 		return;
646 
647 	default:		/* presumably an error */
648 		/* Cause a hub reset after 10 consecutive errors */
649 		dev_dbg (hub->intfdev, "transfer --> %d\n", status);
650 		if ((++hub->nerrors < 10) || hub->error)
651 			goto resubmit;
652 		hub->error = status;
653 		/* FALL THROUGH */
654 
655 	/* let hub_wq handle things */
656 	case 0:			/* we got data:  port status changed */
657 		bits = 0;
658 		for (i = 0; i < urb->actual_length; ++i)
659 			bits |= ((unsigned long) ((*hub->buffer)[i]))
660 					<< (i*8);
661 		hub->event_bits[0] = bits;
662 		break;
663 	}
664 
665 	hub->nerrors = 0;
666 
667 	/* Something happened, let hub_wq figure it out */
668 	kick_hub_wq(hub);
669 
670 resubmit:
671 	if (hub->quiescing)
672 		return;
673 
674 	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
675 			&& status != -ENODEV && status != -EPERM)
676 		dev_err (hub->intfdev, "resubmit --> %d\n", status);
677 }
678 
679 /* USB 2.0 spec Section 11.24.2.3 */
680 static inline int
681 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
682 {
683 	/* Need to clear both directions for control ep */
684 	if (((devinfo >> 11) & USB_ENDPOINT_XFERTYPE_MASK) ==
685 			USB_ENDPOINT_XFER_CONTROL) {
686 		int status = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
687 				HUB_CLEAR_TT_BUFFER, USB_RT_PORT,
688 				devinfo ^ 0x8000, tt, NULL, 0, 1000);
689 		if (status)
690 			return status;
691 	}
692 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
693 			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
694 			       tt, NULL, 0, 1000);
695 }
696 
697 /*
698  * enumeration blocks hub_wq for a long time. we use keventd instead, since
699  * long blocking there is the exception, not the rule.  accordingly, HCDs
700  * talking to TTs must queue control transfers (not just bulk and iso), so
701  * both can talk to the same hub concurrently.
702  */
703 static void hub_tt_work(struct work_struct *work)
704 {
705 	struct usb_hub		*hub =
706 		container_of(work, struct usb_hub, tt.clear_work);
707 	unsigned long		flags;
708 
709 	spin_lock_irqsave (&hub->tt.lock, flags);
710 	while (!list_empty(&hub->tt.clear_list)) {
711 		struct list_head	*next;
712 		struct usb_tt_clear	*clear;
713 		struct usb_device	*hdev = hub->hdev;
714 		const struct hc_driver	*drv;
715 		int			status;
716 
717 		next = hub->tt.clear_list.next;
718 		clear = list_entry (next, struct usb_tt_clear, clear_list);
719 		list_del (&clear->clear_list);
720 
721 		/* drop lock so HCD can concurrently report other TT errors */
722 		spin_unlock_irqrestore (&hub->tt.lock, flags);
723 		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
724 		if (status && status != -ENODEV)
725 			dev_err (&hdev->dev,
726 				"clear tt %d (%04x) error %d\n",
727 				clear->tt, clear->devinfo, status);
728 
729 		/* Tell the HCD, even if the operation failed */
730 		drv = clear->hcd->driver;
731 		if (drv->clear_tt_buffer_complete)
732 			(drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
733 
734 		kfree(clear);
735 		spin_lock_irqsave(&hub->tt.lock, flags);
736 	}
737 	spin_unlock_irqrestore (&hub->tt.lock, flags);
738 }
739 
740 /**
741  * usb_hub_set_port_power - control hub port's power state
742  * @hdev: USB device belonging to the usb hub
743  * @hub: target hub
744  * @port1: port index
745  * @set: expected status
746  *
747  * call this function to control port's power via setting or
748  * clearing the port's PORT_POWER feature.
749  *
750  * Return: 0 if successful. A negative error code otherwise.
751  */
752 int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
753 			   int port1, bool set)
754 {
755 	int ret;
756 
757 	if (set)
758 		ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
759 	else
760 		ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
761 
762 	if (ret)
763 		return ret;
764 
765 	if (set)
766 		set_bit(port1, hub->power_bits);
767 	else
768 		clear_bit(port1, hub->power_bits);
769 	return 0;
770 }
771 
772 /**
773  * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
774  * @urb: an URB associated with the failed or incomplete split transaction
775  *
776  * High speed HCDs use this to tell the hub driver that some split control or
777  * bulk transaction failed in a way that requires clearing internal state of
778  * a transaction translator.  This is normally detected (and reported) from
779  * interrupt context.
780  *
781  * It may not be possible for that hub to handle additional full (or low)
782  * speed transactions until that state is fully cleared out.
783  *
784  * Return: 0 if successful. A negative error code otherwise.
785  */
786 int usb_hub_clear_tt_buffer(struct urb *urb)
787 {
788 	struct usb_device	*udev = urb->dev;
789 	int			pipe = urb->pipe;
790 	struct usb_tt		*tt = udev->tt;
791 	unsigned long		flags;
792 	struct usb_tt_clear	*clear;
793 
794 	/* we've got to cope with an arbitrary number of pending TT clears,
795 	 * since each TT has "at least two" buffers that can need it (and
796 	 * there can be many TTs per hub).  even if they're uncommon.
797 	 */
798 	clear = kmalloc(sizeof *clear, GFP_ATOMIC);
799 	if (clear == NULL) {
800 		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
801 		/* FIXME recover somehow ... RESET_TT? */
802 		return -ENOMEM;
803 	}
804 
805 	/* info that CLEAR_TT_BUFFER needs */
806 	clear->tt = tt->multi ? udev->ttport : 1;
807 	clear->devinfo = usb_pipeendpoint (pipe);
808 	clear->devinfo |= udev->devnum << 4;
809 	clear->devinfo |= usb_pipecontrol (pipe)
810 			? (USB_ENDPOINT_XFER_CONTROL << 11)
811 			: (USB_ENDPOINT_XFER_BULK << 11);
812 	if (usb_pipein (pipe))
813 		clear->devinfo |= 1 << 15;
814 
815 	/* info for completion callback */
816 	clear->hcd = bus_to_hcd(udev->bus);
817 	clear->ep = urb->ep;
818 
819 	/* tell keventd to clear state for this TT */
820 	spin_lock_irqsave (&tt->lock, flags);
821 	list_add_tail (&clear->clear_list, &tt->clear_list);
822 	schedule_work(&tt->clear_work);
823 	spin_unlock_irqrestore (&tt->lock, flags);
824 	return 0;
825 }
826 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
827 
828 static void hub_power_on(struct usb_hub *hub, bool do_delay)
829 {
830 	int port1;
831 
832 	/* Enable power on each port.  Some hubs have reserved values
833 	 * of LPSM (> 2) in their descriptors, even though they are
834 	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
835 	 * but only emulate it.  In all cases, the ports won't work
836 	 * unless we send these messages to the hub.
837 	 */
838 	if (hub_is_port_power_switchable(hub))
839 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
840 	else
841 		dev_dbg(hub->intfdev, "trying to enable port power on "
842 				"non-switchable hub\n");
843 	for (port1 = 1; port1 <= hub->hdev->maxchild; port1++)
844 		if (test_bit(port1, hub->power_bits))
845 			set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
846 		else
847 			usb_clear_port_feature(hub->hdev, port1,
848 						USB_PORT_FEAT_POWER);
849 	if (do_delay)
850 		msleep(hub_power_on_good_delay(hub));
851 }
852 
853 static int hub_hub_status(struct usb_hub *hub,
854 		u16 *status, u16 *change)
855 {
856 	int ret;
857 
858 	mutex_lock(&hub->status_mutex);
859 	ret = get_hub_status(hub->hdev, &hub->status->hub);
860 	if (ret < 0) {
861 		if (ret != -ENODEV)
862 			dev_err(hub->intfdev,
863 				"%s failed (err = %d)\n", __func__, ret);
864 	} else {
865 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
866 		*change = le16_to_cpu(hub->status->hub.wHubChange);
867 		ret = 0;
868 	}
869 	mutex_unlock(&hub->status_mutex);
870 	return ret;
871 }
872 
873 static int hub_set_port_link_state(struct usb_hub *hub, int port1,
874 			unsigned int link_status)
875 {
876 	return set_port_feature(hub->hdev,
877 			port1 | (link_status << 3),
878 			USB_PORT_FEAT_LINK_STATE);
879 }
880 
881 /*
882  * If USB 3.0 ports are placed into the Disabled state, they will no longer
883  * detect any device connects or disconnects.  This is generally not what the
884  * USB core wants, since it expects a disabled port to produce a port status
885  * change event when a new device connects.
886  *
887  * Instead, set the link state to Disabled, wait for the link to settle into
888  * that state, clear any change bits, and then put the port into the RxDetect
889  * state.
890  */
891 static int hub_usb3_port_disable(struct usb_hub *hub, int port1)
892 {
893 	int ret;
894 	int total_time;
895 	u16 portchange, portstatus;
896 
897 	if (!hub_is_superspeed(hub->hdev))
898 		return -EINVAL;
899 
900 	ret = hub_port_status(hub, port1, &portstatus, &portchange);
901 	if (ret < 0)
902 		return ret;
903 
904 	/*
905 	 * USB controller Advanced Micro Devices, Inc. [AMD] FCH USB XHCI
906 	 * Controller [1022:7814] will have spurious result making the following
907 	 * usb 3.0 device hotplugging route to the 2.0 root hub and recognized
908 	 * as high-speed device if we set the usb 3.0 port link state to
909 	 * Disabled. Since it's already in USB_SS_PORT_LS_RX_DETECT state, we
910 	 * check the state here to avoid the bug.
911 	 */
912 	if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
913 				USB_SS_PORT_LS_RX_DETECT) {
914 		dev_dbg(&hub->ports[port1 - 1]->dev,
915 			 "Not disabling port; link state is RxDetect\n");
916 		return ret;
917 	}
918 
919 	ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED);
920 	if (ret)
921 		return ret;
922 
923 	/* Wait for the link to enter the disabled state. */
924 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
925 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
926 		if (ret < 0)
927 			return ret;
928 
929 		if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
930 				USB_SS_PORT_LS_SS_DISABLED)
931 			break;
932 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
933 			break;
934 		msleep(HUB_DEBOUNCE_STEP);
935 	}
936 	if (total_time >= HUB_DEBOUNCE_TIMEOUT)
937 		dev_warn(&hub->ports[port1 - 1]->dev,
938 				"Could not disable after %d ms\n", total_time);
939 
940 	return hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_RX_DETECT);
941 }
942 
943 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
944 {
945 	struct usb_port *port_dev = hub->ports[port1 - 1];
946 	struct usb_device *hdev = hub->hdev;
947 	int ret = 0;
948 
949 	if (port_dev->child && set_state)
950 		usb_set_device_state(port_dev->child, USB_STATE_NOTATTACHED);
951 	if (!hub->error) {
952 		if (hub_is_superspeed(hub->hdev))
953 			ret = hub_usb3_port_disable(hub, port1);
954 		else
955 			ret = usb_clear_port_feature(hdev, port1,
956 					USB_PORT_FEAT_ENABLE);
957 	}
958 	if (ret && ret != -ENODEV)
959 		dev_err(&port_dev->dev, "cannot disable (err = %d)\n", ret);
960 	return ret;
961 }
962 
963 /*
964  * Disable a port and mark a logical connect-change event, so that some
965  * time later hub_wq will disconnect() any existing usb_device on the port
966  * and will re-enumerate if there actually is a device attached.
967  */
968 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
969 {
970 	dev_dbg(&hub->ports[port1 - 1]->dev, "logical disconnect\n");
971 	hub_port_disable(hub, port1, 1);
972 
973 	/* FIXME let caller ask to power down the port:
974 	 *  - some devices won't enumerate without a VBUS power cycle
975 	 *  - SRP saves power that way
976 	 *  - ... new call, TBD ...
977 	 * That's easy if this hub can switch power per-port, and
978 	 * hub_wq reactivates the port later (timer, SRP, etc).
979 	 * Powerdown must be optional, because of reset/DFU.
980 	 */
981 
982 	set_bit(port1, hub->change_bits);
983 	kick_hub_wq(hub);
984 }
985 
986 /**
987  * usb_remove_device - disable a device's port on its parent hub
988  * @udev: device to be disabled and removed
989  * Context: @udev locked, must be able to sleep.
990  *
991  * After @udev's port has been disabled, hub_wq is notified and it will
992  * see that the device has been disconnected.  When the device is
993  * physically unplugged and something is plugged in, the events will
994  * be received and processed normally.
995  *
996  * Return: 0 if successful. A negative error code otherwise.
997  */
998 int usb_remove_device(struct usb_device *udev)
999 {
1000 	struct usb_hub *hub;
1001 	struct usb_interface *intf;
1002 
1003 	if (!udev->parent)	/* Can't remove a root hub */
1004 		return -EINVAL;
1005 	hub = usb_hub_to_struct_hub(udev->parent);
1006 	intf = to_usb_interface(hub->intfdev);
1007 
1008 	usb_autopm_get_interface(intf);
1009 	set_bit(udev->portnum, hub->removed_bits);
1010 	hub_port_logical_disconnect(hub, udev->portnum);
1011 	usb_autopm_put_interface(intf);
1012 	return 0;
1013 }
1014 
1015 enum hub_activation_type {
1016 	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
1017 	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
1018 };
1019 
1020 static void hub_init_func2(struct work_struct *ws);
1021 static void hub_init_func3(struct work_struct *ws);
1022 
1023 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
1024 {
1025 	struct usb_device *hdev = hub->hdev;
1026 	struct usb_hcd *hcd;
1027 	int ret;
1028 	int port1;
1029 	int status;
1030 	bool need_debounce_delay = false;
1031 	unsigned delay;
1032 
1033 	/* Continue a partial initialization */
1034 	if (type == HUB_INIT2)
1035 		goto init2;
1036 	if (type == HUB_INIT3)
1037 		goto init3;
1038 
1039 	/* The superspeed hub except for root hub has to use Hub Depth
1040 	 * value as an offset into the route string to locate the bits
1041 	 * it uses to determine the downstream port number. So hub driver
1042 	 * should send a set hub depth request to superspeed hub after
1043 	 * the superspeed hub is set configuration in initialization or
1044 	 * reset procedure.
1045 	 *
1046 	 * After a resume, port power should still be on.
1047 	 * For any other type of activation, turn it on.
1048 	 */
1049 	if (type != HUB_RESUME) {
1050 		if (hdev->parent && hub_is_superspeed(hdev)) {
1051 			ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
1052 					HUB_SET_DEPTH, USB_RT_HUB,
1053 					hdev->level - 1, 0, NULL, 0,
1054 					USB_CTRL_SET_TIMEOUT);
1055 			if (ret < 0)
1056 				dev_err(hub->intfdev,
1057 						"set hub depth failed\n");
1058 		}
1059 
1060 		/* Speed up system boot by using a delayed_work for the
1061 		 * hub's initial power-up delays.  This is pretty awkward
1062 		 * and the implementation looks like a home-brewed sort of
1063 		 * setjmp/longjmp, but it saves at least 100 ms for each
1064 		 * root hub (assuming usbcore is compiled into the kernel
1065 		 * rather than as a module).  It adds up.
1066 		 *
1067 		 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
1068 		 * because for those activation types the ports have to be
1069 		 * operational when we return.  In theory this could be done
1070 		 * for HUB_POST_RESET, but it's easier not to.
1071 		 */
1072 		if (type == HUB_INIT) {
1073 			unsigned delay = hub_power_on_good_delay(hub);
1074 
1075 			hub_power_on(hub, false);
1076 			INIT_DELAYED_WORK(&hub->init_work, hub_init_func2);
1077 			queue_delayed_work(system_power_efficient_wq,
1078 					&hub->init_work,
1079 					msecs_to_jiffies(delay));
1080 
1081 			/* Suppress autosuspend until init is done */
1082 			usb_autopm_get_interface_no_resume(
1083 					to_usb_interface(hub->intfdev));
1084 			return;		/* Continues at init2: below */
1085 		} else if (type == HUB_RESET_RESUME) {
1086 			/* The internal host controller state for the hub device
1087 			 * may be gone after a host power loss on system resume.
1088 			 * Update the device's info so the HW knows it's a hub.
1089 			 */
1090 			hcd = bus_to_hcd(hdev->bus);
1091 			if (hcd->driver->update_hub_device) {
1092 				ret = hcd->driver->update_hub_device(hcd, hdev,
1093 						&hub->tt, GFP_NOIO);
1094 				if (ret < 0) {
1095 					dev_err(hub->intfdev, "Host not "
1096 							"accepting hub info "
1097 							"update.\n");
1098 					dev_err(hub->intfdev, "LS/FS devices "
1099 							"and hubs may not work "
1100 							"under this hub\n.");
1101 				}
1102 			}
1103 			hub_power_on(hub, true);
1104 		} else {
1105 			hub_power_on(hub, true);
1106 		}
1107 	}
1108  init2:
1109 
1110 	/*
1111 	 * Check each port and set hub->change_bits to let hub_wq know
1112 	 * which ports need attention.
1113 	 */
1114 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1115 		struct usb_port *port_dev = hub->ports[port1 - 1];
1116 		struct usb_device *udev = port_dev->child;
1117 		u16 portstatus, portchange;
1118 
1119 		portstatus = portchange = 0;
1120 		status = hub_port_status(hub, port1, &portstatus, &portchange);
1121 		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1122 			dev_dbg(&port_dev->dev, "status %04x change %04x\n",
1123 					portstatus, portchange);
1124 
1125 		/*
1126 		 * After anything other than HUB_RESUME (i.e., initialization
1127 		 * or any sort of reset), every port should be disabled.
1128 		 * Unconnected ports should likewise be disabled (paranoia),
1129 		 * and so should ports for which we have no usb_device.
1130 		 */
1131 		if ((portstatus & USB_PORT_STAT_ENABLE) && (
1132 				type != HUB_RESUME ||
1133 				!(portstatus & USB_PORT_STAT_CONNECTION) ||
1134 				!udev ||
1135 				udev->state == USB_STATE_NOTATTACHED)) {
1136 			/*
1137 			 * USB3 protocol ports will automatically transition
1138 			 * to Enabled state when detect an USB3.0 device attach.
1139 			 * Do not disable USB3 protocol ports, just pretend
1140 			 * power was lost
1141 			 */
1142 			portstatus &= ~USB_PORT_STAT_ENABLE;
1143 			if (!hub_is_superspeed(hdev))
1144 				usb_clear_port_feature(hdev, port1,
1145 						   USB_PORT_FEAT_ENABLE);
1146 		}
1147 
1148 		/* Clear status-change flags; we'll debounce later */
1149 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
1150 			need_debounce_delay = true;
1151 			usb_clear_port_feature(hub->hdev, port1,
1152 					USB_PORT_FEAT_C_CONNECTION);
1153 		}
1154 		if (portchange & USB_PORT_STAT_C_ENABLE) {
1155 			need_debounce_delay = true;
1156 			usb_clear_port_feature(hub->hdev, port1,
1157 					USB_PORT_FEAT_C_ENABLE);
1158 		}
1159 		if (portchange & USB_PORT_STAT_C_RESET) {
1160 			need_debounce_delay = true;
1161 			usb_clear_port_feature(hub->hdev, port1,
1162 					USB_PORT_FEAT_C_RESET);
1163 		}
1164 		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
1165 				hub_is_superspeed(hub->hdev)) {
1166 			need_debounce_delay = true;
1167 			usb_clear_port_feature(hub->hdev, port1,
1168 					USB_PORT_FEAT_C_BH_PORT_RESET);
1169 		}
1170 		/* We can forget about a "removed" device when there's a
1171 		 * physical disconnect or the connect status changes.
1172 		 */
1173 		if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
1174 				(portchange & USB_PORT_STAT_C_CONNECTION))
1175 			clear_bit(port1, hub->removed_bits);
1176 
1177 		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
1178 			/* Tell hub_wq to disconnect the device or
1179 			 * check for a new connection
1180 			 */
1181 			if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
1182 			    (portstatus & USB_PORT_STAT_OVERCURRENT))
1183 				set_bit(port1, hub->change_bits);
1184 
1185 		} else if (portstatus & USB_PORT_STAT_ENABLE) {
1186 			bool port_resumed = (portstatus &
1187 					USB_PORT_STAT_LINK_STATE) ==
1188 				USB_SS_PORT_LS_U0;
1189 			/* The power session apparently survived the resume.
1190 			 * If there was an overcurrent or suspend change
1191 			 * (i.e., remote wakeup request), have hub_wq
1192 			 * take care of it.  Look at the port link state
1193 			 * for USB 3.0 hubs, since they don't have a suspend
1194 			 * change bit, and they don't set the port link change
1195 			 * bit on device-initiated resume.
1196 			 */
1197 			if (portchange || (hub_is_superspeed(hub->hdev) &&
1198 						port_resumed))
1199 				set_bit(port1, hub->change_bits);
1200 
1201 		} else if (udev->persist_enabled) {
1202 #ifdef CONFIG_PM
1203 			udev->reset_resume = 1;
1204 #endif
1205 			/* Don't set the change_bits when the device
1206 			 * was powered off.
1207 			 */
1208 			if (test_bit(port1, hub->power_bits))
1209 				set_bit(port1, hub->change_bits);
1210 
1211 		} else {
1212 			/* The power session is gone; tell hub_wq */
1213 			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1214 			set_bit(port1, hub->change_bits);
1215 		}
1216 	}
1217 
1218 	/* If no port-status-change flags were set, we don't need any
1219 	 * debouncing.  If flags were set we can try to debounce the
1220 	 * ports all at once right now, instead of letting hub_wq do them
1221 	 * one at a time later on.
1222 	 *
1223 	 * If any port-status changes do occur during this delay, hub_wq
1224 	 * will see them later and handle them normally.
1225 	 */
1226 	if (need_debounce_delay) {
1227 		delay = HUB_DEBOUNCE_STABLE;
1228 
1229 		/* Don't do a long sleep inside a workqueue routine */
1230 		if (type == HUB_INIT2) {
1231 			INIT_DELAYED_WORK(&hub->init_work, hub_init_func3);
1232 			queue_delayed_work(system_power_efficient_wq,
1233 					&hub->init_work,
1234 					msecs_to_jiffies(delay));
1235 			return;		/* Continues at init3: below */
1236 		} else {
1237 			msleep(delay);
1238 		}
1239 	}
1240  init3:
1241 	hub->quiescing = 0;
1242 
1243 	status = usb_submit_urb(hub->urb, GFP_NOIO);
1244 	if (status < 0)
1245 		dev_err(hub->intfdev, "activate --> %d\n", status);
1246 	if (hub->has_indicators && blinkenlights)
1247 		queue_delayed_work(system_power_efficient_wq,
1248 				&hub->leds, LED_CYCLE_PERIOD);
1249 
1250 	/* Scan all ports that need attention */
1251 	kick_hub_wq(hub);
1252 
1253 	/* Allow autosuspend if it was suppressed */
1254 	if (type <= HUB_INIT3)
1255 		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
1256 }
1257 
1258 /* Implement the continuations for the delays above */
1259 static void hub_init_func2(struct work_struct *ws)
1260 {
1261 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1262 
1263 	hub_activate(hub, HUB_INIT2);
1264 }
1265 
1266 static void hub_init_func3(struct work_struct *ws)
1267 {
1268 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1269 
1270 	hub_activate(hub, HUB_INIT3);
1271 }
1272 
1273 enum hub_quiescing_type {
1274 	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
1275 };
1276 
1277 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
1278 {
1279 	struct usb_device *hdev = hub->hdev;
1280 	int i;
1281 
1282 	cancel_delayed_work_sync(&hub->init_work);
1283 
1284 	/* hub_wq and related activity won't re-trigger */
1285 	hub->quiescing = 1;
1286 
1287 	if (type != HUB_SUSPEND) {
1288 		/* Disconnect all the children */
1289 		for (i = 0; i < hdev->maxchild; ++i) {
1290 			if (hub->ports[i]->child)
1291 				usb_disconnect(&hub->ports[i]->child);
1292 		}
1293 	}
1294 
1295 	/* Stop hub_wq and related activity */
1296 	usb_kill_urb(hub->urb);
1297 	if (hub->has_indicators)
1298 		cancel_delayed_work_sync(&hub->leds);
1299 	if (hub->tt.hub)
1300 		flush_work(&hub->tt.clear_work);
1301 }
1302 
1303 static void hub_pm_barrier_for_all_ports(struct usb_hub *hub)
1304 {
1305 	int i;
1306 
1307 	for (i = 0; i < hub->hdev->maxchild; ++i)
1308 		pm_runtime_barrier(&hub->ports[i]->dev);
1309 }
1310 
1311 /* caller has locked the hub device */
1312 static int hub_pre_reset(struct usb_interface *intf)
1313 {
1314 	struct usb_hub *hub = usb_get_intfdata(intf);
1315 
1316 	hub_quiesce(hub, HUB_PRE_RESET);
1317 	hub->in_reset = 1;
1318 	hub_pm_barrier_for_all_ports(hub);
1319 	return 0;
1320 }
1321 
1322 /* caller has locked the hub device */
1323 static int hub_post_reset(struct usb_interface *intf)
1324 {
1325 	struct usb_hub *hub = usb_get_intfdata(intf);
1326 
1327 	hub->in_reset = 0;
1328 	hub_pm_barrier_for_all_ports(hub);
1329 	hub_activate(hub, HUB_POST_RESET);
1330 	return 0;
1331 }
1332 
1333 static int hub_configure(struct usb_hub *hub,
1334 	struct usb_endpoint_descriptor *endpoint)
1335 {
1336 	struct usb_hcd *hcd;
1337 	struct usb_device *hdev = hub->hdev;
1338 	struct device *hub_dev = hub->intfdev;
1339 	u16 hubstatus, hubchange;
1340 	u16 wHubCharacteristics;
1341 	unsigned int pipe;
1342 	int maxp, ret, i;
1343 	char *message = "out of memory";
1344 	unsigned unit_load;
1345 	unsigned full_load;
1346 	unsigned maxchild;
1347 
1348 	hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
1349 	if (!hub->buffer) {
1350 		ret = -ENOMEM;
1351 		goto fail;
1352 	}
1353 
1354 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
1355 	if (!hub->status) {
1356 		ret = -ENOMEM;
1357 		goto fail;
1358 	}
1359 	mutex_init(&hub->status_mutex);
1360 
1361 	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
1362 	if (!hub->descriptor) {
1363 		ret = -ENOMEM;
1364 		goto fail;
1365 	}
1366 
1367 	/* Request the entire hub descriptor.
1368 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
1369 	 * but the hub can/will return fewer bytes here.
1370 	 */
1371 	ret = get_hub_descriptor(hdev, hub->descriptor);
1372 	if (ret < 0) {
1373 		message = "can't read hub descriptor";
1374 		goto fail;
1375 	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
1376 		message = "hub has too many ports!";
1377 		ret = -ENODEV;
1378 		goto fail;
1379 	} else if (hub->descriptor->bNbrPorts == 0) {
1380 		message = "hub doesn't have any ports!";
1381 		ret = -ENODEV;
1382 		goto fail;
1383 	}
1384 
1385 	maxchild = hub->descriptor->bNbrPorts;
1386 	dev_info(hub_dev, "%d port%s detected\n", maxchild,
1387 			(maxchild == 1) ? "" : "s");
1388 
1389 	hub->ports = kzalloc(maxchild * sizeof(struct usb_port *), GFP_KERNEL);
1390 	if (!hub->ports) {
1391 		ret = -ENOMEM;
1392 		goto fail;
1393 	}
1394 
1395 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
1396 	if (hub_is_superspeed(hdev)) {
1397 		unit_load = 150;
1398 		full_load = 900;
1399 	} else {
1400 		unit_load = 100;
1401 		full_load = 500;
1402 	}
1403 
1404 	/* FIXME for USB 3.0, skip for now */
1405 	if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
1406 			!(hub_is_superspeed(hdev))) {
1407 		int	i;
1408 		char	portstr[USB_MAXCHILDREN + 1];
1409 
1410 		for (i = 0; i < maxchild; i++)
1411 			portstr[i] = hub->descriptor->u.hs.DeviceRemovable
1412 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1413 				? 'F' : 'R';
1414 		portstr[maxchild] = 0;
1415 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1416 	} else
1417 		dev_dbg(hub_dev, "standalone hub\n");
1418 
1419 	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1420 	case HUB_CHAR_COMMON_LPSM:
1421 		dev_dbg(hub_dev, "ganged power switching\n");
1422 		break;
1423 	case HUB_CHAR_INDV_PORT_LPSM:
1424 		dev_dbg(hub_dev, "individual port power switching\n");
1425 		break;
1426 	case HUB_CHAR_NO_LPSM:
1427 	case HUB_CHAR_LPSM:
1428 		dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1429 		break;
1430 	}
1431 
1432 	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1433 	case HUB_CHAR_COMMON_OCPM:
1434 		dev_dbg(hub_dev, "global over-current protection\n");
1435 		break;
1436 	case HUB_CHAR_INDV_PORT_OCPM:
1437 		dev_dbg(hub_dev, "individual port over-current protection\n");
1438 		break;
1439 	case HUB_CHAR_NO_OCPM:
1440 	case HUB_CHAR_OCPM:
1441 		dev_dbg(hub_dev, "no over-current protection\n");
1442 		break;
1443 	}
1444 
1445 	spin_lock_init (&hub->tt.lock);
1446 	INIT_LIST_HEAD (&hub->tt.clear_list);
1447 	INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1448 	switch (hdev->descriptor.bDeviceProtocol) {
1449 	case USB_HUB_PR_FS:
1450 		break;
1451 	case USB_HUB_PR_HS_SINGLE_TT:
1452 		dev_dbg(hub_dev, "Single TT\n");
1453 		hub->tt.hub = hdev;
1454 		break;
1455 	case USB_HUB_PR_HS_MULTI_TT:
1456 		ret = usb_set_interface(hdev, 0, 1);
1457 		if (ret == 0) {
1458 			dev_dbg(hub_dev, "TT per port\n");
1459 			hub->tt.multi = 1;
1460 		} else
1461 			dev_err(hub_dev, "Using single TT (err %d)\n",
1462 				ret);
1463 		hub->tt.hub = hdev;
1464 		break;
1465 	case USB_HUB_PR_SS:
1466 		/* USB 3.0 hubs don't have a TT */
1467 		break;
1468 	default:
1469 		dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1470 			hdev->descriptor.bDeviceProtocol);
1471 		break;
1472 	}
1473 
1474 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1475 	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1476 	case HUB_TTTT_8_BITS:
1477 		if (hdev->descriptor.bDeviceProtocol != 0) {
1478 			hub->tt.think_time = 666;
1479 			dev_dbg(hub_dev, "TT requires at most %d "
1480 					"FS bit times (%d ns)\n",
1481 				8, hub->tt.think_time);
1482 		}
1483 		break;
1484 	case HUB_TTTT_16_BITS:
1485 		hub->tt.think_time = 666 * 2;
1486 		dev_dbg(hub_dev, "TT requires at most %d "
1487 				"FS bit times (%d ns)\n",
1488 			16, hub->tt.think_time);
1489 		break;
1490 	case HUB_TTTT_24_BITS:
1491 		hub->tt.think_time = 666 * 3;
1492 		dev_dbg(hub_dev, "TT requires at most %d "
1493 				"FS bit times (%d ns)\n",
1494 			24, hub->tt.think_time);
1495 		break;
1496 	case HUB_TTTT_32_BITS:
1497 		hub->tt.think_time = 666 * 4;
1498 		dev_dbg(hub_dev, "TT requires at most %d "
1499 				"FS bit times (%d ns)\n",
1500 			32, hub->tt.think_time);
1501 		break;
1502 	}
1503 
1504 	/* probe() zeroes hub->indicator[] */
1505 	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1506 		hub->has_indicators = 1;
1507 		dev_dbg(hub_dev, "Port indicators are supported\n");
1508 	}
1509 
1510 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
1511 		hub->descriptor->bPwrOn2PwrGood * 2);
1512 
1513 	/* power budgeting mostly matters with bus-powered hubs,
1514 	 * and battery-powered root hubs (may provide just 8 mA).
1515 	 */
1516 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1517 	if (ret) {
1518 		message = "can't get hub status";
1519 		goto fail;
1520 	}
1521 	hcd = bus_to_hcd(hdev->bus);
1522 	if (hdev == hdev->bus->root_hub) {
1523 		if (hcd->power_budget > 0)
1524 			hdev->bus_mA = hcd->power_budget;
1525 		else
1526 			hdev->bus_mA = full_load * maxchild;
1527 		if (hdev->bus_mA >= full_load)
1528 			hub->mA_per_port = full_load;
1529 		else {
1530 			hub->mA_per_port = hdev->bus_mA;
1531 			hub->limited_power = 1;
1532 		}
1533 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1534 		int remaining = hdev->bus_mA -
1535 			hub->descriptor->bHubContrCurrent;
1536 
1537 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1538 			hub->descriptor->bHubContrCurrent);
1539 		hub->limited_power = 1;
1540 
1541 		if (remaining < maxchild * unit_load)
1542 			dev_warn(hub_dev,
1543 					"insufficient power available "
1544 					"to use all downstream ports\n");
1545 		hub->mA_per_port = unit_load;	/* 7.2.1 */
1546 
1547 	} else {	/* Self-powered external hub */
1548 		/* FIXME: What about battery-powered external hubs that
1549 		 * provide less current per port? */
1550 		hub->mA_per_port = full_load;
1551 	}
1552 	if (hub->mA_per_port < full_load)
1553 		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1554 				hub->mA_per_port);
1555 
1556 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
1557 	if (ret < 0) {
1558 		message = "can't get hub status";
1559 		goto fail;
1560 	}
1561 
1562 	/* local power status reports aren't always correct */
1563 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1564 		dev_dbg(hub_dev, "local power source is %s\n",
1565 			(hubstatus & HUB_STATUS_LOCAL_POWER)
1566 			? "lost (inactive)" : "good");
1567 
1568 	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1569 		dev_dbg(hub_dev, "%sover-current condition exists\n",
1570 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1571 
1572 	/* set up the interrupt endpoint
1573 	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1574 	 * bytes as USB2.0[11.12.3] says because some hubs are known
1575 	 * to send more data (and thus cause overflow). For root hubs,
1576 	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
1577 	 * to be big enough for at least USB_MAXCHILDREN ports. */
1578 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1579 	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
1580 
1581 	if (maxp > sizeof(*hub->buffer))
1582 		maxp = sizeof(*hub->buffer);
1583 
1584 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1585 	if (!hub->urb) {
1586 		ret = -ENOMEM;
1587 		goto fail;
1588 	}
1589 
1590 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1591 		hub, endpoint->bInterval);
1592 
1593 	/* maybe cycle the hub leds */
1594 	if (hub->has_indicators && blinkenlights)
1595 		hub->indicator[0] = INDICATOR_CYCLE;
1596 
1597 	mutex_lock(&usb_port_peer_mutex);
1598 	for (i = 0; i < maxchild; i++) {
1599 		ret = usb_hub_create_port_device(hub, i + 1);
1600 		if (ret < 0) {
1601 			dev_err(hub->intfdev,
1602 				"couldn't create port%d device.\n", i + 1);
1603 			break;
1604 		}
1605 	}
1606 	hdev->maxchild = i;
1607 	for (i = 0; i < hdev->maxchild; i++) {
1608 		struct usb_port *port_dev = hub->ports[i];
1609 
1610 		pm_runtime_put(&port_dev->dev);
1611 	}
1612 
1613 	mutex_unlock(&usb_port_peer_mutex);
1614 	if (ret < 0)
1615 		goto fail;
1616 
1617 	/* Update the HCD's internal representation of this hub before hub_wq
1618 	 * starts getting port status changes for devices under the hub.
1619 	 */
1620 	if (hcd->driver->update_hub_device) {
1621 		ret = hcd->driver->update_hub_device(hcd, hdev,
1622 				&hub->tt, GFP_KERNEL);
1623 		if (ret < 0) {
1624 			message = "can't update HCD hub info";
1625 			goto fail;
1626 		}
1627 	}
1628 
1629 	usb_hub_adjust_deviceremovable(hdev, hub->descriptor);
1630 
1631 	hub_activate(hub, HUB_INIT);
1632 	return 0;
1633 
1634 fail:
1635 	dev_err (hub_dev, "config failed, %s (err %d)\n",
1636 			message, ret);
1637 	/* hub_disconnect() frees urb and descriptor */
1638 	return ret;
1639 }
1640 
1641 static void hub_release(struct kref *kref)
1642 {
1643 	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1644 
1645 	usb_put_dev(hub->hdev);
1646 	usb_put_intf(to_usb_interface(hub->intfdev));
1647 	kfree(hub);
1648 }
1649 
1650 static unsigned highspeed_hubs;
1651 
1652 static void hub_disconnect(struct usb_interface *intf)
1653 {
1654 	struct usb_hub *hub = usb_get_intfdata(intf);
1655 	struct usb_device *hdev = interface_to_usbdev(intf);
1656 	int port1;
1657 
1658 	/*
1659 	 * Stop adding new hub events. We do not want to block here and thus
1660 	 * will not try to remove any pending work item.
1661 	 */
1662 	hub->disconnected = 1;
1663 
1664 	/* Disconnect all children and quiesce the hub */
1665 	hub->error = 0;
1666 	hub_quiesce(hub, HUB_DISCONNECT);
1667 
1668 	mutex_lock(&usb_port_peer_mutex);
1669 
1670 	/* Avoid races with recursively_mark_NOTATTACHED() */
1671 	spin_lock_irq(&device_state_lock);
1672 	port1 = hdev->maxchild;
1673 	hdev->maxchild = 0;
1674 	usb_set_intfdata(intf, NULL);
1675 	spin_unlock_irq(&device_state_lock);
1676 
1677 	for (; port1 > 0; --port1)
1678 		usb_hub_remove_port_device(hub, port1);
1679 
1680 	mutex_unlock(&usb_port_peer_mutex);
1681 
1682 	if (hub->hdev->speed == USB_SPEED_HIGH)
1683 		highspeed_hubs--;
1684 
1685 	usb_free_urb(hub->urb);
1686 	kfree(hub->ports);
1687 	kfree(hub->descriptor);
1688 	kfree(hub->status);
1689 	kfree(hub->buffer);
1690 
1691 	pm_suspend_ignore_children(&intf->dev, false);
1692 	kref_put(&hub->kref, hub_release);
1693 }
1694 
1695 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1696 {
1697 	struct usb_host_interface *desc;
1698 	struct usb_endpoint_descriptor *endpoint;
1699 	struct usb_device *hdev;
1700 	struct usb_hub *hub;
1701 
1702 	desc = intf->cur_altsetting;
1703 	hdev = interface_to_usbdev(intf);
1704 
1705 	/*
1706 	 * Set default autosuspend delay as 0 to speedup bus suspend,
1707 	 * based on the below considerations:
1708 	 *
1709 	 * - Unlike other drivers, the hub driver does not rely on the
1710 	 *   autosuspend delay to provide enough time to handle a wakeup
1711 	 *   event, and the submitted status URB is just to check future
1712 	 *   change on hub downstream ports, so it is safe to do it.
1713 	 *
1714 	 * - The patch might cause one or more auto supend/resume for
1715 	 *   below very rare devices when they are plugged into hub
1716 	 *   first time:
1717 	 *
1718 	 *   	devices having trouble initializing, and disconnect
1719 	 *   	themselves from the bus and then reconnect a second
1720 	 *   	or so later
1721 	 *
1722 	 *   	devices just for downloading firmware, and disconnects
1723 	 *   	themselves after completing it
1724 	 *
1725 	 *   For these quite rare devices, their drivers may change the
1726 	 *   autosuspend delay of their parent hub in the probe() to one
1727 	 *   appropriate value to avoid the subtle problem if someone
1728 	 *   does care it.
1729 	 *
1730 	 * - The patch may cause one or more auto suspend/resume on
1731 	 *   hub during running 'lsusb', but it is probably too
1732 	 *   infrequent to worry about.
1733 	 *
1734 	 * - Change autosuspend delay of hub can avoid unnecessary auto
1735 	 *   suspend timer for hub, also may decrease power consumption
1736 	 *   of USB bus.
1737 	 *
1738 	 * - If user has indicated to prevent autosuspend by passing
1739 	 *   usbcore.autosuspend = -1 then keep autosuspend disabled.
1740 	 */
1741 #ifdef CONFIG_PM
1742 	if (hdev->dev.power.autosuspend_delay >= 0)
1743 		pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
1744 #endif
1745 
1746 	/*
1747 	 * Hubs have proper suspend/resume support, except for root hubs
1748 	 * where the controller driver doesn't have bus_suspend and
1749 	 * bus_resume methods.
1750 	 */
1751 	if (hdev->parent) {		/* normal device */
1752 		usb_enable_autosuspend(hdev);
1753 	} else {			/* root hub */
1754 		const struct hc_driver *drv = bus_to_hcd(hdev->bus)->driver;
1755 
1756 		if (drv->bus_suspend && drv->bus_resume)
1757 			usb_enable_autosuspend(hdev);
1758 	}
1759 
1760 	if (hdev->level == MAX_TOPO_LEVEL) {
1761 		dev_err(&intf->dev,
1762 			"Unsupported bus topology: hub nested too deep\n");
1763 		return -E2BIG;
1764 	}
1765 
1766 #ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
1767 	if (hdev->parent) {
1768 		dev_warn(&intf->dev, "ignoring external hub\n");
1769 		return -ENODEV;
1770 	}
1771 #endif
1772 
1773 	/* Some hubs have a subclass of 1, which AFAICT according to the */
1774 	/*  specs is not defined, but it works */
1775 	if ((desc->desc.bInterfaceSubClass != 0) &&
1776 	    (desc->desc.bInterfaceSubClass != 1)) {
1777 descriptor_error:
1778 		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
1779 		return -EIO;
1780 	}
1781 
1782 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
1783 	if (desc->desc.bNumEndpoints != 1)
1784 		goto descriptor_error;
1785 
1786 	endpoint = &desc->endpoint[0].desc;
1787 
1788 	/* If it's not an interrupt in endpoint, we'd better punt! */
1789 	if (!usb_endpoint_is_int_in(endpoint))
1790 		goto descriptor_error;
1791 
1792 	/* We found a hub */
1793 	dev_info (&intf->dev, "USB hub found\n");
1794 
1795 	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1796 	if (!hub) {
1797 		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
1798 		return -ENOMEM;
1799 	}
1800 
1801 	kref_init(&hub->kref);
1802 	hub->intfdev = &intf->dev;
1803 	hub->hdev = hdev;
1804 	INIT_DELAYED_WORK(&hub->leds, led_work);
1805 	INIT_DELAYED_WORK(&hub->init_work, NULL);
1806 	INIT_WORK(&hub->events, hub_event);
1807 	usb_get_intf(intf);
1808 	usb_get_dev(hdev);
1809 
1810 	usb_set_intfdata (intf, hub);
1811 	intf->needs_remote_wakeup = 1;
1812 	pm_suspend_ignore_children(&intf->dev, true);
1813 
1814 	if (hdev->speed == USB_SPEED_HIGH)
1815 		highspeed_hubs++;
1816 
1817 	if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
1818 		hub->quirk_check_port_auto_suspend = 1;
1819 
1820 	if (hub_configure(hub, endpoint) >= 0)
1821 		return 0;
1822 
1823 	hub_disconnect (intf);
1824 	return -ENODEV;
1825 }
1826 
1827 static int
1828 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1829 {
1830 	struct usb_device *hdev = interface_to_usbdev (intf);
1831 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1832 
1833 	/* assert ifno == 0 (part of hub spec) */
1834 	switch (code) {
1835 	case USBDEVFS_HUB_PORTINFO: {
1836 		struct usbdevfs_hub_portinfo *info = user_data;
1837 		int i;
1838 
1839 		spin_lock_irq(&device_state_lock);
1840 		if (hdev->devnum <= 0)
1841 			info->nports = 0;
1842 		else {
1843 			info->nports = hdev->maxchild;
1844 			for (i = 0; i < info->nports; i++) {
1845 				if (hub->ports[i]->child == NULL)
1846 					info->port[i] = 0;
1847 				else
1848 					info->port[i] =
1849 						hub->ports[i]->child->devnum;
1850 			}
1851 		}
1852 		spin_unlock_irq(&device_state_lock);
1853 
1854 		return info->nports + 1;
1855 		}
1856 
1857 	default:
1858 		return -ENOSYS;
1859 	}
1860 }
1861 
1862 /*
1863  * Allow user programs to claim ports on a hub.  When a device is attached
1864  * to one of these "claimed" ports, the program will "own" the device.
1865  */
1866 static int find_port_owner(struct usb_device *hdev, unsigned port1,
1867 		struct usb_dev_state ***ppowner)
1868 {
1869 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1870 
1871 	if (hdev->state == USB_STATE_NOTATTACHED)
1872 		return -ENODEV;
1873 	if (port1 == 0 || port1 > hdev->maxchild)
1874 		return -EINVAL;
1875 
1876 	/* Devices not managed by the hub driver
1877 	 * will always have maxchild equal to 0.
1878 	 */
1879 	*ppowner = &(hub->ports[port1 - 1]->port_owner);
1880 	return 0;
1881 }
1882 
1883 /* In the following three functions, the caller must hold hdev's lock */
1884 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
1885 		       struct usb_dev_state *owner)
1886 {
1887 	int rc;
1888 	struct usb_dev_state **powner;
1889 
1890 	rc = find_port_owner(hdev, port1, &powner);
1891 	if (rc)
1892 		return rc;
1893 	if (*powner)
1894 		return -EBUSY;
1895 	*powner = owner;
1896 	return rc;
1897 }
1898 EXPORT_SYMBOL_GPL(usb_hub_claim_port);
1899 
1900 int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
1901 			 struct usb_dev_state *owner)
1902 {
1903 	int rc;
1904 	struct usb_dev_state **powner;
1905 
1906 	rc = find_port_owner(hdev, port1, &powner);
1907 	if (rc)
1908 		return rc;
1909 	if (*powner != owner)
1910 		return -ENOENT;
1911 	*powner = NULL;
1912 	return rc;
1913 }
1914 EXPORT_SYMBOL_GPL(usb_hub_release_port);
1915 
1916 void usb_hub_release_all_ports(struct usb_device *hdev, struct usb_dev_state *owner)
1917 {
1918 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1919 	int n;
1920 
1921 	for (n = 0; n < hdev->maxchild; n++) {
1922 		if (hub->ports[n]->port_owner == owner)
1923 			hub->ports[n]->port_owner = NULL;
1924 	}
1925 
1926 }
1927 
1928 /* The caller must hold udev's lock */
1929 bool usb_device_is_owned(struct usb_device *udev)
1930 {
1931 	struct usb_hub *hub;
1932 
1933 	if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
1934 		return false;
1935 	hub = usb_hub_to_struct_hub(udev->parent);
1936 	return !!hub->ports[udev->portnum - 1]->port_owner;
1937 }
1938 
1939 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1940 {
1941 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
1942 	int i;
1943 
1944 	for (i = 0; i < udev->maxchild; ++i) {
1945 		if (hub->ports[i]->child)
1946 			recursively_mark_NOTATTACHED(hub->ports[i]->child);
1947 	}
1948 	if (udev->state == USB_STATE_SUSPENDED)
1949 		udev->active_duration -= jiffies;
1950 	udev->state = USB_STATE_NOTATTACHED;
1951 }
1952 
1953 /**
1954  * usb_set_device_state - change a device's current state (usbcore, hcds)
1955  * @udev: pointer to device whose state should be changed
1956  * @new_state: new state value to be stored
1957  *
1958  * udev->state is _not_ fully protected by the device lock.  Although
1959  * most transitions are made only while holding the lock, the state can
1960  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1961  * is so that devices can be marked as disconnected as soon as possible,
1962  * without having to wait for any semaphores to be released.  As a result,
1963  * all changes to any device's state must be protected by the
1964  * device_state_lock spinlock.
1965  *
1966  * Once a device has been added to the device tree, all changes to its state
1967  * should be made using this routine.  The state should _not_ be set directly.
1968  *
1969  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1970  * Otherwise udev->state is set to new_state, and if new_state is
1971  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1972  * to USB_STATE_NOTATTACHED.
1973  */
1974 void usb_set_device_state(struct usb_device *udev,
1975 		enum usb_device_state new_state)
1976 {
1977 	unsigned long flags;
1978 	int wakeup = -1;
1979 
1980 	spin_lock_irqsave(&device_state_lock, flags);
1981 	if (udev->state == USB_STATE_NOTATTACHED)
1982 		;	/* do nothing */
1983 	else if (new_state != USB_STATE_NOTATTACHED) {
1984 
1985 		/* root hub wakeup capabilities are managed out-of-band
1986 		 * and may involve silicon errata ... ignore them here.
1987 		 */
1988 		if (udev->parent) {
1989 			if (udev->state == USB_STATE_SUSPENDED
1990 					|| new_state == USB_STATE_SUSPENDED)
1991 				;	/* No change to wakeup settings */
1992 			else if (new_state == USB_STATE_CONFIGURED)
1993 				wakeup = (udev->quirks &
1994 					USB_QUIRK_IGNORE_REMOTE_WAKEUP) ? 0 :
1995 					udev->actconfig->desc.bmAttributes &
1996 					USB_CONFIG_ATT_WAKEUP;
1997 			else
1998 				wakeup = 0;
1999 		}
2000 		if (udev->state == USB_STATE_SUSPENDED &&
2001 			new_state != USB_STATE_SUSPENDED)
2002 			udev->active_duration -= jiffies;
2003 		else if (new_state == USB_STATE_SUSPENDED &&
2004 				udev->state != USB_STATE_SUSPENDED)
2005 			udev->active_duration += jiffies;
2006 		udev->state = new_state;
2007 	} else
2008 		recursively_mark_NOTATTACHED(udev);
2009 	spin_unlock_irqrestore(&device_state_lock, flags);
2010 	if (wakeup >= 0)
2011 		device_set_wakeup_capable(&udev->dev, wakeup);
2012 }
2013 EXPORT_SYMBOL_GPL(usb_set_device_state);
2014 
2015 /*
2016  * Choose a device number.
2017  *
2018  * Device numbers are used as filenames in usbfs.  On USB-1.1 and
2019  * USB-2.0 buses they are also used as device addresses, however on
2020  * USB-3.0 buses the address is assigned by the controller hardware
2021  * and it usually is not the same as the device number.
2022  *
2023  * WUSB devices are simple: they have no hubs behind, so the mapping
2024  * device <-> virtual port number becomes 1:1. Why? to simplify the
2025  * life of the device connection logic in
2026  * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
2027  * handshake we need to assign a temporary address in the unauthorized
2028  * space. For simplicity we use the first virtual port number found to
2029  * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
2030  * and that becomes it's address [X < 128] or its unauthorized address
2031  * [X | 0x80].
2032  *
2033  * We add 1 as an offset to the one-based USB-stack port number
2034  * (zero-based wusb virtual port index) for two reasons: (a) dev addr
2035  * 0 is reserved by USB for default address; (b) Linux's USB stack
2036  * uses always #1 for the root hub of the controller. So USB stack's
2037  * port #1, which is wusb virtual-port #0 has address #2.
2038  *
2039  * Devices connected under xHCI are not as simple.  The host controller
2040  * supports virtualization, so the hardware assigns device addresses and
2041  * the HCD must setup data structures before issuing a set address
2042  * command to the hardware.
2043  */
2044 static void choose_devnum(struct usb_device *udev)
2045 {
2046 	int		devnum;
2047 	struct usb_bus	*bus = udev->bus;
2048 
2049 	/* be safe when more hub events are proceed in parallel */
2050 	mutex_lock(&bus->usb_address0_mutex);
2051 	if (udev->wusb) {
2052 		devnum = udev->portnum + 1;
2053 		BUG_ON(test_bit(devnum, bus->devmap.devicemap));
2054 	} else {
2055 		/* Try to allocate the next devnum beginning at
2056 		 * bus->devnum_next. */
2057 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
2058 					    bus->devnum_next);
2059 		if (devnum >= 128)
2060 			devnum = find_next_zero_bit(bus->devmap.devicemap,
2061 						    128, 1);
2062 		bus->devnum_next = (devnum >= 127 ? 1 : devnum + 1);
2063 	}
2064 	if (devnum < 128) {
2065 		set_bit(devnum, bus->devmap.devicemap);
2066 		udev->devnum = devnum;
2067 	}
2068 	mutex_unlock(&bus->usb_address0_mutex);
2069 }
2070 
2071 static void release_devnum(struct usb_device *udev)
2072 {
2073 	if (udev->devnum > 0) {
2074 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
2075 		udev->devnum = -1;
2076 	}
2077 }
2078 
2079 static void update_devnum(struct usb_device *udev, int devnum)
2080 {
2081 	/* The address for a WUSB device is managed by wusbcore. */
2082 	if (!udev->wusb)
2083 		udev->devnum = devnum;
2084 }
2085 
2086 static void hub_free_dev(struct usb_device *udev)
2087 {
2088 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2089 
2090 	/* Root hubs aren't real devices, so don't free HCD resources */
2091 	if (hcd->driver->free_dev && udev->parent)
2092 		hcd->driver->free_dev(hcd, udev);
2093 }
2094 
2095 static void hub_disconnect_children(struct usb_device *udev)
2096 {
2097 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2098 	int i;
2099 
2100 	/* Free up all the children before we remove this device */
2101 	for (i = 0; i < udev->maxchild; i++) {
2102 		if (hub->ports[i]->child)
2103 			usb_disconnect(&hub->ports[i]->child);
2104 	}
2105 }
2106 
2107 /**
2108  * usb_disconnect - disconnect a device (usbcore-internal)
2109  * @pdev: pointer to device being disconnected
2110  * Context: !in_interrupt ()
2111  *
2112  * Something got disconnected. Get rid of it and all of its children.
2113  *
2114  * If *pdev is a normal device then the parent hub must already be locked.
2115  * If *pdev is a root hub then the caller must hold the usb_bus_list_lock,
2116  * which protects the set of root hubs as well as the list of buses.
2117  *
2118  * Only hub drivers (including virtual root hub drivers for host
2119  * controllers) should ever call this.
2120  *
2121  * This call is synchronous, and may not be used in an interrupt context.
2122  */
2123 void usb_disconnect(struct usb_device **pdev)
2124 {
2125 	struct usb_port *port_dev = NULL;
2126 	struct usb_device *udev = *pdev;
2127 	struct usb_hub *hub = NULL;
2128 	int port1 = 1;
2129 
2130 	/* mark the device as inactive, so any further urb submissions for
2131 	 * this device (and any of its children) will fail immediately.
2132 	 * this quiesces everything except pending urbs.
2133 	 */
2134 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2135 	dev_info(&udev->dev, "USB disconnect, device number %d\n",
2136 			udev->devnum);
2137 
2138 	usb_lock_device(udev);
2139 
2140 	hub_disconnect_children(udev);
2141 
2142 	/* deallocate hcd/hardware state ... nuking all pending urbs and
2143 	 * cleaning up all state associated with the current configuration
2144 	 * so that the hardware is now fully quiesced.
2145 	 */
2146 	dev_dbg (&udev->dev, "unregistering device\n");
2147 	usb_disable_device(udev, 0);
2148 	usb_hcd_synchronize_unlinks(udev);
2149 
2150 	if (udev->parent) {
2151 		port1 = udev->portnum;
2152 		hub = usb_hub_to_struct_hub(udev->parent);
2153 		port_dev = hub->ports[port1 - 1];
2154 
2155 		sysfs_remove_link(&udev->dev.kobj, "port");
2156 		sysfs_remove_link(&port_dev->dev.kobj, "device");
2157 
2158 		/*
2159 		 * As usb_port_runtime_resume() de-references udev, make
2160 		 * sure no resumes occur during removal
2161 		 */
2162 		if (!test_and_set_bit(port1, hub->child_usage_bits))
2163 			pm_runtime_get_sync(&port_dev->dev);
2164 	}
2165 
2166 	usb_remove_ep_devs(&udev->ep0);
2167 	usb_unlock_device(udev);
2168 
2169 	/* Unregister the device.  The device driver is responsible
2170 	 * for de-configuring the device and invoking the remove-device
2171 	 * notifier chain (used by usbfs and possibly others).
2172 	 */
2173 	device_del(&udev->dev);
2174 
2175 	/* Free the device number and delete the parent's children[]
2176 	 * (or root_hub) pointer.
2177 	 */
2178 	release_devnum(udev);
2179 
2180 	/* Avoid races with recursively_mark_NOTATTACHED() */
2181 	spin_lock_irq(&device_state_lock);
2182 	*pdev = NULL;
2183 	spin_unlock_irq(&device_state_lock);
2184 
2185 	if (port_dev && test_and_clear_bit(port1, hub->child_usage_bits))
2186 		pm_runtime_put(&port_dev->dev);
2187 
2188 	hub_free_dev(udev);
2189 
2190 	put_device(&udev->dev);
2191 }
2192 
2193 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
2194 static void show_string(struct usb_device *udev, char *id, char *string)
2195 {
2196 	if (!string)
2197 		return;
2198 	dev_info(&udev->dev, "%s: %s\n", id, string);
2199 }
2200 
2201 static void announce_device(struct usb_device *udev)
2202 {
2203 	dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
2204 		le16_to_cpu(udev->descriptor.idVendor),
2205 		le16_to_cpu(udev->descriptor.idProduct));
2206 	dev_info(&udev->dev,
2207 		"New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
2208 		udev->descriptor.iManufacturer,
2209 		udev->descriptor.iProduct,
2210 		udev->descriptor.iSerialNumber);
2211 	show_string(udev, "Product", udev->product);
2212 	show_string(udev, "Manufacturer", udev->manufacturer);
2213 	show_string(udev, "SerialNumber", udev->serial);
2214 }
2215 #else
2216 static inline void announce_device(struct usb_device *udev) { }
2217 #endif
2218 
2219 
2220 /**
2221  * usb_enumerate_device_otg - FIXME (usbcore-internal)
2222  * @udev: newly addressed device (in ADDRESS state)
2223  *
2224  * Finish enumeration for On-The-Go devices
2225  *
2226  * Return: 0 if successful. A negative error code otherwise.
2227  */
2228 static int usb_enumerate_device_otg(struct usb_device *udev)
2229 {
2230 	int err = 0;
2231 
2232 #ifdef	CONFIG_USB_OTG
2233 	/*
2234 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
2235 	 * to wake us after we've powered off VBUS; and HNP, switching roles
2236 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
2237 	 */
2238 	if (!udev->bus->is_b_host
2239 			&& udev->config
2240 			&& udev->parent == udev->bus->root_hub) {
2241 		struct usb_otg_descriptor	*desc = NULL;
2242 		struct usb_bus			*bus = udev->bus;
2243 
2244 		/* descriptor may appear anywhere in config */
2245 		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
2246 					le16_to_cpu(udev->config[0].desc.wTotalLength),
2247 					USB_DT_OTG, (void **) &desc) == 0) {
2248 			if (desc->bmAttributes & USB_OTG_HNP) {
2249 				unsigned		port1 = udev->portnum;
2250 
2251 				dev_info(&udev->dev,
2252 					"Dual-Role OTG device on %sHNP port\n",
2253 					(port1 == bus->otg_port)
2254 						? "" : "non-");
2255 
2256 				/* enable HNP before suspend, it's simpler */
2257 				if (port1 == bus->otg_port)
2258 					bus->b_hnp_enable = 1;
2259 				err = usb_control_msg(udev,
2260 					usb_sndctrlpipe(udev, 0),
2261 					USB_REQ_SET_FEATURE, 0,
2262 					bus->b_hnp_enable
2263 						? USB_DEVICE_B_HNP_ENABLE
2264 						: USB_DEVICE_A_ALT_HNP_SUPPORT,
2265 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
2266 				if (err < 0) {
2267 					/* OTG MESSAGE: report errors here,
2268 					 * customize to match your product.
2269 					 */
2270 					dev_info(&udev->dev,
2271 						"can't set HNP mode: %d\n",
2272 						err);
2273 					bus->b_hnp_enable = 0;
2274 				}
2275 			}
2276 		}
2277 	}
2278 #endif
2279 	return err;
2280 }
2281 
2282 
2283 /**
2284  * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
2285  * @udev: newly addressed device (in ADDRESS state)
2286  *
2287  * This is only called by usb_new_device() and usb_authorize_device()
2288  * and FIXME -- all comments that apply to them apply here wrt to
2289  * environment.
2290  *
2291  * If the device is WUSB and not authorized, we don't attempt to read
2292  * the string descriptors, as they will be errored out by the device
2293  * until it has been authorized.
2294  *
2295  * Return: 0 if successful. A negative error code otherwise.
2296  */
2297 static int usb_enumerate_device(struct usb_device *udev)
2298 {
2299 	int err;
2300 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2301 
2302 	if (udev->config == NULL) {
2303 		err = usb_get_configuration(udev);
2304 		if (err < 0) {
2305 			if (err != -ENODEV)
2306 				dev_err(&udev->dev, "can't read configurations, error %d\n",
2307 						err);
2308 			return err;
2309 		}
2310 	}
2311 
2312 	/* read the standard strings and cache them if present */
2313 	udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
2314 	udev->manufacturer = usb_cache_string(udev,
2315 					      udev->descriptor.iManufacturer);
2316 	udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
2317 
2318 	err = usb_enumerate_device_otg(udev);
2319 	if (err < 0)
2320 		return err;
2321 
2322 	if (IS_ENABLED(CONFIG_USB_OTG_WHITELIST) && hcd->tpl_support &&
2323 		!is_targeted(udev)) {
2324 		/* Maybe it can talk to us, though we can't talk to it.
2325 		 * (Includes HNP test device.)
2326 		 */
2327 		if (IS_ENABLED(CONFIG_USB_OTG) && (udev->bus->b_hnp_enable
2328 			|| udev->bus->is_b_host)) {
2329 			err = usb_port_suspend(udev, PMSG_AUTO_SUSPEND);
2330 			if (err < 0)
2331 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
2332 		}
2333 		return -ENOTSUPP;
2334 	}
2335 
2336 	usb_detect_interface_quirks(udev);
2337 
2338 	return 0;
2339 }
2340 
2341 static void set_usb_port_removable(struct usb_device *udev)
2342 {
2343 	struct usb_device *hdev = udev->parent;
2344 	struct usb_hub *hub;
2345 	u8 port = udev->portnum;
2346 	u16 wHubCharacteristics;
2347 	bool removable = true;
2348 
2349 	if (!hdev)
2350 		return;
2351 
2352 	hub = usb_hub_to_struct_hub(udev->parent);
2353 
2354 	/*
2355 	 * If the platform firmware has provided information about a port,
2356 	 * use that to determine whether it's removable.
2357 	 */
2358 	switch (hub->ports[udev->portnum - 1]->connect_type) {
2359 	case USB_PORT_CONNECT_TYPE_HOT_PLUG:
2360 		udev->removable = USB_DEVICE_REMOVABLE;
2361 		return;
2362 	case USB_PORT_CONNECT_TYPE_HARD_WIRED:
2363 	case USB_PORT_NOT_USED:
2364 		udev->removable = USB_DEVICE_FIXED;
2365 		return;
2366 	default:
2367 		break;
2368 	}
2369 
2370 	/*
2371 	 * Otherwise, check whether the hub knows whether a port is removable
2372 	 * or not
2373 	 */
2374 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2375 
2376 	if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
2377 		return;
2378 
2379 	if (hub_is_superspeed(hdev)) {
2380 		if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
2381 				& (1 << port))
2382 			removable = false;
2383 	} else {
2384 		if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
2385 			removable = false;
2386 	}
2387 
2388 	if (removable)
2389 		udev->removable = USB_DEVICE_REMOVABLE;
2390 	else
2391 		udev->removable = USB_DEVICE_FIXED;
2392 
2393 }
2394 
2395 /**
2396  * usb_new_device - perform initial device setup (usbcore-internal)
2397  * @udev: newly addressed device (in ADDRESS state)
2398  *
2399  * This is called with devices which have been detected but not fully
2400  * enumerated.  The device descriptor is available, but not descriptors
2401  * for any device configuration.  The caller must have locked either
2402  * the parent hub (if udev is a normal device) or else the
2403  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
2404  * udev has already been installed, but udev is not yet visible through
2405  * sysfs or other filesystem code.
2406  *
2407  * This call is synchronous, and may not be used in an interrupt context.
2408  *
2409  * Only the hub driver or root-hub registrar should ever call this.
2410  *
2411  * Return: Whether the device is configured properly or not. Zero if the
2412  * interface was registered with the driver core; else a negative errno
2413  * value.
2414  *
2415  */
2416 int usb_new_device(struct usb_device *udev)
2417 {
2418 	int err;
2419 
2420 	if (udev->parent) {
2421 		/* Initialize non-root-hub device wakeup to disabled;
2422 		 * device (un)configuration controls wakeup capable
2423 		 * sysfs power/wakeup controls wakeup enabled/disabled
2424 		 */
2425 		device_init_wakeup(&udev->dev, 0);
2426 	}
2427 
2428 	/* Tell the runtime-PM framework the device is active */
2429 	pm_runtime_set_active(&udev->dev);
2430 	pm_runtime_get_noresume(&udev->dev);
2431 	pm_runtime_use_autosuspend(&udev->dev);
2432 	pm_runtime_enable(&udev->dev);
2433 
2434 	/* By default, forbid autosuspend for all devices.  It will be
2435 	 * allowed for hubs during binding.
2436 	 */
2437 	usb_disable_autosuspend(udev);
2438 
2439 	err = usb_enumerate_device(udev);	/* Read descriptors */
2440 	if (err < 0)
2441 		goto fail;
2442 	dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
2443 			udev->devnum, udev->bus->busnum,
2444 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2445 	/* export the usbdev device-node for libusb */
2446 	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
2447 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2448 
2449 	/* Tell the world! */
2450 	announce_device(udev);
2451 
2452 	if (udev->serial)
2453 		add_device_randomness(udev->serial, strlen(udev->serial));
2454 	if (udev->product)
2455 		add_device_randomness(udev->product, strlen(udev->product));
2456 	if (udev->manufacturer)
2457 		add_device_randomness(udev->manufacturer,
2458 				      strlen(udev->manufacturer));
2459 
2460 	device_enable_async_suspend(&udev->dev);
2461 
2462 	/* check whether the hub or firmware marks this port as non-removable */
2463 	if (udev->parent)
2464 		set_usb_port_removable(udev);
2465 
2466 	/* Register the device.  The device driver is responsible
2467 	 * for configuring the device and invoking the add-device
2468 	 * notifier chain (used by usbfs and possibly others).
2469 	 */
2470 	err = device_add(&udev->dev);
2471 	if (err) {
2472 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
2473 		goto fail;
2474 	}
2475 
2476 	/* Create link files between child device and usb port device. */
2477 	if (udev->parent) {
2478 		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
2479 		int port1 = udev->portnum;
2480 		struct usb_port	*port_dev = hub->ports[port1 - 1];
2481 
2482 		err = sysfs_create_link(&udev->dev.kobj,
2483 				&port_dev->dev.kobj, "port");
2484 		if (err)
2485 			goto fail;
2486 
2487 		err = sysfs_create_link(&port_dev->dev.kobj,
2488 				&udev->dev.kobj, "device");
2489 		if (err) {
2490 			sysfs_remove_link(&udev->dev.kobj, "port");
2491 			goto fail;
2492 		}
2493 
2494 		if (!test_and_set_bit(port1, hub->child_usage_bits))
2495 			pm_runtime_get_sync(&port_dev->dev);
2496 	}
2497 
2498 	(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
2499 	usb_mark_last_busy(udev);
2500 	pm_runtime_put_sync_autosuspend(&udev->dev);
2501 	return err;
2502 
2503 fail:
2504 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2505 	pm_runtime_disable(&udev->dev);
2506 	pm_runtime_set_suspended(&udev->dev);
2507 	return err;
2508 }
2509 
2510 
2511 /**
2512  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
2513  * @usb_dev: USB device
2514  *
2515  * Move the USB device to a very basic state where interfaces are disabled
2516  * and the device is in fact unconfigured and unusable.
2517  *
2518  * We share a lock (that we have) with device_del(), so we need to
2519  * defer its call.
2520  *
2521  * Return: 0.
2522  */
2523 int usb_deauthorize_device(struct usb_device *usb_dev)
2524 {
2525 	usb_lock_device(usb_dev);
2526 	if (usb_dev->authorized == 0)
2527 		goto out_unauthorized;
2528 
2529 	usb_dev->authorized = 0;
2530 	usb_set_configuration(usb_dev, -1);
2531 
2532 out_unauthorized:
2533 	usb_unlock_device(usb_dev);
2534 	return 0;
2535 }
2536 
2537 
2538 int usb_authorize_device(struct usb_device *usb_dev)
2539 {
2540 	int result = 0, c;
2541 
2542 	usb_lock_device(usb_dev);
2543 	if (usb_dev->authorized == 1)
2544 		goto out_authorized;
2545 
2546 	result = usb_autoresume_device(usb_dev);
2547 	if (result < 0) {
2548 		dev_err(&usb_dev->dev,
2549 			"can't autoresume for authorization: %d\n", result);
2550 		goto error_autoresume;
2551 	}
2552 
2553 	if (usb_dev->wusb) {
2554 		result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
2555 		if (result < 0) {
2556 			dev_err(&usb_dev->dev, "can't re-read device descriptor for "
2557 				"authorization: %d\n", result);
2558 			goto error_device_descriptor;
2559 		}
2560 	}
2561 
2562 	usb_dev->authorized = 1;
2563 	/* Choose and set the configuration.  This registers the interfaces
2564 	 * with the driver core and lets interface drivers bind to them.
2565 	 */
2566 	c = usb_choose_configuration(usb_dev);
2567 	if (c >= 0) {
2568 		result = usb_set_configuration(usb_dev, c);
2569 		if (result) {
2570 			dev_err(&usb_dev->dev,
2571 				"can't set config #%d, error %d\n", c, result);
2572 			/* This need not be fatal.  The user can try to
2573 			 * set other configurations. */
2574 		}
2575 	}
2576 	dev_info(&usb_dev->dev, "authorized to connect\n");
2577 
2578 error_device_descriptor:
2579 	usb_autosuspend_device(usb_dev);
2580 error_autoresume:
2581 out_authorized:
2582 	usb_unlock_device(usb_dev);	/* complements locktree */
2583 	return result;
2584 }
2585 
2586 
2587 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
2588 static unsigned hub_is_wusb(struct usb_hub *hub)
2589 {
2590 	struct usb_hcd *hcd;
2591 	if (hub->hdev->parent != NULL)  /* not a root hub? */
2592 		return 0;
2593 	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
2594 	return hcd->wireless;
2595 }
2596 
2597 
2598 #define PORT_RESET_TRIES	5
2599 #define SET_ADDRESS_TRIES	2
2600 #define GET_DESCRIPTOR_TRIES	2
2601 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
2602 #define USE_NEW_SCHEME(i)	((i) / 2 == (int)old_scheme_first)
2603 
2604 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
2605 #define HUB_SHORT_RESET_TIME	10
2606 #define HUB_BH_RESET_TIME	50
2607 #define HUB_LONG_RESET_TIME	200
2608 #define HUB_RESET_TIMEOUT	800
2609 
2610 /*
2611  * "New scheme" enumeration causes an extra state transition to be
2612  * exposed to an xhci host and causes USB3 devices to receive control
2613  * commands in the default state.  This has been seen to cause
2614  * enumeration failures, so disable this enumeration scheme for USB3
2615  * devices.
2616  */
2617 static bool use_new_scheme(struct usb_device *udev, int retry)
2618 {
2619 	if (udev->speed == USB_SPEED_SUPER)
2620 		return false;
2621 
2622 	return USE_NEW_SCHEME(retry);
2623 }
2624 
2625 /* Is a USB 3.0 port in the Inactive or Compliance Mode state?
2626  * Port worm reset is required to recover
2627  */
2628 static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
2629 		u16 portstatus)
2630 {
2631 	u16 link_state;
2632 
2633 	if (!hub_is_superspeed(hub->hdev))
2634 		return false;
2635 
2636 	if (test_bit(port1, hub->warm_reset_bits))
2637 		return true;
2638 
2639 	link_state = portstatus & USB_PORT_STAT_LINK_STATE;
2640 	return link_state == USB_SS_PORT_LS_SS_INACTIVE
2641 		|| link_state == USB_SS_PORT_LS_COMP_MOD;
2642 }
2643 
2644 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
2645 			struct usb_device *udev, unsigned int delay, bool warm)
2646 {
2647 	int delay_time, ret;
2648 	u16 portstatus;
2649 	u16 portchange;
2650 
2651 	for (delay_time = 0;
2652 			delay_time < HUB_RESET_TIMEOUT;
2653 			delay_time += delay) {
2654 		/* wait to give the device a chance to reset */
2655 		msleep(delay);
2656 
2657 		/* read and decode port status */
2658 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
2659 		if (ret < 0)
2660 			return ret;
2661 
2662 		/* The port state is unknown until the reset completes. */
2663 		if (!(portstatus & USB_PORT_STAT_RESET))
2664 			break;
2665 
2666 		/* switch to the long delay after two short delay failures */
2667 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2668 			delay = HUB_LONG_RESET_TIME;
2669 
2670 		dev_dbg(&hub->ports[port1 - 1]->dev,
2671 				"not %sreset yet, waiting %dms\n",
2672 				warm ? "warm " : "", delay);
2673 	}
2674 
2675 	if ((portstatus & USB_PORT_STAT_RESET))
2676 		return -EBUSY;
2677 
2678 	if (hub_port_warm_reset_required(hub, port1, portstatus))
2679 		return -ENOTCONN;
2680 
2681 	/* Device went away? */
2682 	if (!(portstatus & USB_PORT_STAT_CONNECTION))
2683 		return -ENOTCONN;
2684 
2685 	/* bomb out completely if the connection bounced.  A USB 3.0
2686 	 * connection may bounce if multiple warm resets were issued,
2687 	 * but the device may have successfully re-connected. Ignore it.
2688 	 */
2689 	if (!hub_is_superspeed(hub->hdev) &&
2690 			(portchange & USB_PORT_STAT_C_CONNECTION))
2691 		return -ENOTCONN;
2692 
2693 	if (!(portstatus & USB_PORT_STAT_ENABLE))
2694 		return -EBUSY;
2695 
2696 	if (!udev)
2697 		return 0;
2698 
2699 	if (hub_is_wusb(hub))
2700 		udev->speed = USB_SPEED_WIRELESS;
2701 	else if (hub_is_superspeed(hub->hdev))
2702 		udev->speed = USB_SPEED_SUPER;
2703 	else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2704 		udev->speed = USB_SPEED_HIGH;
2705 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2706 		udev->speed = USB_SPEED_LOW;
2707 	else
2708 		udev->speed = USB_SPEED_FULL;
2709 	return 0;
2710 }
2711 
2712 /* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
2713 static int hub_port_reset(struct usb_hub *hub, int port1,
2714 			struct usb_device *udev, unsigned int delay, bool warm)
2715 {
2716 	int i, status;
2717 	u16 portchange, portstatus;
2718 	struct usb_port *port_dev = hub->ports[port1 - 1];
2719 
2720 	if (!hub_is_superspeed(hub->hdev)) {
2721 		if (warm) {
2722 			dev_err(hub->intfdev, "only USB3 hub support "
2723 						"warm reset\n");
2724 			return -EINVAL;
2725 		}
2726 		/* Block EHCI CF initialization during the port reset.
2727 		 * Some companion controllers don't like it when they mix.
2728 		 */
2729 		down_read(&ehci_cf_port_reset_rwsem);
2730 	} else if (!warm) {
2731 		/*
2732 		 * If the caller hasn't explicitly requested a warm reset,
2733 		 * double check and see if one is needed.
2734 		 */
2735 		if (hub_port_status(hub, port1, &portstatus, &portchange) == 0)
2736 			if (hub_port_warm_reset_required(hub, port1,
2737 							portstatus))
2738 				warm = true;
2739 	}
2740 	clear_bit(port1, hub->warm_reset_bits);
2741 
2742 	/* Reset the port */
2743 	for (i = 0; i < PORT_RESET_TRIES; i++) {
2744 		status = set_port_feature(hub->hdev, port1, (warm ?
2745 					USB_PORT_FEAT_BH_PORT_RESET :
2746 					USB_PORT_FEAT_RESET));
2747 		if (status == -ENODEV) {
2748 			;	/* The hub is gone */
2749 		} else if (status) {
2750 			dev_err(&port_dev->dev,
2751 					"cannot %sreset (err = %d)\n",
2752 					warm ? "warm " : "", status);
2753 		} else {
2754 			status = hub_port_wait_reset(hub, port1, udev, delay,
2755 								warm);
2756 			if (status && status != -ENOTCONN && status != -ENODEV)
2757 				dev_dbg(hub->intfdev,
2758 						"port_wait_reset: err = %d\n",
2759 						status);
2760 		}
2761 
2762 		/* Check for disconnect or reset */
2763 		if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
2764 			usb_clear_port_feature(hub->hdev, port1,
2765 					USB_PORT_FEAT_C_RESET);
2766 
2767 			if (!hub_is_superspeed(hub->hdev))
2768 				goto done;
2769 
2770 			usb_clear_port_feature(hub->hdev, port1,
2771 					USB_PORT_FEAT_C_BH_PORT_RESET);
2772 			usb_clear_port_feature(hub->hdev, port1,
2773 					USB_PORT_FEAT_C_PORT_LINK_STATE);
2774 			usb_clear_port_feature(hub->hdev, port1,
2775 					USB_PORT_FEAT_C_CONNECTION);
2776 
2777 			/*
2778 			 * If a USB 3.0 device migrates from reset to an error
2779 			 * state, re-issue the warm reset.
2780 			 */
2781 			if (hub_port_status(hub, port1,
2782 					&portstatus, &portchange) < 0)
2783 				goto done;
2784 
2785 			if (!hub_port_warm_reset_required(hub, port1,
2786 					portstatus))
2787 				goto done;
2788 
2789 			/*
2790 			 * If the port is in SS.Inactive or Compliance Mode, the
2791 			 * hot or warm reset failed.  Try another warm reset.
2792 			 */
2793 			if (!warm) {
2794 				dev_dbg(&port_dev->dev,
2795 						"hot reset failed, warm reset\n");
2796 				warm = true;
2797 			}
2798 		}
2799 
2800 		dev_dbg(&port_dev->dev,
2801 				"not enabled, trying %sreset again...\n",
2802 				warm ? "warm " : "");
2803 		delay = HUB_LONG_RESET_TIME;
2804 	}
2805 
2806 	dev_err(&port_dev->dev, "Cannot enable. Maybe the USB cable is bad?\n");
2807 
2808 done:
2809 	if (status == 0) {
2810 		/* TRSTRCY = 10 ms; plus some extra */
2811 		msleep(10 + 40);
2812 		if (udev) {
2813 			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2814 
2815 			update_devnum(udev, 0);
2816 			/* The xHC may think the device is already reset,
2817 			 * so ignore the status.
2818 			 */
2819 			if (hcd->driver->reset_device)
2820 				hcd->driver->reset_device(hcd, udev);
2821 
2822 			usb_set_device_state(udev, USB_STATE_DEFAULT);
2823 		}
2824 	} else {
2825 		if (udev)
2826 			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2827 	}
2828 
2829 	if (!hub_is_superspeed(hub->hdev))
2830 		up_read(&ehci_cf_port_reset_rwsem);
2831 
2832 	return status;
2833 }
2834 
2835 /* Check if a port is power on */
2836 static int port_is_power_on(struct usb_hub *hub, unsigned portstatus)
2837 {
2838 	int ret = 0;
2839 
2840 	if (hub_is_superspeed(hub->hdev)) {
2841 		if (portstatus & USB_SS_PORT_STAT_POWER)
2842 			ret = 1;
2843 	} else {
2844 		if (portstatus & USB_PORT_STAT_POWER)
2845 			ret = 1;
2846 	}
2847 
2848 	return ret;
2849 }
2850 
2851 static void usb_lock_port(struct usb_port *port_dev)
2852 		__acquires(&port_dev->status_lock)
2853 {
2854 	mutex_lock(&port_dev->status_lock);
2855 	__acquire(&port_dev->status_lock);
2856 }
2857 
2858 static void usb_unlock_port(struct usb_port *port_dev)
2859 		__releases(&port_dev->status_lock)
2860 {
2861 	mutex_unlock(&port_dev->status_lock);
2862 	__release(&port_dev->status_lock);
2863 }
2864 
2865 #ifdef	CONFIG_PM
2866 
2867 /* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
2868 static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
2869 {
2870 	int ret = 0;
2871 
2872 	if (hub_is_superspeed(hub->hdev)) {
2873 		if ((portstatus & USB_PORT_STAT_LINK_STATE)
2874 				== USB_SS_PORT_LS_U3)
2875 			ret = 1;
2876 	} else {
2877 		if (portstatus & USB_PORT_STAT_SUSPEND)
2878 			ret = 1;
2879 	}
2880 
2881 	return ret;
2882 }
2883 
2884 /* Determine whether the device on a port is ready for a normal resume,
2885  * is ready for a reset-resume, or should be disconnected.
2886  */
2887 static int check_port_resume_type(struct usb_device *udev,
2888 		struct usb_hub *hub, int port1,
2889 		int status, u16 portchange, u16 portstatus)
2890 {
2891 	struct usb_port *port_dev = hub->ports[port1 - 1];
2892 	int retries = 3;
2893 
2894  retry:
2895 	/* Is a warm reset needed to recover the connection? */
2896 	if (status == 0 && udev->reset_resume
2897 		&& hub_port_warm_reset_required(hub, port1, portstatus)) {
2898 		/* pass */;
2899 	}
2900 	/* Is the device still present? */
2901 	else if (status || port_is_suspended(hub, portstatus) ||
2902 			!port_is_power_on(hub, portstatus)) {
2903 		if (status >= 0)
2904 			status = -ENODEV;
2905 	} else if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2906 		if (retries--) {
2907 			usleep_range(200, 300);
2908 			status = hub_port_status(hub, port1, &portstatus,
2909 							     &portchange);
2910 			goto retry;
2911 		}
2912 		status = -ENODEV;
2913 	}
2914 
2915 	/* Can't do a normal resume if the port isn't enabled,
2916 	 * so try a reset-resume instead.
2917 	 */
2918 	else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
2919 		if (udev->persist_enabled)
2920 			udev->reset_resume = 1;
2921 		else
2922 			status = -ENODEV;
2923 	}
2924 
2925 	if (status) {
2926 		dev_dbg(&port_dev->dev, "status %04x.%04x after resume, %d\n",
2927 				portchange, portstatus, status);
2928 	} else if (udev->reset_resume) {
2929 
2930 		/* Late port handoff can set status-change bits */
2931 		if (portchange & USB_PORT_STAT_C_CONNECTION)
2932 			usb_clear_port_feature(hub->hdev, port1,
2933 					USB_PORT_FEAT_C_CONNECTION);
2934 		if (portchange & USB_PORT_STAT_C_ENABLE)
2935 			usb_clear_port_feature(hub->hdev, port1,
2936 					USB_PORT_FEAT_C_ENABLE);
2937 	}
2938 
2939 	return status;
2940 }
2941 
2942 int usb_disable_ltm(struct usb_device *udev)
2943 {
2944 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2945 
2946 	/* Check if the roothub and device supports LTM. */
2947 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2948 			!usb_device_supports_ltm(udev))
2949 		return 0;
2950 
2951 	/* Clear Feature LTM Enable can only be sent if the device is
2952 	 * configured.
2953 	 */
2954 	if (!udev->actconfig)
2955 		return 0;
2956 
2957 	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2958 			USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2959 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2960 			USB_CTRL_SET_TIMEOUT);
2961 }
2962 EXPORT_SYMBOL_GPL(usb_disable_ltm);
2963 
2964 void usb_enable_ltm(struct usb_device *udev)
2965 {
2966 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2967 
2968 	/* Check if the roothub and device supports LTM. */
2969 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2970 			!usb_device_supports_ltm(udev))
2971 		return;
2972 
2973 	/* Set Feature LTM Enable can only be sent if the device is
2974 	 * configured.
2975 	 */
2976 	if (!udev->actconfig)
2977 		return;
2978 
2979 	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2980 			USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2981 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2982 			USB_CTRL_SET_TIMEOUT);
2983 }
2984 EXPORT_SYMBOL_GPL(usb_enable_ltm);
2985 
2986 /*
2987  * usb_enable_remote_wakeup - enable remote wakeup for a device
2988  * @udev: target device
2989  *
2990  * For USB-2 devices: Set the device's remote wakeup feature.
2991  *
2992  * For USB-3 devices: Assume there's only one function on the device and
2993  * enable remote wake for the first interface.  FIXME if the interface
2994  * association descriptor shows there's more than one function.
2995  */
2996 static int usb_enable_remote_wakeup(struct usb_device *udev)
2997 {
2998 	if (udev->speed < USB_SPEED_SUPER)
2999 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3000 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
3001 				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3002 				USB_CTRL_SET_TIMEOUT);
3003 	else
3004 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3005 				USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
3006 				USB_INTRF_FUNC_SUSPEND,
3007 				USB_INTRF_FUNC_SUSPEND_RW |
3008 					USB_INTRF_FUNC_SUSPEND_LP,
3009 				NULL, 0, USB_CTRL_SET_TIMEOUT);
3010 }
3011 
3012 /*
3013  * usb_disable_remote_wakeup - disable remote wakeup for a device
3014  * @udev: target device
3015  *
3016  * For USB-2 devices: Clear the device's remote wakeup feature.
3017  *
3018  * For USB-3 devices: Assume there's only one function on the device and
3019  * disable remote wake for the first interface.  FIXME if the interface
3020  * association descriptor shows there's more than one function.
3021  */
3022 static int usb_disable_remote_wakeup(struct usb_device *udev)
3023 {
3024 	if (udev->speed < USB_SPEED_SUPER)
3025 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3026 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
3027 				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3028 				USB_CTRL_SET_TIMEOUT);
3029 	else
3030 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3031 				USB_REQ_CLEAR_FEATURE, USB_RECIP_INTERFACE,
3032 				USB_INTRF_FUNC_SUSPEND,	0, NULL, 0,
3033 				USB_CTRL_SET_TIMEOUT);
3034 }
3035 
3036 /* Count of wakeup-enabled devices at or below udev */
3037 static unsigned wakeup_enabled_descendants(struct usb_device *udev)
3038 {
3039 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
3040 
3041 	return udev->do_remote_wakeup +
3042 			(hub ? hub->wakeup_enabled_descendants : 0);
3043 }
3044 
3045 /*
3046  * usb_port_suspend - suspend a usb device's upstream port
3047  * @udev: device that's no longer in active use, not a root hub
3048  * Context: must be able to sleep; device not locked; pm locks held
3049  *
3050  * Suspends a USB device that isn't in active use, conserving power.
3051  * Devices may wake out of a suspend, if anything important happens,
3052  * using the remote wakeup mechanism.  They may also be taken out of
3053  * suspend by the host, using usb_port_resume().  It's also routine
3054  * to disconnect devices while they are suspended.
3055  *
3056  * This only affects the USB hardware for a device; its interfaces
3057  * (and, for hubs, child devices) must already have been suspended.
3058  *
3059  * Selective port suspend reduces power; most suspended devices draw
3060  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
3061  * All devices below the suspended port are also suspended.
3062  *
3063  * Devices leave suspend state when the host wakes them up.  Some devices
3064  * also support "remote wakeup", where the device can activate the USB
3065  * tree above them to deliver data, such as a keypress or packet.  In
3066  * some cases, this wakes the USB host.
3067  *
3068  * Suspending OTG devices may trigger HNP, if that's been enabled
3069  * between a pair of dual-role devices.  That will change roles, such
3070  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
3071  *
3072  * Devices on USB hub ports have only one "suspend" state, corresponding
3073  * to ACPI D2, "may cause the device to lose some context".
3074  * State transitions include:
3075  *
3076  *   - suspend, resume ... when the VBUS power link stays live
3077  *   - suspend, disconnect ... VBUS lost
3078  *
3079  * Once VBUS drop breaks the circuit, the port it's using has to go through
3080  * normal re-enumeration procedures, starting with enabling VBUS power.
3081  * Other than re-initializing the hub (plug/unplug, except for root hubs),
3082  * Linux (2.6) currently has NO mechanisms to initiate that:  no hub_wq
3083  * timer, no SRP, no requests through sysfs.
3084  *
3085  * If Runtime PM isn't enabled or used, non-SuperSpeed devices may not get
3086  * suspended until their bus goes into global suspend (i.e., the root
3087  * hub is suspended).  Nevertheless, we change @udev->state to
3088  * USB_STATE_SUSPENDED as this is the device's "logical" state.  The actual
3089  * upstream port setting is stored in @udev->port_is_suspended.
3090  *
3091  * Returns 0 on success, else negative errno.
3092  */
3093 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
3094 {
3095 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3096 	struct usb_port *port_dev = hub->ports[udev->portnum - 1];
3097 	int		port1 = udev->portnum;
3098 	int		status;
3099 	bool		really_suspend = true;
3100 
3101 	usb_lock_port(port_dev);
3102 
3103 	/* enable remote wakeup when appropriate; this lets the device
3104 	 * wake up the upstream hub (including maybe the root hub).
3105 	 *
3106 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
3107 	 * we don't explicitly enable it here.
3108 	 */
3109 	if (udev->do_remote_wakeup) {
3110 		status = usb_enable_remote_wakeup(udev);
3111 		if (status) {
3112 			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
3113 					status);
3114 			/* bail if autosuspend is requested */
3115 			if (PMSG_IS_AUTO(msg))
3116 				goto err_wakeup;
3117 		}
3118 	}
3119 
3120 	/* disable USB2 hardware LPM */
3121 	if (udev->usb2_hw_lpm_enabled == 1)
3122 		usb_set_usb2_hardware_lpm(udev, 0);
3123 
3124 	if (usb_disable_ltm(udev)) {
3125 		dev_err(&udev->dev, "Failed to disable LTM before suspend\n.");
3126 		status = -ENOMEM;
3127 		if (PMSG_IS_AUTO(msg))
3128 			goto err_ltm;
3129 	}
3130 	if (usb_unlocked_disable_lpm(udev)) {
3131 		dev_err(&udev->dev, "Failed to disable LPM before suspend\n.");
3132 		status = -ENOMEM;
3133 		if (PMSG_IS_AUTO(msg))
3134 			goto err_lpm3;
3135 	}
3136 
3137 	/* see 7.1.7.6 */
3138 	if (hub_is_superspeed(hub->hdev))
3139 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);
3140 
3141 	/*
3142 	 * For system suspend, we do not need to enable the suspend feature
3143 	 * on individual USB-2 ports.  The devices will automatically go
3144 	 * into suspend a few ms after the root hub stops sending packets.
3145 	 * The USB 2.0 spec calls this "global suspend".
3146 	 *
3147 	 * However, many USB hubs have a bug: They don't relay wakeup requests
3148 	 * from a downstream port if the port's suspend feature isn't on.
3149 	 * Therefore we will turn on the suspend feature if udev or any of its
3150 	 * descendants is enabled for remote wakeup.
3151 	 */
3152 	else if (PMSG_IS_AUTO(msg) || wakeup_enabled_descendants(udev) > 0)
3153 		status = set_port_feature(hub->hdev, port1,
3154 				USB_PORT_FEAT_SUSPEND);
3155 	else {
3156 		really_suspend = false;
3157 		status = 0;
3158 	}
3159 	if (status) {
3160 		dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
3161 
3162 		/* Try to enable USB3 LPM and LTM again */
3163 		usb_unlocked_enable_lpm(udev);
3164  err_lpm3:
3165 		usb_enable_ltm(udev);
3166  err_ltm:
3167 		/* Try to enable USB2 hardware LPM again */
3168 		if (udev->usb2_hw_lpm_capable == 1)
3169 			usb_set_usb2_hardware_lpm(udev, 1);
3170 
3171 		if (udev->do_remote_wakeup)
3172 			(void) usb_disable_remote_wakeup(udev);
3173  err_wakeup:
3174 
3175 		/* System sleep transitions should never fail */
3176 		if (!PMSG_IS_AUTO(msg))
3177 			status = 0;
3178 	} else {
3179 		dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
3180 				(PMSG_IS_AUTO(msg) ? "auto-" : ""),
3181 				udev->do_remote_wakeup);
3182 		if (really_suspend) {
3183 			udev->port_is_suspended = 1;
3184 
3185 			/* device has up to 10 msec to fully suspend */
3186 			msleep(10);
3187 		}
3188 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
3189 	}
3190 
3191 	if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled
3192 			&& test_and_clear_bit(port1, hub->child_usage_bits))
3193 		pm_runtime_put_sync(&port_dev->dev);
3194 
3195 	usb_mark_last_busy(hub->hdev);
3196 
3197 	usb_unlock_port(port_dev);
3198 	return status;
3199 }
3200 
3201 /*
3202  * If the USB "suspend" state is in use (rather than "global suspend"),
3203  * many devices will be individually taken out of suspend state using
3204  * special "resume" signaling.  This routine kicks in shortly after
3205  * hardware resume signaling is finished, either because of selective
3206  * resume (by host) or remote wakeup (by device) ... now see what changed
3207  * in the tree that's rooted at this device.
3208  *
3209  * If @udev->reset_resume is set then the device is reset before the
3210  * status check is done.
3211  */
3212 static int finish_port_resume(struct usb_device *udev)
3213 {
3214 	int	status = 0;
3215 	u16	devstatus = 0;
3216 
3217 	/* caller owns the udev device lock */
3218 	dev_dbg(&udev->dev, "%s\n",
3219 		udev->reset_resume ? "finish reset-resume" : "finish resume");
3220 
3221 	/* usb ch9 identifies four variants of SUSPENDED, based on what
3222 	 * state the device resumes to.  Linux currently won't see the
3223 	 * first two on the host side; they'd be inside hub_port_init()
3224 	 * during many timeouts, but hub_wq can't suspend until later.
3225 	 */
3226 	usb_set_device_state(udev, udev->actconfig
3227 			? USB_STATE_CONFIGURED
3228 			: USB_STATE_ADDRESS);
3229 
3230 	/* 10.5.4.5 says not to reset a suspended port if the attached
3231 	 * device is enabled for remote wakeup.  Hence the reset
3232 	 * operation is carried out here, after the port has been
3233 	 * resumed.
3234 	 */
3235 	if (udev->reset_resume) {
3236 		/*
3237 		 * If the device morphs or switches modes when it is reset,
3238 		 * we don't want to perform a reset-resume.  We'll fail the
3239 		 * resume, which will cause a logical disconnect, and then
3240 		 * the device will be rediscovered.
3241 		 */
3242  retry_reset_resume:
3243 		if (udev->quirks & USB_QUIRK_RESET)
3244 			status = -ENODEV;
3245 		else
3246 			status = usb_reset_and_verify_device(udev);
3247 	}
3248 
3249 	/* 10.5.4.5 says be sure devices in the tree are still there.
3250 	 * For now let's assume the device didn't go crazy on resume,
3251 	 * and device drivers will know about any resume quirks.
3252 	 */
3253 	if (status == 0) {
3254 		devstatus = 0;
3255 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3256 
3257 		/* If a normal resume failed, try doing a reset-resume */
3258 		if (status && !udev->reset_resume && udev->persist_enabled) {
3259 			dev_dbg(&udev->dev, "retry with reset-resume\n");
3260 			udev->reset_resume = 1;
3261 			goto retry_reset_resume;
3262 		}
3263 	}
3264 
3265 	if (status) {
3266 		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
3267 				status);
3268 	/*
3269 	 * There are a few quirky devices which violate the standard
3270 	 * by claiming to have remote wakeup enabled after a reset,
3271 	 * which crash if the feature is cleared, hence check for
3272 	 * udev->reset_resume
3273 	 */
3274 	} else if (udev->actconfig && !udev->reset_resume) {
3275 		if (udev->speed < USB_SPEED_SUPER) {
3276 			if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3277 				status = usb_disable_remote_wakeup(udev);
3278 		} else {
3279 			status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
3280 					&devstatus);
3281 			if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3282 					| USB_INTRF_STAT_FUNC_RW))
3283 				status = usb_disable_remote_wakeup(udev);
3284 		}
3285 
3286 		if (status)
3287 			dev_dbg(&udev->dev,
3288 				"disable remote wakeup, status %d\n",
3289 				status);
3290 		status = 0;
3291 	}
3292 	return status;
3293 }
3294 
3295 /*
3296  * There are some SS USB devices which take longer time for link training.
3297  * XHCI specs 4.19.4 says that when Link training is successful, port
3298  * sets CSC bit to 1. So if SW reads port status before successful link
3299  * training, then it will not find device to be present.
3300  * USB Analyzer log with such buggy devices show that in some cases
3301  * device switch on the RX termination after long delay of host enabling
3302  * the VBUS. In few other cases it has been seen that device fails to
3303  * negotiate link training in first attempt. It has been
3304  * reported till now that few devices take as long as 2000 ms to train
3305  * the link after host enabling its VBUS and termination. Following
3306  * routine implements a 2000 ms timeout for link training. If in a case
3307  * link trains before timeout, loop will exit earlier.
3308  *
3309  * FIXME: If a device was connected before suspend, but was removed
3310  * while system was asleep, then the loop in the following routine will
3311  * only exit at timeout.
3312  *
3313  * This routine should only be called when persist is enabled for a SS
3314  * device.
3315  */
3316 static int wait_for_ss_port_enable(struct usb_device *udev,
3317 		struct usb_hub *hub, int *port1,
3318 		u16 *portchange, u16 *portstatus)
3319 {
3320 	int status = 0, delay_ms = 0;
3321 
3322 	while (delay_ms < 2000) {
3323 		if (status || *portstatus & USB_PORT_STAT_CONNECTION)
3324 			break;
3325 		msleep(20);
3326 		delay_ms += 20;
3327 		status = hub_port_status(hub, *port1, portstatus, portchange);
3328 	}
3329 	return status;
3330 }
3331 
3332 /*
3333  * usb_port_resume - re-activate a suspended usb device's upstream port
3334  * @udev: device to re-activate, not a root hub
3335  * Context: must be able to sleep; device not locked; pm locks held
3336  *
3337  * This will re-activate the suspended device, increasing power usage
3338  * while letting drivers communicate again with its endpoints.
3339  * USB resume explicitly guarantees that the power session between
3340  * the host and the device is the same as it was when the device
3341  * suspended.
3342  *
3343  * If @udev->reset_resume is set then this routine won't check that the
3344  * port is still enabled.  Furthermore, finish_port_resume() above will
3345  * reset @udev.  The end result is that a broken power session can be
3346  * recovered and @udev will appear to persist across a loss of VBUS power.
3347  *
3348  * For example, if a host controller doesn't maintain VBUS suspend current
3349  * during a system sleep or is reset when the system wakes up, all the USB
3350  * power sessions below it will be broken.  This is especially troublesome
3351  * for mass-storage devices containing mounted filesystems, since the
3352  * device will appear to have disconnected and all the memory mappings
3353  * to it will be lost.  Using the USB_PERSIST facility, the device can be
3354  * made to appear as if it had not disconnected.
3355  *
3356  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
3357  * every effort to insure that the same device is present after the
3358  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
3359  * quite possible for a device to remain unaltered but its media to be
3360  * changed.  If the user replaces a flash memory card while the system is
3361  * asleep, he will have only himself to blame when the filesystem on the
3362  * new card is corrupted and the system crashes.
3363  *
3364  * Returns 0 on success, else negative errno.
3365  */
3366 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
3367 {
3368 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3369 	struct usb_port *port_dev = hub->ports[udev->portnum  - 1];
3370 	int		port1 = udev->portnum;
3371 	int		status;
3372 	u16		portchange, portstatus;
3373 
3374 	if (!test_and_set_bit(port1, hub->child_usage_bits)) {
3375 		status = pm_runtime_get_sync(&port_dev->dev);
3376 		if (status < 0) {
3377 			dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
3378 					status);
3379 			return status;
3380 		}
3381 	}
3382 
3383 	usb_lock_port(port_dev);
3384 
3385 	/* Skip the initial Clear-Suspend step for a remote wakeup */
3386 	status = hub_port_status(hub, port1, &portstatus, &portchange);
3387 	if (status == 0 && !port_is_suspended(hub, portstatus))
3388 		goto SuspendCleared;
3389 
3390 	/* see 7.1.7.7; affects power usage, but not budgeting */
3391 	if (hub_is_superspeed(hub->hdev))
3392 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
3393 	else
3394 		status = usb_clear_port_feature(hub->hdev,
3395 				port1, USB_PORT_FEAT_SUSPEND);
3396 	if (status) {
3397 		dev_dbg(&port_dev->dev, "can't resume, status %d\n", status);
3398 	} else {
3399 		/* drive resume for USB_RESUME_TIMEOUT msec */
3400 		dev_dbg(&udev->dev, "usb %sresume\n",
3401 				(PMSG_IS_AUTO(msg) ? "auto-" : ""));
3402 		msleep(USB_RESUME_TIMEOUT);
3403 
3404 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
3405 		 * stop resume signaling.  Then finish the resume
3406 		 * sequence.
3407 		 */
3408 		status = hub_port_status(hub, port1, &portstatus, &portchange);
3409 
3410 		/* TRSMRCY = 10 msec */
3411 		msleep(10);
3412 	}
3413 
3414  SuspendCleared:
3415 	if (status == 0) {
3416 		udev->port_is_suspended = 0;
3417 		if (hub_is_superspeed(hub->hdev)) {
3418 			if (portchange & USB_PORT_STAT_C_LINK_STATE)
3419 				usb_clear_port_feature(hub->hdev, port1,
3420 					USB_PORT_FEAT_C_PORT_LINK_STATE);
3421 		} else {
3422 			if (portchange & USB_PORT_STAT_C_SUSPEND)
3423 				usb_clear_port_feature(hub->hdev, port1,
3424 						USB_PORT_FEAT_C_SUSPEND);
3425 		}
3426 	}
3427 
3428 	if (udev->persist_enabled && hub_is_superspeed(hub->hdev))
3429 		status = wait_for_ss_port_enable(udev, hub, &port1, &portchange,
3430 				&portstatus);
3431 
3432 	status = check_port_resume_type(udev,
3433 			hub, port1, status, portchange, portstatus);
3434 	if (status == 0)
3435 		status = finish_port_resume(udev);
3436 	if (status < 0) {
3437 		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
3438 		hub_port_logical_disconnect(hub, port1);
3439 	} else  {
3440 		/* Try to enable USB2 hardware LPM */
3441 		if (udev->usb2_hw_lpm_capable == 1)
3442 			usb_set_usb2_hardware_lpm(udev, 1);
3443 
3444 		/* Try to enable USB3 LTM and LPM */
3445 		usb_enable_ltm(udev);
3446 		usb_unlocked_enable_lpm(udev);
3447 	}
3448 
3449 	usb_unlock_port(port_dev);
3450 
3451 	return status;
3452 }
3453 
3454 int usb_remote_wakeup(struct usb_device *udev)
3455 {
3456 	int	status = 0;
3457 
3458 	usb_lock_device(udev);
3459 	if (udev->state == USB_STATE_SUSPENDED) {
3460 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
3461 		status = usb_autoresume_device(udev);
3462 		if (status == 0) {
3463 			/* Let the drivers do their thing, then... */
3464 			usb_autosuspend_device(udev);
3465 		}
3466 	}
3467 	usb_unlock_device(udev);
3468 	return status;
3469 }
3470 
3471 /* Returns 1 if there was a remote wakeup and a connect status change. */
3472 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
3473 		u16 portstatus, u16 portchange)
3474 		__must_hold(&port_dev->status_lock)
3475 {
3476 	struct usb_port *port_dev = hub->ports[port - 1];
3477 	struct usb_device *hdev;
3478 	struct usb_device *udev;
3479 	int connect_change = 0;
3480 	int ret;
3481 
3482 	hdev = hub->hdev;
3483 	udev = port_dev->child;
3484 	if (!hub_is_superspeed(hdev)) {
3485 		if (!(portchange & USB_PORT_STAT_C_SUSPEND))
3486 			return 0;
3487 		usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
3488 	} else {
3489 		if (!udev || udev->state != USB_STATE_SUSPENDED ||
3490 				 (portstatus & USB_PORT_STAT_LINK_STATE) !=
3491 				 USB_SS_PORT_LS_U0)
3492 			return 0;
3493 	}
3494 
3495 	if (udev) {
3496 		/* TRSMRCY = 10 msec */
3497 		msleep(10);
3498 
3499 		usb_unlock_port(port_dev);
3500 		ret = usb_remote_wakeup(udev);
3501 		usb_lock_port(port_dev);
3502 		if (ret < 0)
3503 			connect_change = 1;
3504 	} else {
3505 		ret = -ENODEV;
3506 		hub_port_disable(hub, port, 1);
3507 	}
3508 	dev_dbg(&port_dev->dev, "resume, status %d\n", ret);
3509 	return connect_change;
3510 }
3511 
3512 static int check_ports_changed(struct usb_hub *hub)
3513 {
3514 	int port1;
3515 
3516 	for (port1 = 1; port1 <= hub->hdev->maxchild; ++port1) {
3517 		u16 portstatus, portchange;
3518 		int status;
3519 
3520 		status = hub_port_status(hub, port1, &portstatus, &portchange);
3521 		if (!status && portchange)
3522 			return 1;
3523 	}
3524 	return 0;
3525 }
3526 
3527 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
3528 {
3529 	struct usb_hub		*hub = usb_get_intfdata (intf);
3530 	struct usb_device	*hdev = hub->hdev;
3531 	unsigned		port1;
3532 	int			status;
3533 
3534 	/*
3535 	 * Warn if children aren't already suspended.
3536 	 * Also, add up the number of wakeup-enabled descendants.
3537 	 */
3538 	hub->wakeup_enabled_descendants = 0;
3539 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3540 		struct usb_port *port_dev = hub->ports[port1 - 1];
3541 		struct usb_device *udev = port_dev->child;
3542 
3543 		if (udev && udev->can_submit) {
3544 			dev_warn(&port_dev->dev, "device %s not suspended yet\n",
3545 					dev_name(&udev->dev));
3546 			if (PMSG_IS_AUTO(msg))
3547 				return -EBUSY;
3548 		}
3549 		if (udev)
3550 			hub->wakeup_enabled_descendants +=
3551 					wakeup_enabled_descendants(udev);
3552 	}
3553 
3554 	if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
3555 		/* check if there are changes pending on hub ports */
3556 		if (check_ports_changed(hub)) {
3557 			if (PMSG_IS_AUTO(msg))
3558 				return -EBUSY;
3559 			pm_wakeup_event(&hdev->dev, 2000);
3560 		}
3561 	}
3562 
3563 	if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
3564 		/* Enable hub to send remote wakeup for all ports. */
3565 		for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3566 			status = set_port_feature(hdev,
3567 					port1 |
3568 					USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
3569 					USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
3570 					USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
3571 					USB_PORT_FEAT_REMOTE_WAKE_MASK);
3572 		}
3573 	}
3574 
3575 	dev_dbg(&intf->dev, "%s\n", __func__);
3576 
3577 	/* stop hub_wq and related activity */
3578 	hub_quiesce(hub, HUB_SUSPEND);
3579 	return 0;
3580 }
3581 
3582 static int hub_resume(struct usb_interface *intf)
3583 {
3584 	struct usb_hub *hub = usb_get_intfdata(intf);
3585 
3586 	dev_dbg(&intf->dev, "%s\n", __func__);
3587 	hub_activate(hub, HUB_RESUME);
3588 	return 0;
3589 }
3590 
3591 static int hub_reset_resume(struct usb_interface *intf)
3592 {
3593 	struct usb_hub *hub = usb_get_intfdata(intf);
3594 
3595 	dev_dbg(&intf->dev, "%s\n", __func__);
3596 	hub_activate(hub, HUB_RESET_RESUME);
3597 	return 0;
3598 }
3599 
3600 /**
3601  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
3602  * @rhdev: struct usb_device for the root hub
3603  *
3604  * The USB host controller driver calls this function when its root hub
3605  * is resumed and Vbus power has been interrupted or the controller
3606  * has been reset.  The routine marks @rhdev as having lost power.
3607  * When the hub driver is resumed it will take notice and carry out
3608  * power-session recovery for all the "USB-PERSIST"-enabled child devices;
3609  * the others will be disconnected.
3610  */
3611 void usb_root_hub_lost_power(struct usb_device *rhdev)
3612 {
3613 	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
3614 	rhdev->reset_resume = 1;
3615 }
3616 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
3617 
3618 static const char * const usb3_lpm_names[]  = {
3619 	"U0",
3620 	"U1",
3621 	"U2",
3622 	"U3",
3623 };
3624 
3625 /*
3626  * Send a Set SEL control transfer to the device, prior to enabling
3627  * device-initiated U1 or U2.  This lets the device know the exit latencies from
3628  * the time the device initiates a U1 or U2 exit, to the time it will receive a
3629  * packet from the host.
3630  *
3631  * This function will fail if the SEL or PEL values for udev are greater than
3632  * the maximum allowed values for the link state to be enabled.
3633  */
3634 static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state)
3635 {
3636 	struct usb_set_sel_req *sel_values;
3637 	unsigned long long u1_sel;
3638 	unsigned long long u1_pel;
3639 	unsigned long long u2_sel;
3640 	unsigned long long u2_pel;
3641 	int ret;
3642 
3643 	if (udev->state != USB_STATE_CONFIGURED)
3644 		return 0;
3645 
3646 	/* Convert SEL and PEL stored in ns to us */
3647 	u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
3648 	u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
3649 	u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
3650 	u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);
3651 
3652 	/*
3653 	 * Make sure that the calculated SEL and PEL values for the link
3654 	 * state we're enabling aren't bigger than the max SEL/PEL
3655 	 * value that will fit in the SET SEL control transfer.
3656 	 * Otherwise the device would get an incorrect idea of the exit
3657 	 * latency for the link state, and could start a device-initiated
3658 	 * U1/U2 when the exit latencies are too high.
3659 	 */
3660 	if ((state == USB3_LPM_U1 &&
3661 				(u1_sel > USB3_LPM_MAX_U1_SEL_PEL ||
3662 				 u1_pel > USB3_LPM_MAX_U1_SEL_PEL)) ||
3663 			(state == USB3_LPM_U2 &&
3664 			 (u2_sel > USB3_LPM_MAX_U2_SEL_PEL ||
3665 			  u2_pel > USB3_LPM_MAX_U2_SEL_PEL))) {
3666 		dev_dbg(&udev->dev, "Device-initiated %s disabled due to long SEL %llu us or PEL %llu us\n",
3667 				usb3_lpm_names[state], u1_sel, u1_pel);
3668 		return -EINVAL;
3669 	}
3670 
3671 	/*
3672 	 * If we're enabling device-initiated LPM for one link state,
3673 	 * but the other link state has a too high SEL or PEL value,
3674 	 * just set those values to the max in the Set SEL request.
3675 	 */
3676 	if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL)
3677 		u1_sel = USB3_LPM_MAX_U1_SEL_PEL;
3678 
3679 	if (u1_pel > USB3_LPM_MAX_U1_SEL_PEL)
3680 		u1_pel = USB3_LPM_MAX_U1_SEL_PEL;
3681 
3682 	if (u2_sel > USB3_LPM_MAX_U2_SEL_PEL)
3683 		u2_sel = USB3_LPM_MAX_U2_SEL_PEL;
3684 
3685 	if (u2_pel > USB3_LPM_MAX_U2_SEL_PEL)
3686 		u2_pel = USB3_LPM_MAX_U2_SEL_PEL;
3687 
3688 	/*
3689 	 * usb_enable_lpm() can be called as part of a failed device reset,
3690 	 * which may be initiated by an error path of a mass storage driver.
3691 	 * Therefore, use GFP_NOIO.
3692 	 */
3693 	sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
3694 	if (!sel_values)
3695 		return -ENOMEM;
3696 
3697 	sel_values->u1_sel = u1_sel;
3698 	sel_values->u1_pel = u1_pel;
3699 	sel_values->u2_sel = cpu_to_le16(u2_sel);
3700 	sel_values->u2_pel = cpu_to_le16(u2_pel);
3701 
3702 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3703 			USB_REQ_SET_SEL,
3704 			USB_RECIP_DEVICE,
3705 			0, 0,
3706 			sel_values, sizeof *(sel_values),
3707 			USB_CTRL_SET_TIMEOUT);
3708 	kfree(sel_values);
3709 	return ret;
3710 }
3711 
3712 /*
3713  * Enable or disable device-initiated U1 or U2 transitions.
3714  */
3715 static int usb_set_device_initiated_lpm(struct usb_device *udev,
3716 		enum usb3_link_state state, bool enable)
3717 {
3718 	int ret;
3719 	int feature;
3720 
3721 	switch (state) {
3722 	case USB3_LPM_U1:
3723 		feature = USB_DEVICE_U1_ENABLE;
3724 		break;
3725 	case USB3_LPM_U2:
3726 		feature = USB_DEVICE_U2_ENABLE;
3727 		break;
3728 	default:
3729 		dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n",
3730 				__func__, enable ? "enable" : "disable");
3731 		return -EINVAL;
3732 	}
3733 
3734 	if (udev->state != USB_STATE_CONFIGURED) {
3735 		dev_dbg(&udev->dev, "%s: Can't %s %s state "
3736 				"for unconfigured device.\n",
3737 				__func__, enable ? "enable" : "disable",
3738 				usb3_lpm_names[state]);
3739 		return 0;
3740 	}
3741 
3742 	if (enable) {
3743 		/*
3744 		 * Now send the control transfer to enable device-initiated LPM
3745 		 * for either U1 or U2.
3746 		 */
3747 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3748 				USB_REQ_SET_FEATURE,
3749 				USB_RECIP_DEVICE,
3750 				feature,
3751 				0, NULL, 0,
3752 				USB_CTRL_SET_TIMEOUT);
3753 	} else {
3754 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3755 				USB_REQ_CLEAR_FEATURE,
3756 				USB_RECIP_DEVICE,
3757 				feature,
3758 				0, NULL, 0,
3759 				USB_CTRL_SET_TIMEOUT);
3760 	}
3761 	if (ret < 0) {
3762 		dev_warn(&udev->dev, "%s of device-initiated %s failed.\n",
3763 				enable ? "Enable" : "Disable",
3764 				usb3_lpm_names[state]);
3765 		return -EBUSY;
3766 	}
3767 	return 0;
3768 }
3769 
3770 static int usb_set_lpm_timeout(struct usb_device *udev,
3771 		enum usb3_link_state state, int timeout)
3772 {
3773 	int ret;
3774 	int feature;
3775 
3776 	switch (state) {
3777 	case USB3_LPM_U1:
3778 		feature = USB_PORT_FEAT_U1_TIMEOUT;
3779 		break;
3780 	case USB3_LPM_U2:
3781 		feature = USB_PORT_FEAT_U2_TIMEOUT;
3782 		break;
3783 	default:
3784 		dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n",
3785 				__func__);
3786 		return -EINVAL;
3787 	}
3788 
3789 	if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT &&
3790 			timeout != USB3_LPM_DEVICE_INITIATED) {
3791 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, "
3792 				"which is a reserved value.\n",
3793 				usb3_lpm_names[state], timeout);
3794 		return -EINVAL;
3795 	}
3796 
3797 	ret = set_port_feature(udev->parent,
3798 			USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum,
3799 			feature);
3800 	if (ret < 0) {
3801 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x,"
3802 				"error code %i\n", usb3_lpm_names[state],
3803 				timeout, ret);
3804 		return -EBUSY;
3805 	}
3806 	if (state == USB3_LPM_U1)
3807 		udev->u1_params.timeout = timeout;
3808 	else
3809 		udev->u2_params.timeout = timeout;
3810 	return 0;
3811 }
3812 
3813 /*
3814  * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated
3815  * U1/U2 entry.
3816  *
3817  * We will attempt to enable U1 or U2, but there are no guarantees that the
3818  * control transfers to set the hub timeout or enable device-initiated U1/U2
3819  * will be successful.
3820  *
3821  * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI
3822  * driver know about it.  If that call fails, it should be harmless, and just
3823  * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency.
3824  */
3825 static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3826 		enum usb3_link_state state)
3827 {
3828 	int timeout, ret;
3829 	__u8 u1_mel = udev->bos->ss_cap->bU1devExitLat;
3830 	__le16 u2_mel = udev->bos->ss_cap->bU2DevExitLat;
3831 
3832 	/* If the device says it doesn't have *any* exit latency to come out of
3833 	 * U1 or U2, it's probably lying.  Assume it doesn't implement that link
3834 	 * state.
3835 	 */
3836 	if ((state == USB3_LPM_U1 && u1_mel == 0) ||
3837 			(state == USB3_LPM_U2 && u2_mel == 0))
3838 		return;
3839 
3840 	/*
3841 	 * First, let the device know about the exit latencies
3842 	 * associated with the link state we're about to enable.
3843 	 */
3844 	ret = usb_req_set_sel(udev, state);
3845 	if (ret < 0) {
3846 		dev_warn(&udev->dev, "Set SEL for device-initiated %s failed.\n",
3847 				usb3_lpm_names[state]);
3848 		return;
3849 	}
3850 
3851 	/* We allow the host controller to set the U1/U2 timeout internally
3852 	 * first, so that it can change its schedule to account for the
3853 	 * additional latency to send data to a device in a lower power
3854 	 * link state.
3855 	 */
3856 	timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state);
3857 
3858 	/* xHCI host controller doesn't want to enable this LPM state. */
3859 	if (timeout == 0)
3860 		return;
3861 
3862 	if (timeout < 0) {
3863 		dev_warn(&udev->dev, "Could not enable %s link state, "
3864 				"xHCI error %i.\n", usb3_lpm_names[state],
3865 				timeout);
3866 		return;
3867 	}
3868 
3869 	if (usb_set_lpm_timeout(udev, state, timeout))
3870 		/* If we can't set the parent hub U1/U2 timeout,
3871 		 * device-initiated LPM won't be allowed either, so let the xHCI
3872 		 * host know that this link state won't be enabled.
3873 		 */
3874 		hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
3875 
3876 	/* Only a configured device will accept the Set Feature U1/U2_ENABLE */
3877 	else if (udev->actconfig)
3878 		usb_set_device_initiated_lpm(udev, state, true);
3879 
3880 }
3881 
3882 /*
3883  * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated
3884  * U1/U2 entry.
3885  *
3886  * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry.
3887  * If zero is returned, the parent will not allow the link to go into U1/U2.
3888  *
3889  * If zero is returned, device-initiated U1/U2 entry may still be enabled, but
3890  * it won't have an effect on the bus link state because the parent hub will
3891  * still disallow device-initiated U1/U2 entry.
3892  *
3893  * If zero is returned, the xHCI host controller may still think U1/U2 entry is
3894  * possible.  The result will be slightly more bus bandwidth will be taken up
3895  * (to account for U1/U2 exit latency), but it should be harmless.
3896  */
3897 static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3898 		enum usb3_link_state state)
3899 {
3900 	switch (state) {
3901 	case USB3_LPM_U1:
3902 	case USB3_LPM_U2:
3903 		break;
3904 	default:
3905 		dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n",
3906 				__func__);
3907 		return -EINVAL;
3908 	}
3909 
3910 	if (usb_set_lpm_timeout(udev, state, 0))
3911 		return -EBUSY;
3912 
3913 	usb_set_device_initiated_lpm(udev, state, false);
3914 
3915 	if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state))
3916 		dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
3917 				"bus schedule bandwidth may be impacted.\n",
3918 				usb3_lpm_names[state]);
3919 	return 0;
3920 }
3921 
3922 /*
3923  * Disable hub-initiated and device-initiated U1 and U2 entry.
3924  * Caller must own the bandwidth_mutex.
3925  *
3926  * This will call usb_enable_lpm() on failure, which will decrement
3927  * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero.
3928  */
3929 int usb_disable_lpm(struct usb_device *udev)
3930 {
3931 	struct usb_hcd *hcd;
3932 
3933 	if (!udev || !udev->parent ||
3934 			udev->speed != USB_SPEED_SUPER ||
3935 			!udev->lpm_capable ||
3936 			udev->state < USB_STATE_DEFAULT)
3937 		return 0;
3938 
3939 	hcd = bus_to_hcd(udev->bus);
3940 	if (!hcd || !hcd->driver->disable_usb3_lpm_timeout)
3941 		return 0;
3942 
3943 	udev->lpm_disable_count++;
3944 	if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
3945 		return 0;
3946 
3947 	/* If LPM is enabled, attempt to disable it. */
3948 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
3949 		goto enable_lpm;
3950 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
3951 		goto enable_lpm;
3952 
3953 	return 0;
3954 
3955 enable_lpm:
3956 	usb_enable_lpm(udev);
3957 	return -EBUSY;
3958 }
3959 EXPORT_SYMBOL_GPL(usb_disable_lpm);
3960 
3961 /* Grab the bandwidth_mutex before calling usb_disable_lpm() */
3962 int usb_unlocked_disable_lpm(struct usb_device *udev)
3963 {
3964 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3965 	int ret;
3966 
3967 	if (!hcd)
3968 		return -EINVAL;
3969 
3970 	mutex_lock(hcd->bandwidth_mutex);
3971 	ret = usb_disable_lpm(udev);
3972 	mutex_unlock(hcd->bandwidth_mutex);
3973 
3974 	return ret;
3975 }
3976 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
3977 
3978 /*
3979  * Attempt to enable device-initiated and hub-initiated U1 and U2 entry.  The
3980  * xHCI host policy may prevent U1 or U2 from being enabled.
3981  *
3982  * Other callers may have disabled link PM, so U1 and U2 entry will be disabled
3983  * until the lpm_disable_count drops to zero.  Caller must own the
3984  * bandwidth_mutex.
3985  */
3986 void usb_enable_lpm(struct usb_device *udev)
3987 {
3988 	struct usb_hcd *hcd;
3989 
3990 	if (!udev || !udev->parent ||
3991 			udev->speed != USB_SPEED_SUPER ||
3992 			!udev->lpm_capable ||
3993 			udev->state < USB_STATE_DEFAULT)
3994 		return;
3995 
3996 	udev->lpm_disable_count--;
3997 	hcd = bus_to_hcd(udev->bus);
3998 	/* Double check that we can both enable and disable LPM.
3999 	 * Device must be configured to accept set feature U1/U2 timeout.
4000 	 */
4001 	if (!hcd || !hcd->driver->enable_usb3_lpm_timeout ||
4002 			!hcd->driver->disable_usb3_lpm_timeout)
4003 		return;
4004 
4005 	if (udev->lpm_disable_count > 0)
4006 		return;
4007 
4008 	usb_enable_link_state(hcd, udev, USB3_LPM_U1);
4009 	usb_enable_link_state(hcd, udev, USB3_LPM_U2);
4010 }
4011 EXPORT_SYMBOL_GPL(usb_enable_lpm);
4012 
4013 /* Grab the bandwidth_mutex before calling usb_enable_lpm() */
4014 void usb_unlocked_enable_lpm(struct usb_device *udev)
4015 {
4016 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4017 
4018 	if (!hcd)
4019 		return;
4020 
4021 	mutex_lock(hcd->bandwidth_mutex);
4022 	usb_enable_lpm(udev);
4023 	mutex_unlock(hcd->bandwidth_mutex);
4024 }
4025 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4026 
4027 
4028 #else	/* CONFIG_PM */
4029 
4030 #define hub_suspend		NULL
4031 #define hub_resume		NULL
4032 #define hub_reset_resume	NULL
4033 
4034 int usb_disable_lpm(struct usb_device *udev)
4035 {
4036 	return 0;
4037 }
4038 EXPORT_SYMBOL_GPL(usb_disable_lpm);
4039 
4040 void usb_enable_lpm(struct usb_device *udev) { }
4041 EXPORT_SYMBOL_GPL(usb_enable_lpm);
4042 
4043 int usb_unlocked_disable_lpm(struct usb_device *udev)
4044 {
4045 	return 0;
4046 }
4047 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
4048 
4049 void usb_unlocked_enable_lpm(struct usb_device *udev) { }
4050 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4051 
4052 int usb_disable_ltm(struct usb_device *udev)
4053 {
4054 	return 0;
4055 }
4056 EXPORT_SYMBOL_GPL(usb_disable_ltm);
4057 
4058 void usb_enable_ltm(struct usb_device *udev) { }
4059 EXPORT_SYMBOL_GPL(usb_enable_ltm);
4060 
4061 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
4062 		u16 portstatus, u16 portchange)
4063 {
4064 	return 0;
4065 }
4066 
4067 #endif	/* CONFIG_PM */
4068 
4069 
4070 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
4071  *
4072  * Between connect detection and reset signaling there must be a delay
4073  * of 100ms at least for debounce and power-settling.  The corresponding
4074  * timer shall restart whenever the downstream port detects a disconnect.
4075  *
4076  * Apparently there are some bluetooth and irda-dongles and a number of
4077  * low-speed devices for which this debounce period may last over a second.
4078  * Not covered by the spec - but easy to deal with.
4079  *
4080  * This implementation uses a 1500ms total debounce timeout; if the
4081  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
4082  * every 25ms for transient disconnects.  When the port status has been
4083  * unchanged for 100ms it returns the port status.
4084  */
4085 int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
4086 {
4087 	int ret;
4088 	u16 portchange, portstatus;
4089 	unsigned connection = 0xffff;
4090 	int total_time, stable_time = 0;
4091 	struct usb_port *port_dev = hub->ports[port1 - 1];
4092 
4093 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
4094 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
4095 		if (ret < 0)
4096 			return ret;
4097 
4098 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
4099 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
4100 			if (!must_be_connected ||
4101 			     (connection == USB_PORT_STAT_CONNECTION))
4102 				stable_time += HUB_DEBOUNCE_STEP;
4103 			if (stable_time >= HUB_DEBOUNCE_STABLE)
4104 				break;
4105 		} else {
4106 			stable_time = 0;
4107 			connection = portstatus & USB_PORT_STAT_CONNECTION;
4108 		}
4109 
4110 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
4111 			usb_clear_port_feature(hub->hdev, port1,
4112 					USB_PORT_FEAT_C_CONNECTION);
4113 		}
4114 
4115 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
4116 			break;
4117 		msleep(HUB_DEBOUNCE_STEP);
4118 	}
4119 
4120 	dev_dbg(&port_dev->dev, "debounce total %dms stable %dms status 0x%x\n",
4121 			total_time, stable_time, portstatus);
4122 
4123 	if (stable_time < HUB_DEBOUNCE_STABLE)
4124 		return -ETIMEDOUT;
4125 	return portstatus;
4126 }
4127 
4128 void usb_ep0_reinit(struct usb_device *udev)
4129 {
4130 	usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
4131 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
4132 	usb_enable_endpoint(udev, &udev->ep0, true);
4133 }
4134 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
4135 
4136 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
4137 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
4138 
4139 static int hub_set_address(struct usb_device *udev, int devnum)
4140 {
4141 	int retval;
4142 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4143 
4144 	/*
4145 	 * The host controller will choose the device address,
4146 	 * instead of the core having chosen it earlier
4147 	 */
4148 	if (!hcd->driver->address_device && devnum <= 1)
4149 		return -EINVAL;
4150 	if (udev->state == USB_STATE_ADDRESS)
4151 		return 0;
4152 	if (udev->state != USB_STATE_DEFAULT)
4153 		return -EINVAL;
4154 	if (hcd->driver->address_device)
4155 		retval = hcd->driver->address_device(hcd, udev);
4156 	else
4157 		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
4158 				USB_REQ_SET_ADDRESS, 0, devnum, 0,
4159 				NULL, 0, USB_CTRL_SET_TIMEOUT);
4160 	if (retval == 0) {
4161 		update_devnum(udev, devnum);
4162 		/* Device now using proper address. */
4163 		usb_set_device_state(udev, USB_STATE_ADDRESS);
4164 		usb_ep0_reinit(udev);
4165 	}
4166 	return retval;
4167 }
4168 
4169 /*
4170  * There are reports of USB 3.0 devices that say they support USB 2.0 Link PM
4171  * when they're plugged into a USB 2.0 port, but they don't work when LPM is
4172  * enabled.
4173  *
4174  * Only enable USB 2.0 Link PM if the port is internal (hardwired), or the
4175  * device says it supports the new USB 2.0 Link PM errata by setting the BESL
4176  * support bit in the BOS descriptor.
4177  */
4178 static void hub_set_initial_usb2_lpm_policy(struct usb_device *udev)
4179 {
4180 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4181 	int connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
4182 
4183 	if (!udev->usb2_hw_lpm_capable)
4184 		return;
4185 
4186 	if (hub)
4187 		connect_type = hub->ports[udev->portnum - 1]->connect_type;
4188 
4189 	if ((udev->bos->ext_cap->bmAttributes & cpu_to_le32(USB_BESL_SUPPORT)) ||
4190 			connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
4191 		udev->usb2_hw_lpm_allowed = 1;
4192 		usb_set_usb2_hardware_lpm(udev, 1);
4193 	}
4194 }
4195 
4196 static int hub_enable_device(struct usb_device *udev)
4197 {
4198 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4199 
4200 	if (!hcd->driver->enable_device)
4201 		return 0;
4202 	if (udev->state == USB_STATE_ADDRESS)
4203 		return 0;
4204 	if (udev->state != USB_STATE_DEFAULT)
4205 		return -EINVAL;
4206 
4207 	return hcd->driver->enable_device(hcd, udev);
4208 }
4209 
4210 /* Reset device, (re)assign address, get device descriptor.
4211  * Device connection must be stable, no more debouncing needed.
4212  * Returns device in USB_STATE_ADDRESS, except on error.
4213  *
4214  * If this is called for an already-existing device (as part of
4215  * usb_reset_and_verify_device), the caller must own the device lock and
4216  * the port lock.  For a newly detected device that is not accessible
4217  * through any global pointers, it's not necessary to lock the device,
4218  * but it is still necessary to lock the port.
4219  */
4220 static int
4221 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
4222 		int retry_counter)
4223 {
4224 	struct usb_device	*hdev = hub->hdev;
4225 	struct usb_hcd		*hcd = bus_to_hcd(hdev->bus);
4226 	int			i, j, retval;
4227 	unsigned		delay = HUB_SHORT_RESET_TIME;
4228 	enum usb_device_speed	oldspeed = udev->speed;
4229 	const char		*speed;
4230 	int			devnum = udev->devnum;
4231 
4232 	/* root hub ports have a slightly longer reset period
4233 	 * (from USB 2.0 spec, section 7.1.7.5)
4234 	 */
4235 	if (!hdev->parent) {
4236 		delay = HUB_ROOT_RESET_TIME;
4237 		if (port1 == hdev->bus->otg_port)
4238 			hdev->bus->b_hnp_enable = 0;
4239 	}
4240 
4241 	/* Some low speed devices have problems with the quick delay, so */
4242 	/*  be a bit pessimistic with those devices. RHbug #23670 */
4243 	if (oldspeed == USB_SPEED_LOW)
4244 		delay = HUB_LONG_RESET_TIME;
4245 
4246 	mutex_lock(&hdev->bus->usb_address0_mutex);
4247 
4248 	/* Reset the device; full speed may morph to high speed */
4249 	/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
4250 	retval = hub_port_reset(hub, port1, udev, delay, false);
4251 	if (retval < 0)		/* error or disconnect */
4252 		goto fail;
4253 	/* success, speed is known */
4254 
4255 	retval = -ENODEV;
4256 
4257 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
4258 		dev_dbg(&udev->dev, "device reset changed speed!\n");
4259 		goto fail;
4260 	}
4261 	oldspeed = udev->speed;
4262 
4263 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
4264 	 * it's fixed size except for full speed devices.
4265 	 * For Wireless USB devices, ep0 max packet is always 512 (tho
4266 	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
4267 	 */
4268 	switch (udev->speed) {
4269 	case USB_SPEED_SUPER:
4270 	case USB_SPEED_WIRELESS:	/* fixed at 512 */
4271 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
4272 		break;
4273 	case USB_SPEED_HIGH:		/* fixed at 64 */
4274 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4275 		break;
4276 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
4277 		/* to determine the ep0 maxpacket size, try to read
4278 		 * the device descriptor to get bMaxPacketSize0 and
4279 		 * then correct our initial guess.
4280 		 */
4281 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4282 		break;
4283 	case USB_SPEED_LOW:		/* fixed at 8 */
4284 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
4285 		break;
4286 	default:
4287 		goto fail;
4288 	}
4289 
4290 	if (udev->speed == USB_SPEED_WIRELESS)
4291 		speed = "variable speed Wireless";
4292 	else
4293 		speed = usb_speed_string(udev->speed);
4294 
4295 	if (udev->speed != USB_SPEED_SUPER)
4296 		dev_info(&udev->dev,
4297 				"%s %s USB device number %d using %s\n",
4298 				(udev->config) ? "reset" : "new", speed,
4299 				devnum, udev->bus->controller->driver->name);
4300 
4301 	/* Set up TT records, if needed  */
4302 	if (hdev->tt) {
4303 		udev->tt = hdev->tt;
4304 		udev->ttport = hdev->ttport;
4305 	} else if (udev->speed != USB_SPEED_HIGH
4306 			&& hdev->speed == USB_SPEED_HIGH) {
4307 		if (!hub->tt.hub) {
4308 			dev_err(&udev->dev, "parent hub has no TT\n");
4309 			retval = -EINVAL;
4310 			goto fail;
4311 		}
4312 		udev->tt = &hub->tt;
4313 		udev->ttport = port1;
4314 	}
4315 
4316 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
4317 	 * Because device hardware and firmware is sometimes buggy in
4318 	 * this area, and this is how Linux has done it for ages.
4319 	 * Change it cautiously.
4320 	 *
4321 	 * NOTE:  If use_new_scheme() is true we will start by issuing
4322 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
4323 	 * so it may help with some non-standards-compliant devices.
4324 	 * Otherwise we start with SET_ADDRESS and then try to read the
4325 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
4326 	 * value.
4327 	 */
4328 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
4329 		bool did_new_scheme = false;
4330 
4331 		if (use_new_scheme(udev, retry_counter)) {
4332 			struct usb_device_descriptor *buf;
4333 			int r = 0;
4334 
4335 			did_new_scheme = true;
4336 			retval = hub_enable_device(udev);
4337 			if (retval < 0) {
4338 				dev_err(&udev->dev,
4339 					"hub failed to enable device, error %d\n",
4340 					retval);
4341 				goto fail;
4342 			}
4343 
4344 #define GET_DESCRIPTOR_BUFSIZE	64
4345 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
4346 			if (!buf) {
4347 				retval = -ENOMEM;
4348 				continue;
4349 			}
4350 
4351 			/* Retry on all errors; some devices are flakey.
4352 			 * 255 is for WUSB devices, we actually need to use
4353 			 * 512 (WUSB1.0[4.8.1]).
4354 			 */
4355 			for (j = 0; j < 3; ++j) {
4356 				buf->bMaxPacketSize0 = 0;
4357 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
4358 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
4359 					USB_DT_DEVICE << 8, 0,
4360 					buf, GET_DESCRIPTOR_BUFSIZE,
4361 					initial_descriptor_timeout);
4362 				switch (buf->bMaxPacketSize0) {
4363 				case 8: case 16: case 32: case 64: case 255:
4364 					if (buf->bDescriptorType ==
4365 							USB_DT_DEVICE) {
4366 						r = 0;
4367 						break;
4368 					}
4369 					/* FALL THROUGH */
4370 				default:
4371 					if (r == 0)
4372 						r = -EPROTO;
4373 					break;
4374 				}
4375 				if (r == 0)
4376 					break;
4377 			}
4378 			udev->descriptor.bMaxPacketSize0 =
4379 					buf->bMaxPacketSize0;
4380 			kfree(buf);
4381 
4382 			retval = hub_port_reset(hub, port1, udev, delay, false);
4383 			if (retval < 0)		/* error or disconnect */
4384 				goto fail;
4385 			if (oldspeed != udev->speed) {
4386 				dev_dbg(&udev->dev,
4387 					"device reset changed speed!\n");
4388 				retval = -ENODEV;
4389 				goto fail;
4390 			}
4391 			if (r) {
4392 				if (r != -ENODEV)
4393 					dev_err(&udev->dev, "device descriptor read/64, error %d\n",
4394 							r);
4395 				retval = -EMSGSIZE;
4396 				continue;
4397 			}
4398 #undef GET_DESCRIPTOR_BUFSIZE
4399 		}
4400 
4401 		/*
4402 		 * If device is WUSB, we already assigned an
4403 		 * unauthorized address in the Connect Ack sequence;
4404 		 * authorization will assign the final address.
4405 		 */
4406 		if (udev->wusb == 0) {
4407 			for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
4408 				retval = hub_set_address(udev, devnum);
4409 				if (retval >= 0)
4410 					break;
4411 				msleep(200);
4412 			}
4413 			if (retval < 0) {
4414 				if (retval != -ENODEV)
4415 					dev_err(&udev->dev, "device not accepting address %d, error %d\n",
4416 							devnum, retval);
4417 				goto fail;
4418 			}
4419 			if (udev->speed == USB_SPEED_SUPER) {
4420 				devnum = udev->devnum;
4421 				dev_info(&udev->dev,
4422 						"%s SuperSpeed USB device number %d using %s\n",
4423 						(udev->config) ? "reset" : "new",
4424 						devnum, udev->bus->controller->driver->name);
4425 			}
4426 
4427 			/* cope with hardware quirkiness:
4428 			 *  - let SET_ADDRESS settle, some device hardware wants it
4429 			 *  - read ep0 maxpacket even for high and low speed,
4430 			 */
4431 			msleep(10);
4432 			/* use_new_scheme() checks the speed which may have
4433 			 * changed since the initial look so we cache the result
4434 			 * in did_new_scheme
4435 			 */
4436 			if (did_new_scheme)
4437 				break;
4438 		}
4439 
4440 		retval = usb_get_device_descriptor(udev, 8);
4441 		if (retval < 8) {
4442 			if (retval != -ENODEV)
4443 				dev_err(&udev->dev,
4444 					"device descriptor read/8, error %d\n",
4445 					retval);
4446 			if (retval >= 0)
4447 				retval = -EMSGSIZE;
4448 		} else {
4449 			retval = 0;
4450 			break;
4451 		}
4452 	}
4453 	if (retval)
4454 		goto fail;
4455 
4456 	/*
4457 	 * Some superspeed devices have finished the link training process
4458 	 * and attached to a superspeed hub port, but the device descriptor
4459 	 * got from those devices show they aren't superspeed devices. Warm
4460 	 * reset the port attached by the devices can fix them.
4461 	 */
4462 	if ((udev->speed == USB_SPEED_SUPER) &&
4463 			(le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
4464 		dev_err(&udev->dev, "got a wrong device descriptor, "
4465 				"warm reset device\n");
4466 		hub_port_reset(hub, port1, udev,
4467 				HUB_BH_RESET_TIME, true);
4468 		retval = -EINVAL;
4469 		goto fail;
4470 	}
4471 
4472 	if (udev->descriptor.bMaxPacketSize0 == 0xff ||
4473 			udev->speed == USB_SPEED_SUPER)
4474 		i = 512;
4475 	else
4476 		i = udev->descriptor.bMaxPacketSize0;
4477 	if (usb_endpoint_maxp(&udev->ep0.desc) != i) {
4478 		if (udev->speed == USB_SPEED_LOW ||
4479 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
4480 			dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i);
4481 			retval = -EMSGSIZE;
4482 			goto fail;
4483 		}
4484 		if (udev->speed == USB_SPEED_FULL)
4485 			dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
4486 		else
4487 			dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
4488 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
4489 		usb_ep0_reinit(udev);
4490 	}
4491 
4492 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
4493 	if (retval < (signed)sizeof(udev->descriptor)) {
4494 		if (retval != -ENODEV)
4495 			dev_err(&udev->dev, "device descriptor read/all, error %d\n",
4496 					retval);
4497 		if (retval >= 0)
4498 			retval = -ENOMSG;
4499 		goto fail;
4500 	}
4501 
4502 	if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
4503 		retval = usb_get_bos_descriptor(udev);
4504 		if (!retval) {
4505 			udev->lpm_capable = usb_device_supports_lpm(udev);
4506 			usb_set_lpm_parameters(udev);
4507 		}
4508 	}
4509 
4510 	retval = 0;
4511 	/* notify HCD that we have a device connected and addressed */
4512 	if (hcd->driver->update_device)
4513 		hcd->driver->update_device(hcd, udev);
4514 	hub_set_initial_usb2_lpm_policy(udev);
4515 fail:
4516 	if (retval) {
4517 		hub_port_disable(hub, port1, 0);
4518 		update_devnum(udev, devnum);	/* for disconnect processing */
4519 	}
4520 	mutex_unlock(&hdev->bus->usb_address0_mutex);
4521 	return retval;
4522 }
4523 
4524 static void
4525 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
4526 {
4527 	struct usb_qualifier_descriptor	*qual;
4528 	int				status;
4529 
4530 	if (udev->quirks & USB_QUIRK_DEVICE_QUALIFIER)
4531 		return;
4532 
4533 	qual = kmalloc (sizeof *qual, GFP_KERNEL);
4534 	if (qual == NULL)
4535 		return;
4536 
4537 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
4538 			qual, sizeof *qual);
4539 	if (status == sizeof *qual) {
4540 		dev_info(&udev->dev, "not running at top speed; "
4541 			"connect to a high speed hub\n");
4542 		/* hub LEDs are probably harder to miss than syslog */
4543 		if (hub->has_indicators) {
4544 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
4545 			queue_delayed_work(system_power_efficient_wq,
4546 					&hub->leds, 0);
4547 		}
4548 	}
4549 	kfree(qual);
4550 }
4551 
4552 static unsigned
4553 hub_power_remaining (struct usb_hub *hub)
4554 {
4555 	struct usb_device *hdev = hub->hdev;
4556 	int remaining;
4557 	int port1;
4558 
4559 	if (!hub->limited_power)
4560 		return 0;
4561 
4562 	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
4563 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
4564 		struct usb_port *port_dev = hub->ports[port1 - 1];
4565 		struct usb_device *udev = port_dev->child;
4566 		unsigned unit_load;
4567 		int delta;
4568 
4569 		if (!udev)
4570 			continue;
4571 		if (hub_is_superspeed(udev))
4572 			unit_load = 150;
4573 		else
4574 			unit_load = 100;
4575 
4576 		/*
4577 		 * Unconfigured devices may not use more than one unit load,
4578 		 * or 8mA for OTG ports
4579 		 */
4580 		if (udev->actconfig)
4581 			delta = usb_get_max_power(udev, udev->actconfig);
4582 		else if (port1 != udev->bus->otg_port || hdev->parent)
4583 			delta = unit_load;
4584 		else
4585 			delta = 8;
4586 		if (delta > hub->mA_per_port)
4587 			dev_warn(&port_dev->dev, "%dmA is over %umA budget!\n",
4588 					delta, hub->mA_per_port);
4589 		remaining -= delta;
4590 	}
4591 	if (remaining < 0) {
4592 		dev_warn(hub->intfdev, "%dmA over power budget!\n",
4593 			-remaining);
4594 		remaining = 0;
4595 	}
4596 	return remaining;
4597 }
4598 
4599 static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
4600 		u16 portchange)
4601 {
4602 	int status, i;
4603 	unsigned unit_load;
4604 	struct usb_device *hdev = hub->hdev;
4605 	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
4606 	struct usb_port *port_dev = hub->ports[port1 - 1];
4607 	struct usb_device *udev = port_dev->child;
4608 	static int unreliable_port = -1;
4609 
4610 	/* Disconnect any existing devices under this port */
4611 	if (udev) {
4612 		if (hcd->usb_phy && !hdev->parent)
4613 			usb_phy_notify_disconnect(hcd->usb_phy, udev->speed);
4614 		usb_disconnect(&port_dev->child);
4615 	}
4616 
4617 	/* We can forget about a "removed" device when there's a physical
4618 	 * disconnect or the connect status changes.
4619 	 */
4620 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4621 			(portchange & USB_PORT_STAT_C_CONNECTION))
4622 		clear_bit(port1, hub->removed_bits);
4623 
4624 	if (portchange & (USB_PORT_STAT_C_CONNECTION |
4625 				USB_PORT_STAT_C_ENABLE)) {
4626 		status = hub_port_debounce_be_stable(hub, port1);
4627 		if (status < 0) {
4628 			if (status != -ENODEV &&
4629 				port1 != unreliable_port &&
4630 				printk_ratelimit())
4631 				dev_err(&port_dev->dev, "connect-debounce failed\n");
4632 			portstatus &= ~USB_PORT_STAT_CONNECTION;
4633 			unreliable_port = port1;
4634 		} else {
4635 			portstatus = status;
4636 		}
4637 	}
4638 
4639 	/* Return now if debouncing failed or nothing is connected or
4640 	 * the device was "removed".
4641 	 */
4642 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4643 			test_bit(port1, hub->removed_bits)) {
4644 
4645 		/*
4646 		 * maybe switch power back on (e.g. root hub was reset)
4647 		 * but only if the port isn't owned by someone else.
4648 		 */
4649 		if (hub_is_port_power_switchable(hub)
4650 				&& !port_is_power_on(hub, portstatus)
4651 				&& !port_dev->port_owner)
4652 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
4653 
4654 		if (portstatus & USB_PORT_STAT_ENABLE)
4655 			goto done;
4656 		return;
4657 	}
4658 	if (hub_is_superspeed(hub->hdev))
4659 		unit_load = 150;
4660 	else
4661 		unit_load = 100;
4662 
4663 	status = 0;
4664 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
4665 
4666 		/* reallocate for each attempt, since references
4667 		 * to the previous one can escape in various ways
4668 		 */
4669 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
4670 		if (!udev) {
4671 			dev_err(&port_dev->dev,
4672 					"couldn't allocate usb_device\n");
4673 			goto done;
4674 		}
4675 
4676 		usb_set_device_state(udev, USB_STATE_POWERED);
4677 		udev->bus_mA = hub->mA_per_port;
4678 		udev->level = hdev->level + 1;
4679 		udev->wusb = hub_is_wusb(hub);
4680 
4681 		/* Only USB 3.0 devices are connected to SuperSpeed hubs. */
4682 		if (hub_is_superspeed(hub->hdev))
4683 			udev->speed = USB_SPEED_SUPER;
4684 		else
4685 			udev->speed = USB_SPEED_UNKNOWN;
4686 
4687 		choose_devnum(udev);
4688 		if (udev->devnum <= 0) {
4689 			status = -ENOTCONN;	/* Don't retry */
4690 			goto loop;
4691 		}
4692 
4693 		/* reset (non-USB 3.0 devices) and get descriptor */
4694 		usb_lock_port(port_dev);
4695 		status = hub_port_init(hub, udev, port1, i);
4696 		usb_unlock_port(port_dev);
4697 		if (status < 0)
4698 			goto loop;
4699 
4700 		usb_detect_quirks(udev);
4701 		if (udev->quirks & USB_QUIRK_DELAY_INIT)
4702 			msleep(1000);
4703 
4704 		/* consecutive bus-powered hubs aren't reliable; they can
4705 		 * violate the voltage drop budget.  if the new child has
4706 		 * a "powered" LED, users should notice we didn't enable it
4707 		 * (without reading syslog), even without per-port LEDs
4708 		 * on the parent.
4709 		 */
4710 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
4711 				&& udev->bus_mA <= unit_load) {
4712 			u16	devstat;
4713 
4714 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
4715 					&devstat);
4716 			if (status) {
4717 				dev_dbg(&udev->dev, "get status %d ?\n", status);
4718 				goto loop_disable;
4719 			}
4720 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
4721 				dev_err(&udev->dev,
4722 					"can't connect bus-powered hub "
4723 					"to this port\n");
4724 				if (hub->has_indicators) {
4725 					hub->indicator[port1-1] =
4726 						INDICATOR_AMBER_BLINK;
4727 					queue_delayed_work(
4728 						system_power_efficient_wq,
4729 						&hub->leds, 0);
4730 				}
4731 				status = -ENOTCONN;	/* Don't retry */
4732 				goto loop_disable;
4733 			}
4734 		}
4735 
4736 		/* check for devices running slower than they could */
4737 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
4738 				&& udev->speed == USB_SPEED_FULL
4739 				&& highspeed_hubs != 0)
4740 			check_highspeed (hub, udev, port1);
4741 
4742 		/* Store the parent's children[] pointer.  At this point
4743 		 * udev becomes globally accessible, although presumably
4744 		 * no one will look at it until hdev is unlocked.
4745 		 */
4746 		status = 0;
4747 
4748 		mutex_lock(&usb_port_peer_mutex);
4749 
4750 		/* We mustn't add new devices if the parent hub has
4751 		 * been disconnected; we would race with the
4752 		 * recursively_mark_NOTATTACHED() routine.
4753 		 */
4754 		spin_lock_irq(&device_state_lock);
4755 		if (hdev->state == USB_STATE_NOTATTACHED)
4756 			status = -ENOTCONN;
4757 		else
4758 			port_dev->child = udev;
4759 		spin_unlock_irq(&device_state_lock);
4760 		mutex_unlock(&usb_port_peer_mutex);
4761 
4762 		/* Run it through the hoops (find a driver, etc) */
4763 		if (!status) {
4764 			status = usb_new_device(udev);
4765 			if (status) {
4766 				mutex_lock(&usb_port_peer_mutex);
4767 				spin_lock_irq(&device_state_lock);
4768 				port_dev->child = NULL;
4769 				spin_unlock_irq(&device_state_lock);
4770 				mutex_unlock(&usb_port_peer_mutex);
4771 			} else {
4772 				if (hcd->usb_phy && !hdev->parent)
4773 					usb_phy_notify_connect(hcd->usb_phy,
4774 							udev->speed);
4775 			}
4776 		}
4777 
4778 		if (status)
4779 			goto loop_disable;
4780 
4781 		status = hub_power_remaining(hub);
4782 		if (status)
4783 			dev_dbg(hub->intfdev, "%dmA power budget left\n", status);
4784 
4785 		return;
4786 
4787 loop_disable:
4788 		hub_port_disable(hub, port1, 1);
4789 loop:
4790 		usb_ep0_reinit(udev);
4791 		release_devnum(udev);
4792 		hub_free_dev(udev);
4793 		usb_put_dev(udev);
4794 		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
4795 			break;
4796 	}
4797 	if (hub->hdev->parent ||
4798 			!hcd->driver->port_handed_over ||
4799 			!(hcd->driver->port_handed_over)(hcd, port1)) {
4800 		if (status != -ENOTCONN && status != -ENODEV)
4801 			dev_err(&port_dev->dev,
4802 					"unable to enumerate USB device\n");
4803 	}
4804 
4805 done:
4806 	hub_port_disable(hub, port1, 1);
4807 	if (hcd->driver->relinquish_port && !hub->hdev->parent)
4808 		hcd->driver->relinquish_port(hcd, port1);
4809 
4810 }
4811 
4812 /* Handle physical or logical connection change events.
4813  * This routine is called when:
4814  *	a port connection-change occurs;
4815  *	a port enable-change occurs (often caused by EMI);
4816  *	usb_reset_and_verify_device() encounters changed descriptors (as from
4817  *		a firmware download)
4818  * caller already locked the hub
4819  */
4820 static void hub_port_connect_change(struct usb_hub *hub, int port1,
4821 					u16 portstatus, u16 portchange)
4822 		__must_hold(&port_dev->status_lock)
4823 {
4824 	struct usb_port *port_dev = hub->ports[port1 - 1];
4825 	struct usb_device *udev = port_dev->child;
4826 	int status = -ENODEV;
4827 
4828 	dev_dbg(&port_dev->dev, "status %04x, change %04x, %s\n", portstatus,
4829 			portchange, portspeed(hub, portstatus));
4830 
4831 	if (hub->has_indicators) {
4832 		set_port_led(hub, port1, HUB_LED_AUTO);
4833 		hub->indicator[port1-1] = INDICATOR_AUTO;
4834 	}
4835 
4836 #ifdef	CONFIG_USB_OTG
4837 	/* during HNP, don't repeat the debounce */
4838 	if (hub->hdev->bus->is_b_host)
4839 		portchange &= ~(USB_PORT_STAT_C_CONNECTION |
4840 				USB_PORT_STAT_C_ENABLE);
4841 #endif
4842 
4843 	/* Try to resuscitate an existing device */
4844 	if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
4845 			udev->state != USB_STATE_NOTATTACHED) {
4846 		if (portstatus & USB_PORT_STAT_ENABLE) {
4847 			status = 0;		/* Nothing to do */
4848 #ifdef CONFIG_PM
4849 		} else if (udev->state == USB_STATE_SUSPENDED &&
4850 				udev->persist_enabled) {
4851 			/* For a suspended device, treat this as a
4852 			 * remote wakeup event.
4853 			 */
4854 			usb_unlock_port(port_dev);
4855 			status = usb_remote_wakeup(udev);
4856 			usb_lock_port(port_dev);
4857 #endif
4858 		} else {
4859 			/* Don't resuscitate */;
4860 		}
4861 	}
4862 	clear_bit(port1, hub->change_bits);
4863 
4864 	/* successfully revalidated the connection */
4865 	if (status == 0)
4866 		return;
4867 
4868 	usb_unlock_port(port_dev);
4869 	hub_port_connect(hub, port1, portstatus, portchange);
4870 	usb_lock_port(port_dev);
4871 }
4872 
4873 static void port_event(struct usb_hub *hub, int port1)
4874 		__must_hold(&port_dev->status_lock)
4875 {
4876 	int connect_change;
4877 	struct usb_port *port_dev = hub->ports[port1 - 1];
4878 	struct usb_device *udev = port_dev->child;
4879 	struct usb_device *hdev = hub->hdev;
4880 	u16 portstatus, portchange;
4881 
4882 	connect_change = test_bit(port1, hub->change_bits);
4883 	clear_bit(port1, hub->event_bits);
4884 	clear_bit(port1, hub->wakeup_bits);
4885 
4886 	if (hub_port_status(hub, port1, &portstatus, &portchange) < 0)
4887 		return;
4888 
4889 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
4890 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
4891 		connect_change = 1;
4892 	}
4893 
4894 	if (portchange & USB_PORT_STAT_C_ENABLE) {
4895 		if (!connect_change)
4896 			dev_dbg(&port_dev->dev, "enable change, status %08x\n",
4897 					portstatus);
4898 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
4899 
4900 		/*
4901 		 * EM interference sometimes causes badly shielded USB devices
4902 		 * to be shutdown by the hub, this hack enables them again.
4903 		 * Works at least with mouse driver.
4904 		 */
4905 		if (!(portstatus & USB_PORT_STAT_ENABLE)
4906 		    && !connect_change && udev) {
4907 			dev_err(&port_dev->dev, "disabled by hub (EMI?), re-enabling...\n");
4908 			connect_change = 1;
4909 		}
4910 	}
4911 
4912 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
4913 		u16 status = 0, unused;
4914 
4915 		dev_dbg(&port_dev->dev, "over-current change\n");
4916 		usb_clear_port_feature(hdev, port1,
4917 				USB_PORT_FEAT_C_OVER_CURRENT);
4918 		msleep(100);	/* Cool down */
4919 		hub_power_on(hub, true);
4920 		hub_port_status(hub, port1, &status, &unused);
4921 		if (status & USB_PORT_STAT_OVERCURRENT)
4922 			dev_err(&port_dev->dev, "over-current condition\n");
4923 	}
4924 
4925 	if (portchange & USB_PORT_STAT_C_RESET) {
4926 		dev_dbg(&port_dev->dev, "reset change\n");
4927 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_RESET);
4928 	}
4929 	if ((portchange & USB_PORT_STAT_C_BH_RESET)
4930 	    && hub_is_superspeed(hdev)) {
4931 		dev_dbg(&port_dev->dev, "warm reset change\n");
4932 		usb_clear_port_feature(hdev, port1,
4933 				USB_PORT_FEAT_C_BH_PORT_RESET);
4934 	}
4935 	if (portchange & USB_PORT_STAT_C_LINK_STATE) {
4936 		dev_dbg(&port_dev->dev, "link state change\n");
4937 		usb_clear_port_feature(hdev, port1,
4938 				USB_PORT_FEAT_C_PORT_LINK_STATE);
4939 	}
4940 	if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) {
4941 		dev_warn(&port_dev->dev, "config error\n");
4942 		usb_clear_port_feature(hdev, port1,
4943 				USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
4944 	}
4945 
4946 	/* skip port actions that require the port to be powered on */
4947 	if (!pm_runtime_active(&port_dev->dev))
4948 		return;
4949 
4950 	if (hub_handle_remote_wakeup(hub, port1, portstatus, portchange))
4951 		connect_change = 1;
4952 
4953 	/*
4954 	 * Warm reset a USB3 protocol port if it's in
4955 	 * SS.Inactive state.
4956 	 */
4957 	if (hub_port_warm_reset_required(hub, port1, portstatus)) {
4958 		dev_dbg(&port_dev->dev, "do warm reset\n");
4959 		if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
4960 				|| udev->state == USB_STATE_NOTATTACHED) {
4961 			if (hub_port_reset(hub, port1, NULL,
4962 					HUB_BH_RESET_TIME, true) < 0)
4963 				hub_port_disable(hub, port1, 1);
4964 		} else {
4965 			usb_unlock_port(port_dev);
4966 			usb_lock_device(udev);
4967 			usb_reset_device(udev);
4968 			usb_unlock_device(udev);
4969 			usb_lock_port(port_dev);
4970 			connect_change = 0;
4971 		}
4972 	}
4973 
4974 	if (connect_change)
4975 		hub_port_connect_change(hub, port1, portstatus, portchange);
4976 }
4977 
4978 static void hub_event(struct work_struct *work)
4979 {
4980 	struct usb_device *hdev;
4981 	struct usb_interface *intf;
4982 	struct usb_hub *hub;
4983 	struct device *hub_dev;
4984 	u16 hubstatus;
4985 	u16 hubchange;
4986 	int i, ret;
4987 
4988 	hub = container_of(work, struct usb_hub, events);
4989 	hdev = hub->hdev;
4990 	hub_dev = hub->intfdev;
4991 	intf = to_usb_interface(hub_dev);
4992 
4993 	dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
4994 			hdev->state, hdev->maxchild,
4995 			/* NOTE: expects max 15 ports... */
4996 			(u16) hub->change_bits[0],
4997 			(u16) hub->event_bits[0]);
4998 
4999 	/* Lock the device, then check to see if we were
5000 	 * disconnected while waiting for the lock to succeed. */
5001 	usb_lock_device(hdev);
5002 	if (unlikely(hub->disconnected))
5003 		goto out_hdev_lock;
5004 
5005 	/* If the hub has died, clean up after it */
5006 	if (hdev->state == USB_STATE_NOTATTACHED) {
5007 		hub->error = -ENODEV;
5008 		hub_quiesce(hub, HUB_DISCONNECT);
5009 		goto out_hdev_lock;
5010 	}
5011 
5012 	/* Autoresume */
5013 	ret = usb_autopm_get_interface(intf);
5014 	if (ret) {
5015 		dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
5016 		goto out_hdev_lock;
5017 	}
5018 
5019 	/* If this is an inactive hub, do nothing */
5020 	if (hub->quiescing)
5021 		goto out_autopm;
5022 
5023 	if (hub->error) {
5024 		dev_dbg(hub_dev, "resetting for error %d\n", hub->error);
5025 
5026 		ret = usb_reset_device(hdev);
5027 		if (ret) {
5028 			dev_dbg(hub_dev, "error resetting hub: %d\n", ret);
5029 			goto out_autopm;
5030 		}
5031 
5032 		hub->nerrors = 0;
5033 		hub->error = 0;
5034 	}
5035 
5036 	/* deal with port status changes */
5037 	for (i = 1; i <= hdev->maxchild; i++) {
5038 		struct usb_port *port_dev = hub->ports[i - 1];
5039 
5040 		if (test_bit(i, hub->event_bits)
5041 				|| test_bit(i, hub->change_bits)
5042 				|| test_bit(i, hub->wakeup_bits)) {
5043 			/*
5044 			 * The get_noresume and barrier ensure that if
5045 			 * the port was in the process of resuming, we
5046 			 * flush that work and keep the port active for
5047 			 * the duration of the port_event().  However,
5048 			 * if the port is runtime pm suspended
5049 			 * (powered-off), we leave it in that state, run
5050 			 * an abbreviated port_event(), and move on.
5051 			 */
5052 			pm_runtime_get_noresume(&port_dev->dev);
5053 			pm_runtime_barrier(&port_dev->dev);
5054 			usb_lock_port(port_dev);
5055 			port_event(hub, i);
5056 			usb_unlock_port(port_dev);
5057 			pm_runtime_put_sync(&port_dev->dev);
5058 		}
5059 	}
5060 
5061 	/* deal with hub status changes */
5062 	if (test_and_clear_bit(0, hub->event_bits) == 0)
5063 		;	/* do nothing */
5064 	else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
5065 		dev_err(hub_dev, "get_hub_status failed\n");
5066 	else {
5067 		if (hubchange & HUB_CHANGE_LOCAL_POWER) {
5068 			dev_dbg(hub_dev, "power change\n");
5069 			clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
5070 			if (hubstatus & HUB_STATUS_LOCAL_POWER)
5071 				/* FIXME: Is this always true? */
5072 				hub->limited_power = 1;
5073 			else
5074 				hub->limited_power = 0;
5075 		}
5076 		if (hubchange & HUB_CHANGE_OVERCURRENT) {
5077 			u16 status = 0;
5078 			u16 unused;
5079 
5080 			dev_dbg(hub_dev, "over-current change\n");
5081 			clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
5082 			msleep(500);	/* Cool down */
5083 			hub_power_on(hub, true);
5084 			hub_hub_status(hub, &status, &unused);
5085 			if (status & HUB_STATUS_OVERCURRENT)
5086 				dev_err(hub_dev, "over-current condition\n");
5087 		}
5088 	}
5089 
5090 out_autopm:
5091 	/* Balance the usb_autopm_get_interface() above */
5092 	usb_autopm_put_interface_no_suspend(intf);
5093 out_hdev_lock:
5094 	usb_unlock_device(hdev);
5095 
5096 	/* Balance the stuff in kick_hub_wq() and allow autosuspend */
5097 	usb_autopm_put_interface(intf);
5098 	kref_put(&hub->kref, hub_release);
5099 }
5100 
5101 static const struct usb_device_id hub_id_table[] = {
5102     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5103 			| USB_DEVICE_ID_MATCH_INT_CLASS,
5104       .idVendor = USB_VENDOR_GENESYS_LOGIC,
5105       .bInterfaceClass = USB_CLASS_HUB,
5106       .driver_info = HUB_QUIRK_CHECK_PORT_AUTOSUSPEND},
5107     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
5108       .bDeviceClass = USB_CLASS_HUB},
5109     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
5110       .bInterfaceClass = USB_CLASS_HUB},
5111     { }						/* Terminating entry */
5112 };
5113 
5114 MODULE_DEVICE_TABLE (usb, hub_id_table);
5115 
5116 static struct usb_driver hub_driver = {
5117 	.name =		"hub",
5118 	.probe =	hub_probe,
5119 	.disconnect =	hub_disconnect,
5120 	.suspend =	hub_suspend,
5121 	.resume =	hub_resume,
5122 	.reset_resume =	hub_reset_resume,
5123 	.pre_reset =	hub_pre_reset,
5124 	.post_reset =	hub_post_reset,
5125 	.unlocked_ioctl = hub_ioctl,
5126 	.id_table =	hub_id_table,
5127 	.supports_autosuspend =	1,
5128 };
5129 
5130 int usb_hub_init(void)
5131 {
5132 	if (usb_register(&hub_driver) < 0) {
5133 		printk(KERN_ERR "%s: can't register hub driver\n",
5134 			usbcore_name);
5135 		return -1;
5136 	}
5137 
5138 	/*
5139 	 * The workqueue needs to be freezable to avoid interfering with
5140 	 * USB-PERSIST port handover. Otherwise it might see that a full-speed
5141 	 * device was gone before the EHCI controller had handed its port
5142 	 * over to the companion full-speed controller.
5143 	 */
5144 	hub_wq = alloc_workqueue("usb_hub_wq", WQ_FREEZABLE, 0);
5145 	if (hub_wq)
5146 		return 0;
5147 
5148 	/* Fall through if kernel_thread failed */
5149 	usb_deregister(&hub_driver);
5150 	pr_err("%s: can't allocate workqueue for usb hub\n", usbcore_name);
5151 
5152 	return -1;
5153 }
5154 
5155 void usb_hub_cleanup(void)
5156 {
5157 	destroy_workqueue(hub_wq);
5158 
5159 	/*
5160 	 * Hub resources are freed for us by usb_deregister. It calls
5161 	 * usb_driver_purge on every device which in turn calls that
5162 	 * devices disconnect function if it is using this driver.
5163 	 * The hub_disconnect function takes care of releasing the
5164 	 * individual hub resources. -greg
5165 	 */
5166 	usb_deregister(&hub_driver);
5167 } /* usb_hub_cleanup() */
5168 
5169 static int descriptors_changed(struct usb_device *udev,
5170 		struct usb_device_descriptor *old_device_descriptor,
5171 		struct usb_host_bos *old_bos)
5172 {
5173 	int		changed = 0;
5174 	unsigned	index;
5175 	unsigned	serial_len = 0;
5176 	unsigned	len;
5177 	unsigned	old_length;
5178 	int		length;
5179 	char		*buf;
5180 
5181 	if (memcmp(&udev->descriptor, old_device_descriptor,
5182 			sizeof(*old_device_descriptor)) != 0)
5183 		return 1;
5184 
5185 	if ((old_bos && !udev->bos) || (!old_bos && udev->bos))
5186 		return 1;
5187 	if (udev->bos) {
5188 		len = le16_to_cpu(udev->bos->desc->wTotalLength);
5189 		if (len != le16_to_cpu(old_bos->desc->wTotalLength))
5190 			return 1;
5191 		if (memcmp(udev->bos->desc, old_bos->desc, len))
5192 			return 1;
5193 	}
5194 
5195 	/* Since the idVendor, idProduct, and bcdDevice values in the
5196 	 * device descriptor haven't changed, we will assume the
5197 	 * Manufacturer and Product strings haven't changed either.
5198 	 * But the SerialNumber string could be different (e.g., a
5199 	 * different flash card of the same brand).
5200 	 */
5201 	if (udev->serial)
5202 		serial_len = strlen(udev->serial) + 1;
5203 
5204 	len = serial_len;
5205 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5206 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5207 		len = max(len, old_length);
5208 	}
5209 
5210 	buf = kmalloc(len, GFP_NOIO);
5211 	if (buf == NULL) {
5212 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
5213 		/* assume the worst */
5214 		return 1;
5215 	}
5216 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5217 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5218 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
5219 				old_length);
5220 		if (length != old_length) {
5221 			dev_dbg(&udev->dev, "config index %d, error %d\n",
5222 					index, length);
5223 			changed = 1;
5224 			break;
5225 		}
5226 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
5227 				!= 0) {
5228 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
5229 				index,
5230 				((struct usb_config_descriptor *) buf)->
5231 					bConfigurationValue);
5232 			changed = 1;
5233 			break;
5234 		}
5235 	}
5236 
5237 	if (!changed && serial_len) {
5238 		length = usb_string(udev, udev->descriptor.iSerialNumber,
5239 				buf, serial_len);
5240 		if (length + 1 != serial_len) {
5241 			dev_dbg(&udev->dev, "serial string error %d\n",
5242 					length);
5243 			changed = 1;
5244 		} else if (memcmp(buf, udev->serial, length) != 0) {
5245 			dev_dbg(&udev->dev, "serial string changed\n");
5246 			changed = 1;
5247 		}
5248 	}
5249 
5250 	kfree(buf);
5251 	return changed;
5252 }
5253 
5254 /**
5255  * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
5256  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5257  *
5258  * WARNING - don't use this routine to reset a composite device
5259  * (one with multiple interfaces owned by separate drivers)!
5260  * Use usb_reset_device() instead.
5261  *
5262  * Do a port reset, reassign the device's address, and establish its
5263  * former operating configuration.  If the reset fails, or the device's
5264  * descriptors change from their values before the reset, or the original
5265  * configuration and altsettings cannot be restored, a flag will be set
5266  * telling hub_wq to pretend the device has been disconnected and then
5267  * re-connected.  All drivers will be unbound, and the device will be
5268  * re-enumerated and probed all over again.
5269  *
5270  * Return: 0 if the reset succeeded, -ENODEV if the device has been
5271  * flagged for logical disconnection, or some other negative error code
5272  * if the reset wasn't even attempted.
5273  *
5274  * Note:
5275  * The caller must own the device lock and the port lock, the latter is
5276  * taken by usb_reset_device().  For example, it's safe to use
5277  * usb_reset_device() from a driver probe() routine after downloading
5278  * new firmware.  For calls that might not occur during probe(), drivers
5279  * should lock the device using usb_lock_device_for_reset().
5280  *
5281  * Locking exception: This routine may also be called from within an
5282  * autoresume handler.  Such usage won't conflict with other tasks
5283  * holding the device lock because these tasks should always call
5284  * usb_autopm_resume_device(), thereby preventing any unwanted
5285  * autoresume.  The autoresume handler is expected to have already
5286  * acquired the port lock before calling this routine.
5287  */
5288 static int usb_reset_and_verify_device(struct usb_device *udev)
5289 {
5290 	struct usb_device		*parent_hdev = udev->parent;
5291 	struct usb_hub			*parent_hub;
5292 	struct usb_hcd			*hcd = bus_to_hcd(udev->bus);
5293 	struct usb_device_descriptor	descriptor = udev->descriptor;
5294 	struct usb_host_bos		*bos;
5295 	int				i, j, ret = 0;
5296 	int				port1 = udev->portnum;
5297 
5298 	if (udev->state == USB_STATE_NOTATTACHED ||
5299 			udev->state == USB_STATE_SUSPENDED) {
5300 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5301 				udev->state);
5302 		return -EINVAL;
5303 	}
5304 
5305 	if (!parent_hdev)
5306 		return -EISDIR;
5307 
5308 	parent_hub = usb_hub_to_struct_hub(parent_hdev);
5309 
5310 	/* Disable USB2 hardware LPM.
5311 	 * It will be re-enabled by the enumeration process.
5312 	 */
5313 	if (udev->usb2_hw_lpm_enabled == 1)
5314 		usb_set_usb2_hardware_lpm(udev, 0);
5315 
5316 	bos = udev->bos;
5317 	udev->bos = NULL;
5318 
5319 	/* Disable LPM and LTM while we reset the device and reinstall the alt
5320 	 * settings.  Device-initiated LPM settings, and system exit latency
5321 	 * settings are cleared when the device is reset, so we have to set
5322 	 * them up again.
5323 	 */
5324 	ret = usb_unlocked_disable_lpm(udev);
5325 	if (ret) {
5326 		dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
5327 		goto re_enumerate;
5328 	}
5329 	ret = usb_disable_ltm(udev);
5330 	if (ret) {
5331 		dev_err(&udev->dev, "%s Failed to disable LTM\n.",
5332 				__func__);
5333 		goto re_enumerate;
5334 	}
5335 
5336 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
5337 
5338 		/* ep0 maxpacket size may change; let the HCD know about it.
5339 		 * Other endpoints will be handled by re-enumeration. */
5340 		usb_ep0_reinit(udev);
5341 		ret = hub_port_init(parent_hub, udev, port1, i);
5342 		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
5343 			break;
5344 	}
5345 
5346 	if (ret < 0)
5347 		goto re_enumerate;
5348 
5349 	/* Device might have changed firmware (DFU or similar) */
5350 	if (descriptors_changed(udev, &descriptor, bos)) {
5351 		dev_info(&udev->dev, "device firmware changed\n");
5352 		udev->descriptor = descriptor;	/* for disconnect() calls */
5353 		goto re_enumerate;
5354 	}
5355 
5356 	/* Restore the device's previous configuration */
5357 	if (!udev->actconfig)
5358 		goto done;
5359 
5360 	mutex_lock(hcd->bandwidth_mutex);
5361 	ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
5362 	if (ret < 0) {
5363 		dev_warn(&udev->dev,
5364 				"Busted HC?  Not enough HCD resources for "
5365 				"old configuration.\n");
5366 		mutex_unlock(hcd->bandwidth_mutex);
5367 		goto re_enumerate;
5368 	}
5369 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
5370 			USB_REQ_SET_CONFIGURATION, 0,
5371 			udev->actconfig->desc.bConfigurationValue, 0,
5372 			NULL, 0, USB_CTRL_SET_TIMEOUT);
5373 	if (ret < 0) {
5374 		dev_err(&udev->dev,
5375 			"can't restore configuration #%d (error=%d)\n",
5376 			udev->actconfig->desc.bConfigurationValue, ret);
5377 		mutex_unlock(hcd->bandwidth_mutex);
5378 		goto re_enumerate;
5379 	}
5380 	mutex_unlock(hcd->bandwidth_mutex);
5381 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
5382 
5383 	/* Put interfaces back into the same altsettings as before.
5384 	 * Don't bother to send the Set-Interface request for interfaces
5385 	 * that were already in altsetting 0; besides being unnecessary,
5386 	 * many devices can't handle it.  Instead just reset the host-side
5387 	 * endpoint state.
5388 	 */
5389 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
5390 		struct usb_host_config *config = udev->actconfig;
5391 		struct usb_interface *intf = config->interface[i];
5392 		struct usb_interface_descriptor *desc;
5393 
5394 		desc = &intf->cur_altsetting->desc;
5395 		if (desc->bAlternateSetting == 0) {
5396 			usb_disable_interface(udev, intf, true);
5397 			usb_enable_interface(udev, intf, true);
5398 			ret = 0;
5399 		} else {
5400 			/* Let the bandwidth allocation function know that this
5401 			 * device has been reset, and it will have to use
5402 			 * alternate setting 0 as the current alternate setting.
5403 			 */
5404 			intf->resetting_device = 1;
5405 			ret = usb_set_interface(udev, desc->bInterfaceNumber,
5406 					desc->bAlternateSetting);
5407 			intf->resetting_device = 0;
5408 		}
5409 		if (ret < 0) {
5410 			dev_err(&udev->dev, "failed to restore interface %d "
5411 				"altsetting %d (error=%d)\n",
5412 				desc->bInterfaceNumber,
5413 				desc->bAlternateSetting,
5414 				ret);
5415 			goto re_enumerate;
5416 		}
5417 		/* Resetting also frees any allocated streams */
5418 		for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++)
5419 			intf->cur_altsetting->endpoint[j].streams = 0;
5420 	}
5421 
5422 done:
5423 	/* Now that the alt settings are re-installed, enable LTM and LPM. */
5424 	usb_set_usb2_hardware_lpm(udev, 1);
5425 	usb_unlocked_enable_lpm(udev);
5426 	usb_enable_ltm(udev);
5427 	usb_release_bos_descriptor(udev);
5428 	udev->bos = bos;
5429 	return 0;
5430 
5431 re_enumerate:
5432 	/* LPM state doesn't matter when we're about to destroy the device. */
5433 	hub_port_logical_disconnect(parent_hub, port1);
5434 	usb_release_bos_descriptor(udev);
5435 	udev->bos = bos;
5436 	return -ENODEV;
5437 }
5438 
5439 /**
5440  * usb_reset_device - warn interface drivers and perform a USB port reset
5441  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5442  *
5443  * Warns all drivers bound to registered interfaces (using their pre_reset
5444  * method), performs the port reset, and then lets the drivers know that
5445  * the reset is over (using their post_reset method).
5446  *
5447  * Return: The same as for usb_reset_and_verify_device().
5448  *
5449  * Note:
5450  * The caller must own the device lock.  For example, it's safe to use
5451  * this from a driver probe() routine after downloading new firmware.
5452  * For calls that might not occur during probe(), drivers should lock
5453  * the device using usb_lock_device_for_reset().
5454  *
5455  * If an interface is currently being probed or disconnected, we assume
5456  * its driver knows how to handle resets.  For all other interfaces,
5457  * if the driver doesn't have pre_reset and post_reset methods then
5458  * we attempt to unbind it and rebind afterward.
5459  */
5460 int usb_reset_device(struct usb_device *udev)
5461 {
5462 	int ret;
5463 	int i;
5464 	unsigned int noio_flag;
5465 	struct usb_port *port_dev;
5466 	struct usb_host_config *config = udev->actconfig;
5467 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
5468 
5469 	if (udev->state == USB_STATE_NOTATTACHED ||
5470 			udev->state == USB_STATE_SUSPENDED) {
5471 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5472 				udev->state);
5473 		return -EINVAL;
5474 	}
5475 
5476 	if (!udev->parent) {
5477 		/* this requires hcd-specific logic; see ohci_restart() */
5478 		dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
5479 		return -EISDIR;
5480 	}
5481 
5482 	port_dev = hub->ports[udev->portnum - 1];
5483 
5484 	/*
5485 	 * Don't allocate memory with GFP_KERNEL in current
5486 	 * context to avoid possible deadlock if usb mass
5487 	 * storage interface or usbnet interface(iSCSI case)
5488 	 * is included in current configuration. The easist
5489 	 * approach is to do it for every device reset,
5490 	 * because the device 'memalloc_noio' flag may have
5491 	 * not been set before reseting the usb device.
5492 	 */
5493 	noio_flag = memalloc_noio_save();
5494 
5495 	/* Prevent autosuspend during the reset */
5496 	usb_autoresume_device(udev);
5497 
5498 	if (config) {
5499 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
5500 			struct usb_interface *cintf = config->interface[i];
5501 			struct usb_driver *drv;
5502 			int unbind = 0;
5503 
5504 			if (cintf->dev.driver) {
5505 				drv = to_usb_driver(cintf->dev.driver);
5506 				if (drv->pre_reset && drv->post_reset)
5507 					unbind = (drv->pre_reset)(cintf);
5508 				else if (cintf->condition ==
5509 						USB_INTERFACE_BOUND)
5510 					unbind = 1;
5511 				if (unbind)
5512 					usb_forced_unbind_intf(cintf);
5513 			}
5514 		}
5515 	}
5516 
5517 	usb_lock_port(port_dev);
5518 	ret = usb_reset_and_verify_device(udev);
5519 	usb_unlock_port(port_dev);
5520 
5521 	if (config) {
5522 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
5523 			struct usb_interface *cintf = config->interface[i];
5524 			struct usb_driver *drv;
5525 			int rebind = cintf->needs_binding;
5526 
5527 			if (!rebind && cintf->dev.driver) {
5528 				drv = to_usb_driver(cintf->dev.driver);
5529 				if (drv->post_reset)
5530 					rebind = (drv->post_reset)(cintf);
5531 				else if (cintf->condition ==
5532 						USB_INTERFACE_BOUND)
5533 					rebind = 1;
5534 				if (rebind)
5535 					cintf->needs_binding = 1;
5536 			}
5537 		}
5538 		usb_unbind_and_rebind_marked_interfaces(udev);
5539 	}
5540 
5541 	usb_autosuspend_device(udev);
5542 	memalloc_noio_restore(noio_flag);
5543 	return ret;
5544 }
5545 EXPORT_SYMBOL_GPL(usb_reset_device);
5546 
5547 
5548 /**
5549  * usb_queue_reset_device - Reset a USB device from an atomic context
5550  * @iface: USB interface belonging to the device to reset
5551  *
5552  * This function can be used to reset a USB device from an atomic
5553  * context, where usb_reset_device() won't work (as it blocks).
5554  *
5555  * Doing a reset via this method is functionally equivalent to calling
5556  * usb_reset_device(), except for the fact that it is delayed to a
5557  * workqueue. This means that any drivers bound to other interfaces
5558  * might be unbound, as well as users from usbfs in user space.
5559  *
5560  * Corner cases:
5561  *
5562  * - Scheduling two resets at the same time from two different drivers
5563  *   attached to two different interfaces of the same device is
5564  *   possible; depending on how the driver attached to each interface
5565  *   handles ->pre_reset(), the second reset might happen or not.
5566  *
5567  * - If the reset is delayed so long that the interface is unbound from
5568  *   its driver, the reset will be skipped.
5569  *
5570  * - This function can be called during .probe().  It can also be called
5571  *   during .disconnect(), but doing so is pointless because the reset
5572  *   will not occur.  If you really want to reset the device during
5573  *   .disconnect(), call usb_reset_device() directly -- but watch out
5574  *   for nested unbinding issues!
5575  */
5576 void usb_queue_reset_device(struct usb_interface *iface)
5577 {
5578 	if (schedule_work(&iface->reset_ws))
5579 		usb_get_intf(iface);
5580 }
5581 EXPORT_SYMBOL_GPL(usb_queue_reset_device);
5582 
5583 /**
5584  * usb_hub_find_child - Get the pointer of child device
5585  * attached to the port which is specified by @port1.
5586  * @hdev: USB device belonging to the usb hub
5587  * @port1: port num to indicate which port the child device
5588  *	is attached to.
5589  *
5590  * USB drivers call this function to get hub's child device
5591  * pointer.
5592  *
5593  * Return: %NULL if input param is invalid and
5594  * child's usb_device pointer if non-NULL.
5595  */
5596 struct usb_device *usb_hub_find_child(struct usb_device *hdev,
5597 		int port1)
5598 {
5599 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5600 
5601 	if (port1 < 1 || port1 > hdev->maxchild)
5602 		return NULL;
5603 	return hub->ports[port1 - 1]->child;
5604 }
5605 EXPORT_SYMBOL_GPL(usb_hub_find_child);
5606 
5607 void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
5608 		struct usb_hub_descriptor *desc)
5609 {
5610 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5611 	enum usb_port_connect_type connect_type;
5612 	int i;
5613 
5614 	if (!hub)
5615 		return;
5616 
5617 	if (!hub_is_superspeed(hdev)) {
5618 		for (i = 1; i <= hdev->maxchild; i++) {
5619 			struct usb_port *port_dev = hub->ports[i - 1];
5620 
5621 			connect_type = port_dev->connect_type;
5622 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5623 				u8 mask = 1 << (i%8);
5624 
5625 				if (!(desc->u.hs.DeviceRemovable[i/8] & mask)) {
5626 					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
5627 					desc->u.hs.DeviceRemovable[i/8]	|= mask;
5628 				}
5629 			}
5630 		}
5631 	} else {
5632 		u16 port_removable = le16_to_cpu(desc->u.ss.DeviceRemovable);
5633 
5634 		for (i = 1; i <= hdev->maxchild; i++) {
5635 			struct usb_port *port_dev = hub->ports[i - 1];
5636 
5637 			connect_type = port_dev->connect_type;
5638 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5639 				u16 mask = 1 << i;
5640 
5641 				if (!(port_removable & mask)) {
5642 					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
5643 					port_removable |= mask;
5644 				}
5645 			}
5646 		}
5647 
5648 		desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
5649 	}
5650 }
5651 
5652 #ifdef CONFIG_ACPI
5653 /**
5654  * usb_get_hub_port_acpi_handle - Get the usb port's acpi handle
5655  * @hdev: USB device belonging to the usb hub
5656  * @port1: port num of the port
5657  *
5658  * Return: Port's acpi handle if successful, %NULL if params are
5659  * invalid.
5660  */
5661 acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
5662 	int port1)
5663 {
5664 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5665 
5666 	if (!hub)
5667 		return NULL;
5668 
5669 	return ACPI_HANDLE(&hub->ports[port1 - 1]->dev);
5670 }
5671 #endif
5672