xref: /openbmc/linux/drivers/usb/core/hub.c (revision 206a81c1)
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/kthread.h>
26 #include <linux/mutex.h>
27 #include <linux/freezer.h>
28 #include <linux/random.h>
29 #include <linux/pm_qos.h>
30 
31 #include <asm/uaccess.h>
32 #include <asm/byteorder.h>
33 
34 #include "hub.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 /* khubd's worklist and its lock */
45 static DEFINE_SPINLOCK(hub_event_lock);
46 static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */
47 
48 /* Wakes up khubd */
49 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
50 
51 static struct task_struct *khubd_task;
52 
53 /* synchronize hub-port add/remove and peering operations */
54 DEFINE_MUTEX(usb_port_peer_mutex);
55 
56 /* cycle leds on hubs that aren't blinking for attention */
57 static bool blinkenlights = 0;
58 module_param (blinkenlights, bool, S_IRUGO);
59 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
60 
61 /*
62  * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
63  * 10 seconds to send reply for the initial 64-byte descriptor request.
64  */
65 /* define initial 64-byte descriptor request timeout in milliseconds */
66 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
67 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
68 MODULE_PARM_DESC(initial_descriptor_timeout,
69 		"initial 64-byte descriptor request timeout in milliseconds "
70 		"(default 5000 - 5.0 seconds)");
71 
72 /*
73  * As of 2.6.10 we introduce a new USB device initialization scheme which
74  * closely resembles the way Windows works.  Hopefully it will be compatible
75  * with a wider range of devices than the old scheme.  However some previously
76  * working devices may start giving rise to "device not accepting address"
77  * errors; if that happens the user can try the old scheme by adjusting the
78  * following module parameters.
79  *
80  * For maximum flexibility there are two boolean parameters to control the
81  * hub driver's behavior.  On the first initialization attempt, if the
82  * "old_scheme_first" parameter is set then the old scheme will be used,
83  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
84  * is set, then the driver will make another attempt, using the other scheme.
85  */
86 static bool old_scheme_first = 0;
87 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
88 MODULE_PARM_DESC(old_scheme_first,
89 		 "start with the old device initialization scheme");
90 
91 static bool use_both_schemes = 1;
92 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
93 MODULE_PARM_DESC(use_both_schemes,
94 		"try the other device initialization scheme if the "
95 		"first one fails");
96 
97 /* Mutual exclusion for EHCI CF initialization.  This interferes with
98  * port reset on some companion controllers.
99  */
100 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
101 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
102 
103 #define HUB_DEBOUNCE_TIMEOUT	2000
104 #define HUB_DEBOUNCE_STEP	  25
105 #define HUB_DEBOUNCE_STABLE	 100
106 
107 static int usb_reset_and_verify_device(struct usb_device *udev);
108 
109 static inline char *portspeed(struct usb_hub *hub, int portstatus)
110 {
111 	if (hub_is_superspeed(hub->hdev))
112 		return "5.0 Gb/s";
113 	if (portstatus & USB_PORT_STAT_HIGH_SPEED)
114 		return "480 Mb/s";
115 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
116 		return "1.5 Mb/s";
117 	else
118 		return "12 Mb/s";
119 }
120 
121 /* Note that hdev or one of its children must be locked! */
122 struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
123 {
124 	if (!hdev || !hdev->actconfig || !hdev->maxchild)
125 		return NULL;
126 	return usb_get_intfdata(hdev->actconfig->interface[0]);
127 }
128 
129 static int usb_device_supports_lpm(struct usb_device *udev)
130 {
131 	/* USB 2.1 (and greater) devices indicate LPM support through
132 	 * their USB 2.0 Extended Capabilities BOS descriptor.
133 	 */
134 	if (udev->speed == USB_SPEED_HIGH) {
135 		if (udev->bos->ext_cap &&
136 			(USB_LPM_SUPPORT &
137 			 le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
138 			return 1;
139 		return 0;
140 	}
141 
142 	/*
143 	 * According to the USB 3.0 spec, all USB 3.0 devices must support LPM.
144 	 * However, there are some that don't, and they set the U1/U2 exit
145 	 * latencies to zero.
146 	 */
147 	if (!udev->bos->ss_cap) {
148 		dev_info(&udev->dev, "No LPM exit latency info found, disabling LPM.\n");
149 		return 0;
150 	}
151 
152 	if (udev->bos->ss_cap->bU1devExitLat == 0 &&
153 			udev->bos->ss_cap->bU2DevExitLat == 0) {
154 		if (udev->parent)
155 			dev_info(&udev->dev, "LPM exit latency is zeroed, disabling LPM.\n");
156 		else
157 			dev_info(&udev->dev, "We don't know the algorithms for LPM for this host, disabling LPM.\n");
158 		return 0;
159 	}
160 
161 	if (!udev->parent || udev->parent->lpm_capable)
162 		return 1;
163 	return 0;
164 }
165 
166 /*
167  * Set the Maximum Exit Latency (MEL) for the host to initiate a transition from
168  * either U1 or U2.
169  */
170 static void usb_set_lpm_mel(struct usb_device *udev,
171 		struct usb3_lpm_parameters *udev_lpm_params,
172 		unsigned int udev_exit_latency,
173 		struct usb_hub *hub,
174 		struct usb3_lpm_parameters *hub_lpm_params,
175 		unsigned int hub_exit_latency)
176 {
177 	unsigned int total_mel;
178 	unsigned int device_mel;
179 	unsigned int hub_mel;
180 
181 	/*
182 	 * Calculate the time it takes to transition all links from the roothub
183 	 * to the parent hub into U0.  The parent hub must then decode the
184 	 * packet (hub header decode latency) to figure out which port it was
185 	 * bound for.
186 	 *
187 	 * The Hub Header decode latency is expressed in 0.1us intervals (0x1
188 	 * means 0.1us).  Multiply that by 100 to get nanoseconds.
189 	 */
190 	total_mel = hub_lpm_params->mel +
191 		(hub->descriptor->u.ss.bHubHdrDecLat * 100);
192 
193 	/*
194 	 * How long will it take to transition the downstream hub's port into
195 	 * U0?  The greater of either the hub exit latency or the device exit
196 	 * latency.
197 	 *
198 	 * The BOS U1/U2 exit latencies are expressed in 1us intervals.
199 	 * Multiply that by 1000 to get nanoseconds.
200 	 */
201 	device_mel = udev_exit_latency * 1000;
202 	hub_mel = hub_exit_latency * 1000;
203 	if (device_mel > hub_mel)
204 		total_mel += device_mel;
205 	else
206 		total_mel += hub_mel;
207 
208 	udev_lpm_params->mel = total_mel;
209 }
210 
211 /*
212  * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
213  * a transition from either U1 or U2.
214  */
215 static void usb_set_lpm_pel(struct usb_device *udev,
216 		struct usb3_lpm_parameters *udev_lpm_params,
217 		unsigned int udev_exit_latency,
218 		struct usb_hub *hub,
219 		struct usb3_lpm_parameters *hub_lpm_params,
220 		unsigned int hub_exit_latency,
221 		unsigned int port_to_port_exit_latency)
222 {
223 	unsigned int first_link_pel;
224 	unsigned int hub_pel;
225 
226 	/*
227 	 * First, the device sends an LFPS to transition the link between the
228 	 * device and the parent hub into U0.  The exit latency is the bigger of
229 	 * the device exit latency or the hub exit latency.
230 	 */
231 	if (udev_exit_latency > hub_exit_latency)
232 		first_link_pel = udev_exit_latency * 1000;
233 	else
234 		first_link_pel = hub_exit_latency * 1000;
235 
236 	/*
237 	 * When the hub starts to receive the LFPS, there is a slight delay for
238 	 * it to figure out that one of the ports is sending an LFPS.  Then it
239 	 * will forward the LFPS to its upstream link.  The exit latency is the
240 	 * delay, plus the PEL that we calculated for this hub.
241 	 */
242 	hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;
243 
244 	/*
245 	 * According to figure C-7 in the USB 3.0 spec, the PEL for this device
246 	 * is the greater of the two exit latencies.
247 	 */
248 	if (first_link_pel > hub_pel)
249 		udev_lpm_params->pel = first_link_pel;
250 	else
251 		udev_lpm_params->pel = hub_pel;
252 }
253 
254 /*
255  * Set the System Exit Latency (SEL) to indicate the total worst-case time from
256  * when a device initiates a transition to U0, until when it will receive the
257  * first packet from the host controller.
258  *
259  * Section C.1.5.1 describes the four components to this:
260  *  - t1: device PEL
261  *  - t2: time for the ERDY to make it from the device to the host.
262  *  - t3: a host-specific delay to process the ERDY.
263  *  - t4: time for the packet to make it from the host to the device.
264  *
265  * t3 is specific to both the xHCI host and the platform the host is integrated
266  * into.  The Intel HW folks have said it's negligible, FIXME if a different
267  * vendor says otherwise.
268  */
269 static void usb_set_lpm_sel(struct usb_device *udev,
270 		struct usb3_lpm_parameters *udev_lpm_params)
271 {
272 	struct usb_device *parent;
273 	unsigned int num_hubs;
274 	unsigned int total_sel;
275 
276 	/* t1 = device PEL */
277 	total_sel = udev_lpm_params->pel;
278 	/* How many external hubs are in between the device & the root port. */
279 	for (parent = udev->parent, num_hubs = 0; parent->parent;
280 			parent = parent->parent)
281 		num_hubs++;
282 	/* t2 = 2.1us + 250ns * (num_hubs - 1) */
283 	if (num_hubs > 0)
284 		total_sel += 2100 + 250 * (num_hubs - 1);
285 
286 	/* t4 = 250ns * num_hubs */
287 	total_sel += 250 * num_hubs;
288 
289 	udev_lpm_params->sel = total_sel;
290 }
291 
292 static void usb_set_lpm_parameters(struct usb_device *udev)
293 {
294 	struct usb_hub *hub;
295 	unsigned int port_to_port_delay;
296 	unsigned int udev_u1_del;
297 	unsigned int udev_u2_del;
298 	unsigned int hub_u1_del;
299 	unsigned int hub_u2_del;
300 
301 	if (!udev->lpm_capable || udev->speed != USB_SPEED_SUPER)
302 		return;
303 
304 	hub = usb_hub_to_struct_hub(udev->parent);
305 	/* It doesn't take time to transition the roothub into U0, since it
306 	 * doesn't have an upstream link.
307 	 */
308 	if (!hub)
309 		return;
310 
311 	udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
312 	udev_u2_del = le16_to_cpu(udev->bos->ss_cap->bU2DevExitLat);
313 	hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
314 	hub_u2_del = le16_to_cpu(udev->parent->bos->ss_cap->bU2DevExitLat);
315 
316 	usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
317 			hub, &udev->parent->u1_params, hub_u1_del);
318 
319 	usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
320 			hub, &udev->parent->u2_params, hub_u2_del);
321 
322 	/*
323 	 * Appendix C, section C.2.2.2, says that there is a slight delay from
324 	 * when the parent hub notices the downstream port is trying to
325 	 * transition to U0 to when the hub initiates a U0 transition on its
326 	 * upstream port.  The section says the delays are tPort2PortU1EL and
327 	 * tPort2PortU2EL, but it doesn't define what they are.
328 	 *
329 	 * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
330 	 * about the same delays.  Use the maximum delay calculations from those
331 	 * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
332 	 * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
333 	 * assume the device exit latencies they are talking about are the hub
334 	 * exit latencies.
335 	 *
336 	 * What do we do if the U2 exit latency is less than the U1 exit
337 	 * latency?  It's possible, although not likely...
338 	 */
339 	port_to_port_delay = 1;
340 
341 	usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
342 			hub, &udev->parent->u1_params, hub_u1_del,
343 			port_to_port_delay);
344 
345 	if (hub_u2_del > hub_u1_del)
346 		port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
347 	else
348 		port_to_port_delay = 1 + hub_u1_del;
349 
350 	usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
351 			hub, &udev->parent->u2_params, hub_u2_del,
352 			port_to_port_delay);
353 
354 	/* Now that we've got PEL, calculate SEL. */
355 	usb_set_lpm_sel(udev, &udev->u1_params);
356 	usb_set_lpm_sel(udev, &udev->u2_params);
357 }
358 
359 /* USB 2.0 spec Section 11.24.4.5 */
360 static int get_hub_descriptor(struct usb_device *hdev, void *data)
361 {
362 	int i, ret, size;
363 	unsigned dtype;
364 
365 	if (hub_is_superspeed(hdev)) {
366 		dtype = USB_DT_SS_HUB;
367 		size = USB_DT_SS_HUB_SIZE;
368 	} else {
369 		dtype = USB_DT_HUB;
370 		size = sizeof(struct usb_hub_descriptor);
371 	}
372 
373 	for (i = 0; i < 3; i++) {
374 		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
375 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
376 			dtype << 8, 0, data, size,
377 			USB_CTRL_GET_TIMEOUT);
378 		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
379 			return ret;
380 	}
381 	return -EINVAL;
382 }
383 
384 /*
385  * USB 2.0 spec Section 11.24.2.1
386  */
387 static int clear_hub_feature(struct usb_device *hdev, int feature)
388 {
389 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
390 		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
391 }
392 
393 /*
394  * USB 2.0 spec Section 11.24.2.2
395  */
396 int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
397 {
398 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
399 		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
400 		NULL, 0, 1000);
401 }
402 
403 /*
404  * USB 2.0 spec Section 11.24.2.13
405  */
406 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
407 {
408 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
409 		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
410 		NULL, 0, 1000);
411 }
412 
413 static char *to_led_name(int selector)
414 {
415 	switch (selector) {
416 	case HUB_LED_AMBER:
417 		return "amber";
418 	case HUB_LED_GREEN:
419 		return "green";
420 	case HUB_LED_OFF:
421 		return "off";
422 	case HUB_LED_AUTO:
423 		return "auto";
424 	default:
425 		return "??";
426 	}
427 }
428 
429 /*
430  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
431  * for info about using port indicators
432  */
433 static void set_port_led(struct usb_hub *hub, int port1, int selector)
434 {
435 	struct usb_port *port_dev = hub->ports[port1 - 1];
436 	int status;
437 
438 	status = set_port_feature(hub->hdev, (selector << 8) | port1,
439 			USB_PORT_FEAT_INDICATOR);
440 	dev_dbg(&port_dev->dev, "indicator %s status %d\n",
441 		to_led_name(selector), status);
442 }
443 
444 #define	LED_CYCLE_PERIOD	((2*HZ)/3)
445 
446 static void led_work (struct work_struct *work)
447 {
448 	struct usb_hub		*hub =
449 		container_of(work, struct usb_hub, leds.work);
450 	struct usb_device	*hdev = hub->hdev;
451 	unsigned		i;
452 	unsigned		changed = 0;
453 	int			cursor = -1;
454 
455 	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
456 		return;
457 
458 	for (i = 0; i < hdev->maxchild; i++) {
459 		unsigned	selector, mode;
460 
461 		/* 30%-50% duty cycle */
462 
463 		switch (hub->indicator[i]) {
464 		/* cycle marker */
465 		case INDICATOR_CYCLE:
466 			cursor = i;
467 			selector = HUB_LED_AUTO;
468 			mode = INDICATOR_AUTO;
469 			break;
470 		/* blinking green = sw attention */
471 		case INDICATOR_GREEN_BLINK:
472 			selector = HUB_LED_GREEN;
473 			mode = INDICATOR_GREEN_BLINK_OFF;
474 			break;
475 		case INDICATOR_GREEN_BLINK_OFF:
476 			selector = HUB_LED_OFF;
477 			mode = INDICATOR_GREEN_BLINK;
478 			break;
479 		/* blinking amber = hw attention */
480 		case INDICATOR_AMBER_BLINK:
481 			selector = HUB_LED_AMBER;
482 			mode = INDICATOR_AMBER_BLINK_OFF;
483 			break;
484 		case INDICATOR_AMBER_BLINK_OFF:
485 			selector = HUB_LED_OFF;
486 			mode = INDICATOR_AMBER_BLINK;
487 			break;
488 		/* blink green/amber = reserved */
489 		case INDICATOR_ALT_BLINK:
490 			selector = HUB_LED_GREEN;
491 			mode = INDICATOR_ALT_BLINK_OFF;
492 			break;
493 		case INDICATOR_ALT_BLINK_OFF:
494 			selector = HUB_LED_AMBER;
495 			mode = INDICATOR_ALT_BLINK;
496 			break;
497 		default:
498 			continue;
499 		}
500 		if (selector != HUB_LED_AUTO)
501 			changed = 1;
502 		set_port_led(hub, i + 1, selector);
503 		hub->indicator[i] = mode;
504 	}
505 	if (!changed && blinkenlights) {
506 		cursor++;
507 		cursor %= hdev->maxchild;
508 		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
509 		hub->indicator[cursor] = INDICATOR_CYCLE;
510 		changed++;
511 	}
512 	if (changed)
513 		queue_delayed_work(system_power_efficient_wq,
514 				&hub->leds, LED_CYCLE_PERIOD);
515 }
516 
517 /* use a short timeout for hub/port status fetches */
518 #define	USB_STS_TIMEOUT		1000
519 #define	USB_STS_RETRIES		5
520 
521 /*
522  * USB 2.0 spec Section 11.24.2.6
523  */
524 static int get_hub_status(struct usb_device *hdev,
525 		struct usb_hub_status *data)
526 {
527 	int i, status = -ETIMEDOUT;
528 
529 	for (i = 0; i < USB_STS_RETRIES &&
530 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
531 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
532 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
533 			data, sizeof(*data), USB_STS_TIMEOUT);
534 	}
535 	return status;
536 }
537 
538 /*
539  * USB 2.0 spec Section 11.24.2.7
540  */
541 static int get_port_status(struct usb_device *hdev, int port1,
542 		struct usb_port_status *data)
543 {
544 	int i, status = -ETIMEDOUT;
545 
546 	for (i = 0; i < USB_STS_RETRIES &&
547 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
548 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
549 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
550 			data, sizeof(*data), USB_STS_TIMEOUT);
551 	}
552 	return status;
553 }
554 
555 static int hub_port_status(struct usb_hub *hub, int port1,
556 		u16 *status, u16 *change)
557 {
558 	int ret;
559 
560 	mutex_lock(&hub->status_mutex);
561 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
562 	if (ret < 4) {
563 		if (ret != -ENODEV)
564 			dev_err(hub->intfdev,
565 				"%s failed (err = %d)\n", __func__, ret);
566 		if (ret >= 0)
567 			ret = -EIO;
568 	} else {
569 		*status = le16_to_cpu(hub->status->port.wPortStatus);
570 		*change = le16_to_cpu(hub->status->port.wPortChange);
571 
572 		ret = 0;
573 	}
574 	mutex_unlock(&hub->status_mutex);
575 	return ret;
576 }
577 
578 static void kick_khubd(struct usb_hub *hub)
579 {
580 	unsigned long	flags;
581 
582 	spin_lock_irqsave(&hub_event_lock, flags);
583 	if (!hub->disconnected && list_empty(&hub->event_list)) {
584 		list_add_tail(&hub->event_list, &hub_event_list);
585 
586 		/* Suppress autosuspend until khubd runs */
587 		usb_autopm_get_interface_no_resume(
588 				to_usb_interface(hub->intfdev));
589 		wake_up(&khubd_wait);
590 	}
591 	spin_unlock_irqrestore(&hub_event_lock, flags);
592 }
593 
594 void usb_kick_khubd(struct usb_device *hdev)
595 {
596 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
597 
598 	if (hub)
599 		kick_khubd(hub);
600 }
601 
602 /*
603  * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
604  * Notification, which indicates it had initiated remote wakeup.
605  *
606  * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
607  * device initiates resume, so the USB core will not receive notice of the
608  * resume through the normal hub interrupt URB.
609  */
610 void usb_wakeup_notification(struct usb_device *hdev,
611 		unsigned int portnum)
612 {
613 	struct usb_hub *hub;
614 
615 	if (!hdev)
616 		return;
617 
618 	hub = usb_hub_to_struct_hub(hdev);
619 	if (hub) {
620 		set_bit(portnum, hub->wakeup_bits);
621 		kick_khubd(hub);
622 	}
623 }
624 EXPORT_SYMBOL_GPL(usb_wakeup_notification);
625 
626 /* completion function, fires on port status changes and various faults */
627 static void hub_irq(struct urb *urb)
628 {
629 	struct usb_hub *hub = urb->context;
630 	int status = urb->status;
631 	unsigned i;
632 	unsigned long bits;
633 
634 	switch (status) {
635 	case -ENOENT:		/* synchronous unlink */
636 	case -ECONNRESET:	/* async unlink */
637 	case -ESHUTDOWN:	/* hardware going away */
638 		return;
639 
640 	default:		/* presumably an error */
641 		/* Cause a hub reset after 10 consecutive errors */
642 		dev_dbg (hub->intfdev, "transfer --> %d\n", status);
643 		if ((++hub->nerrors < 10) || hub->error)
644 			goto resubmit;
645 		hub->error = status;
646 		/* FALL THROUGH */
647 
648 	/* let khubd handle things */
649 	case 0:			/* we got data:  port status changed */
650 		bits = 0;
651 		for (i = 0; i < urb->actual_length; ++i)
652 			bits |= ((unsigned long) ((*hub->buffer)[i]))
653 					<< (i*8);
654 		hub->event_bits[0] = bits;
655 		break;
656 	}
657 
658 	hub->nerrors = 0;
659 
660 	/* Something happened, let khubd figure it out */
661 	kick_khubd(hub);
662 
663 resubmit:
664 	if (hub->quiescing)
665 		return;
666 
667 	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
668 			&& status != -ENODEV && status != -EPERM)
669 		dev_err (hub->intfdev, "resubmit --> %d\n", status);
670 }
671 
672 /* USB 2.0 spec Section 11.24.2.3 */
673 static inline int
674 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
675 {
676 	/* Need to clear both directions for control ep */
677 	if (((devinfo >> 11) & USB_ENDPOINT_XFERTYPE_MASK) ==
678 			USB_ENDPOINT_XFER_CONTROL) {
679 		int status = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
680 				HUB_CLEAR_TT_BUFFER, USB_RT_PORT,
681 				devinfo ^ 0x8000, tt, NULL, 0, 1000);
682 		if (status)
683 			return status;
684 	}
685 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
686 			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
687 			       tt, NULL, 0, 1000);
688 }
689 
690 /*
691  * enumeration blocks khubd for a long time. we use keventd instead, since
692  * long blocking there is the exception, not the rule.  accordingly, HCDs
693  * talking to TTs must queue control transfers (not just bulk and iso), so
694  * both can talk to the same hub concurrently.
695  */
696 static void hub_tt_work(struct work_struct *work)
697 {
698 	struct usb_hub		*hub =
699 		container_of(work, struct usb_hub, tt.clear_work);
700 	unsigned long		flags;
701 
702 	spin_lock_irqsave (&hub->tt.lock, flags);
703 	while (!list_empty(&hub->tt.clear_list)) {
704 		struct list_head	*next;
705 		struct usb_tt_clear	*clear;
706 		struct usb_device	*hdev = hub->hdev;
707 		const struct hc_driver	*drv;
708 		int			status;
709 
710 		next = hub->tt.clear_list.next;
711 		clear = list_entry (next, struct usb_tt_clear, clear_list);
712 		list_del (&clear->clear_list);
713 
714 		/* drop lock so HCD can concurrently report other TT errors */
715 		spin_unlock_irqrestore (&hub->tt.lock, flags);
716 		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
717 		if (status && status != -ENODEV)
718 			dev_err (&hdev->dev,
719 				"clear tt %d (%04x) error %d\n",
720 				clear->tt, clear->devinfo, status);
721 
722 		/* Tell the HCD, even if the operation failed */
723 		drv = clear->hcd->driver;
724 		if (drv->clear_tt_buffer_complete)
725 			(drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
726 
727 		kfree(clear);
728 		spin_lock_irqsave(&hub->tt.lock, flags);
729 	}
730 	spin_unlock_irqrestore (&hub->tt.lock, flags);
731 }
732 
733 /**
734  * usb_hub_set_port_power - control hub port's power state
735  * @hdev: USB device belonging to the usb hub
736  * @hub: target hub
737  * @port1: port index
738  * @set: expected status
739  *
740  * call this function to control port's power via setting or
741  * clearing the port's PORT_POWER feature.
742  *
743  * Return: 0 if successful. A negative error code otherwise.
744  */
745 int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
746 			   int port1, bool set)
747 {
748 	int ret;
749 
750 	if (set)
751 		ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
752 	else
753 		ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
754 
755 	if (ret)
756 		return ret;
757 
758 	if (set)
759 		set_bit(port1, hub->power_bits);
760 	else
761 		clear_bit(port1, hub->power_bits);
762 	return 0;
763 }
764 
765 /**
766  * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
767  * @urb: an URB associated with the failed or incomplete split transaction
768  *
769  * High speed HCDs use this to tell the hub driver that some split control or
770  * bulk transaction failed in a way that requires clearing internal state of
771  * a transaction translator.  This is normally detected (and reported) from
772  * interrupt context.
773  *
774  * It may not be possible for that hub to handle additional full (or low)
775  * speed transactions until that state is fully cleared out.
776  *
777  * Return: 0 if successful. A negative error code otherwise.
778  */
779 int usb_hub_clear_tt_buffer(struct urb *urb)
780 {
781 	struct usb_device	*udev = urb->dev;
782 	int			pipe = urb->pipe;
783 	struct usb_tt		*tt = udev->tt;
784 	unsigned long		flags;
785 	struct usb_tt_clear	*clear;
786 
787 	/* we've got to cope with an arbitrary number of pending TT clears,
788 	 * since each TT has "at least two" buffers that can need it (and
789 	 * there can be many TTs per hub).  even if they're uncommon.
790 	 */
791 	if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
792 		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
793 		/* FIXME recover somehow ... RESET_TT? */
794 		return -ENOMEM;
795 	}
796 
797 	/* info that CLEAR_TT_BUFFER needs */
798 	clear->tt = tt->multi ? udev->ttport : 1;
799 	clear->devinfo = usb_pipeendpoint (pipe);
800 	clear->devinfo |= udev->devnum << 4;
801 	clear->devinfo |= usb_pipecontrol (pipe)
802 			? (USB_ENDPOINT_XFER_CONTROL << 11)
803 			: (USB_ENDPOINT_XFER_BULK << 11);
804 	if (usb_pipein (pipe))
805 		clear->devinfo |= 1 << 15;
806 
807 	/* info for completion callback */
808 	clear->hcd = bus_to_hcd(udev->bus);
809 	clear->ep = urb->ep;
810 
811 	/* tell keventd to clear state for this TT */
812 	spin_lock_irqsave (&tt->lock, flags);
813 	list_add_tail (&clear->clear_list, &tt->clear_list);
814 	schedule_work(&tt->clear_work);
815 	spin_unlock_irqrestore (&tt->lock, flags);
816 	return 0;
817 }
818 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
819 
820 static void hub_power_on(struct usb_hub *hub, bool do_delay)
821 {
822 	int port1;
823 
824 	/* Enable power on each port.  Some hubs have reserved values
825 	 * of LPSM (> 2) in their descriptors, even though they are
826 	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
827 	 * but only emulate it.  In all cases, the ports won't work
828 	 * unless we send these messages to the hub.
829 	 */
830 	if (hub_is_port_power_switchable(hub))
831 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
832 	else
833 		dev_dbg(hub->intfdev, "trying to enable port power on "
834 				"non-switchable hub\n");
835 	for (port1 = 1; port1 <= hub->hdev->maxchild; port1++)
836 		if (test_bit(port1, hub->power_bits))
837 			set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
838 		else
839 			usb_clear_port_feature(hub->hdev, port1,
840 						USB_PORT_FEAT_POWER);
841 	if (do_delay)
842 		msleep(hub_power_on_good_delay(hub));
843 }
844 
845 static int hub_hub_status(struct usb_hub *hub,
846 		u16 *status, u16 *change)
847 {
848 	int ret;
849 
850 	mutex_lock(&hub->status_mutex);
851 	ret = get_hub_status(hub->hdev, &hub->status->hub);
852 	if (ret < 0) {
853 		if (ret != -ENODEV)
854 			dev_err(hub->intfdev,
855 				"%s failed (err = %d)\n", __func__, ret);
856 	} else {
857 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
858 		*change = le16_to_cpu(hub->status->hub.wHubChange);
859 		ret = 0;
860 	}
861 	mutex_unlock(&hub->status_mutex);
862 	return ret;
863 }
864 
865 static int hub_set_port_link_state(struct usb_hub *hub, int port1,
866 			unsigned int link_status)
867 {
868 	return set_port_feature(hub->hdev,
869 			port1 | (link_status << 3),
870 			USB_PORT_FEAT_LINK_STATE);
871 }
872 
873 /*
874  * If USB 3.0 ports are placed into the Disabled state, they will no longer
875  * detect any device connects or disconnects.  This is generally not what the
876  * USB core wants, since it expects a disabled port to produce a port status
877  * change event when a new device connects.
878  *
879  * Instead, set the link state to Disabled, wait for the link to settle into
880  * that state, clear any change bits, and then put the port into the RxDetect
881  * state.
882  */
883 static int hub_usb3_port_disable(struct usb_hub *hub, int port1)
884 {
885 	int ret;
886 	int total_time;
887 	u16 portchange, portstatus;
888 
889 	if (!hub_is_superspeed(hub->hdev))
890 		return -EINVAL;
891 
892 	ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED);
893 	if (ret)
894 		return ret;
895 
896 	/* Wait for the link to enter the disabled state. */
897 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
898 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
899 		if (ret < 0)
900 			return ret;
901 
902 		if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
903 				USB_SS_PORT_LS_SS_DISABLED)
904 			break;
905 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
906 			break;
907 		msleep(HUB_DEBOUNCE_STEP);
908 	}
909 	if (total_time >= HUB_DEBOUNCE_TIMEOUT)
910 		dev_warn(&hub->ports[port1 - 1]->dev,
911 				"Could not disable after %d ms\n", total_time);
912 
913 	return hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_RX_DETECT);
914 }
915 
916 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
917 {
918 	struct usb_port *port_dev = hub->ports[port1 - 1];
919 	struct usb_device *hdev = hub->hdev;
920 	int ret = 0;
921 
922 	if (port_dev->child && set_state)
923 		usb_set_device_state(port_dev->child, USB_STATE_NOTATTACHED);
924 	if (!hub->error) {
925 		if (hub_is_superspeed(hub->hdev))
926 			ret = hub_usb3_port_disable(hub, port1);
927 		else
928 			ret = usb_clear_port_feature(hdev, port1,
929 					USB_PORT_FEAT_ENABLE);
930 	}
931 	if (ret && ret != -ENODEV)
932 		dev_err(&port_dev->dev, "cannot disable (err = %d)\n", ret);
933 	return ret;
934 }
935 
936 /*
937  * Disable a port and mark a logical connect-change event, so that some
938  * time later khubd will disconnect() any existing usb_device on the port
939  * and will re-enumerate if there actually is a device attached.
940  */
941 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
942 {
943 	dev_dbg(&hub->ports[port1 - 1]->dev, "logical disconnect\n");
944 	hub_port_disable(hub, port1, 1);
945 
946 	/* FIXME let caller ask to power down the port:
947 	 *  - some devices won't enumerate without a VBUS power cycle
948 	 *  - SRP saves power that way
949 	 *  - ... new call, TBD ...
950 	 * That's easy if this hub can switch power per-port, and
951 	 * khubd reactivates the port later (timer, SRP, etc).
952 	 * Powerdown must be optional, because of reset/DFU.
953 	 */
954 
955 	set_bit(port1, hub->change_bits);
956 	kick_khubd(hub);
957 }
958 
959 /**
960  * usb_remove_device - disable a device's port on its parent hub
961  * @udev: device to be disabled and removed
962  * Context: @udev locked, must be able to sleep.
963  *
964  * After @udev's port has been disabled, khubd is notified and it will
965  * see that the device has been disconnected.  When the device is
966  * physically unplugged and something is plugged in, the events will
967  * be received and processed normally.
968  *
969  * Return: 0 if successful. A negative error code otherwise.
970  */
971 int usb_remove_device(struct usb_device *udev)
972 {
973 	struct usb_hub *hub;
974 	struct usb_interface *intf;
975 
976 	if (!udev->parent)	/* Can't remove a root hub */
977 		return -EINVAL;
978 	hub = usb_hub_to_struct_hub(udev->parent);
979 	intf = to_usb_interface(hub->intfdev);
980 
981 	usb_autopm_get_interface(intf);
982 	set_bit(udev->portnum, hub->removed_bits);
983 	hub_port_logical_disconnect(hub, udev->portnum);
984 	usb_autopm_put_interface(intf);
985 	return 0;
986 }
987 
988 enum hub_activation_type {
989 	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
990 	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
991 };
992 
993 static void hub_init_func2(struct work_struct *ws);
994 static void hub_init_func3(struct work_struct *ws);
995 
996 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
997 {
998 	struct usb_device *hdev = hub->hdev;
999 	struct usb_hcd *hcd;
1000 	int ret;
1001 	int port1;
1002 	int status;
1003 	bool need_debounce_delay = false;
1004 	unsigned delay;
1005 
1006 	/* Continue a partial initialization */
1007 	if (type == HUB_INIT2)
1008 		goto init2;
1009 	if (type == HUB_INIT3)
1010 		goto init3;
1011 
1012 	/* The superspeed hub except for root hub has to use Hub Depth
1013 	 * value as an offset into the route string to locate the bits
1014 	 * it uses to determine the downstream port number. So hub driver
1015 	 * should send a set hub depth request to superspeed hub after
1016 	 * the superspeed hub is set configuration in initialization or
1017 	 * reset procedure.
1018 	 *
1019 	 * After a resume, port power should still be on.
1020 	 * For any other type of activation, turn it on.
1021 	 */
1022 	if (type != HUB_RESUME) {
1023 		if (hdev->parent && hub_is_superspeed(hdev)) {
1024 			ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
1025 					HUB_SET_DEPTH, USB_RT_HUB,
1026 					hdev->level - 1, 0, NULL, 0,
1027 					USB_CTRL_SET_TIMEOUT);
1028 			if (ret < 0)
1029 				dev_err(hub->intfdev,
1030 						"set hub depth failed\n");
1031 		}
1032 
1033 		/* Speed up system boot by using a delayed_work for the
1034 		 * hub's initial power-up delays.  This is pretty awkward
1035 		 * and the implementation looks like a home-brewed sort of
1036 		 * setjmp/longjmp, but it saves at least 100 ms for each
1037 		 * root hub (assuming usbcore is compiled into the kernel
1038 		 * rather than as a module).  It adds up.
1039 		 *
1040 		 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
1041 		 * because for those activation types the ports have to be
1042 		 * operational when we return.  In theory this could be done
1043 		 * for HUB_POST_RESET, but it's easier not to.
1044 		 */
1045 		if (type == HUB_INIT) {
1046 			unsigned delay = hub_power_on_good_delay(hub);
1047 
1048 			hub_power_on(hub, false);
1049 			INIT_DELAYED_WORK(&hub->init_work, hub_init_func2);
1050 			queue_delayed_work(system_power_efficient_wq,
1051 					&hub->init_work,
1052 					msecs_to_jiffies(delay));
1053 
1054 			/* Suppress autosuspend until init is done */
1055 			usb_autopm_get_interface_no_resume(
1056 					to_usb_interface(hub->intfdev));
1057 			return;		/* Continues at init2: below */
1058 		} else if (type == HUB_RESET_RESUME) {
1059 			/* The internal host controller state for the hub device
1060 			 * may be gone after a host power loss on system resume.
1061 			 * Update the device's info so the HW knows it's a hub.
1062 			 */
1063 			hcd = bus_to_hcd(hdev->bus);
1064 			if (hcd->driver->update_hub_device) {
1065 				ret = hcd->driver->update_hub_device(hcd, hdev,
1066 						&hub->tt, GFP_NOIO);
1067 				if (ret < 0) {
1068 					dev_err(hub->intfdev, "Host not "
1069 							"accepting hub info "
1070 							"update.\n");
1071 					dev_err(hub->intfdev, "LS/FS devices "
1072 							"and hubs may not work "
1073 							"under this hub\n.");
1074 				}
1075 			}
1076 			hub_power_on(hub, true);
1077 		} else {
1078 			hub_power_on(hub, true);
1079 		}
1080 	}
1081  init2:
1082 
1083 	/*
1084 	 * Check each port and set hub->change_bits to let khubd know
1085 	 * which ports need attention.
1086 	 */
1087 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1088 		struct usb_port *port_dev = hub->ports[port1 - 1];
1089 		struct usb_device *udev = port_dev->child;
1090 		u16 portstatus, portchange;
1091 
1092 		portstatus = portchange = 0;
1093 		status = hub_port_status(hub, port1, &portstatus, &portchange);
1094 		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1095 			dev_dbg(&port_dev->dev, "status %04x change %04x\n",
1096 					portstatus, portchange);
1097 
1098 		/*
1099 		 * After anything other than HUB_RESUME (i.e., initialization
1100 		 * or any sort of reset), every port should be disabled.
1101 		 * Unconnected ports should likewise be disabled (paranoia),
1102 		 * and so should ports for which we have no usb_device.
1103 		 */
1104 		if ((portstatus & USB_PORT_STAT_ENABLE) && (
1105 				type != HUB_RESUME ||
1106 				!(portstatus & USB_PORT_STAT_CONNECTION) ||
1107 				!udev ||
1108 				udev->state == USB_STATE_NOTATTACHED)) {
1109 			/*
1110 			 * USB3 protocol ports will automatically transition
1111 			 * to Enabled state when detect an USB3.0 device attach.
1112 			 * Do not disable USB3 protocol ports, just pretend
1113 			 * power was lost
1114 			 */
1115 			portstatus &= ~USB_PORT_STAT_ENABLE;
1116 			if (!hub_is_superspeed(hdev))
1117 				usb_clear_port_feature(hdev, port1,
1118 						   USB_PORT_FEAT_ENABLE);
1119 		}
1120 
1121 		/* Clear status-change flags; we'll debounce later */
1122 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
1123 			need_debounce_delay = true;
1124 			usb_clear_port_feature(hub->hdev, port1,
1125 					USB_PORT_FEAT_C_CONNECTION);
1126 		}
1127 		if (portchange & USB_PORT_STAT_C_ENABLE) {
1128 			need_debounce_delay = true;
1129 			usb_clear_port_feature(hub->hdev, port1,
1130 					USB_PORT_FEAT_C_ENABLE);
1131 		}
1132 		if (portchange & USB_PORT_STAT_C_RESET) {
1133 			need_debounce_delay = true;
1134 			usb_clear_port_feature(hub->hdev, port1,
1135 					USB_PORT_FEAT_C_RESET);
1136 		}
1137 		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
1138 				hub_is_superspeed(hub->hdev)) {
1139 			need_debounce_delay = true;
1140 			usb_clear_port_feature(hub->hdev, port1,
1141 					USB_PORT_FEAT_C_BH_PORT_RESET);
1142 		}
1143 		/* We can forget about a "removed" device when there's a
1144 		 * physical disconnect or the connect status changes.
1145 		 */
1146 		if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
1147 				(portchange & USB_PORT_STAT_C_CONNECTION))
1148 			clear_bit(port1, hub->removed_bits);
1149 
1150 		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
1151 			/* Tell khubd to disconnect the device or
1152 			 * check for a new connection
1153 			 */
1154 			if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
1155 			    (portstatus & USB_PORT_STAT_OVERCURRENT))
1156 				set_bit(port1, hub->change_bits);
1157 
1158 		} else if (portstatus & USB_PORT_STAT_ENABLE) {
1159 			bool port_resumed = (portstatus &
1160 					USB_PORT_STAT_LINK_STATE) ==
1161 				USB_SS_PORT_LS_U0;
1162 			/* The power session apparently survived the resume.
1163 			 * If there was an overcurrent or suspend change
1164 			 * (i.e., remote wakeup request), have khubd
1165 			 * take care of it.  Look at the port link state
1166 			 * for USB 3.0 hubs, since they don't have a suspend
1167 			 * change bit, and they don't set the port link change
1168 			 * bit on device-initiated resume.
1169 			 */
1170 			if (portchange || (hub_is_superspeed(hub->hdev) &&
1171 						port_resumed))
1172 				set_bit(port1, hub->change_bits);
1173 
1174 		} else if (udev->persist_enabled) {
1175 #ifdef CONFIG_PM
1176 			udev->reset_resume = 1;
1177 #endif
1178 			/* Don't set the change_bits when the device
1179 			 * was powered off.
1180 			 */
1181 			if (test_bit(port1, hub->power_bits))
1182 				set_bit(port1, hub->change_bits);
1183 
1184 		} else {
1185 			/* The power session is gone; tell khubd */
1186 			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1187 			set_bit(port1, hub->change_bits);
1188 		}
1189 	}
1190 
1191 	/* If no port-status-change flags were set, we don't need any
1192 	 * debouncing.  If flags were set we can try to debounce the
1193 	 * ports all at once right now, instead of letting khubd do them
1194 	 * one at a time later on.
1195 	 *
1196 	 * If any port-status changes do occur during this delay, khubd
1197 	 * will see them later and handle them normally.
1198 	 */
1199 	if (need_debounce_delay) {
1200 		delay = HUB_DEBOUNCE_STABLE;
1201 
1202 		/* Don't do a long sleep inside a workqueue routine */
1203 		if (type == HUB_INIT2) {
1204 			INIT_DELAYED_WORK(&hub->init_work, hub_init_func3);
1205 			queue_delayed_work(system_power_efficient_wq,
1206 					&hub->init_work,
1207 					msecs_to_jiffies(delay));
1208 			return;		/* Continues at init3: below */
1209 		} else {
1210 			msleep(delay);
1211 		}
1212 	}
1213  init3:
1214 	hub->quiescing = 0;
1215 
1216 	status = usb_submit_urb(hub->urb, GFP_NOIO);
1217 	if (status < 0)
1218 		dev_err(hub->intfdev, "activate --> %d\n", status);
1219 	if (hub->has_indicators && blinkenlights)
1220 		queue_delayed_work(system_power_efficient_wq,
1221 				&hub->leds, LED_CYCLE_PERIOD);
1222 
1223 	/* Scan all ports that need attention */
1224 	kick_khubd(hub);
1225 
1226 	/* Allow autosuspend if it was suppressed */
1227 	if (type <= HUB_INIT3)
1228 		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
1229 }
1230 
1231 /* Implement the continuations for the delays above */
1232 static void hub_init_func2(struct work_struct *ws)
1233 {
1234 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1235 
1236 	hub_activate(hub, HUB_INIT2);
1237 }
1238 
1239 static void hub_init_func3(struct work_struct *ws)
1240 {
1241 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1242 
1243 	hub_activate(hub, HUB_INIT3);
1244 }
1245 
1246 enum hub_quiescing_type {
1247 	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
1248 };
1249 
1250 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
1251 {
1252 	struct usb_device *hdev = hub->hdev;
1253 	int i;
1254 
1255 	cancel_delayed_work_sync(&hub->init_work);
1256 
1257 	/* khubd and related activity won't re-trigger */
1258 	hub->quiescing = 1;
1259 
1260 	if (type != HUB_SUSPEND) {
1261 		/* Disconnect all the children */
1262 		for (i = 0; i < hdev->maxchild; ++i) {
1263 			if (hub->ports[i]->child)
1264 				usb_disconnect(&hub->ports[i]->child);
1265 		}
1266 	}
1267 
1268 	/* Stop khubd and related activity */
1269 	usb_kill_urb(hub->urb);
1270 	if (hub->has_indicators)
1271 		cancel_delayed_work_sync(&hub->leds);
1272 	if (hub->tt.hub)
1273 		flush_work(&hub->tt.clear_work);
1274 }
1275 
1276 static void hub_pm_barrier_for_all_ports(struct usb_hub *hub)
1277 {
1278 	int i;
1279 
1280 	for (i = 0; i < hub->hdev->maxchild; ++i)
1281 		pm_runtime_barrier(&hub->ports[i]->dev);
1282 }
1283 
1284 /* caller has locked the hub device */
1285 static int hub_pre_reset(struct usb_interface *intf)
1286 {
1287 	struct usb_hub *hub = usb_get_intfdata(intf);
1288 
1289 	hub_quiesce(hub, HUB_PRE_RESET);
1290 	hub->in_reset = 1;
1291 	hub_pm_barrier_for_all_ports(hub);
1292 	return 0;
1293 }
1294 
1295 /* caller has locked the hub device */
1296 static int hub_post_reset(struct usb_interface *intf)
1297 {
1298 	struct usb_hub *hub = usb_get_intfdata(intf);
1299 
1300 	hub->in_reset = 0;
1301 	hub_pm_barrier_for_all_ports(hub);
1302 	hub_activate(hub, HUB_POST_RESET);
1303 	return 0;
1304 }
1305 
1306 static int hub_configure(struct usb_hub *hub,
1307 	struct usb_endpoint_descriptor *endpoint)
1308 {
1309 	struct usb_hcd *hcd;
1310 	struct usb_device *hdev = hub->hdev;
1311 	struct device *hub_dev = hub->intfdev;
1312 	u16 hubstatus, hubchange;
1313 	u16 wHubCharacteristics;
1314 	unsigned int pipe;
1315 	int maxp, ret, i;
1316 	char *message = "out of memory";
1317 	unsigned unit_load;
1318 	unsigned full_load;
1319 	unsigned maxchild;
1320 
1321 	hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
1322 	if (!hub->buffer) {
1323 		ret = -ENOMEM;
1324 		goto fail;
1325 	}
1326 
1327 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
1328 	if (!hub->status) {
1329 		ret = -ENOMEM;
1330 		goto fail;
1331 	}
1332 	mutex_init(&hub->status_mutex);
1333 
1334 	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
1335 	if (!hub->descriptor) {
1336 		ret = -ENOMEM;
1337 		goto fail;
1338 	}
1339 
1340 	/* Request the entire hub descriptor.
1341 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
1342 	 * but the hub can/will return fewer bytes here.
1343 	 */
1344 	ret = get_hub_descriptor(hdev, hub->descriptor);
1345 	if (ret < 0) {
1346 		message = "can't read hub descriptor";
1347 		goto fail;
1348 	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
1349 		message = "hub has too many ports!";
1350 		ret = -ENODEV;
1351 		goto fail;
1352 	} else if (hub->descriptor->bNbrPorts == 0) {
1353 		message = "hub doesn't have any ports!";
1354 		ret = -ENODEV;
1355 		goto fail;
1356 	}
1357 
1358 	maxchild = hub->descriptor->bNbrPorts;
1359 	dev_info(hub_dev, "%d port%s detected\n", maxchild,
1360 			(maxchild == 1) ? "" : "s");
1361 
1362 	hub->ports = kzalloc(maxchild * sizeof(struct usb_port *), GFP_KERNEL);
1363 	if (!hub->ports) {
1364 		ret = -ENOMEM;
1365 		goto fail;
1366 	}
1367 
1368 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
1369 	if (hub_is_superspeed(hdev)) {
1370 		unit_load = 150;
1371 		full_load = 900;
1372 	} else {
1373 		unit_load = 100;
1374 		full_load = 500;
1375 	}
1376 
1377 	/* FIXME for USB 3.0, skip for now */
1378 	if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
1379 			!(hub_is_superspeed(hdev))) {
1380 		int	i;
1381 		char	portstr[USB_MAXCHILDREN + 1];
1382 
1383 		for (i = 0; i < maxchild; i++)
1384 			portstr[i] = hub->descriptor->u.hs.DeviceRemovable
1385 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1386 				? 'F' : 'R';
1387 		portstr[maxchild] = 0;
1388 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1389 	} else
1390 		dev_dbg(hub_dev, "standalone hub\n");
1391 
1392 	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1393 	case HUB_CHAR_COMMON_LPSM:
1394 		dev_dbg(hub_dev, "ganged power switching\n");
1395 		break;
1396 	case HUB_CHAR_INDV_PORT_LPSM:
1397 		dev_dbg(hub_dev, "individual port power switching\n");
1398 		break;
1399 	case HUB_CHAR_NO_LPSM:
1400 	case HUB_CHAR_LPSM:
1401 		dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1402 		break;
1403 	}
1404 
1405 	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1406 	case HUB_CHAR_COMMON_OCPM:
1407 		dev_dbg(hub_dev, "global over-current protection\n");
1408 		break;
1409 	case HUB_CHAR_INDV_PORT_OCPM:
1410 		dev_dbg(hub_dev, "individual port over-current protection\n");
1411 		break;
1412 	case HUB_CHAR_NO_OCPM:
1413 	case HUB_CHAR_OCPM:
1414 		dev_dbg(hub_dev, "no over-current protection\n");
1415 		break;
1416 	}
1417 
1418 	spin_lock_init (&hub->tt.lock);
1419 	INIT_LIST_HEAD (&hub->tt.clear_list);
1420 	INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1421 	switch (hdev->descriptor.bDeviceProtocol) {
1422 	case USB_HUB_PR_FS:
1423 		break;
1424 	case USB_HUB_PR_HS_SINGLE_TT:
1425 		dev_dbg(hub_dev, "Single TT\n");
1426 		hub->tt.hub = hdev;
1427 		break;
1428 	case USB_HUB_PR_HS_MULTI_TT:
1429 		ret = usb_set_interface(hdev, 0, 1);
1430 		if (ret == 0) {
1431 			dev_dbg(hub_dev, "TT per port\n");
1432 			hub->tt.multi = 1;
1433 		} else
1434 			dev_err(hub_dev, "Using single TT (err %d)\n",
1435 				ret);
1436 		hub->tt.hub = hdev;
1437 		break;
1438 	case USB_HUB_PR_SS:
1439 		/* USB 3.0 hubs don't have a TT */
1440 		break;
1441 	default:
1442 		dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1443 			hdev->descriptor.bDeviceProtocol);
1444 		break;
1445 	}
1446 
1447 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1448 	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1449 	case HUB_TTTT_8_BITS:
1450 		if (hdev->descriptor.bDeviceProtocol != 0) {
1451 			hub->tt.think_time = 666;
1452 			dev_dbg(hub_dev, "TT requires at most %d "
1453 					"FS bit times (%d ns)\n",
1454 				8, hub->tt.think_time);
1455 		}
1456 		break;
1457 	case HUB_TTTT_16_BITS:
1458 		hub->tt.think_time = 666 * 2;
1459 		dev_dbg(hub_dev, "TT requires at most %d "
1460 				"FS bit times (%d ns)\n",
1461 			16, hub->tt.think_time);
1462 		break;
1463 	case HUB_TTTT_24_BITS:
1464 		hub->tt.think_time = 666 * 3;
1465 		dev_dbg(hub_dev, "TT requires at most %d "
1466 				"FS bit times (%d ns)\n",
1467 			24, hub->tt.think_time);
1468 		break;
1469 	case HUB_TTTT_32_BITS:
1470 		hub->tt.think_time = 666 * 4;
1471 		dev_dbg(hub_dev, "TT requires at most %d "
1472 				"FS bit times (%d ns)\n",
1473 			32, hub->tt.think_time);
1474 		break;
1475 	}
1476 
1477 	/* probe() zeroes hub->indicator[] */
1478 	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1479 		hub->has_indicators = 1;
1480 		dev_dbg(hub_dev, "Port indicators are supported\n");
1481 	}
1482 
1483 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
1484 		hub->descriptor->bPwrOn2PwrGood * 2);
1485 
1486 	/* power budgeting mostly matters with bus-powered hubs,
1487 	 * and battery-powered root hubs (may provide just 8 mA).
1488 	 */
1489 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1490 	if (ret) {
1491 		message = "can't get hub status";
1492 		goto fail;
1493 	}
1494 	hcd = bus_to_hcd(hdev->bus);
1495 	if (hdev == hdev->bus->root_hub) {
1496 		if (hcd->power_budget > 0)
1497 			hdev->bus_mA = hcd->power_budget;
1498 		else
1499 			hdev->bus_mA = full_load * maxchild;
1500 		if (hdev->bus_mA >= full_load)
1501 			hub->mA_per_port = full_load;
1502 		else {
1503 			hub->mA_per_port = hdev->bus_mA;
1504 			hub->limited_power = 1;
1505 		}
1506 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1507 		int remaining = hdev->bus_mA -
1508 			hub->descriptor->bHubContrCurrent;
1509 
1510 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1511 			hub->descriptor->bHubContrCurrent);
1512 		hub->limited_power = 1;
1513 
1514 		if (remaining < maxchild * unit_load)
1515 			dev_warn(hub_dev,
1516 					"insufficient power available "
1517 					"to use all downstream ports\n");
1518 		hub->mA_per_port = unit_load;	/* 7.2.1 */
1519 
1520 	} else {	/* Self-powered external hub */
1521 		/* FIXME: What about battery-powered external hubs that
1522 		 * provide less current per port? */
1523 		hub->mA_per_port = full_load;
1524 	}
1525 	if (hub->mA_per_port < full_load)
1526 		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1527 				hub->mA_per_port);
1528 
1529 	/* Update the HCD's internal representation of this hub before khubd
1530 	 * starts getting port status changes for devices under the hub.
1531 	 */
1532 	if (hcd->driver->update_hub_device) {
1533 		ret = hcd->driver->update_hub_device(hcd, hdev,
1534 				&hub->tt, GFP_KERNEL);
1535 		if (ret < 0) {
1536 			message = "can't update HCD hub info";
1537 			goto fail;
1538 		}
1539 	}
1540 
1541 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
1542 	if (ret < 0) {
1543 		message = "can't get hub status";
1544 		goto fail;
1545 	}
1546 
1547 	/* local power status reports aren't always correct */
1548 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1549 		dev_dbg(hub_dev, "local power source is %s\n",
1550 			(hubstatus & HUB_STATUS_LOCAL_POWER)
1551 			? "lost (inactive)" : "good");
1552 
1553 	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1554 		dev_dbg(hub_dev, "%sover-current condition exists\n",
1555 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1556 
1557 	/* set up the interrupt endpoint
1558 	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1559 	 * bytes as USB2.0[11.12.3] says because some hubs are known
1560 	 * to send more data (and thus cause overflow). For root hubs,
1561 	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
1562 	 * to be big enough for at least USB_MAXCHILDREN ports. */
1563 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1564 	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
1565 
1566 	if (maxp > sizeof(*hub->buffer))
1567 		maxp = sizeof(*hub->buffer);
1568 
1569 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1570 	if (!hub->urb) {
1571 		ret = -ENOMEM;
1572 		goto fail;
1573 	}
1574 
1575 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1576 		hub, endpoint->bInterval);
1577 
1578 	/* maybe cycle the hub leds */
1579 	if (hub->has_indicators && blinkenlights)
1580 		hub->indicator[0] = INDICATOR_CYCLE;
1581 
1582 	mutex_lock(&usb_port_peer_mutex);
1583 	for (i = 0; i < maxchild; i++) {
1584 		ret = usb_hub_create_port_device(hub, i + 1);
1585 		if (ret < 0) {
1586 			dev_err(hub->intfdev,
1587 				"couldn't create port%d device.\n", i + 1);
1588 			break;
1589 		}
1590 	}
1591 	hdev->maxchild = i;
1592 	mutex_unlock(&usb_port_peer_mutex);
1593 	if (ret < 0)
1594 		goto fail;
1595 
1596 	usb_hub_adjust_deviceremovable(hdev, hub->descriptor);
1597 
1598 	hub_activate(hub, HUB_INIT);
1599 	return 0;
1600 
1601 fail:
1602 	dev_err (hub_dev, "config failed, %s (err %d)\n",
1603 			message, ret);
1604 	/* hub_disconnect() frees urb and descriptor */
1605 	return ret;
1606 }
1607 
1608 static void hub_release(struct kref *kref)
1609 {
1610 	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1611 
1612 	usb_put_intf(to_usb_interface(hub->intfdev));
1613 	kfree(hub);
1614 }
1615 
1616 static unsigned highspeed_hubs;
1617 
1618 static void hub_disconnect(struct usb_interface *intf)
1619 {
1620 	struct usb_hub *hub = usb_get_intfdata(intf);
1621 	struct usb_device *hdev = interface_to_usbdev(intf);
1622 	int port1;
1623 
1624 	/* Take the hub off the event list and don't let it be added again */
1625 	spin_lock_irq(&hub_event_lock);
1626 	if (!list_empty(&hub->event_list)) {
1627 		list_del_init(&hub->event_list);
1628 		usb_autopm_put_interface_no_suspend(intf);
1629 	}
1630 	hub->disconnected = 1;
1631 	spin_unlock_irq(&hub_event_lock);
1632 
1633 	/* Disconnect all children and quiesce the hub */
1634 	hub->error = 0;
1635 	hub_quiesce(hub, HUB_DISCONNECT);
1636 
1637 	mutex_lock(&usb_port_peer_mutex);
1638 
1639 	/* Avoid races with recursively_mark_NOTATTACHED() */
1640 	spin_lock_irq(&device_state_lock);
1641 	port1 = hdev->maxchild;
1642 	hdev->maxchild = 0;
1643 	usb_set_intfdata(intf, NULL);
1644 	spin_unlock_irq(&device_state_lock);
1645 
1646 	for (; port1 > 0; --port1)
1647 		usb_hub_remove_port_device(hub, port1);
1648 
1649 	mutex_unlock(&usb_port_peer_mutex);
1650 
1651 	if (hub->hdev->speed == USB_SPEED_HIGH)
1652 		highspeed_hubs--;
1653 
1654 	usb_free_urb(hub->urb);
1655 	kfree(hub->ports);
1656 	kfree(hub->descriptor);
1657 	kfree(hub->status);
1658 	kfree(hub->buffer);
1659 
1660 	pm_suspend_ignore_children(&intf->dev, false);
1661 	kref_put(&hub->kref, hub_release);
1662 }
1663 
1664 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1665 {
1666 	struct usb_host_interface *desc;
1667 	struct usb_endpoint_descriptor *endpoint;
1668 	struct usb_device *hdev;
1669 	struct usb_hub *hub;
1670 
1671 	desc = intf->cur_altsetting;
1672 	hdev = interface_to_usbdev(intf);
1673 
1674 	/*
1675 	 * Set default autosuspend delay as 0 to speedup bus suspend,
1676 	 * based on the below considerations:
1677 	 *
1678 	 * - Unlike other drivers, the hub driver does not rely on the
1679 	 *   autosuspend delay to provide enough time to handle a wakeup
1680 	 *   event, and the submitted status URB is just to check future
1681 	 *   change on hub downstream ports, so it is safe to do it.
1682 	 *
1683 	 * - The patch might cause one or more auto supend/resume for
1684 	 *   below very rare devices when they are plugged into hub
1685 	 *   first time:
1686 	 *
1687 	 *   	devices having trouble initializing, and disconnect
1688 	 *   	themselves from the bus and then reconnect a second
1689 	 *   	or so later
1690 	 *
1691 	 *   	devices just for downloading firmware, and disconnects
1692 	 *   	themselves after completing it
1693 	 *
1694 	 *   For these quite rare devices, their drivers may change the
1695 	 *   autosuspend delay of their parent hub in the probe() to one
1696 	 *   appropriate value to avoid the subtle problem if someone
1697 	 *   does care it.
1698 	 *
1699 	 * - The patch may cause one or more auto suspend/resume on
1700 	 *   hub during running 'lsusb', but it is probably too
1701 	 *   infrequent to worry about.
1702 	 *
1703 	 * - Change autosuspend delay of hub can avoid unnecessary auto
1704 	 *   suspend timer for hub, also may decrease power consumption
1705 	 *   of USB bus.
1706 	 */
1707 	pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
1708 
1709 	/*
1710 	 * Hubs have proper suspend/resume support, except for root hubs
1711 	 * where the controller driver doesn't have bus_suspend and
1712 	 * bus_resume methods.
1713 	 */
1714 	if (hdev->parent) {		/* normal device */
1715 		usb_enable_autosuspend(hdev);
1716 	} else {			/* root hub */
1717 		const struct hc_driver *drv = bus_to_hcd(hdev->bus)->driver;
1718 
1719 		if (drv->bus_suspend && drv->bus_resume)
1720 			usb_enable_autosuspend(hdev);
1721 	}
1722 
1723 	if (hdev->level == MAX_TOPO_LEVEL) {
1724 		dev_err(&intf->dev,
1725 			"Unsupported bus topology: hub nested too deep\n");
1726 		return -E2BIG;
1727 	}
1728 
1729 #ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
1730 	if (hdev->parent) {
1731 		dev_warn(&intf->dev, "ignoring external hub\n");
1732 		return -ENODEV;
1733 	}
1734 #endif
1735 
1736 	/* Some hubs have a subclass of 1, which AFAICT according to the */
1737 	/*  specs is not defined, but it works */
1738 	if ((desc->desc.bInterfaceSubClass != 0) &&
1739 	    (desc->desc.bInterfaceSubClass != 1)) {
1740 descriptor_error:
1741 		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
1742 		return -EIO;
1743 	}
1744 
1745 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
1746 	if (desc->desc.bNumEndpoints != 1)
1747 		goto descriptor_error;
1748 
1749 	endpoint = &desc->endpoint[0].desc;
1750 
1751 	/* If it's not an interrupt in endpoint, we'd better punt! */
1752 	if (!usb_endpoint_is_int_in(endpoint))
1753 		goto descriptor_error;
1754 
1755 	/* We found a hub */
1756 	dev_info (&intf->dev, "USB hub found\n");
1757 
1758 	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1759 	if (!hub) {
1760 		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
1761 		return -ENOMEM;
1762 	}
1763 
1764 	kref_init(&hub->kref);
1765 	INIT_LIST_HEAD(&hub->event_list);
1766 	hub->intfdev = &intf->dev;
1767 	hub->hdev = hdev;
1768 	INIT_DELAYED_WORK(&hub->leds, led_work);
1769 	INIT_DELAYED_WORK(&hub->init_work, NULL);
1770 	usb_get_intf(intf);
1771 
1772 	usb_set_intfdata (intf, hub);
1773 	intf->needs_remote_wakeup = 1;
1774 	pm_suspend_ignore_children(&intf->dev, true);
1775 
1776 	if (hdev->speed == USB_SPEED_HIGH)
1777 		highspeed_hubs++;
1778 
1779 	if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
1780 		hub->quirk_check_port_auto_suspend = 1;
1781 
1782 	if (hub_configure(hub, endpoint) >= 0)
1783 		return 0;
1784 
1785 	hub_disconnect (intf);
1786 	return -ENODEV;
1787 }
1788 
1789 static int
1790 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1791 {
1792 	struct usb_device *hdev = interface_to_usbdev (intf);
1793 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1794 
1795 	/* assert ifno == 0 (part of hub spec) */
1796 	switch (code) {
1797 	case USBDEVFS_HUB_PORTINFO: {
1798 		struct usbdevfs_hub_portinfo *info = user_data;
1799 		int i;
1800 
1801 		spin_lock_irq(&device_state_lock);
1802 		if (hdev->devnum <= 0)
1803 			info->nports = 0;
1804 		else {
1805 			info->nports = hdev->maxchild;
1806 			for (i = 0; i < info->nports; i++) {
1807 				if (hub->ports[i]->child == NULL)
1808 					info->port[i] = 0;
1809 				else
1810 					info->port[i] =
1811 						hub->ports[i]->child->devnum;
1812 			}
1813 		}
1814 		spin_unlock_irq(&device_state_lock);
1815 
1816 		return info->nports + 1;
1817 		}
1818 
1819 	default:
1820 		return -ENOSYS;
1821 	}
1822 }
1823 
1824 /*
1825  * Allow user programs to claim ports on a hub.  When a device is attached
1826  * to one of these "claimed" ports, the program will "own" the device.
1827  */
1828 static int find_port_owner(struct usb_device *hdev, unsigned port1,
1829 		struct usb_dev_state ***ppowner)
1830 {
1831 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1832 
1833 	if (hdev->state == USB_STATE_NOTATTACHED)
1834 		return -ENODEV;
1835 	if (port1 == 0 || port1 > hdev->maxchild)
1836 		return -EINVAL;
1837 
1838 	/* Devices not managed by the hub driver
1839 	 * will always have maxchild equal to 0.
1840 	 */
1841 	*ppowner = &(hub->ports[port1 - 1]->port_owner);
1842 	return 0;
1843 }
1844 
1845 /* In the following three functions, the caller must hold hdev's lock */
1846 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
1847 		       struct usb_dev_state *owner)
1848 {
1849 	int rc;
1850 	struct usb_dev_state **powner;
1851 
1852 	rc = find_port_owner(hdev, port1, &powner);
1853 	if (rc)
1854 		return rc;
1855 	if (*powner)
1856 		return -EBUSY;
1857 	*powner = owner;
1858 	return rc;
1859 }
1860 EXPORT_SYMBOL_GPL(usb_hub_claim_port);
1861 
1862 int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
1863 			 struct usb_dev_state *owner)
1864 {
1865 	int rc;
1866 	struct usb_dev_state **powner;
1867 
1868 	rc = find_port_owner(hdev, port1, &powner);
1869 	if (rc)
1870 		return rc;
1871 	if (*powner != owner)
1872 		return -ENOENT;
1873 	*powner = NULL;
1874 	return rc;
1875 }
1876 EXPORT_SYMBOL_GPL(usb_hub_release_port);
1877 
1878 void usb_hub_release_all_ports(struct usb_device *hdev, struct usb_dev_state *owner)
1879 {
1880 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1881 	int n;
1882 
1883 	for (n = 0; n < hdev->maxchild; n++) {
1884 		if (hub->ports[n]->port_owner == owner)
1885 			hub->ports[n]->port_owner = NULL;
1886 	}
1887 
1888 }
1889 
1890 /* The caller must hold udev's lock */
1891 bool usb_device_is_owned(struct usb_device *udev)
1892 {
1893 	struct usb_hub *hub;
1894 
1895 	if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
1896 		return false;
1897 	hub = usb_hub_to_struct_hub(udev->parent);
1898 	return !!hub->ports[udev->portnum - 1]->port_owner;
1899 }
1900 
1901 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1902 {
1903 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
1904 	int i;
1905 
1906 	for (i = 0; i < udev->maxchild; ++i) {
1907 		if (hub->ports[i]->child)
1908 			recursively_mark_NOTATTACHED(hub->ports[i]->child);
1909 	}
1910 	if (udev->state == USB_STATE_SUSPENDED)
1911 		udev->active_duration -= jiffies;
1912 	udev->state = USB_STATE_NOTATTACHED;
1913 }
1914 
1915 /**
1916  * usb_set_device_state - change a device's current state (usbcore, hcds)
1917  * @udev: pointer to device whose state should be changed
1918  * @new_state: new state value to be stored
1919  *
1920  * udev->state is _not_ fully protected by the device lock.  Although
1921  * most transitions are made only while holding the lock, the state can
1922  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1923  * is so that devices can be marked as disconnected as soon as possible,
1924  * without having to wait for any semaphores to be released.  As a result,
1925  * all changes to any device's state must be protected by the
1926  * device_state_lock spinlock.
1927  *
1928  * Once a device has been added to the device tree, all changes to its state
1929  * should be made using this routine.  The state should _not_ be set directly.
1930  *
1931  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1932  * Otherwise udev->state is set to new_state, and if new_state is
1933  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1934  * to USB_STATE_NOTATTACHED.
1935  */
1936 void usb_set_device_state(struct usb_device *udev,
1937 		enum usb_device_state new_state)
1938 {
1939 	unsigned long flags;
1940 	int wakeup = -1;
1941 
1942 	spin_lock_irqsave(&device_state_lock, flags);
1943 	if (udev->state == USB_STATE_NOTATTACHED)
1944 		;	/* do nothing */
1945 	else if (new_state != USB_STATE_NOTATTACHED) {
1946 
1947 		/* root hub wakeup capabilities are managed out-of-band
1948 		 * and may involve silicon errata ... ignore them here.
1949 		 */
1950 		if (udev->parent) {
1951 			if (udev->state == USB_STATE_SUSPENDED
1952 					|| new_state == USB_STATE_SUSPENDED)
1953 				;	/* No change to wakeup settings */
1954 			else if (new_state == USB_STATE_CONFIGURED)
1955 				wakeup = udev->actconfig->desc.bmAttributes
1956 					 & USB_CONFIG_ATT_WAKEUP;
1957 			else
1958 				wakeup = 0;
1959 		}
1960 		if (udev->state == USB_STATE_SUSPENDED &&
1961 			new_state != USB_STATE_SUSPENDED)
1962 			udev->active_duration -= jiffies;
1963 		else if (new_state == USB_STATE_SUSPENDED &&
1964 				udev->state != USB_STATE_SUSPENDED)
1965 			udev->active_duration += jiffies;
1966 		udev->state = new_state;
1967 	} else
1968 		recursively_mark_NOTATTACHED(udev);
1969 	spin_unlock_irqrestore(&device_state_lock, flags);
1970 	if (wakeup >= 0)
1971 		device_set_wakeup_capable(&udev->dev, wakeup);
1972 }
1973 EXPORT_SYMBOL_GPL(usb_set_device_state);
1974 
1975 /*
1976  * Choose a device number.
1977  *
1978  * Device numbers are used as filenames in usbfs.  On USB-1.1 and
1979  * USB-2.0 buses they are also used as device addresses, however on
1980  * USB-3.0 buses the address is assigned by the controller hardware
1981  * and it usually is not the same as the device number.
1982  *
1983  * WUSB devices are simple: they have no hubs behind, so the mapping
1984  * device <-> virtual port number becomes 1:1. Why? to simplify the
1985  * life of the device connection logic in
1986  * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
1987  * handshake we need to assign a temporary address in the unauthorized
1988  * space. For simplicity we use the first virtual port number found to
1989  * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
1990  * and that becomes it's address [X < 128] or its unauthorized address
1991  * [X | 0x80].
1992  *
1993  * We add 1 as an offset to the one-based USB-stack port number
1994  * (zero-based wusb virtual port index) for two reasons: (a) dev addr
1995  * 0 is reserved by USB for default address; (b) Linux's USB stack
1996  * uses always #1 for the root hub of the controller. So USB stack's
1997  * port #1, which is wusb virtual-port #0 has address #2.
1998  *
1999  * Devices connected under xHCI are not as simple.  The host controller
2000  * supports virtualization, so the hardware assigns device addresses and
2001  * the HCD must setup data structures before issuing a set address
2002  * command to the hardware.
2003  */
2004 static void choose_devnum(struct usb_device *udev)
2005 {
2006 	int		devnum;
2007 	struct usb_bus	*bus = udev->bus;
2008 
2009 	/* If khubd ever becomes multithreaded, this will need a lock */
2010 	if (udev->wusb) {
2011 		devnum = udev->portnum + 1;
2012 		BUG_ON(test_bit(devnum, bus->devmap.devicemap));
2013 	} else {
2014 		/* Try to allocate the next devnum beginning at
2015 		 * bus->devnum_next. */
2016 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
2017 					    bus->devnum_next);
2018 		if (devnum >= 128)
2019 			devnum = find_next_zero_bit(bus->devmap.devicemap,
2020 						    128, 1);
2021 		bus->devnum_next = (devnum >= 127 ? 1 : devnum + 1);
2022 	}
2023 	if (devnum < 128) {
2024 		set_bit(devnum, bus->devmap.devicemap);
2025 		udev->devnum = devnum;
2026 	}
2027 }
2028 
2029 static void release_devnum(struct usb_device *udev)
2030 {
2031 	if (udev->devnum > 0) {
2032 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
2033 		udev->devnum = -1;
2034 	}
2035 }
2036 
2037 static void update_devnum(struct usb_device *udev, int devnum)
2038 {
2039 	/* The address for a WUSB device is managed by wusbcore. */
2040 	if (!udev->wusb)
2041 		udev->devnum = devnum;
2042 }
2043 
2044 static void hub_free_dev(struct usb_device *udev)
2045 {
2046 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2047 
2048 	/* Root hubs aren't real devices, so don't free HCD resources */
2049 	if (hcd->driver->free_dev && udev->parent)
2050 		hcd->driver->free_dev(hcd, udev);
2051 }
2052 
2053 static void hub_disconnect_children(struct usb_device *udev)
2054 {
2055 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2056 	int i;
2057 
2058 	/* Free up all the children before we remove this device */
2059 	for (i = 0; i < udev->maxchild; i++) {
2060 		if (hub->ports[i]->child)
2061 			usb_disconnect(&hub->ports[i]->child);
2062 	}
2063 }
2064 
2065 /**
2066  * usb_disconnect - disconnect a device (usbcore-internal)
2067  * @pdev: pointer to device being disconnected
2068  * Context: !in_interrupt ()
2069  *
2070  * Something got disconnected. Get rid of it and all of its children.
2071  *
2072  * If *pdev is a normal device then the parent hub must already be locked.
2073  * If *pdev is a root hub then the caller must hold the usb_bus_list_lock,
2074  * which protects the set of root hubs as well as the list of buses.
2075  *
2076  * Only hub drivers (including virtual root hub drivers for host
2077  * controllers) should ever call this.
2078  *
2079  * This call is synchronous, and may not be used in an interrupt context.
2080  */
2081 void usb_disconnect(struct usb_device **pdev)
2082 {
2083 	struct usb_port *port_dev = NULL;
2084 	struct usb_device *udev = *pdev;
2085 	struct usb_hub *hub;
2086 	int port1;
2087 
2088 	/* mark the device as inactive, so any further urb submissions for
2089 	 * this device (and any of its children) will fail immediately.
2090 	 * this quiesces everything except pending urbs.
2091 	 */
2092 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2093 	dev_info(&udev->dev, "USB disconnect, device number %d\n",
2094 			udev->devnum);
2095 
2096 	usb_lock_device(udev);
2097 
2098 	hub_disconnect_children(udev);
2099 
2100 	/* deallocate hcd/hardware state ... nuking all pending urbs and
2101 	 * cleaning up all state associated with the current configuration
2102 	 * so that the hardware is now fully quiesced.
2103 	 */
2104 	dev_dbg (&udev->dev, "unregistering device\n");
2105 	usb_disable_device(udev, 0);
2106 	usb_hcd_synchronize_unlinks(udev);
2107 
2108 	if (udev->parent) {
2109 		port1 = udev->portnum;
2110 		hub = usb_hub_to_struct_hub(udev->parent);
2111 		port_dev = hub->ports[port1 - 1];
2112 
2113 		sysfs_remove_link(&udev->dev.kobj, "port");
2114 		sysfs_remove_link(&port_dev->dev.kobj, "device");
2115 
2116 		/*
2117 		 * As usb_port_runtime_resume() de-references udev, make
2118 		 * sure no resumes occur during removal
2119 		 */
2120 		if (!test_and_set_bit(port1, hub->child_usage_bits))
2121 			pm_runtime_get_sync(&port_dev->dev);
2122 	}
2123 
2124 	usb_remove_ep_devs(&udev->ep0);
2125 	usb_unlock_device(udev);
2126 
2127 	/* Unregister the device.  The device driver is responsible
2128 	 * for de-configuring the device and invoking the remove-device
2129 	 * notifier chain (used by usbfs and possibly others).
2130 	 */
2131 	device_del(&udev->dev);
2132 
2133 	/* Free the device number and delete the parent's children[]
2134 	 * (or root_hub) pointer.
2135 	 */
2136 	release_devnum(udev);
2137 
2138 	/* Avoid races with recursively_mark_NOTATTACHED() */
2139 	spin_lock_irq(&device_state_lock);
2140 	*pdev = NULL;
2141 	spin_unlock_irq(&device_state_lock);
2142 
2143 	if (port_dev && test_and_clear_bit(port1, hub->child_usage_bits))
2144 		pm_runtime_put(&port_dev->dev);
2145 
2146 	hub_free_dev(udev);
2147 
2148 	put_device(&udev->dev);
2149 }
2150 
2151 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
2152 static void show_string(struct usb_device *udev, char *id, char *string)
2153 {
2154 	if (!string)
2155 		return;
2156 	dev_info(&udev->dev, "%s: %s\n", id, string);
2157 }
2158 
2159 static void announce_device(struct usb_device *udev)
2160 {
2161 	dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
2162 		le16_to_cpu(udev->descriptor.idVendor),
2163 		le16_to_cpu(udev->descriptor.idProduct));
2164 	dev_info(&udev->dev,
2165 		"New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
2166 		udev->descriptor.iManufacturer,
2167 		udev->descriptor.iProduct,
2168 		udev->descriptor.iSerialNumber);
2169 	show_string(udev, "Product", udev->product);
2170 	show_string(udev, "Manufacturer", udev->manufacturer);
2171 	show_string(udev, "SerialNumber", udev->serial);
2172 }
2173 #else
2174 static inline void announce_device(struct usb_device *udev) { }
2175 #endif
2176 
2177 #ifdef	CONFIG_USB_OTG
2178 #include "otg_whitelist.h"
2179 #endif
2180 
2181 /**
2182  * usb_enumerate_device_otg - FIXME (usbcore-internal)
2183  * @udev: newly addressed device (in ADDRESS state)
2184  *
2185  * Finish enumeration for On-The-Go devices
2186  *
2187  * Return: 0 if successful. A negative error code otherwise.
2188  */
2189 static int usb_enumerate_device_otg(struct usb_device *udev)
2190 {
2191 	int err = 0;
2192 
2193 #ifdef	CONFIG_USB_OTG
2194 	/*
2195 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
2196 	 * to wake us after we've powered off VBUS; and HNP, switching roles
2197 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
2198 	 */
2199 	if (!udev->bus->is_b_host
2200 			&& udev->config
2201 			&& udev->parent == udev->bus->root_hub) {
2202 		struct usb_otg_descriptor	*desc = NULL;
2203 		struct usb_bus			*bus = udev->bus;
2204 
2205 		/* descriptor may appear anywhere in config */
2206 		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
2207 					le16_to_cpu(udev->config[0].desc.wTotalLength),
2208 					USB_DT_OTG, (void **) &desc) == 0) {
2209 			if (desc->bmAttributes & USB_OTG_HNP) {
2210 				unsigned		port1 = udev->portnum;
2211 
2212 				dev_info(&udev->dev,
2213 					"Dual-Role OTG device on %sHNP port\n",
2214 					(port1 == bus->otg_port)
2215 						? "" : "non-");
2216 
2217 				/* enable HNP before suspend, it's simpler */
2218 				if (port1 == bus->otg_port)
2219 					bus->b_hnp_enable = 1;
2220 				err = usb_control_msg(udev,
2221 					usb_sndctrlpipe(udev, 0),
2222 					USB_REQ_SET_FEATURE, 0,
2223 					bus->b_hnp_enable
2224 						? USB_DEVICE_B_HNP_ENABLE
2225 						: USB_DEVICE_A_ALT_HNP_SUPPORT,
2226 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
2227 				if (err < 0) {
2228 					/* OTG MESSAGE: report errors here,
2229 					 * customize to match your product.
2230 					 */
2231 					dev_info(&udev->dev,
2232 						"can't set HNP mode: %d\n",
2233 						err);
2234 					bus->b_hnp_enable = 0;
2235 				}
2236 			}
2237 		}
2238 	}
2239 
2240 	if (!is_targeted(udev)) {
2241 
2242 		/* Maybe it can talk to us, though we can't talk to it.
2243 		 * (Includes HNP test device.)
2244 		 */
2245 		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
2246 			err = usb_port_suspend(udev, PMSG_SUSPEND);
2247 			if (err < 0)
2248 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
2249 		}
2250 		err = -ENOTSUPP;
2251 		goto fail;
2252 	}
2253 fail:
2254 #endif
2255 	return err;
2256 }
2257 
2258 
2259 /**
2260  * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
2261  * @udev: newly addressed device (in ADDRESS state)
2262  *
2263  * This is only called by usb_new_device() and usb_authorize_device()
2264  * and FIXME -- all comments that apply to them apply here wrt to
2265  * environment.
2266  *
2267  * If the device is WUSB and not authorized, we don't attempt to read
2268  * the string descriptors, as they will be errored out by the device
2269  * until it has been authorized.
2270  *
2271  * Return: 0 if successful. A negative error code otherwise.
2272  */
2273 static int usb_enumerate_device(struct usb_device *udev)
2274 {
2275 	int err;
2276 
2277 	if (udev->config == NULL) {
2278 		err = usb_get_configuration(udev);
2279 		if (err < 0) {
2280 			if (err != -ENODEV)
2281 				dev_err(&udev->dev, "can't read configurations, error %d\n",
2282 						err);
2283 			return err;
2284 		}
2285 	}
2286 
2287 	/* read the standard strings and cache them if present */
2288 	udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
2289 	udev->manufacturer = usb_cache_string(udev,
2290 					      udev->descriptor.iManufacturer);
2291 	udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
2292 
2293 	err = usb_enumerate_device_otg(udev);
2294 	if (err < 0)
2295 		return err;
2296 
2297 	usb_detect_interface_quirks(udev);
2298 
2299 	return 0;
2300 }
2301 
2302 static void set_usb_port_removable(struct usb_device *udev)
2303 {
2304 	struct usb_device *hdev = udev->parent;
2305 	struct usb_hub *hub;
2306 	u8 port = udev->portnum;
2307 	u16 wHubCharacteristics;
2308 	bool removable = true;
2309 
2310 	if (!hdev)
2311 		return;
2312 
2313 	hub = usb_hub_to_struct_hub(udev->parent);
2314 
2315 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2316 
2317 	if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
2318 		return;
2319 
2320 	if (hub_is_superspeed(hdev)) {
2321 		if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
2322 				& (1 << port))
2323 			removable = false;
2324 	} else {
2325 		if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
2326 			removable = false;
2327 	}
2328 
2329 	if (removable)
2330 		udev->removable = USB_DEVICE_REMOVABLE;
2331 	else
2332 		udev->removable = USB_DEVICE_FIXED;
2333 
2334 	/*
2335 	 * Platform firmware may have populated an alternative value for
2336 	 * removable.  If the parent port has a known connect_type use
2337 	 * that instead.
2338 	 */
2339 	switch (hub->ports[udev->portnum - 1]->connect_type) {
2340 	case USB_PORT_CONNECT_TYPE_HOT_PLUG:
2341 		udev->removable = USB_DEVICE_REMOVABLE;
2342 		break;
2343 	case USB_PORT_CONNECT_TYPE_HARD_WIRED:
2344 		udev->removable = USB_DEVICE_FIXED;
2345 		break;
2346 	default: /* use what was set above */
2347 		break;
2348 	}
2349 }
2350 
2351 /**
2352  * usb_new_device - perform initial device setup (usbcore-internal)
2353  * @udev: newly addressed device (in ADDRESS state)
2354  *
2355  * This is called with devices which have been detected but not fully
2356  * enumerated.  The device descriptor is available, but not descriptors
2357  * for any device configuration.  The caller must have locked either
2358  * the parent hub (if udev is a normal device) or else the
2359  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
2360  * udev has already been installed, but udev is not yet visible through
2361  * sysfs or other filesystem code.
2362  *
2363  * This call is synchronous, and may not be used in an interrupt context.
2364  *
2365  * Only the hub driver or root-hub registrar should ever call this.
2366  *
2367  * Return: Whether the device is configured properly or not. Zero if the
2368  * interface was registered with the driver core; else a negative errno
2369  * value.
2370  *
2371  */
2372 int usb_new_device(struct usb_device *udev)
2373 {
2374 	int err;
2375 
2376 	if (udev->parent) {
2377 		/* Initialize non-root-hub device wakeup to disabled;
2378 		 * device (un)configuration controls wakeup capable
2379 		 * sysfs power/wakeup controls wakeup enabled/disabled
2380 		 */
2381 		device_init_wakeup(&udev->dev, 0);
2382 	}
2383 
2384 	/* Tell the runtime-PM framework the device is active */
2385 	pm_runtime_set_active(&udev->dev);
2386 	pm_runtime_get_noresume(&udev->dev);
2387 	pm_runtime_use_autosuspend(&udev->dev);
2388 	pm_runtime_enable(&udev->dev);
2389 
2390 	/* By default, forbid autosuspend for all devices.  It will be
2391 	 * allowed for hubs during binding.
2392 	 */
2393 	usb_disable_autosuspend(udev);
2394 
2395 	err = usb_enumerate_device(udev);	/* Read descriptors */
2396 	if (err < 0)
2397 		goto fail;
2398 	dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
2399 			udev->devnum, udev->bus->busnum,
2400 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2401 	/* export the usbdev device-node for libusb */
2402 	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
2403 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2404 
2405 	/* Tell the world! */
2406 	announce_device(udev);
2407 
2408 	if (udev->serial)
2409 		add_device_randomness(udev->serial, strlen(udev->serial));
2410 	if (udev->product)
2411 		add_device_randomness(udev->product, strlen(udev->product));
2412 	if (udev->manufacturer)
2413 		add_device_randomness(udev->manufacturer,
2414 				      strlen(udev->manufacturer));
2415 
2416 	device_enable_async_suspend(&udev->dev);
2417 
2418 	/* check whether the hub or firmware marks this port as non-removable */
2419 	if (udev->parent)
2420 		set_usb_port_removable(udev);
2421 
2422 	/* Register the device.  The device driver is responsible
2423 	 * for configuring the device and invoking the add-device
2424 	 * notifier chain (used by usbfs and possibly others).
2425 	 */
2426 	err = device_add(&udev->dev);
2427 	if (err) {
2428 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
2429 		goto fail;
2430 	}
2431 
2432 	/* Create link files between child device and usb port device. */
2433 	if (udev->parent) {
2434 		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
2435 		int port1 = udev->portnum;
2436 		struct usb_port	*port_dev = hub->ports[port1 - 1];
2437 
2438 		err = sysfs_create_link(&udev->dev.kobj,
2439 				&port_dev->dev.kobj, "port");
2440 		if (err)
2441 			goto fail;
2442 
2443 		err = sysfs_create_link(&port_dev->dev.kobj,
2444 				&udev->dev.kobj, "device");
2445 		if (err) {
2446 			sysfs_remove_link(&udev->dev.kobj, "port");
2447 			goto fail;
2448 		}
2449 
2450 		if (!test_and_set_bit(port1, hub->child_usage_bits))
2451 			pm_runtime_get_sync(&port_dev->dev);
2452 	}
2453 
2454 	(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
2455 	usb_mark_last_busy(udev);
2456 	pm_runtime_put_sync_autosuspend(&udev->dev);
2457 	return err;
2458 
2459 fail:
2460 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2461 	pm_runtime_disable(&udev->dev);
2462 	pm_runtime_set_suspended(&udev->dev);
2463 	return err;
2464 }
2465 
2466 
2467 /**
2468  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
2469  * @usb_dev: USB device
2470  *
2471  * Move the USB device to a very basic state where interfaces are disabled
2472  * and the device is in fact unconfigured and unusable.
2473  *
2474  * We share a lock (that we have) with device_del(), so we need to
2475  * defer its call.
2476  *
2477  * Return: 0.
2478  */
2479 int usb_deauthorize_device(struct usb_device *usb_dev)
2480 {
2481 	usb_lock_device(usb_dev);
2482 	if (usb_dev->authorized == 0)
2483 		goto out_unauthorized;
2484 
2485 	usb_dev->authorized = 0;
2486 	usb_set_configuration(usb_dev, -1);
2487 
2488 out_unauthorized:
2489 	usb_unlock_device(usb_dev);
2490 	return 0;
2491 }
2492 
2493 
2494 int usb_authorize_device(struct usb_device *usb_dev)
2495 {
2496 	int result = 0, c;
2497 
2498 	usb_lock_device(usb_dev);
2499 	if (usb_dev->authorized == 1)
2500 		goto out_authorized;
2501 
2502 	result = usb_autoresume_device(usb_dev);
2503 	if (result < 0) {
2504 		dev_err(&usb_dev->dev,
2505 			"can't autoresume for authorization: %d\n", result);
2506 		goto error_autoresume;
2507 	}
2508 	result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
2509 	if (result < 0) {
2510 		dev_err(&usb_dev->dev, "can't re-read device descriptor for "
2511 			"authorization: %d\n", result);
2512 		goto error_device_descriptor;
2513 	}
2514 
2515 	usb_dev->authorized = 1;
2516 	/* Choose and set the configuration.  This registers the interfaces
2517 	 * with the driver core and lets interface drivers bind to them.
2518 	 */
2519 	c = usb_choose_configuration(usb_dev);
2520 	if (c >= 0) {
2521 		result = usb_set_configuration(usb_dev, c);
2522 		if (result) {
2523 			dev_err(&usb_dev->dev,
2524 				"can't set config #%d, error %d\n", c, result);
2525 			/* This need not be fatal.  The user can try to
2526 			 * set other configurations. */
2527 		}
2528 	}
2529 	dev_info(&usb_dev->dev, "authorized to connect\n");
2530 
2531 error_device_descriptor:
2532 	usb_autosuspend_device(usb_dev);
2533 error_autoresume:
2534 out_authorized:
2535 	usb_unlock_device(usb_dev);	/* complements locktree */
2536 	return result;
2537 }
2538 
2539 
2540 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
2541 static unsigned hub_is_wusb(struct usb_hub *hub)
2542 {
2543 	struct usb_hcd *hcd;
2544 	if (hub->hdev->parent != NULL)  /* not a root hub? */
2545 		return 0;
2546 	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
2547 	return hcd->wireless;
2548 }
2549 
2550 
2551 #define PORT_RESET_TRIES	5
2552 #define SET_ADDRESS_TRIES	2
2553 #define GET_DESCRIPTOR_TRIES	2
2554 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
2555 #define USE_NEW_SCHEME(i)	((i) / 2 == (int)old_scheme_first)
2556 
2557 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
2558 #define HUB_SHORT_RESET_TIME	10
2559 #define HUB_BH_RESET_TIME	50
2560 #define HUB_LONG_RESET_TIME	200
2561 #define HUB_RESET_TIMEOUT	800
2562 
2563 /*
2564  * "New scheme" enumeration causes an extra state transition to be
2565  * exposed to an xhci host and causes USB3 devices to receive control
2566  * commands in the default state.  This has been seen to cause
2567  * enumeration failures, so disable this enumeration scheme for USB3
2568  * devices.
2569  */
2570 static bool use_new_scheme(struct usb_device *udev, int retry)
2571 {
2572 	if (udev->speed == USB_SPEED_SUPER)
2573 		return false;
2574 
2575 	return USE_NEW_SCHEME(retry);
2576 }
2577 
2578 static int hub_port_reset(struct usb_hub *hub, int port1,
2579 			struct usb_device *udev, unsigned int delay, bool warm);
2580 
2581 /* Is a USB 3.0 port in the Inactive or Compliance Mode state?
2582  * Port worm reset is required to recover
2583  */
2584 static bool hub_port_warm_reset_required(struct usb_hub *hub, u16 portstatus)
2585 {
2586 	return hub_is_superspeed(hub->hdev) &&
2587 		(((portstatus & USB_PORT_STAT_LINK_STATE) ==
2588 		  USB_SS_PORT_LS_SS_INACTIVE) ||
2589 		 ((portstatus & USB_PORT_STAT_LINK_STATE) ==
2590 		  USB_SS_PORT_LS_COMP_MOD)) ;
2591 }
2592 
2593 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
2594 			struct usb_device *udev, unsigned int delay, bool warm)
2595 {
2596 	int delay_time, ret;
2597 	u16 portstatus;
2598 	u16 portchange;
2599 
2600 	for (delay_time = 0;
2601 			delay_time < HUB_RESET_TIMEOUT;
2602 			delay_time += delay) {
2603 		/* wait to give the device a chance to reset */
2604 		msleep(delay);
2605 
2606 		/* read and decode port status */
2607 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
2608 		if (ret < 0)
2609 			return ret;
2610 
2611 		/* The port state is unknown until the reset completes. */
2612 		if (!(portstatus & USB_PORT_STAT_RESET))
2613 			break;
2614 
2615 		/* switch to the long delay after two short delay failures */
2616 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2617 			delay = HUB_LONG_RESET_TIME;
2618 
2619 		dev_dbg(&hub->ports[port1 - 1]->dev,
2620 				"not %sreset yet, waiting %dms\n",
2621 				warm ? "warm " : "", delay);
2622 	}
2623 
2624 	if ((portstatus & USB_PORT_STAT_RESET))
2625 		return -EBUSY;
2626 
2627 	if (hub_port_warm_reset_required(hub, portstatus))
2628 		return -ENOTCONN;
2629 
2630 	/* Device went away? */
2631 	if (!(portstatus & USB_PORT_STAT_CONNECTION))
2632 		return -ENOTCONN;
2633 
2634 	/* bomb out completely if the connection bounced.  A USB 3.0
2635 	 * connection may bounce if multiple warm resets were issued,
2636 	 * but the device may have successfully re-connected. Ignore it.
2637 	 */
2638 	if (!hub_is_superspeed(hub->hdev) &&
2639 			(portchange & USB_PORT_STAT_C_CONNECTION))
2640 		return -ENOTCONN;
2641 
2642 	if (!(portstatus & USB_PORT_STAT_ENABLE))
2643 		return -EBUSY;
2644 
2645 	if (!udev)
2646 		return 0;
2647 
2648 	if (hub_is_wusb(hub))
2649 		udev->speed = USB_SPEED_WIRELESS;
2650 	else if (hub_is_superspeed(hub->hdev))
2651 		udev->speed = USB_SPEED_SUPER;
2652 	else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2653 		udev->speed = USB_SPEED_HIGH;
2654 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2655 		udev->speed = USB_SPEED_LOW;
2656 	else
2657 		udev->speed = USB_SPEED_FULL;
2658 	return 0;
2659 }
2660 
2661 static void hub_port_finish_reset(struct usb_hub *hub, int port1,
2662 			struct usb_device *udev, int *status)
2663 {
2664 	switch (*status) {
2665 	case 0:
2666 		/* TRSTRCY = 10 ms; plus some extra */
2667 		msleep(10 + 40);
2668 		if (udev) {
2669 			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2670 
2671 			update_devnum(udev, 0);
2672 			/* The xHC may think the device is already reset,
2673 			 * so ignore the status.
2674 			 */
2675 			if (hcd->driver->reset_device)
2676 				hcd->driver->reset_device(hcd, udev);
2677 		}
2678 		/* FALL THROUGH */
2679 	case -ENOTCONN:
2680 	case -ENODEV:
2681 		usb_clear_port_feature(hub->hdev,
2682 				port1, USB_PORT_FEAT_C_RESET);
2683 		if (hub_is_superspeed(hub->hdev)) {
2684 			usb_clear_port_feature(hub->hdev, port1,
2685 					USB_PORT_FEAT_C_BH_PORT_RESET);
2686 			usb_clear_port_feature(hub->hdev, port1,
2687 					USB_PORT_FEAT_C_PORT_LINK_STATE);
2688 			usb_clear_port_feature(hub->hdev, port1,
2689 					USB_PORT_FEAT_C_CONNECTION);
2690 		}
2691 		if (udev)
2692 			usb_set_device_state(udev, *status
2693 					? USB_STATE_NOTATTACHED
2694 					: USB_STATE_DEFAULT);
2695 		break;
2696 	}
2697 }
2698 
2699 /* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
2700 static int hub_port_reset(struct usb_hub *hub, int port1,
2701 			struct usb_device *udev, unsigned int delay, bool warm)
2702 {
2703 	int i, status;
2704 	u16 portchange, portstatus;
2705 	struct usb_port *port_dev = hub->ports[port1 - 1];
2706 
2707 	if (!hub_is_superspeed(hub->hdev)) {
2708 		if (warm) {
2709 			dev_err(hub->intfdev, "only USB3 hub support "
2710 						"warm reset\n");
2711 			return -EINVAL;
2712 		}
2713 		/* Block EHCI CF initialization during the port reset.
2714 		 * Some companion controllers don't like it when they mix.
2715 		 */
2716 		down_read(&ehci_cf_port_reset_rwsem);
2717 	} else if (!warm) {
2718 		/*
2719 		 * If the caller hasn't explicitly requested a warm reset,
2720 		 * double check and see if one is needed.
2721 		 */
2722 		status = hub_port_status(hub, port1,
2723 					&portstatus, &portchange);
2724 		if (status < 0)
2725 			goto done;
2726 
2727 		if (hub_port_warm_reset_required(hub, portstatus))
2728 			warm = true;
2729 	}
2730 
2731 	/* Reset the port */
2732 	for (i = 0; i < PORT_RESET_TRIES; i++) {
2733 		status = set_port_feature(hub->hdev, port1, (warm ?
2734 					USB_PORT_FEAT_BH_PORT_RESET :
2735 					USB_PORT_FEAT_RESET));
2736 		if (status == -ENODEV) {
2737 			;	/* The hub is gone */
2738 		} else if (status) {
2739 			dev_err(&port_dev->dev,
2740 					"cannot %sreset (err = %d)\n",
2741 					warm ? "warm " : "", status);
2742 		} else {
2743 			status = hub_port_wait_reset(hub, port1, udev, delay,
2744 								warm);
2745 			if (status && status != -ENOTCONN && status != -ENODEV)
2746 				dev_dbg(hub->intfdev,
2747 						"port_wait_reset: err = %d\n",
2748 						status);
2749 		}
2750 
2751 		/* Check for disconnect or reset */
2752 		if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
2753 			hub_port_finish_reset(hub, port1, udev, &status);
2754 
2755 			if (!hub_is_superspeed(hub->hdev))
2756 				goto done;
2757 
2758 			/*
2759 			 * If a USB 3.0 device migrates from reset to an error
2760 			 * state, re-issue the warm reset.
2761 			 */
2762 			if (hub_port_status(hub, port1,
2763 					&portstatus, &portchange) < 0)
2764 				goto done;
2765 
2766 			if (!hub_port_warm_reset_required(hub, portstatus))
2767 				goto done;
2768 
2769 			/*
2770 			 * If the port is in SS.Inactive or Compliance Mode, the
2771 			 * hot or warm reset failed.  Try another warm reset.
2772 			 */
2773 			if (!warm) {
2774 				dev_dbg(&port_dev->dev,
2775 						"hot reset failed, warm reset\n");
2776 				warm = true;
2777 			}
2778 		}
2779 
2780 		dev_dbg(&port_dev->dev,
2781 				"not enabled, trying %sreset again...\n",
2782 				warm ? "warm " : "");
2783 		delay = HUB_LONG_RESET_TIME;
2784 	}
2785 
2786 	dev_err(&port_dev->dev, "Cannot enable. Maybe the USB cable is bad?\n");
2787 
2788 done:
2789 	if (!hub_is_superspeed(hub->hdev))
2790 		up_read(&ehci_cf_port_reset_rwsem);
2791 
2792 	return status;
2793 }
2794 
2795 /* Check if a port is power on */
2796 static int port_is_power_on(struct usb_hub *hub, unsigned portstatus)
2797 {
2798 	int ret = 0;
2799 
2800 	if (hub_is_superspeed(hub->hdev)) {
2801 		if (portstatus & USB_SS_PORT_STAT_POWER)
2802 			ret = 1;
2803 	} else {
2804 		if (portstatus & USB_PORT_STAT_POWER)
2805 			ret = 1;
2806 	}
2807 
2808 	return ret;
2809 }
2810 
2811 static void usb_lock_port(struct usb_port *port_dev)
2812 		__acquires(&port_dev->status_lock)
2813 {
2814 	mutex_lock(&port_dev->status_lock);
2815 	__acquire(&port_dev->status_lock);
2816 }
2817 
2818 static void usb_unlock_port(struct usb_port *port_dev)
2819 		__releases(&port_dev->status_lock)
2820 {
2821 	mutex_unlock(&port_dev->status_lock);
2822 	__release(&port_dev->status_lock);
2823 }
2824 
2825 #ifdef	CONFIG_PM
2826 
2827 /* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
2828 static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
2829 {
2830 	int ret = 0;
2831 
2832 	if (hub_is_superspeed(hub->hdev)) {
2833 		if ((portstatus & USB_PORT_STAT_LINK_STATE)
2834 				== USB_SS_PORT_LS_U3)
2835 			ret = 1;
2836 	} else {
2837 		if (portstatus & USB_PORT_STAT_SUSPEND)
2838 			ret = 1;
2839 	}
2840 
2841 	return ret;
2842 }
2843 
2844 /* Determine whether the device on a port is ready for a normal resume,
2845  * is ready for a reset-resume, or should be disconnected.
2846  */
2847 static int check_port_resume_type(struct usb_device *udev,
2848 		struct usb_hub *hub, int port1,
2849 		int status, unsigned portchange, unsigned portstatus)
2850 {
2851 	struct usb_port *port_dev = hub->ports[port1 - 1];
2852 
2853 	/* Is the device still present? */
2854 	if (status || port_is_suspended(hub, portstatus) ||
2855 			!port_is_power_on(hub, portstatus) ||
2856 			!(portstatus & USB_PORT_STAT_CONNECTION)) {
2857 		if (status >= 0)
2858 			status = -ENODEV;
2859 	}
2860 
2861 	/* Can't do a normal resume if the port isn't enabled,
2862 	 * so try a reset-resume instead.
2863 	 */
2864 	else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
2865 		if (udev->persist_enabled)
2866 			udev->reset_resume = 1;
2867 		else
2868 			status = -ENODEV;
2869 	}
2870 
2871 	if (status) {
2872 		dev_dbg(&port_dev->dev, "status %04x.%04x after resume, %d\n",
2873 				portchange, portstatus, status);
2874 	} else if (udev->reset_resume) {
2875 
2876 		/* Late port handoff can set status-change bits */
2877 		if (portchange & USB_PORT_STAT_C_CONNECTION)
2878 			usb_clear_port_feature(hub->hdev, port1,
2879 					USB_PORT_FEAT_C_CONNECTION);
2880 		if (portchange & USB_PORT_STAT_C_ENABLE)
2881 			usb_clear_port_feature(hub->hdev, port1,
2882 					USB_PORT_FEAT_C_ENABLE);
2883 	}
2884 
2885 	return status;
2886 }
2887 
2888 int usb_disable_ltm(struct usb_device *udev)
2889 {
2890 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2891 
2892 	/* Check if the roothub and device supports LTM. */
2893 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2894 			!usb_device_supports_ltm(udev))
2895 		return 0;
2896 
2897 	/* Clear Feature LTM Enable can only be sent if the device is
2898 	 * configured.
2899 	 */
2900 	if (!udev->actconfig)
2901 		return 0;
2902 
2903 	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2904 			USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2905 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2906 			USB_CTRL_SET_TIMEOUT);
2907 }
2908 EXPORT_SYMBOL_GPL(usb_disable_ltm);
2909 
2910 void usb_enable_ltm(struct usb_device *udev)
2911 {
2912 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2913 
2914 	/* Check if the roothub and device supports LTM. */
2915 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2916 			!usb_device_supports_ltm(udev))
2917 		return;
2918 
2919 	/* Set Feature LTM Enable can only be sent if the device is
2920 	 * configured.
2921 	 */
2922 	if (!udev->actconfig)
2923 		return;
2924 
2925 	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2926 			USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2927 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2928 			USB_CTRL_SET_TIMEOUT);
2929 }
2930 EXPORT_SYMBOL_GPL(usb_enable_ltm);
2931 
2932 /*
2933  * usb_enable_remote_wakeup - enable remote wakeup for a device
2934  * @udev: target device
2935  *
2936  * For USB-2 devices: Set the device's remote wakeup feature.
2937  *
2938  * For USB-3 devices: Assume there's only one function on the device and
2939  * enable remote wake for the first interface.  FIXME if the interface
2940  * association descriptor shows there's more than one function.
2941  */
2942 static int usb_enable_remote_wakeup(struct usb_device *udev)
2943 {
2944 	if (udev->speed < USB_SPEED_SUPER)
2945 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2946 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2947 				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
2948 				USB_CTRL_SET_TIMEOUT);
2949 	else
2950 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2951 				USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
2952 				USB_INTRF_FUNC_SUSPEND,
2953 				USB_INTRF_FUNC_SUSPEND_RW |
2954 					USB_INTRF_FUNC_SUSPEND_LP,
2955 				NULL, 0, USB_CTRL_SET_TIMEOUT);
2956 }
2957 
2958 /*
2959  * usb_disable_remote_wakeup - disable remote wakeup for a device
2960  * @udev: target device
2961  *
2962  * For USB-2 devices: Clear the device's remote wakeup feature.
2963  *
2964  * For USB-3 devices: Assume there's only one function on the device and
2965  * disable remote wake for the first interface.  FIXME if the interface
2966  * association descriptor shows there's more than one function.
2967  */
2968 static int usb_disable_remote_wakeup(struct usb_device *udev)
2969 {
2970 	if (udev->speed < USB_SPEED_SUPER)
2971 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2972 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2973 				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
2974 				USB_CTRL_SET_TIMEOUT);
2975 	else
2976 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2977 				USB_REQ_CLEAR_FEATURE, USB_RECIP_INTERFACE,
2978 				USB_INTRF_FUNC_SUSPEND,	0, NULL, 0,
2979 				USB_CTRL_SET_TIMEOUT);
2980 }
2981 
2982 /* Count of wakeup-enabled devices at or below udev */
2983 static unsigned wakeup_enabled_descendants(struct usb_device *udev)
2984 {
2985 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2986 
2987 	return udev->do_remote_wakeup +
2988 			(hub ? hub->wakeup_enabled_descendants : 0);
2989 }
2990 
2991 /*
2992  * usb_port_suspend - suspend a usb device's upstream port
2993  * @udev: device that's no longer in active use, not a root hub
2994  * Context: must be able to sleep; device not locked; pm locks held
2995  *
2996  * Suspends a USB device that isn't in active use, conserving power.
2997  * Devices may wake out of a suspend, if anything important happens,
2998  * using the remote wakeup mechanism.  They may also be taken out of
2999  * suspend by the host, using usb_port_resume().  It's also routine
3000  * to disconnect devices while they are suspended.
3001  *
3002  * This only affects the USB hardware for a device; its interfaces
3003  * (and, for hubs, child devices) must already have been suspended.
3004  *
3005  * Selective port suspend reduces power; most suspended devices draw
3006  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
3007  * All devices below the suspended port are also suspended.
3008  *
3009  * Devices leave suspend state when the host wakes them up.  Some devices
3010  * also support "remote wakeup", where the device can activate the USB
3011  * tree above them to deliver data, such as a keypress or packet.  In
3012  * some cases, this wakes the USB host.
3013  *
3014  * Suspending OTG devices may trigger HNP, if that's been enabled
3015  * between a pair of dual-role devices.  That will change roles, such
3016  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
3017  *
3018  * Devices on USB hub ports have only one "suspend" state, corresponding
3019  * to ACPI D2, "may cause the device to lose some context".
3020  * State transitions include:
3021  *
3022  *   - suspend, resume ... when the VBUS power link stays live
3023  *   - suspend, disconnect ... VBUS lost
3024  *
3025  * Once VBUS drop breaks the circuit, the port it's using has to go through
3026  * normal re-enumeration procedures, starting with enabling VBUS power.
3027  * Other than re-initializing the hub (plug/unplug, except for root hubs),
3028  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
3029  * timer, no SRP, no requests through sysfs.
3030  *
3031  * If Runtime PM isn't enabled or used, non-SuperSpeed devices may not get
3032  * suspended until their bus goes into global suspend (i.e., the root
3033  * hub is suspended).  Nevertheless, we change @udev->state to
3034  * USB_STATE_SUSPENDED as this is the device's "logical" state.  The actual
3035  * upstream port setting is stored in @udev->port_is_suspended.
3036  *
3037  * Returns 0 on success, else negative errno.
3038  */
3039 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
3040 {
3041 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3042 	struct usb_port *port_dev = hub->ports[udev->portnum - 1];
3043 	int		port1 = udev->portnum;
3044 	int		status;
3045 	bool		really_suspend = true;
3046 
3047 	usb_lock_port(port_dev);
3048 
3049 	/* enable remote wakeup when appropriate; this lets the device
3050 	 * wake up the upstream hub (including maybe the root hub).
3051 	 *
3052 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
3053 	 * we don't explicitly enable it here.
3054 	 */
3055 	if (udev->do_remote_wakeup) {
3056 		status = usb_enable_remote_wakeup(udev);
3057 		if (status) {
3058 			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
3059 					status);
3060 			/* bail if autosuspend is requested */
3061 			if (PMSG_IS_AUTO(msg))
3062 				goto err_wakeup;
3063 		}
3064 	}
3065 
3066 	/* disable USB2 hardware LPM */
3067 	if (udev->usb2_hw_lpm_enabled == 1)
3068 		usb_set_usb2_hardware_lpm(udev, 0);
3069 
3070 	if (usb_disable_ltm(udev)) {
3071 		dev_err(&udev->dev, "Failed to disable LTM before suspend\n.");
3072 		status = -ENOMEM;
3073 		if (PMSG_IS_AUTO(msg))
3074 			goto err_ltm;
3075 	}
3076 	if (usb_unlocked_disable_lpm(udev)) {
3077 		dev_err(&udev->dev, "Failed to disable LPM before suspend\n.");
3078 		status = -ENOMEM;
3079 		if (PMSG_IS_AUTO(msg))
3080 			goto err_lpm3;
3081 	}
3082 
3083 	/* see 7.1.7.6 */
3084 	if (hub_is_superspeed(hub->hdev))
3085 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);
3086 
3087 	/*
3088 	 * For system suspend, we do not need to enable the suspend feature
3089 	 * on individual USB-2 ports.  The devices will automatically go
3090 	 * into suspend a few ms after the root hub stops sending packets.
3091 	 * The USB 2.0 spec calls this "global suspend".
3092 	 *
3093 	 * However, many USB hubs have a bug: They don't relay wakeup requests
3094 	 * from a downstream port if the port's suspend feature isn't on.
3095 	 * Therefore we will turn on the suspend feature if udev or any of its
3096 	 * descendants is enabled for remote wakeup.
3097 	 */
3098 	else if (PMSG_IS_AUTO(msg) || wakeup_enabled_descendants(udev) > 0)
3099 		status = set_port_feature(hub->hdev, port1,
3100 				USB_PORT_FEAT_SUSPEND);
3101 	else {
3102 		really_suspend = false;
3103 		status = 0;
3104 	}
3105 	if (status) {
3106 		dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
3107 
3108 		/* Try to enable USB3 LPM and LTM again */
3109 		usb_unlocked_enable_lpm(udev);
3110  err_lpm3:
3111 		usb_enable_ltm(udev);
3112  err_ltm:
3113 		/* Try to enable USB2 hardware LPM again */
3114 		if (udev->usb2_hw_lpm_capable == 1)
3115 			usb_set_usb2_hardware_lpm(udev, 1);
3116 
3117 		if (udev->do_remote_wakeup)
3118 			(void) usb_disable_remote_wakeup(udev);
3119  err_wakeup:
3120 
3121 		/* System sleep transitions should never fail */
3122 		if (!PMSG_IS_AUTO(msg))
3123 			status = 0;
3124 	} else {
3125 		dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
3126 				(PMSG_IS_AUTO(msg) ? "auto-" : ""),
3127 				udev->do_remote_wakeup);
3128 		if (really_suspend) {
3129 			udev->port_is_suspended = 1;
3130 
3131 			/* device has up to 10 msec to fully suspend */
3132 			msleep(10);
3133 		}
3134 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
3135 	}
3136 
3137 	if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled
3138 			&& test_and_clear_bit(port1, hub->child_usage_bits))
3139 		pm_runtime_put_sync(&port_dev->dev);
3140 
3141 	usb_mark_last_busy(hub->hdev);
3142 
3143 	usb_unlock_port(port_dev);
3144 	return status;
3145 }
3146 
3147 /*
3148  * If the USB "suspend" state is in use (rather than "global suspend"),
3149  * many devices will be individually taken out of suspend state using
3150  * special "resume" signaling.  This routine kicks in shortly after
3151  * hardware resume signaling is finished, either because of selective
3152  * resume (by host) or remote wakeup (by device) ... now see what changed
3153  * in the tree that's rooted at this device.
3154  *
3155  * If @udev->reset_resume is set then the device is reset before the
3156  * status check is done.
3157  */
3158 static int finish_port_resume(struct usb_device *udev)
3159 {
3160 	int	status = 0;
3161 	u16	devstatus = 0;
3162 
3163 	/* caller owns the udev device lock */
3164 	dev_dbg(&udev->dev, "%s\n",
3165 		udev->reset_resume ? "finish reset-resume" : "finish resume");
3166 
3167 	/* usb ch9 identifies four variants of SUSPENDED, based on what
3168 	 * state the device resumes to.  Linux currently won't see the
3169 	 * first two on the host side; they'd be inside hub_port_init()
3170 	 * during many timeouts, but khubd can't suspend until later.
3171 	 */
3172 	usb_set_device_state(udev, udev->actconfig
3173 			? USB_STATE_CONFIGURED
3174 			: USB_STATE_ADDRESS);
3175 
3176 	/* 10.5.4.5 says not to reset a suspended port if the attached
3177 	 * device is enabled for remote wakeup.  Hence the reset
3178 	 * operation is carried out here, after the port has been
3179 	 * resumed.
3180 	 */
3181 	if (udev->reset_resume) {
3182 		/*
3183 		 * If the device morphs or switches modes when it is reset,
3184 		 * we don't want to perform a reset-resume.  We'll fail the
3185 		 * resume, which will cause a logical disconnect, and then
3186 		 * the device will be rediscovered.
3187 		 */
3188  retry_reset_resume:
3189 		if (udev->quirks & USB_QUIRK_RESET)
3190 			status = -ENODEV;
3191 		else
3192 			status = usb_reset_and_verify_device(udev);
3193 	}
3194 
3195 	/* 10.5.4.5 says be sure devices in the tree are still there.
3196 	 * For now let's assume the device didn't go crazy on resume,
3197 	 * and device drivers will know about any resume quirks.
3198 	 */
3199 	if (status == 0) {
3200 		devstatus = 0;
3201 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3202 
3203 		/* If a normal resume failed, try doing a reset-resume */
3204 		if (status && !udev->reset_resume && udev->persist_enabled) {
3205 			dev_dbg(&udev->dev, "retry with reset-resume\n");
3206 			udev->reset_resume = 1;
3207 			goto retry_reset_resume;
3208 		}
3209 	}
3210 
3211 	if (status) {
3212 		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
3213 				status);
3214 	/*
3215 	 * There are a few quirky devices which violate the standard
3216 	 * by claiming to have remote wakeup enabled after a reset,
3217 	 * which crash if the feature is cleared, hence check for
3218 	 * udev->reset_resume
3219 	 */
3220 	} else if (udev->actconfig && !udev->reset_resume) {
3221 		if (udev->speed < USB_SPEED_SUPER) {
3222 			if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3223 				status = usb_disable_remote_wakeup(udev);
3224 		} else {
3225 			status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
3226 					&devstatus);
3227 			if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3228 					| USB_INTRF_STAT_FUNC_RW))
3229 				status = usb_disable_remote_wakeup(udev);
3230 		}
3231 
3232 		if (status)
3233 			dev_dbg(&udev->dev,
3234 				"disable remote wakeup, status %d\n",
3235 				status);
3236 		status = 0;
3237 	}
3238 	return status;
3239 }
3240 
3241 /*
3242  * usb_port_resume - re-activate a suspended usb device's upstream port
3243  * @udev: device to re-activate, not a root hub
3244  * Context: must be able to sleep; device not locked; pm locks held
3245  *
3246  * This will re-activate the suspended device, increasing power usage
3247  * while letting drivers communicate again with its endpoints.
3248  * USB resume explicitly guarantees that the power session between
3249  * the host and the device is the same as it was when the device
3250  * suspended.
3251  *
3252  * If @udev->reset_resume is set then this routine won't check that the
3253  * port is still enabled.  Furthermore, finish_port_resume() above will
3254  * reset @udev.  The end result is that a broken power session can be
3255  * recovered and @udev will appear to persist across a loss of VBUS power.
3256  *
3257  * For example, if a host controller doesn't maintain VBUS suspend current
3258  * during a system sleep or is reset when the system wakes up, all the USB
3259  * power sessions below it will be broken.  This is especially troublesome
3260  * for mass-storage devices containing mounted filesystems, since the
3261  * device will appear to have disconnected and all the memory mappings
3262  * to it will be lost.  Using the USB_PERSIST facility, the device can be
3263  * made to appear as if it had not disconnected.
3264  *
3265  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
3266  * every effort to insure that the same device is present after the
3267  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
3268  * quite possible for a device to remain unaltered but its media to be
3269  * changed.  If the user replaces a flash memory card while the system is
3270  * asleep, he will have only himself to blame when the filesystem on the
3271  * new card is corrupted and the system crashes.
3272  *
3273  * Returns 0 on success, else negative errno.
3274  */
3275 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
3276 {
3277 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3278 	struct usb_port *port_dev = hub->ports[udev->portnum  - 1];
3279 	int		port1 = udev->portnum;
3280 	int		status;
3281 	u16		portchange, portstatus;
3282 
3283 	if (!test_and_set_bit(port1, hub->child_usage_bits)) {
3284 		status = pm_runtime_get_sync(&port_dev->dev);
3285 		if (status < 0) {
3286 			dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
3287 					status);
3288 			return status;
3289 		}
3290 	}
3291 
3292 	usb_lock_port(port_dev);
3293 
3294 	/* Skip the initial Clear-Suspend step for a remote wakeup */
3295 	status = hub_port_status(hub, port1, &portstatus, &portchange);
3296 	if (status == 0 && !port_is_suspended(hub, portstatus))
3297 		goto SuspendCleared;
3298 
3299 	/* see 7.1.7.7; affects power usage, but not budgeting */
3300 	if (hub_is_superspeed(hub->hdev))
3301 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
3302 	else
3303 		status = usb_clear_port_feature(hub->hdev,
3304 				port1, USB_PORT_FEAT_SUSPEND);
3305 	if (status) {
3306 		dev_dbg(&port_dev->dev, "can't resume, status %d\n", status);
3307 	} else {
3308 		/* drive resume for at least 20 msec */
3309 		dev_dbg(&udev->dev, "usb %sresume\n",
3310 				(PMSG_IS_AUTO(msg) ? "auto-" : ""));
3311 		msleep(25);
3312 
3313 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
3314 		 * stop resume signaling.  Then finish the resume
3315 		 * sequence.
3316 		 */
3317 		status = hub_port_status(hub, port1, &portstatus, &portchange);
3318 
3319 		/* TRSMRCY = 10 msec */
3320 		msleep(10);
3321 	}
3322 
3323  SuspendCleared:
3324 	if (status == 0) {
3325 		udev->port_is_suspended = 0;
3326 		if (hub_is_superspeed(hub->hdev)) {
3327 			if (portchange & USB_PORT_STAT_C_LINK_STATE)
3328 				usb_clear_port_feature(hub->hdev, port1,
3329 					USB_PORT_FEAT_C_PORT_LINK_STATE);
3330 		} else {
3331 			if (portchange & USB_PORT_STAT_C_SUSPEND)
3332 				usb_clear_port_feature(hub->hdev, port1,
3333 						USB_PORT_FEAT_C_SUSPEND);
3334 		}
3335 	}
3336 
3337 	status = check_port_resume_type(udev,
3338 			hub, port1, status, portchange, portstatus);
3339 	if (status == 0)
3340 		status = finish_port_resume(udev);
3341 	if (status < 0) {
3342 		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
3343 		hub_port_logical_disconnect(hub, port1);
3344 	} else  {
3345 		/* Try to enable USB2 hardware LPM */
3346 		if (udev->usb2_hw_lpm_capable == 1)
3347 			usb_set_usb2_hardware_lpm(udev, 1);
3348 
3349 		/* Try to enable USB3 LTM and LPM */
3350 		usb_enable_ltm(udev);
3351 		usb_unlocked_enable_lpm(udev);
3352 	}
3353 
3354 	usb_unlock_port(port_dev);
3355 
3356 	return status;
3357 }
3358 
3359 #ifdef	CONFIG_PM_RUNTIME
3360 
3361 int usb_remote_wakeup(struct usb_device *udev)
3362 {
3363 	int	status = 0;
3364 
3365 	usb_lock_device(udev);
3366 	if (udev->state == USB_STATE_SUSPENDED) {
3367 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
3368 		status = usb_autoresume_device(udev);
3369 		if (status == 0) {
3370 			/* Let the drivers do their thing, then... */
3371 			usb_autosuspend_device(udev);
3372 		}
3373 	}
3374 	usb_unlock_device(udev);
3375 	return status;
3376 }
3377 
3378 /* Returns 1 if there was a remote wakeup and a connect status change. */
3379 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
3380 		u16 portstatus, u16 portchange)
3381 		__must_hold(&port_dev->status_lock)
3382 {
3383 	struct usb_port *port_dev = hub->ports[port - 1];
3384 	struct usb_device *hdev;
3385 	struct usb_device *udev;
3386 	int connect_change = 0;
3387 	int ret;
3388 
3389 	hdev = hub->hdev;
3390 	udev = port_dev->child;
3391 	if (!hub_is_superspeed(hdev)) {
3392 		if (!(portchange & USB_PORT_STAT_C_SUSPEND))
3393 			return 0;
3394 		usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
3395 	} else {
3396 		if (!udev || udev->state != USB_STATE_SUSPENDED ||
3397 				 (portstatus & USB_PORT_STAT_LINK_STATE) !=
3398 				 USB_SS_PORT_LS_U0)
3399 			return 0;
3400 	}
3401 
3402 	if (udev) {
3403 		/* TRSMRCY = 10 msec */
3404 		msleep(10);
3405 
3406 		usb_unlock_port(port_dev);
3407 		ret = usb_remote_wakeup(udev);
3408 		usb_lock_port(port_dev);
3409 		if (ret < 0)
3410 			connect_change = 1;
3411 	} else {
3412 		ret = -ENODEV;
3413 		hub_port_disable(hub, port, 1);
3414 	}
3415 	dev_dbg(&port_dev->dev, "resume, status %d\n", ret);
3416 	return connect_change;
3417 }
3418 
3419 #else
3420 
3421 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
3422 		u16 portstatus, u16 portchange)
3423 {
3424 	return 0;
3425 }
3426 
3427 #endif
3428 
3429 static int check_ports_changed(struct usb_hub *hub)
3430 {
3431 	int port1;
3432 
3433 	for (port1 = 1; port1 <= hub->hdev->maxchild; ++port1) {
3434 		u16 portstatus, portchange;
3435 		int status;
3436 
3437 		status = hub_port_status(hub, port1, &portstatus, &portchange);
3438 		if (!status && portchange)
3439 			return 1;
3440 	}
3441 	return 0;
3442 }
3443 
3444 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
3445 {
3446 	struct usb_hub		*hub = usb_get_intfdata (intf);
3447 	struct usb_device	*hdev = hub->hdev;
3448 	unsigned		port1;
3449 	int			status;
3450 
3451 	/*
3452 	 * Warn if children aren't already suspended.
3453 	 * Also, add up the number of wakeup-enabled descendants.
3454 	 */
3455 	hub->wakeup_enabled_descendants = 0;
3456 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3457 		struct usb_port *port_dev = hub->ports[port1 - 1];
3458 		struct usb_device *udev = port_dev->child;
3459 
3460 		if (udev && udev->can_submit) {
3461 			dev_warn(&port_dev->dev, "not suspended yet\n");
3462 			if (PMSG_IS_AUTO(msg))
3463 				return -EBUSY;
3464 		}
3465 		if (udev)
3466 			hub->wakeup_enabled_descendants +=
3467 					wakeup_enabled_descendants(udev);
3468 	}
3469 
3470 	if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
3471 		/* check if there are changes pending on hub ports */
3472 		if (check_ports_changed(hub)) {
3473 			if (PMSG_IS_AUTO(msg))
3474 				return -EBUSY;
3475 			pm_wakeup_event(&hdev->dev, 2000);
3476 		}
3477 	}
3478 
3479 	if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
3480 		/* Enable hub to send remote wakeup for all ports. */
3481 		for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3482 			status = set_port_feature(hdev,
3483 					port1 |
3484 					USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
3485 					USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
3486 					USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
3487 					USB_PORT_FEAT_REMOTE_WAKE_MASK);
3488 		}
3489 	}
3490 
3491 	dev_dbg(&intf->dev, "%s\n", __func__);
3492 
3493 	/* stop khubd and related activity */
3494 	hub_quiesce(hub, HUB_SUSPEND);
3495 	return 0;
3496 }
3497 
3498 static int hub_resume(struct usb_interface *intf)
3499 {
3500 	struct usb_hub *hub = usb_get_intfdata(intf);
3501 
3502 	dev_dbg(&intf->dev, "%s\n", __func__);
3503 	hub_activate(hub, HUB_RESUME);
3504 	return 0;
3505 }
3506 
3507 static int hub_reset_resume(struct usb_interface *intf)
3508 {
3509 	struct usb_hub *hub = usb_get_intfdata(intf);
3510 
3511 	dev_dbg(&intf->dev, "%s\n", __func__);
3512 	hub_activate(hub, HUB_RESET_RESUME);
3513 	return 0;
3514 }
3515 
3516 /**
3517  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
3518  * @rhdev: struct usb_device for the root hub
3519  *
3520  * The USB host controller driver calls this function when its root hub
3521  * is resumed and Vbus power has been interrupted or the controller
3522  * has been reset.  The routine marks @rhdev as having lost power.
3523  * When the hub driver is resumed it will take notice and carry out
3524  * power-session recovery for all the "USB-PERSIST"-enabled child devices;
3525  * the others will be disconnected.
3526  */
3527 void usb_root_hub_lost_power(struct usb_device *rhdev)
3528 {
3529 	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
3530 	rhdev->reset_resume = 1;
3531 }
3532 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
3533 
3534 static const char * const usb3_lpm_names[]  = {
3535 	"U0",
3536 	"U1",
3537 	"U2",
3538 	"U3",
3539 };
3540 
3541 /*
3542  * Send a Set SEL control transfer to the device, prior to enabling
3543  * device-initiated U1 or U2.  This lets the device know the exit latencies from
3544  * the time the device initiates a U1 or U2 exit, to the time it will receive a
3545  * packet from the host.
3546  *
3547  * This function will fail if the SEL or PEL values for udev are greater than
3548  * the maximum allowed values for the link state to be enabled.
3549  */
3550 static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state)
3551 {
3552 	struct usb_set_sel_req *sel_values;
3553 	unsigned long long u1_sel;
3554 	unsigned long long u1_pel;
3555 	unsigned long long u2_sel;
3556 	unsigned long long u2_pel;
3557 	int ret;
3558 
3559 	if (udev->state != USB_STATE_CONFIGURED)
3560 		return 0;
3561 
3562 	/* Convert SEL and PEL stored in ns to us */
3563 	u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
3564 	u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
3565 	u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
3566 	u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);
3567 
3568 	/*
3569 	 * Make sure that the calculated SEL and PEL values for the link
3570 	 * state we're enabling aren't bigger than the max SEL/PEL
3571 	 * value that will fit in the SET SEL control transfer.
3572 	 * Otherwise the device would get an incorrect idea of the exit
3573 	 * latency for the link state, and could start a device-initiated
3574 	 * U1/U2 when the exit latencies are too high.
3575 	 */
3576 	if ((state == USB3_LPM_U1 &&
3577 				(u1_sel > USB3_LPM_MAX_U1_SEL_PEL ||
3578 				 u1_pel > USB3_LPM_MAX_U1_SEL_PEL)) ||
3579 			(state == USB3_LPM_U2 &&
3580 			 (u2_sel > USB3_LPM_MAX_U2_SEL_PEL ||
3581 			  u2_pel > USB3_LPM_MAX_U2_SEL_PEL))) {
3582 		dev_dbg(&udev->dev, "Device-initiated %s disabled due to long SEL %llu us or PEL %llu us\n",
3583 				usb3_lpm_names[state], u1_sel, u1_pel);
3584 		return -EINVAL;
3585 	}
3586 
3587 	/*
3588 	 * If we're enabling device-initiated LPM for one link state,
3589 	 * but the other link state has a too high SEL or PEL value,
3590 	 * just set those values to the max in the Set SEL request.
3591 	 */
3592 	if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL)
3593 		u1_sel = USB3_LPM_MAX_U1_SEL_PEL;
3594 
3595 	if (u1_pel > USB3_LPM_MAX_U1_SEL_PEL)
3596 		u1_pel = USB3_LPM_MAX_U1_SEL_PEL;
3597 
3598 	if (u2_sel > USB3_LPM_MAX_U2_SEL_PEL)
3599 		u2_sel = USB3_LPM_MAX_U2_SEL_PEL;
3600 
3601 	if (u2_pel > USB3_LPM_MAX_U2_SEL_PEL)
3602 		u2_pel = USB3_LPM_MAX_U2_SEL_PEL;
3603 
3604 	/*
3605 	 * usb_enable_lpm() can be called as part of a failed device reset,
3606 	 * which may be initiated by an error path of a mass storage driver.
3607 	 * Therefore, use GFP_NOIO.
3608 	 */
3609 	sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
3610 	if (!sel_values)
3611 		return -ENOMEM;
3612 
3613 	sel_values->u1_sel = u1_sel;
3614 	sel_values->u1_pel = u1_pel;
3615 	sel_values->u2_sel = cpu_to_le16(u2_sel);
3616 	sel_values->u2_pel = cpu_to_le16(u2_pel);
3617 
3618 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3619 			USB_REQ_SET_SEL,
3620 			USB_RECIP_DEVICE,
3621 			0, 0,
3622 			sel_values, sizeof *(sel_values),
3623 			USB_CTRL_SET_TIMEOUT);
3624 	kfree(sel_values);
3625 	return ret;
3626 }
3627 
3628 /*
3629  * Enable or disable device-initiated U1 or U2 transitions.
3630  */
3631 static int usb_set_device_initiated_lpm(struct usb_device *udev,
3632 		enum usb3_link_state state, bool enable)
3633 {
3634 	int ret;
3635 	int feature;
3636 
3637 	switch (state) {
3638 	case USB3_LPM_U1:
3639 		feature = USB_DEVICE_U1_ENABLE;
3640 		break;
3641 	case USB3_LPM_U2:
3642 		feature = USB_DEVICE_U2_ENABLE;
3643 		break;
3644 	default:
3645 		dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n",
3646 				__func__, enable ? "enable" : "disable");
3647 		return -EINVAL;
3648 	}
3649 
3650 	if (udev->state != USB_STATE_CONFIGURED) {
3651 		dev_dbg(&udev->dev, "%s: Can't %s %s state "
3652 				"for unconfigured device.\n",
3653 				__func__, enable ? "enable" : "disable",
3654 				usb3_lpm_names[state]);
3655 		return 0;
3656 	}
3657 
3658 	if (enable) {
3659 		/*
3660 		 * Now send the control transfer to enable device-initiated LPM
3661 		 * for either U1 or U2.
3662 		 */
3663 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3664 				USB_REQ_SET_FEATURE,
3665 				USB_RECIP_DEVICE,
3666 				feature,
3667 				0, NULL, 0,
3668 				USB_CTRL_SET_TIMEOUT);
3669 	} else {
3670 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3671 				USB_REQ_CLEAR_FEATURE,
3672 				USB_RECIP_DEVICE,
3673 				feature,
3674 				0, NULL, 0,
3675 				USB_CTRL_SET_TIMEOUT);
3676 	}
3677 	if (ret < 0) {
3678 		dev_warn(&udev->dev, "%s of device-initiated %s failed.\n",
3679 				enable ? "Enable" : "Disable",
3680 				usb3_lpm_names[state]);
3681 		return -EBUSY;
3682 	}
3683 	return 0;
3684 }
3685 
3686 static int usb_set_lpm_timeout(struct usb_device *udev,
3687 		enum usb3_link_state state, int timeout)
3688 {
3689 	int ret;
3690 	int feature;
3691 
3692 	switch (state) {
3693 	case USB3_LPM_U1:
3694 		feature = USB_PORT_FEAT_U1_TIMEOUT;
3695 		break;
3696 	case USB3_LPM_U2:
3697 		feature = USB_PORT_FEAT_U2_TIMEOUT;
3698 		break;
3699 	default:
3700 		dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n",
3701 				__func__);
3702 		return -EINVAL;
3703 	}
3704 
3705 	if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT &&
3706 			timeout != USB3_LPM_DEVICE_INITIATED) {
3707 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, "
3708 				"which is a reserved value.\n",
3709 				usb3_lpm_names[state], timeout);
3710 		return -EINVAL;
3711 	}
3712 
3713 	ret = set_port_feature(udev->parent,
3714 			USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum,
3715 			feature);
3716 	if (ret < 0) {
3717 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x,"
3718 				"error code %i\n", usb3_lpm_names[state],
3719 				timeout, ret);
3720 		return -EBUSY;
3721 	}
3722 	if (state == USB3_LPM_U1)
3723 		udev->u1_params.timeout = timeout;
3724 	else
3725 		udev->u2_params.timeout = timeout;
3726 	return 0;
3727 }
3728 
3729 /*
3730  * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated
3731  * U1/U2 entry.
3732  *
3733  * We will attempt to enable U1 or U2, but there are no guarantees that the
3734  * control transfers to set the hub timeout or enable device-initiated U1/U2
3735  * will be successful.
3736  *
3737  * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI
3738  * driver know about it.  If that call fails, it should be harmless, and just
3739  * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency.
3740  */
3741 static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3742 		enum usb3_link_state state)
3743 {
3744 	int timeout, ret;
3745 	__u8 u1_mel = udev->bos->ss_cap->bU1devExitLat;
3746 	__le16 u2_mel = udev->bos->ss_cap->bU2DevExitLat;
3747 
3748 	/* If the device says it doesn't have *any* exit latency to come out of
3749 	 * U1 or U2, it's probably lying.  Assume it doesn't implement that link
3750 	 * state.
3751 	 */
3752 	if ((state == USB3_LPM_U1 && u1_mel == 0) ||
3753 			(state == USB3_LPM_U2 && u2_mel == 0))
3754 		return;
3755 
3756 	/*
3757 	 * First, let the device know about the exit latencies
3758 	 * associated with the link state we're about to enable.
3759 	 */
3760 	ret = usb_req_set_sel(udev, state);
3761 	if (ret < 0) {
3762 		dev_warn(&udev->dev, "Set SEL for device-initiated %s failed.\n",
3763 				usb3_lpm_names[state]);
3764 		return;
3765 	}
3766 
3767 	/* We allow the host controller to set the U1/U2 timeout internally
3768 	 * first, so that it can change its schedule to account for the
3769 	 * additional latency to send data to a device in a lower power
3770 	 * link state.
3771 	 */
3772 	timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state);
3773 
3774 	/* xHCI host controller doesn't want to enable this LPM state. */
3775 	if (timeout == 0)
3776 		return;
3777 
3778 	if (timeout < 0) {
3779 		dev_warn(&udev->dev, "Could not enable %s link state, "
3780 				"xHCI error %i.\n", usb3_lpm_names[state],
3781 				timeout);
3782 		return;
3783 	}
3784 
3785 	if (usb_set_lpm_timeout(udev, state, timeout))
3786 		/* If we can't set the parent hub U1/U2 timeout,
3787 		 * device-initiated LPM won't be allowed either, so let the xHCI
3788 		 * host know that this link state won't be enabled.
3789 		 */
3790 		hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
3791 
3792 	/* Only a configured device will accept the Set Feature U1/U2_ENABLE */
3793 	else if (udev->actconfig)
3794 		usb_set_device_initiated_lpm(udev, state, true);
3795 
3796 }
3797 
3798 /*
3799  * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated
3800  * U1/U2 entry.
3801  *
3802  * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry.
3803  * If zero is returned, the parent will not allow the link to go into U1/U2.
3804  *
3805  * If zero is returned, device-initiated U1/U2 entry may still be enabled, but
3806  * it won't have an effect on the bus link state because the parent hub will
3807  * still disallow device-initiated U1/U2 entry.
3808  *
3809  * If zero is returned, the xHCI host controller may still think U1/U2 entry is
3810  * possible.  The result will be slightly more bus bandwidth will be taken up
3811  * (to account for U1/U2 exit latency), but it should be harmless.
3812  */
3813 static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3814 		enum usb3_link_state state)
3815 {
3816 	int feature;
3817 
3818 	switch (state) {
3819 	case USB3_LPM_U1:
3820 		feature = USB_PORT_FEAT_U1_TIMEOUT;
3821 		break;
3822 	case USB3_LPM_U2:
3823 		feature = USB_PORT_FEAT_U2_TIMEOUT;
3824 		break;
3825 	default:
3826 		dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n",
3827 				__func__);
3828 		return -EINVAL;
3829 	}
3830 
3831 	if (usb_set_lpm_timeout(udev, state, 0))
3832 		return -EBUSY;
3833 
3834 	usb_set_device_initiated_lpm(udev, state, false);
3835 
3836 	if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state))
3837 		dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
3838 				"bus schedule bandwidth may be impacted.\n",
3839 				usb3_lpm_names[state]);
3840 	return 0;
3841 }
3842 
3843 /*
3844  * Disable hub-initiated and device-initiated U1 and U2 entry.
3845  * Caller must own the bandwidth_mutex.
3846  *
3847  * This will call usb_enable_lpm() on failure, which will decrement
3848  * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero.
3849  */
3850 int usb_disable_lpm(struct usb_device *udev)
3851 {
3852 	struct usb_hcd *hcd;
3853 
3854 	if (!udev || !udev->parent ||
3855 			udev->speed != USB_SPEED_SUPER ||
3856 			!udev->lpm_capable)
3857 		return 0;
3858 
3859 	hcd = bus_to_hcd(udev->bus);
3860 	if (!hcd || !hcd->driver->disable_usb3_lpm_timeout)
3861 		return 0;
3862 
3863 	udev->lpm_disable_count++;
3864 	if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
3865 		return 0;
3866 
3867 	/* If LPM is enabled, attempt to disable it. */
3868 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
3869 		goto enable_lpm;
3870 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
3871 		goto enable_lpm;
3872 
3873 	return 0;
3874 
3875 enable_lpm:
3876 	usb_enable_lpm(udev);
3877 	return -EBUSY;
3878 }
3879 EXPORT_SYMBOL_GPL(usb_disable_lpm);
3880 
3881 /* Grab the bandwidth_mutex before calling usb_disable_lpm() */
3882 int usb_unlocked_disable_lpm(struct usb_device *udev)
3883 {
3884 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3885 	int ret;
3886 
3887 	if (!hcd)
3888 		return -EINVAL;
3889 
3890 	mutex_lock(hcd->bandwidth_mutex);
3891 	ret = usb_disable_lpm(udev);
3892 	mutex_unlock(hcd->bandwidth_mutex);
3893 
3894 	return ret;
3895 }
3896 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
3897 
3898 /*
3899  * Attempt to enable device-initiated and hub-initiated U1 and U2 entry.  The
3900  * xHCI host policy may prevent U1 or U2 from being enabled.
3901  *
3902  * Other callers may have disabled link PM, so U1 and U2 entry will be disabled
3903  * until the lpm_disable_count drops to zero.  Caller must own the
3904  * bandwidth_mutex.
3905  */
3906 void usb_enable_lpm(struct usb_device *udev)
3907 {
3908 	struct usb_hcd *hcd;
3909 
3910 	if (!udev || !udev->parent ||
3911 			udev->speed != USB_SPEED_SUPER ||
3912 			!udev->lpm_capable)
3913 		return;
3914 
3915 	udev->lpm_disable_count--;
3916 	hcd = bus_to_hcd(udev->bus);
3917 	/* Double check that we can both enable and disable LPM.
3918 	 * Device must be configured to accept set feature U1/U2 timeout.
3919 	 */
3920 	if (!hcd || !hcd->driver->enable_usb3_lpm_timeout ||
3921 			!hcd->driver->disable_usb3_lpm_timeout)
3922 		return;
3923 
3924 	if (udev->lpm_disable_count > 0)
3925 		return;
3926 
3927 	usb_enable_link_state(hcd, udev, USB3_LPM_U1);
3928 	usb_enable_link_state(hcd, udev, USB3_LPM_U2);
3929 }
3930 EXPORT_SYMBOL_GPL(usb_enable_lpm);
3931 
3932 /* Grab the bandwidth_mutex before calling usb_enable_lpm() */
3933 void usb_unlocked_enable_lpm(struct usb_device *udev)
3934 {
3935 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3936 
3937 	if (!hcd)
3938 		return;
3939 
3940 	mutex_lock(hcd->bandwidth_mutex);
3941 	usb_enable_lpm(udev);
3942 	mutex_unlock(hcd->bandwidth_mutex);
3943 }
3944 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
3945 
3946 
3947 #else	/* CONFIG_PM */
3948 
3949 #define hub_suspend		NULL
3950 #define hub_resume		NULL
3951 #define hub_reset_resume	NULL
3952 
3953 int usb_disable_lpm(struct usb_device *udev)
3954 {
3955 	return 0;
3956 }
3957 EXPORT_SYMBOL_GPL(usb_disable_lpm);
3958 
3959 void usb_enable_lpm(struct usb_device *udev) { }
3960 EXPORT_SYMBOL_GPL(usb_enable_lpm);
3961 
3962 int usb_unlocked_disable_lpm(struct usb_device *udev)
3963 {
3964 	return 0;
3965 }
3966 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
3967 
3968 void usb_unlocked_enable_lpm(struct usb_device *udev) { }
3969 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
3970 
3971 int usb_disable_ltm(struct usb_device *udev)
3972 {
3973 	return 0;
3974 }
3975 EXPORT_SYMBOL_GPL(usb_disable_ltm);
3976 
3977 void usb_enable_ltm(struct usb_device *udev) { }
3978 EXPORT_SYMBOL_GPL(usb_enable_ltm);
3979 
3980 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
3981 		u16 portstatus, u16 portchange)
3982 {
3983 	return 0;
3984 }
3985 
3986 #endif	/* CONFIG_PM */
3987 
3988 
3989 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
3990  *
3991  * Between connect detection and reset signaling there must be a delay
3992  * of 100ms at least for debounce and power-settling.  The corresponding
3993  * timer shall restart whenever the downstream port detects a disconnect.
3994  *
3995  * Apparently there are some bluetooth and irda-dongles and a number of
3996  * low-speed devices for which this debounce period may last over a second.
3997  * Not covered by the spec - but easy to deal with.
3998  *
3999  * This implementation uses a 1500ms total debounce timeout; if the
4000  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
4001  * every 25ms for transient disconnects.  When the port status has been
4002  * unchanged for 100ms it returns the port status.
4003  */
4004 int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
4005 {
4006 	int ret;
4007 	u16 portchange, portstatus;
4008 	unsigned connection = 0xffff;
4009 	int total_time, stable_time = 0;
4010 	struct usb_port *port_dev = hub->ports[port1 - 1];
4011 
4012 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
4013 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
4014 		if (ret < 0)
4015 			return ret;
4016 
4017 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
4018 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
4019 			if (!must_be_connected ||
4020 			     (connection == USB_PORT_STAT_CONNECTION))
4021 				stable_time += HUB_DEBOUNCE_STEP;
4022 			if (stable_time >= HUB_DEBOUNCE_STABLE)
4023 				break;
4024 		} else {
4025 			stable_time = 0;
4026 			connection = portstatus & USB_PORT_STAT_CONNECTION;
4027 		}
4028 
4029 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
4030 			usb_clear_port_feature(hub->hdev, port1,
4031 					USB_PORT_FEAT_C_CONNECTION);
4032 		}
4033 
4034 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
4035 			break;
4036 		msleep(HUB_DEBOUNCE_STEP);
4037 	}
4038 
4039 	dev_dbg(&port_dev->dev, "debounce total %dms stable %dms status 0x%x\n",
4040 			total_time, stable_time, portstatus);
4041 
4042 	if (stable_time < HUB_DEBOUNCE_STABLE)
4043 		return -ETIMEDOUT;
4044 	return portstatus;
4045 }
4046 
4047 void usb_ep0_reinit(struct usb_device *udev)
4048 {
4049 	usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
4050 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
4051 	usb_enable_endpoint(udev, &udev->ep0, true);
4052 }
4053 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
4054 
4055 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
4056 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
4057 
4058 static int hub_set_address(struct usb_device *udev, int devnum)
4059 {
4060 	int retval;
4061 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4062 
4063 	/*
4064 	 * The host controller will choose the device address,
4065 	 * instead of the core having chosen it earlier
4066 	 */
4067 	if (!hcd->driver->address_device && devnum <= 1)
4068 		return -EINVAL;
4069 	if (udev->state == USB_STATE_ADDRESS)
4070 		return 0;
4071 	if (udev->state != USB_STATE_DEFAULT)
4072 		return -EINVAL;
4073 	if (hcd->driver->address_device)
4074 		retval = hcd->driver->address_device(hcd, udev);
4075 	else
4076 		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
4077 				USB_REQ_SET_ADDRESS, 0, devnum, 0,
4078 				NULL, 0, USB_CTRL_SET_TIMEOUT);
4079 	if (retval == 0) {
4080 		update_devnum(udev, devnum);
4081 		/* Device now using proper address. */
4082 		usb_set_device_state(udev, USB_STATE_ADDRESS);
4083 		usb_ep0_reinit(udev);
4084 	}
4085 	return retval;
4086 }
4087 
4088 /*
4089  * There are reports of USB 3.0 devices that say they support USB 2.0 Link PM
4090  * when they're plugged into a USB 2.0 port, but they don't work when LPM is
4091  * enabled.
4092  *
4093  * Only enable USB 2.0 Link PM if the port is internal (hardwired), or the
4094  * device says it supports the new USB 2.0 Link PM errata by setting the BESL
4095  * support bit in the BOS descriptor.
4096  */
4097 static void hub_set_initial_usb2_lpm_policy(struct usb_device *udev)
4098 {
4099 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4100 	int connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
4101 
4102 	if (!udev->usb2_hw_lpm_capable)
4103 		return;
4104 
4105 	if (hub)
4106 		connect_type = hub->ports[udev->portnum - 1]->connect_type;
4107 
4108 	if ((udev->bos->ext_cap->bmAttributes & cpu_to_le32(USB_BESL_SUPPORT)) ||
4109 			connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
4110 		udev->usb2_hw_lpm_allowed = 1;
4111 		usb_set_usb2_hardware_lpm(udev, 1);
4112 	}
4113 }
4114 
4115 static int hub_enable_device(struct usb_device *udev)
4116 {
4117 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4118 
4119 	if (!hcd->driver->enable_device)
4120 		return 0;
4121 	if (udev->state == USB_STATE_ADDRESS)
4122 		return 0;
4123 	if (udev->state != USB_STATE_DEFAULT)
4124 		return -EINVAL;
4125 
4126 	return hcd->driver->enable_device(hcd, udev);
4127 }
4128 
4129 /* Reset device, (re)assign address, get device descriptor.
4130  * Device connection must be stable, no more debouncing needed.
4131  * Returns device in USB_STATE_ADDRESS, except on error.
4132  *
4133  * If this is called for an already-existing device (as part of
4134  * usb_reset_and_verify_device), the caller must own the device lock and
4135  * the port lock.  For a newly detected device that is not accessible
4136  * through any global pointers, it's not necessary to lock the device,
4137  * but it is still necessary to lock the port.
4138  */
4139 static int
4140 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
4141 		int retry_counter)
4142 {
4143 	struct usb_device	*hdev = hub->hdev;
4144 	struct usb_hcd		*hcd = bus_to_hcd(hdev->bus);
4145 	int			i, j, retval;
4146 	unsigned		delay = HUB_SHORT_RESET_TIME;
4147 	enum usb_device_speed	oldspeed = udev->speed;
4148 	const char		*speed;
4149 	int			devnum = udev->devnum;
4150 
4151 	/* root hub ports have a slightly longer reset period
4152 	 * (from USB 2.0 spec, section 7.1.7.5)
4153 	 */
4154 	if (!hdev->parent) {
4155 		delay = HUB_ROOT_RESET_TIME;
4156 		if (port1 == hdev->bus->otg_port)
4157 			hdev->bus->b_hnp_enable = 0;
4158 	}
4159 
4160 	/* Some low speed devices have problems with the quick delay, so */
4161 	/*  be a bit pessimistic with those devices. RHbug #23670 */
4162 	if (oldspeed == USB_SPEED_LOW)
4163 		delay = HUB_LONG_RESET_TIME;
4164 
4165 	mutex_lock(&hdev->bus->usb_address0_mutex);
4166 
4167 	/* Reset the device; full speed may morph to high speed */
4168 	/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
4169 	retval = hub_port_reset(hub, port1, udev, delay, false);
4170 	if (retval < 0)		/* error or disconnect */
4171 		goto fail;
4172 	/* success, speed is known */
4173 
4174 	retval = -ENODEV;
4175 
4176 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
4177 		dev_dbg(&udev->dev, "device reset changed speed!\n");
4178 		goto fail;
4179 	}
4180 	oldspeed = udev->speed;
4181 
4182 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
4183 	 * it's fixed size except for full speed devices.
4184 	 * For Wireless USB devices, ep0 max packet is always 512 (tho
4185 	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
4186 	 */
4187 	switch (udev->speed) {
4188 	case USB_SPEED_SUPER:
4189 	case USB_SPEED_WIRELESS:	/* fixed at 512 */
4190 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
4191 		break;
4192 	case USB_SPEED_HIGH:		/* fixed at 64 */
4193 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4194 		break;
4195 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
4196 		/* to determine the ep0 maxpacket size, try to read
4197 		 * the device descriptor to get bMaxPacketSize0 and
4198 		 * then correct our initial guess.
4199 		 */
4200 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4201 		break;
4202 	case USB_SPEED_LOW:		/* fixed at 8 */
4203 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
4204 		break;
4205 	default:
4206 		goto fail;
4207 	}
4208 
4209 	if (udev->speed == USB_SPEED_WIRELESS)
4210 		speed = "variable speed Wireless";
4211 	else
4212 		speed = usb_speed_string(udev->speed);
4213 
4214 	if (udev->speed != USB_SPEED_SUPER)
4215 		dev_info(&udev->dev,
4216 				"%s %s USB device number %d using %s\n",
4217 				(udev->config) ? "reset" : "new", speed,
4218 				devnum, udev->bus->controller->driver->name);
4219 
4220 	/* Set up TT records, if needed  */
4221 	if (hdev->tt) {
4222 		udev->tt = hdev->tt;
4223 		udev->ttport = hdev->ttport;
4224 	} else if (udev->speed != USB_SPEED_HIGH
4225 			&& hdev->speed == USB_SPEED_HIGH) {
4226 		if (!hub->tt.hub) {
4227 			dev_err(&udev->dev, "parent hub has no TT\n");
4228 			retval = -EINVAL;
4229 			goto fail;
4230 		}
4231 		udev->tt = &hub->tt;
4232 		udev->ttport = port1;
4233 	}
4234 
4235 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
4236 	 * Because device hardware and firmware is sometimes buggy in
4237 	 * this area, and this is how Linux has done it for ages.
4238 	 * Change it cautiously.
4239 	 *
4240 	 * NOTE:  If use_new_scheme() is true we will start by issuing
4241 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
4242 	 * so it may help with some non-standards-compliant devices.
4243 	 * Otherwise we start with SET_ADDRESS and then try to read the
4244 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
4245 	 * value.
4246 	 */
4247 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
4248 		bool did_new_scheme = false;
4249 
4250 		if (use_new_scheme(udev, retry_counter)) {
4251 			struct usb_device_descriptor *buf;
4252 			int r = 0;
4253 
4254 			did_new_scheme = true;
4255 			retval = hub_enable_device(udev);
4256 			if (retval < 0) {
4257 				dev_err(&udev->dev,
4258 					"hub failed to enable device, error %d\n",
4259 					retval);
4260 				goto fail;
4261 			}
4262 
4263 #define GET_DESCRIPTOR_BUFSIZE	64
4264 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
4265 			if (!buf) {
4266 				retval = -ENOMEM;
4267 				continue;
4268 			}
4269 
4270 			/* Retry on all errors; some devices are flakey.
4271 			 * 255 is for WUSB devices, we actually need to use
4272 			 * 512 (WUSB1.0[4.8.1]).
4273 			 */
4274 			for (j = 0; j < 3; ++j) {
4275 				buf->bMaxPacketSize0 = 0;
4276 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
4277 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
4278 					USB_DT_DEVICE << 8, 0,
4279 					buf, GET_DESCRIPTOR_BUFSIZE,
4280 					initial_descriptor_timeout);
4281 				switch (buf->bMaxPacketSize0) {
4282 				case 8: case 16: case 32: case 64: case 255:
4283 					if (buf->bDescriptorType ==
4284 							USB_DT_DEVICE) {
4285 						r = 0;
4286 						break;
4287 					}
4288 					/* FALL THROUGH */
4289 				default:
4290 					if (r == 0)
4291 						r = -EPROTO;
4292 					break;
4293 				}
4294 				if (r == 0)
4295 					break;
4296 			}
4297 			udev->descriptor.bMaxPacketSize0 =
4298 					buf->bMaxPacketSize0;
4299 			kfree(buf);
4300 
4301 			retval = hub_port_reset(hub, port1, udev, delay, false);
4302 			if (retval < 0)		/* error or disconnect */
4303 				goto fail;
4304 			if (oldspeed != udev->speed) {
4305 				dev_dbg(&udev->dev,
4306 					"device reset changed speed!\n");
4307 				retval = -ENODEV;
4308 				goto fail;
4309 			}
4310 			if (r) {
4311 				if (r != -ENODEV)
4312 					dev_err(&udev->dev, "device descriptor read/64, error %d\n",
4313 							r);
4314 				retval = -EMSGSIZE;
4315 				continue;
4316 			}
4317 #undef GET_DESCRIPTOR_BUFSIZE
4318 		}
4319 
4320 		/*
4321 		 * If device is WUSB, we already assigned an
4322 		 * unauthorized address in the Connect Ack sequence;
4323 		 * authorization will assign the final address.
4324 		 */
4325 		if (udev->wusb == 0) {
4326 			for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
4327 				retval = hub_set_address(udev, devnum);
4328 				if (retval >= 0)
4329 					break;
4330 				msleep(200);
4331 			}
4332 			if (retval < 0) {
4333 				if (retval != -ENODEV)
4334 					dev_err(&udev->dev, "device not accepting address %d, error %d\n",
4335 							devnum, retval);
4336 				goto fail;
4337 			}
4338 			if (udev->speed == USB_SPEED_SUPER) {
4339 				devnum = udev->devnum;
4340 				dev_info(&udev->dev,
4341 						"%s SuperSpeed USB device number %d using %s\n",
4342 						(udev->config) ? "reset" : "new",
4343 						devnum, udev->bus->controller->driver->name);
4344 			}
4345 
4346 			/* cope with hardware quirkiness:
4347 			 *  - let SET_ADDRESS settle, some device hardware wants it
4348 			 *  - read ep0 maxpacket even for high and low speed,
4349 			 */
4350 			msleep(10);
4351 			/* use_new_scheme() checks the speed which may have
4352 			 * changed since the initial look so we cache the result
4353 			 * in did_new_scheme
4354 			 */
4355 			if (did_new_scheme)
4356 				break;
4357 		}
4358 
4359 		retval = usb_get_device_descriptor(udev, 8);
4360 		if (retval < 8) {
4361 			if (retval != -ENODEV)
4362 				dev_err(&udev->dev,
4363 					"device descriptor read/8, error %d\n",
4364 					retval);
4365 			if (retval >= 0)
4366 				retval = -EMSGSIZE;
4367 		} else {
4368 			retval = 0;
4369 			break;
4370 		}
4371 	}
4372 	if (retval)
4373 		goto fail;
4374 
4375 	if (hcd->phy && !hdev->parent)
4376 		usb_phy_notify_connect(hcd->phy, udev->speed);
4377 
4378 	/*
4379 	 * Some superspeed devices have finished the link training process
4380 	 * and attached to a superspeed hub port, but the device descriptor
4381 	 * got from those devices show they aren't superspeed devices. Warm
4382 	 * reset the port attached by the devices can fix them.
4383 	 */
4384 	if ((udev->speed == USB_SPEED_SUPER) &&
4385 			(le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
4386 		dev_err(&udev->dev, "got a wrong device descriptor, "
4387 				"warm reset device\n");
4388 		hub_port_reset(hub, port1, udev,
4389 				HUB_BH_RESET_TIME, true);
4390 		retval = -EINVAL;
4391 		goto fail;
4392 	}
4393 
4394 	if (udev->descriptor.bMaxPacketSize0 == 0xff ||
4395 			udev->speed == USB_SPEED_SUPER)
4396 		i = 512;
4397 	else
4398 		i = udev->descriptor.bMaxPacketSize0;
4399 	if (usb_endpoint_maxp(&udev->ep0.desc) != i) {
4400 		if (udev->speed == USB_SPEED_LOW ||
4401 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
4402 			dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i);
4403 			retval = -EMSGSIZE;
4404 			goto fail;
4405 		}
4406 		if (udev->speed == USB_SPEED_FULL)
4407 			dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
4408 		else
4409 			dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
4410 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
4411 		usb_ep0_reinit(udev);
4412 	}
4413 
4414 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
4415 	if (retval < (signed)sizeof(udev->descriptor)) {
4416 		if (retval != -ENODEV)
4417 			dev_err(&udev->dev, "device descriptor read/all, error %d\n",
4418 					retval);
4419 		if (retval >= 0)
4420 			retval = -ENOMSG;
4421 		goto fail;
4422 	}
4423 
4424 	if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
4425 		retval = usb_get_bos_descriptor(udev);
4426 		if (!retval) {
4427 			udev->lpm_capable = usb_device_supports_lpm(udev);
4428 			usb_set_lpm_parameters(udev);
4429 		}
4430 	}
4431 
4432 	retval = 0;
4433 	/* notify HCD that we have a device connected and addressed */
4434 	if (hcd->driver->update_device)
4435 		hcd->driver->update_device(hcd, udev);
4436 	hub_set_initial_usb2_lpm_policy(udev);
4437 fail:
4438 	if (retval) {
4439 		hub_port_disable(hub, port1, 0);
4440 		update_devnum(udev, devnum);	/* for disconnect processing */
4441 	}
4442 	mutex_unlock(&hdev->bus->usb_address0_mutex);
4443 	return retval;
4444 }
4445 
4446 static void
4447 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
4448 {
4449 	struct usb_qualifier_descriptor	*qual;
4450 	int				status;
4451 
4452 	qual = kmalloc (sizeof *qual, GFP_KERNEL);
4453 	if (qual == NULL)
4454 		return;
4455 
4456 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
4457 			qual, sizeof *qual);
4458 	if (status == sizeof *qual) {
4459 		dev_info(&udev->dev, "not running at top speed; "
4460 			"connect to a high speed hub\n");
4461 		/* hub LEDs are probably harder to miss than syslog */
4462 		if (hub->has_indicators) {
4463 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
4464 			queue_delayed_work(system_power_efficient_wq,
4465 					&hub->leds, 0);
4466 		}
4467 	}
4468 	kfree(qual);
4469 }
4470 
4471 static unsigned
4472 hub_power_remaining (struct usb_hub *hub)
4473 {
4474 	struct usb_device *hdev = hub->hdev;
4475 	int remaining;
4476 	int port1;
4477 
4478 	if (!hub->limited_power)
4479 		return 0;
4480 
4481 	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
4482 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
4483 		struct usb_port *port_dev = hub->ports[port1 - 1];
4484 		struct usb_device *udev = port_dev->child;
4485 		unsigned unit_load;
4486 		int delta;
4487 
4488 		if (!udev)
4489 			continue;
4490 		if (hub_is_superspeed(udev))
4491 			unit_load = 150;
4492 		else
4493 			unit_load = 100;
4494 
4495 		/*
4496 		 * Unconfigured devices may not use more than one unit load,
4497 		 * or 8mA for OTG ports
4498 		 */
4499 		if (udev->actconfig)
4500 			delta = usb_get_max_power(udev, udev->actconfig);
4501 		else if (port1 != udev->bus->otg_port || hdev->parent)
4502 			delta = unit_load;
4503 		else
4504 			delta = 8;
4505 		if (delta > hub->mA_per_port)
4506 			dev_warn(&port_dev->dev, "%dmA is over %umA budget!\n",
4507 					delta, hub->mA_per_port);
4508 		remaining -= delta;
4509 	}
4510 	if (remaining < 0) {
4511 		dev_warn(hub->intfdev, "%dmA over power budget!\n",
4512 			-remaining);
4513 		remaining = 0;
4514 	}
4515 	return remaining;
4516 }
4517 
4518 static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
4519 		u16 portchange)
4520 {
4521 	int status, i;
4522 	unsigned unit_load;
4523 	struct usb_device *hdev = hub->hdev;
4524 	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
4525 	struct usb_port *port_dev = hub->ports[port1 - 1];
4526 	struct usb_device *udev = port_dev->child;
4527 
4528 	/* Disconnect any existing devices under this port */
4529 	if (udev) {
4530 		if (hcd->phy && !hdev->parent &&
4531 				!(portstatus & USB_PORT_STAT_CONNECTION))
4532 			usb_phy_notify_disconnect(hcd->phy, udev->speed);
4533 		usb_disconnect(&port_dev->child);
4534 	}
4535 
4536 	/* We can forget about a "removed" device when there's a physical
4537 	 * disconnect or the connect status changes.
4538 	 */
4539 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4540 			(portchange & USB_PORT_STAT_C_CONNECTION))
4541 		clear_bit(port1, hub->removed_bits);
4542 
4543 	if (portchange & (USB_PORT_STAT_C_CONNECTION |
4544 				USB_PORT_STAT_C_ENABLE)) {
4545 		status = hub_port_debounce_be_stable(hub, port1);
4546 		if (status < 0) {
4547 			if (status != -ENODEV && printk_ratelimit())
4548 				dev_err(&port_dev->dev,
4549 						"connect-debounce failed\n");
4550 			portstatus &= ~USB_PORT_STAT_CONNECTION;
4551 		} else {
4552 			portstatus = status;
4553 		}
4554 	}
4555 
4556 	/* Return now if debouncing failed or nothing is connected or
4557 	 * the device was "removed".
4558 	 */
4559 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4560 			test_bit(port1, hub->removed_bits)) {
4561 
4562 		/* maybe switch power back on (e.g. root hub was reset) */
4563 		if (hub_is_port_power_switchable(hub)
4564 				&& !port_is_power_on(hub, portstatus))
4565 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
4566 
4567 		if (portstatus & USB_PORT_STAT_ENABLE)
4568 			goto done;
4569 		return;
4570 	}
4571 	if (hub_is_superspeed(hub->hdev))
4572 		unit_load = 150;
4573 	else
4574 		unit_load = 100;
4575 
4576 	status = 0;
4577 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
4578 
4579 		/* reallocate for each attempt, since references
4580 		 * to the previous one can escape in various ways
4581 		 */
4582 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
4583 		if (!udev) {
4584 			dev_err(&port_dev->dev,
4585 					"couldn't allocate usb_device\n");
4586 			goto done;
4587 		}
4588 
4589 		usb_set_device_state(udev, USB_STATE_POWERED);
4590 		udev->bus_mA = hub->mA_per_port;
4591 		udev->level = hdev->level + 1;
4592 		udev->wusb = hub_is_wusb(hub);
4593 
4594 		/* Only USB 3.0 devices are connected to SuperSpeed hubs. */
4595 		if (hub_is_superspeed(hub->hdev))
4596 			udev->speed = USB_SPEED_SUPER;
4597 		else
4598 			udev->speed = USB_SPEED_UNKNOWN;
4599 
4600 		choose_devnum(udev);
4601 		if (udev->devnum <= 0) {
4602 			status = -ENOTCONN;	/* Don't retry */
4603 			goto loop;
4604 		}
4605 
4606 		/* reset (non-USB 3.0 devices) and get descriptor */
4607 		usb_lock_port(port_dev);
4608 		status = hub_port_init(hub, udev, port1, i);
4609 		usb_unlock_port(port_dev);
4610 		if (status < 0)
4611 			goto loop;
4612 
4613 		usb_detect_quirks(udev);
4614 		if (udev->quirks & USB_QUIRK_DELAY_INIT)
4615 			msleep(1000);
4616 
4617 		/* consecutive bus-powered hubs aren't reliable; they can
4618 		 * violate the voltage drop budget.  if the new child has
4619 		 * a "powered" LED, users should notice we didn't enable it
4620 		 * (without reading syslog), even without per-port LEDs
4621 		 * on the parent.
4622 		 */
4623 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
4624 				&& udev->bus_mA <= unit_load) {
4625 			u16	devstat;
4626 
4627 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
4628 					&devstat);
4629 			if (status) {
4630 				dev_dbg(&udev->dev, "get status %d ?\n", status);
4631 				goto loop_disable;
4632 			}
4633 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
4634 				dev_err(&udev->dev,
4635 					"can't connect bus-powered hub "
4636 					"to this port\n");
4637 				if (hub->has_indicators) {
4638 					hub->indicator[port1-1] =
4639 						INDICATOR_AMBER_BLINK;
4640 					queue_delayed_work(
4641 						system_power_efficient_wq,
4642 						&hub->leds, 0);
4643 				}
4644 				status = -ENOTCONN;	/* Don't retry */
4645 				goto loop_disable;
4646 			}
4647 		}
4648 
4649 		/* check for devices running slower than they could */
4650 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
4651 				&& udev->speed == USB_SPEED_FULL
4652 				&& highspeed_hubs != 0)
4653 			check_highspeed (hub, udev, port1);
4654 
4655 		/* Store the parent's children[] pointer.  At this point
4656 		 * udev becomes globally accessible, although presumably
4657 		 * no one will look at it until hdev is unlocked.
4658 		 */
4659 		status = 0;
4660 
4661 		mutex_lock(&usb_port_peer_mutex);
4662 
4663 		/* We mustn't add new devices if the parent hub has
4664 		 * been disconnected; we would race with the
4665 		 * recursively_mark_NOTATTACHED() routine.
4666 		 */
4667 		spin_lock_irq(&device_state_lock);
4668 		if (hdev->state == USB_STATE_NOTATTACHED)
4669 			status = -ENOTCONN;
4670 		else
4671 			port_dev->child = udev;
4672 		spin_unlock_irq(&device_state_lock);
4673 		mutex_unlock(&usb_port_peer_mutex);
4674 
4675 		/* Run it through the hoops (find a driver, etc) */
4676 		if (!status) {
4677 			status = usb_new_device(udev);
4678 			if (status) {
4679 				mutex_lock(&usb_port_peer_mutex);
4680 				spin_lock_irq(&device_state_lock);
4681 				port_dev->child = NULL;
4682 				spin_unlock_irq(&device_state_lock);
4683 				mutex_unlock(&usb_port_peer_mutex);
4684 			}
4685 		}
4686 
4687 		if (status)
4688 			goto loop_disable;
4689 
4690 		status = hub_power_remaining(hub);
4691 		if (status)
4692 			dev_dbg(hub->intfdev, "%dmA power budget left\n", status);
4693 
4694 		return;
4695 
4696 loop_disable:
4697 		hub_port_disable(hub, port1, 1);
4698 loop:
4699 		usb_ep0_reinit(udev);
4700 		release_devnum(udev);
4701 		hub_free_dev(udev);
4702 		usb_put_dev(udev);
4703 		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
4704 			break;
4705 	}
4706 	if (hub->hdev->parent ||
4707 			!hcd->driver->port_handed_over ||
4708 			!(hcd->driver->port_handed_over)(hcd, port1)) {
4709 		if (status != -ENOTCONN && status != -ENODEV)
4710 			dev_err(&port_dev->dev,
4711 					"unable to enumerate USB device\n");
4712 	}
4713 
4714 done:
4715 	hub_port_disable(hub, port1, 1);
4716 	if (hcd->driver->relinquish_port && !hub->hdev->parent)
4717 		hcd->driver->relinquish_port(hcd, port1);
4718 
4719 }
4720 
4721 /* Handle physical or logical connection change events.
4722  * This routine is called when:
4723  *	a port connection-change occurs;
4724  *	a port enable-change occurs (often caused by EMI);
4725  *	usb_reset_and_verify_device() encounters changed descriptors (as from
4726  *		a firmware download)
4727  * caller already locked the hub
4728  */
4729 static void hub_port_connect_change(struct usb_hub *hub, int port1,
4730 					u16 portstatus, u16 portchange)
4731 		__must_hold(&port_dev->status_lock)
4732 {
4733 	struct usb_port *port_dev = hub->ports[port1 - 1];
4734 	struct usb_device *udev = port_dev->child;
4735 	int status = -ENODEV;
4736 
4737 	dev_dbg(&port_dev->dev, "status %04x, change %04x, %s\n", portstatus,
4738 			portchange, portspeed(hub, portstatus));
4739 
4740 	if (hub->has_indicators) {
4741 		set_port_led(hub, port1, HUB_LED_AUTO);
4742 		hub->indicator[port1-1] = INDICATOR_AUTO;
4743 	}
4744 
4745 #ifdef	CONFIG_USB_OTG
4746 	/* during HNP, don't repeat the debounce */
4747 	if (hub->hdev->bus->is_b_host)
4748 		portchange &= ~(USB_PORT_STAT_C_CONNECTION |
4749 				USB_PORT_STAT_C_ENABLE);
4750 #endif
4751 
4752 	/* Try to resuscitate an existing device */
4753 	if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
4754 			udev->state != USB_STATE_NOTATTACHED) {
4755 		if (portstatus & USB_PORT_STAT_ENABLE) {
4756 			status = 0;		/* Nothing to do */
4757 #ifdef CONFIG_PM_RUNTIME
4758 		} else if (udev->state == USB_STATE_SUSPENDED &&
4759 				udev->persist_enabled) {
4760 			/* For a suspended device, treat this as a
4761 			 * remote wakeup event.
4762 			 */
4763 			usb_unlock_port(port_dev);
4764 			status = usb_remote_wakeup(udev);
4765 			usb_lock_port(port_dev);
4766 #endif
4767 		} else {
4768 			/* Don't resuscitate */;
4769 		}
4770 	}
4771 	clear_bit(port1, hub->change_bits);
4772 
4773 	/* successfully revalidated the connection */
4774 	if (status == 0)
4775 		return;
4776 
4777 	usb_unlock_port(port_dev);
4778 	hub_port_connect(hub, port1, portstatus, portchange);
4779 	usb_lock_port(port_dev);
4780 }
4781 
4782 static void port_event(struct usb_hub *hub, int port1)
4783 		__must_hold(&port_dev->status_lock)
4784 {
4785 	int connect_change, reset_device = 0;
4786 	struct usb_port *port_dev = hub->ports[port1 - 1];
4787 	struct usb_device *udev = port_dev->child;
4788 	struct usb_device *hdev = hub->hdev;
4789 	u16 portstatus, portchange;
4790 
4791 	connect_change = test_bit(port1, hub->change_bits);
4792 	clear_bit(port1, hub->event_bits);
4793 	clear_bit(port1, hub->wakeup_bits);
4794 
4795 	if (hub_port_status(hub, port1, &portstatus, &portchange) < 0)
4796 		return;
4797 
4798 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
4799 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
4800 		connect_change = 1;
4801 	}
4802 
4803 	if (portchange & USB_PORT_STAT_C_ENABLE) {
4804 		if (!connect_change)
4805 			dev_dbg(&port_dev->dev, "enable change, status %08x\n",
4806 					portstatus);
4807 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
4808 
4809 		/*
4810 		 * EM interference sometimes causes badly shielded USB devices
4811 		 * to be shutdown by the hub, this hack enables them again.
4812 		 * Works at least with mouse driver.
4813 		 */
4814 		if (!(portstatus & USB_PORT_STAT_ENABLE)
4815 		    && !connect_change && udev) {
4816 			dev_err(&port_dev->dev, "disabled by hub (EMI?), re-enabling...\n");
4817 			connect_change = 1;
4818 		}
4819 	}
4820 
4821 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
4822 		u16 status = 0, unused;
4823 
4824 		dev_dbg(&port_dev->dev, "over-current change\n");
4825 		usb_clear_port_feature(hdev, port1,
4826 				USB_PORT_FEAT_C_OVER_CURRENT);
4827 		msleep(100);	/* Cool down */
4828 		hub_power_on(hub, true);
4829 		hub_port_status(hub, port1, &status, &unused);
4830 		if (status & USB_PORT_STAT_OVERCURRENT)
4831 			dev_err(&port_dev->dev, "over-current condition\n");
4832 	}
4833 
4834 	if (portchange & USB_PORT_STAT_C_RESET) {
4835 		dev_dbg(&port_dev->dev, "reset change\n");
4836 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_RESET);
4837 	}
4838 	if ((portchange & USB_PORT_STAT_C_BH_RESET)
4839 	    && hub_is_superspeed(hdev)) {
4840 		dev_dbg(&port_dev->dev, "warm reset change\n");
4841 		usb_clear_port_feature(hdev, port1,
4842 				USB_PORT_FEAT_C_BH_PORT_RESET);
4843 	}
4844 	if (portchange & USB_PORT_STAT_C_LINK_STATE) {
4845 		dev_dbg(&port_dev->dev, "link state change\n");
4846 		usb_clear_port_feature(hdev, port1,
4847 				USB_PORT_FEAT_C_PORT_LINK_STATE);
4848 	}
4849 	if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) {
4850 		dev_warn(&port_dev->dev, "config error\n");
4851 		usb_clear_port_feature(hdev, port1,
4852 				USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
4853 	}
4854 
4855 	/* skip port actions that require the port to be powered on */
4856 	if (!pm_runtime_active(&port_dev->dev))
4857 		return;
4858 
4859 	if (hub_handle_remote_wakeup(hub, port1, portstatus, portchange))
4860 		connect_change = 1;
4861 
4862 	/*
4863 	 * Warm reset a USB3 protocol port if it's in
4864 	 * SS.Inactive state.
4865 	 */
4866 	if (hub_port_warm_reset_required(hub, portstatus)) {
4867 		dev_dbg(&port_dev->dev, "do warm reset\n");
4868 		if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
4869 				|| udev->state == USB_STATE_NOTATTACHED) {
4870 			if (hub_port_reset(hub, port1, NULL,
4871 					HUB_BH_RESET_TIME, true) < 0)
4872 				hub_port_disable(hub, port1, 1);
4873 		} else
4874 			reset_device = 1;
4875 	}
4876 
4877 	/*
4878 	 * On disconnect USB3 protocol ports transit from U0 to
4879 	 * SS.Inactive to Rx.Detect. If this happens a warm-
4880 	 * reset is not needed, but a (re)connect may happen
4881 	 * before khubd runs and sees the disconnect, and the
4882 	 * device may be an unknown state.
4883 	 *
4884 	 * If the port went through SS.Inactive without khubd
4885 	 * seeing it the C_LINK_STATE change flag will be set,
4886 	 * and we reset the dev to put it in a known state.
4887 	 */
4888 	if (reset_device || (udev && hub_is_superspeed(hub->hdev)
4889 				&& (portchange & USB_PORT_STAT_C_LINK_STATE)
4890 				&& (portstatus & USB_PORT_STAT_CONNECTION))) {
4891 		usb_unlock_port(port_dev);
4892 		usb_lock_device(udev);
4893 		usb_reset_device(udev);
4894 		usb_unlock_device(udev);
4895 		usb_lock_port(port_dev);
4896 		connect_change = 0;
4897 	}
4898 
4899 	if (connect_change)
4900 		hub_port_connect_change(hub, port1, portstatus, portchange);
4901 }
4902 
4903 
4904 static void hub_events(void)
4905 {
4906 	struct list_head *tmp;
4907 	struct usb_device *hdev;
4908 	struct usb_interface *intf;
4909 	struct usb_hub *hub;
4910 	struct device *hub_dev;
4911 	u16 hubstatus;
4912 	u16 hubchange;
4913 	int i, ret;
4914 
4915 	/*
4916 	 *  We restart the list every time to avoid a deadlock with
4917 	 * deleting hubs downstream from this one. This should be
4918 	 * safe since we delete the hub from the event list.
4919 	 * Not the most efficient, but avoids deadlocks.
4920 	 */
4921 	while (1) {
4922 
4923 		/* Grab the first entry at the beginning of the list */
4924 		spin_lock_irq(&hub_event_lock);
4925 		if (list_empty(&hub_event_list)) {
4926 			spin_unlock_irq(&hub_event_lock);
4927 			break;
4928 		}
4929 
4930 		tmp = hub_event_list.next;
4931 		list_del_init(tmp);
4932 
4933 		hub = list_entry(tmp, struct usb_hub, event_list);
4934 		kref_get(&hub->kref);
4935 		spin_unlock_irq(&hub_event_lock);
4936 
4937 		hdev = hub->hdev;
4938 		hub_dev = hub->intfdev;
4939 		intf = to_usb_interface(hub_dev);
4940 		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
4941 				hdev->state, hdev->maxchild,
4942 				/* NOTE: expects max 15 ports... */
4943 				(u16) hub->change_bits[0],
4944 				(u16) hub->event_bits[0]);
4945 
4946 		/* Lock the device, then check to see if we were
4947 		 * disconnected while waiting for the lock to succeed. */
4948 		usb_lock_device(hdev);
4949 		if (unlikely(hub->disconnected))
4950 			goto loop_disconnected;
4951 
4952 		/* If the hub has died, clean up after it */
4953 		if (hdev->state == USB_STATE_NOTATTACHED) {
4954 			hub->error = -ENODEV;
4955 			hub_quiesce(hub, HUB_DISCONNECT);
4956 			goto loop;
4957 		}
4958 
4959 		/* Autoresume */
4960 		ret = usb_autopm_get_interface(intf);
4961 		if (ret) {
4962 			dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
4963 			goto loop;
4964 		}
4965 
4966 		/* If this is an inactive hub, do nothing */
4967 		if (hub->quiescing)
4968 			goto loop_autopm;
4969 
4970 		if (hub->error) {
4971 			dev_dbg (hub_dev, "resetting for error %d\n",
4972 				hub->error);
4973 
4974 			ret = usb_reset_device(hdev);
4975 			if (ret) {
4976 				dev_dbg (hub_dev,
4977 					"error resetting hub: %d\n", ret);
4978 				goto loop_autopm;
4979 			}
4980 
4981 			hub->nerrors = 0;
4982 			hub->error = 0;
4983 		}
4984 
4985 		/* deal with port status changes */
4986 		for (i = 1; i <= hdev->maxchild; i++) {
4987 			struct usb_port *port_dev = hub->ports[i - 1];
4988 
4989 			if (test_bit(i, hub->event_bits)
4990 					|| test_bit(i, hub->change_bits)
4991 					|| test_bit(i, hub->wakeup_bits)) {
4992 				/*
4993 				 * The get_noresume and barrier ensure that if
4994 				 * the port was in the process of resuming, we
4995 				 * flush that work and keep the port active for
4996 				 * the duration of the port_event().  However,
4997 				 * if the port is runtime pm suspended
4998 				 * (powered-off), we leave it in that state, run
4999 				 * an abbreviated port_event(), and move on.
5000 				 */
5001 				pm_runtime_get_noresume(&port_dev->dev);
5002 				pm_runtime_barrier(&port_dev->dev);
5003 				usb_lock_port(port_dev);
5004 				port_event(hub, i);
5005 				usb_unlock_port(port_dev);
5006 				pm_runtime_put_sync(&port_dev->dev);
5007 			}
5008 		}
5009 
5010 		/* deal with hub status changes */
5011 		if (test_and_clear_bit(0, hub->event_bits) == 0)
5012 			;	/* do nothing */
5013 		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
5014 			dev_err (hub_dev, "get_hub_status failed\n");
5015 		else {
5016 			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
5017 				dev_dbg (hub_dev, "power change\n");
5018 				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
5019 				if (hubstatus & HUB_STATUS_LOCAL_POWER)
5020 					/* FIXME: Is this always true? */
5021 					hub->limited_power = 1;
5022 				else
5023 					hub->limited_power = 0;
5024 			}
5025 			if (hubchange & HUB_CHANGE_OVERCURRENT) {
5026 				u16 status = 0;
5027 				u16 unused;
5028 
5029 				dev_dbg(hub_dev, "over-current change\n");
5030 				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
5031 				msleep(500);	/* Cool down */
5032 				hub_power_on(hub, true);
5033 				hub_hub_status(hub, &status, &unused);
5034 				if (status & HUB_STATUS_OVERCURRENT)
5035 					dev_err(hub_dev, "over-current "
5036 						"condition\n");
5037 			}
5038 		}
5039 
5040  loop_autopm:
5041 		/* Balance the usb_autopm_get_interface() above */
5042 		usb_autopm_put_interface_no_suspend(intf);
5043  loop:
5044 		/* Balance the usb_autopm_get_interface_no_resume() in
5045 		 * kick_khubd() and allow autosuspend.
5046 		 */
5047 		usb_autopm_put_interface(intf);
5048  loop_disconnected:
5049 		usb_unlock_device(hdev);
5050 		kref_put(&hub->kref, hub_release);
5051 
5052 	} /* end while (1) */
5053 }
5054 
5055 static int hub_thread(void *__unused)
5056 {
5057 	/* khubd needs to be freezable to avoid interfering with USB-PERSIST
5058 	 * port handover.  Otherwise it might see that a full-speed device
5059 	 * was gone before the EHCI controller had handed its port over to
5060 	 * the companion full-speed controller.
5061 	 */
5062 	set_freezable();
5063 
5064 	do {
5065 		hub_events();
5066 		wait_event_freezable(khubd_wait,
5067 				!list_empty(&hub_event_list) ||
5068 				kthread_should_stop());
5069 	} while (!kthread_should_stop() || !list_empty(&hub_event_list));
5070 
5071 	pr_debug("%s: khubd exiting\n", usbcore_name);
5072 	return 0;
5073 }
5074 
5075 static const struct usb_device_id hub_id_table[] = {
5076     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5077 			| USB_DEVICE_ID_MATCH_INT_CLASS,
5078       .idVendor = USB_VENDOR_GENESYS_LOGIC,
5079       .bInterfaceClass = USB_CLASS_HUB,
5080       .driver_info = HUB_QUIRK_CHECK_PORT_AUTOSUSPEND},
5081     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
5082       .bDeviceClass = USB_CLASS_HUB},
5083     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
5084       .bInterfaceClass = USB_CLASS_HUB},
5085     { }						/* Terminating entry */
5086 };
5087 
5088 MODULE_DEVICE_TABLE (usb, hub_id_table);
5089 
5090 static struct usb_driver hub_driver = {
5091 	.name =		"hub",
5092 	.probe =	hub_probe,
5093 	.disconnect =	hub_disconnect,
5094 	.suspend =	hub_suspend,
5095 	.resume =	hub_resume,
5096 	.reset_resume =	hub_reset_resume,
5097 	.pre_reset =	hub_pre_reset,
5098 	.post_reset =	hub_post_reset,
5099 	.unlocked_ioctl = hub_ioctl,
5100 	.id_table =	hub_id_table,
5101 	.supports_autosuspend =	1,
5102 };
5103 
5104 int usb_hub_init(void)
5105 {
5106 	if (usb_register(&hub_driver) < 0) {
5107 		printk(KERN_ERR "%s: can't register hub driver\n",
5108 			usbcore_name);
5109 		return -1;
5110 	}
5111 
5112 	khubd_task = kthread_run(hub_thread, NULL, "khubd");
5113 	if (!IS_ERR(khubd_task))
5114 		return 0;
5115 
5116 	/* Fall through if kernel_thread failed */
5117 	usb_deregister(&hub_driver);
5118 	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
5119 
5120 	return -1;
5121 }
5122 
5123 void usb_hub_cleanup(void)
5124 {
5125 	kthread_stop(khubd_task);
5126 
5127 	/*
5128 	 * Hub resources are freed for us by usb_deregister. It calls
5129 	 * usb_driver_purge on every device which in turn calls that
5130 	 * devices disconnect function if it is using this driver.
5131 	 * The hub_disconnect function takes care of releasing the
5132 	 * individual hub resources. -greg
5133 	 */
5134 	usb_deregister(&hub_driver);
5135 } /* usb_hub_cleanup() */
5136 
5137 static int descriptors_changed(struct usb_device *udev,
5138 		struct usb_device_descriptor *old_device_descriptor,
5139 		struct usb_host_bos *old_bos)
5140 {
5141 	int		changed = 0;
5142 	unsigned	index;
5143 	unsigned	serial_len = 0;
5144 	unsigned	len;
5145 	unsigned	old_length;
5146 	int		length;
5147 	char		*buf;
5148 
5149 	if (memcmp(&udev->descriptor, old_device_descriptor,
5150 			sizeof(*old_device_descriptor)) != 0)
5151 		return 1;
5152 
5153 	if ((old_bos && !udev->bos) || (!old_bos && udev->bos))
5154 		return 1;
5155 	if (udev->bos) {
5156 		len = le16_to_cpu(udev->bos->desc->wTotalLength);
5157 		if (len != le16_to_cpu(old_bos->desc->wTotalLength))
5158 			return 1;
5159 		if (memcmp(udev->bos->desc, old_bos->desc, len))
5160 			return 1;
5161 	}
5162 
5163 	/* Since the idVendor, idProduct, and bcdDevice values in the
5164 	 * device descriptor haven't changed, we will assume the
5165 	 * Manufacturer and Product strings haven't changed either.
5166 	 * But the SerialNumber string could be different (e.g., a
5167 	 * different flash card of the same brand).
5168 	 */
5169 	if (udev->serial)
5170 		serial_len = strlen(udev->serial) + 1;
5171 
5172 	len = serial_len;
5173 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5174 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5175 		len = max(len, old_length);
5176 	}
5177 
5178 	buf = kmalloc(len, GFP_NOIO);
5179 	if (buf == NULL) {
5180 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
5181 		/* assume the worst */
5182 		return 1;
5183 	}
5184 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5185 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5186 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
5187 				old_length);
5188 		if (length != old_length) {
5189 			dev_dbg(&udev->dev, "config index %d, error %d\n",
5190 					index, length);
5191 			changed = 1;
5192 			break;
5193 		}
5194 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
5195 				!= 0) {
5196 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
5197 				index,
5198 				((struct usb_config_descriptor *) buf)->
5199 					bConfigurationValue);
5200 			changed = 1;
5201 			break;
5202 		}
5203 	}
5204 
5205 	if (!changed && serial_len) {
5206 		length = usb_string(udev, udev->descriptor.iSerialNumber,
5207 				buf, serial_len);
5208 		if (length + 1 != serial_len) {
5209 			dev_dbg(&udev->dev, "serial string error %d\n",
5210 					length);
5211 			changed = 1;
5212 		} else if (memcmp(buf, udev->serial, length) != 0) {
5213 			dev_dbg(&udev->dev, "serial string changed\n");
5214 			changed = 1;
5215 		}
5216 	}
5217 
5218 	kfree(buf);
5219 	return changed;
5220 }
5221 
5222 /**
5223  * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
5224  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5225  *
5226  * WARNING - don't use this routine to reset a composite device
5227  * (one with multiple interfaces owned by separate drivers)!
5228  * Use usb_reset_device() instead.
5229  *
5230  * Do a port reset, reassign the device's address, and establish its
5231  * former operating configuration.  If the reset fails, or the device's
5232  * descriptors change from their values before the reset, or the original
5233  * configuration and altsettings cannot be restored, a flag will be set
5234  * telling khubd to pretend the device has been disconnected and then
5235  * re-connected.  All drivers will be unbound, and the device will be
5236  * re-enumerated and probed all over again.
5237  *
5238  * Return: 0 if the reset succeeded, -ENODEV if the device has been
5239  * flagged for logical disconnection, or some other negative error code
5240  * if the reset wasn't even attempted.
5241  *
5242  * Note:
5243  * The caller must own the device lock and the port lock, the latter is
5244  * taken by usb_reset_device().  For example, it's safe to use
5245  * usb_reset_device() from a driver probe() routine after downloading
5246  * new firmware.  For calls that might not occur during probe(), drivers
5247  * should lock the device using usb_lock_device_for_reset().
5248  *
5249  * Locking exception: This routine may also be called from within an
5250  * autoresume handler.  Such usage won't conflict with other tasks
5251  * holding the device lock because these tasks should always call
5252  * usb_autopm_resume_device(), thereby preventing any unwanted
5253  * autoresume.  The autoresume handler is expected to have already
5254  * acquired the port lock before calling this routine.
5255  */
5256 static int usb_reset_and_verify_device(struct usb_device *udev)
5257 {
5258 	struct usb_device		*parent_hdev = udev->parent;
5259 	struct usb_hub			*parent_hub;
5260 	struct usb_hcd			*hcd = bus_to_hcd(udev->bus);
5261 	struct usb_device_descriptor	descriptor = udev->descriptor;
5262 	struct usb_host_bos		*bos;
5263 	int				i, j, ret = 0;
5264 	int				port1 = udev->portnum;
5265 
5266 	if (udev->state == USB_STATE_NOTATTACHED ||
5267 			udev->state == USB_STATE_SUSPENDED) {
5268 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5269 				udev->state);
5270 		return -EINVAL;
5271 	}
5272 
5273 	if (!parent_hdev)
5274 		return -EISDIR;
5275 
5276 	parent_hub = usb_hub_to_struct_hub(parent_hdev);
5277 
5278 	/* Disable USB2 hardware LPM.
5279 	 * It will be re-enabled by the enumeration process.
5280 	 */
5281 	if (udev->usb2_hw_lpm_enabled == 1)
5282 		usb_set_usb2_hardware_lpm(udev, 0);
5283 
5284 	bos = udev->bos;
5285 	udev->bos = NULL;
5286 
5287 	/* Disable LPM and LTM while we reset the device and reinstall the alt
5288 	 * settings.  Device-initiated LPM settings, and system exit latency
5289 	 * settings are cleared when the device is reset, so we have to set
5290 	 * them up again.
5291 	 */
5292 	ret = usb_unlocked_disable_lpm(udev);
5293 	if (ret) {
5294 		dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
5295 		goto re_enumerate;
5296 	}
5297 	ret = usb_disable_ltm(udev);
5298 	if (ret) {
5299 		dev_err(&udev->dev, "%s Failed to disable LTM\n.",
5300 				__func__);
5301 		goto re_enumerate;
5302 	}
5303 
5304 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
5305 
5306 		/* ep0 maxpacket size may change; let the HCD know about it.
5307 		 * Other endpoints will be handled by re-enumeration. */
5308 		usb_ep0_reinit(udev);
5309 		ret = hub_port_init(parent_hub, udev, port1, i);
5310 		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
5311 			break;
5312 	}
5313 
5314 	if (ret < 0)
5315 		goto re_enumerate;
5316 
5317 	/* Device might have changed firmware (DFU or similar) */
5318 	if (descriptors_changed(udev, &descriptor, bos)) {
5319 		dev_info(&udev->dev, "device firmware changed\n");
5320 		udev->descriptor = descriptor;	/* for disconnect() calls */
5321 		goto re_enumerate;
5322 	}
5323 
5324 	/* Restore the device's previous configuration */
5325 	if (!udev->actconfig)
5326 		goto done;
5327 
5328 	mutex_lock(hcd->bandwidth_mutex);
5329 	ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
5330 	if (ret < 0) {
5331 		dev_warn(&udev->dev,
5332 				"Busted HC?  Not enough HCD resources for "
5333 				"old configuration.\n");
5334 		mutex_unlock(hcd->bandwidth_mutex);
5335 		goto re_enumerate;
5336 	}
5337 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
5338 			USB_REQ_SET_CONFIGURATION, 0,
5339 			udev->actconfig->desc.bConfigurationValue, 0,
5340 			NULL, 0, USB_CTRL_SET_TIMEOUT);
5341 	if (ret < 0) {
5342 		dev_err(&udev->dev,
5343 			"can't restore configuration #%d (error=%d)\n",
5344 			udev->actconfig->desc.bConfigurationValue, ret);
5345 		mutex_unlock(hcd->bandwidth_mutex);
5346 		goto re_enumerate;
5347 	}
5348 	mutex_unlock(hcd->bandwidth_mutex);
5349 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
5350 
5351 	/* Put interfaces back into the same altsettings as before.
5352 	 * Don't bother to send the Set-Interface request for interfaces
5353 	 * that were already in altsetting 0; besides being unnecessary,
5354 	 * many devices can't handle it.  Instead just reset the host-side
5355 	 * endpoint state.
5356 	 */
5357 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
5358 		struct usb_host_config *config = udev->actconfig;
5359 		struct usb_interface *intf = config->interface[i];
5360 		struct usb_interface_descriptor *desc;
5361 
5362 		desc = &intf->cur_altsetting->desc;
5363 		if (desc->bAlternateSetting == 0) {
5364 			usb_disable_interface(udev, intf, true);
5365 			usb_enable_interface(udev, intf, true);
5366 			ret = 0;
5367 		} else {
5368 			/* Let the bandwidth allocation function know that this
5369 			 * device has been reset, and it will have to use
5370 			 * alternate setting 0 as the current alternate setting.
5371 			 */
5372 			intf->resetting_device = 1;
5373 			ret = usb_set_interface(udev, desc->bInterfaceNumber,
5374 					desc->bAlternateSetting);
5375 			intf->resetting_device = 0;
5376 		}
5377 		if (ret < 0) {
5378 			dev_err(&udev->dev, "failed to restore interface %d "
5379 				"altsetting %d (error=%d)\n",
5380 				desc->bInterfaceNumber,
5381 				desc->bAlternateSetting,
5382 				ret);
5383 			goto re_enumerate;
5384 		}
5385 		/* Resetting also frees any allocated streams */
5386 		for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++)
5387 			intf->cur_altsetting->endpoint[j].streams = 0;
5388 	}
5389 
5390 done:
5391 	/* Now that the alt settings are re-installed, enable LTM and LPM. */
5392 	usb_set_usb2_hardware_lpm(udev, 1);
5393 	usb_unlocked_enable_lpm(udev);
5394 	usb_enable_ltm(udev);
5395 	usb_release_bos_descriptor(udev);
5396 	udev->bos = bos;
5397 	return 0;
5398 
5399 re_enumerate:
5400 	/* LPM state doesn't matter when we're about to destroy the device. */
5401 	hub_port_logical_disconnect(parent_hub, port1);
5402 	usb_release_bos_descriptor(udev);
5403 	udev->bos = bos;
5404 	return -ENODEV;
5405 }
5406 
5407 /**
5408  * usb_reset_device - warn interface drivers and perform a USB port reset
5409  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5410  *
5411  * Warns all drivers bound to registered interfaces (using their pre_reset
5412  * method), performs the port reset, and then lets the drivers know that
5413  * the reset is over (using their post_reset method).
5414  *
5415  * Return: The same as for usb_reset_and_verify_device().
5416  *
5417  * Note:
5418  * The caller must own the device lock.  For example, it's safe to use
5419  * this from a driver probe() routine after downloading new firmware.
5420  * For calls that might not occur during probe(), drivers should lock
5421  * the device using usb_lock_device_for_reset().
5422  *
5423  * If an interface is currently being probed or disconnected, we assume
5424  * its driver knows how to handle resets.  For all other interfaces,
5425  * if the driver doesn't have pre_reset and post_reset methods then
5426  * we attempt to unbind it and rebind afterward.
5427  */
5428 int usb_reset_device(struct usb_device *udev)
5429 {
5430 	int ret;
5431 	int i;
5432 	unsigned int noio_flag;
5433 	struct usb_port *port_dev;
5434 	struct usb_host_config *config = udev->actconfig;
5435 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
5436 
5437 	if (udev->state == USB_STATE_NOTATTACHED ||
5438 			udev->state == USB_STATE_SUSPENDED) {
5439 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5440 				udev->state);
5441 		return -EINVAL;
5442 	}
5443 
5444 	if (!udev->parent) {
5445 		/* this requires hcd-specific logic; see ohci_restart() */
5446 		dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
5447 		return -EISDIR;
5448 	}
5449 
5450 	port_dev = hub->ports[udev->portnum - 1];
5451 
5452 	/*
5453 	 * Don't allocate memory with GFP_KERNEL in current
5454 	 * context to avoid possible deadlock if usb mass
5455 	 * storage interface or usbnet interface(iSCSI case)
5456 	 * is included in current configuration. The easist
5457 	 * approach is to do it for every device reset,
5458 	 * because the device 'memalloc_noio' flag may have
5459 	 * not been set before reseting the usb device.
5460 	 */
5461 	noio_flag = memalloc_noio_save();
5462 
5463 	/* Prevent autosuspend during the reset */
5464 	usb_autoresume_device(udev);
5465 
5466 	if (config) {
5467 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
5468 			struct usb_interface *cintf = config->interface[i];
5469 			struct usb_driver *drv;
5470 			int unbind = 0;
5471 
5472 			if (cintf->dev.driver) {
5473 				drv = to_usb_driver(cintf->dev.driver);
5474 				if (drv->pre_reset && drv->post_reset)
5475 					unbind = (drv->pre_reset)(cintf);
5476 				else if (cintf->condition ==
5477 						USB_INTERFACE_BOUND)
5478 					unbind = 1;
5479 				if (unbind)
5480 					usb_forced_unbind_intf(cintf);
5481 			}
5482 		}
5483 	}
5484 
5485 	usb_lock_port(port_dev);
5486 	ret = usb_reset_and_verify_device(udev);
5487 	usb_unlock_port(port_dev);
5488 
5489 	if (config) {
5490 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
5491 			struct usb_interface *cintf = config->interface[i];
5492 			struct usb_driver *drv;
5493 			int rebind = cintf->needs_binding;
5494 
5495 			if (!rebind && cintf->dev.driver) {
5496 				drv = to_usb_driver(cintf->dev.driver);
5497 				if (drv->post_reset)
5498 					rebind = (drv->post_reset)(cintf);
5499 				else if (cintf->condition ==
5500 						USB_INTERFACE_BOUND)
5501 					rebind = 1;
5502 				if (rebind)
5503 					cintf->needs_binding = 1;
5504 			}
5505 		}
5506 		usb_unbind_and_rebind_marked_interfaces(udev);
5507 	}
5508 
5509 	usb_autosuspend_device(udev);
5510 	memalloc_noio_restore(noio_flag);
5511 	return ret;
5512 }
5513 EXPORT_SYMBOL_GPL(usb_reset_device);
5514 
5515 
5516 /**
5517  * usb_queue_reset_device - Reset a USB device from an atomic context
5518  * @iface: USB interface belonging to the device to reset
5519  *
5520  * This function can be used to reset a USB device from an atomic
5521  * context, where usb_reset_device() won't work (as it blocks).
5522  *
5523  * Doing a reset via this method is functionally equivalent to calling
5524  * usb_reset_device(), except for the fact that it is delayed to a
5525  * workqueue. This means that any drivers bound to other interfaces
5526  * might be unbound, as well as users from usbfs in user space.
5527  *
5528  * Corner cases:
5529  *
5530  * - Scheduling two resets at the same time from two different drivers
5531  *   attached to two different interfaces of the same device is
5532  *   possible; depending on how the driver attached to each interface
5533  *   handles ->pre_reset(), the second reset might happen or not.
5534  *
5535  * - If a driver is unbound and it had a pending reset, the reset will
5536  *   be cancelled.
5537  *
5538  * - This function can be called during .probe() or .disconnect()
5539  *   times. On return from .disconnect(), any pending resets will be
5540  *   cancelled.
5541  *
5542  * There is no no need to lock/unlock the @reset_ws as schedule_work()
5543  * does its own.
5544  *
5545  * NOTE: We don't do any reference count tracking because it is not
5546  *     needed. The lifecycle of the work_struct is tied to the
5547  *     usb_interface. Before destroying the interface we cancel the
5548  *     work_struct, so the fact that work_struct is queued and or
5549  *     running means the interface (and thus, the device) exist and
5550  *     are referenced.
5551  */
5552 void usb_queue_reset_device(struct usb_interface *iface)
5553 {
5554 	schedule_work(&iface->reset_ws);
5555 }
5556 EXPORT_SYMBOL_GPL(usb_queue_reset_device);
5557 
5558 /**
5559  * usb_hub_find_child - Get the pointer of child device
5560  * attached to the port which is specified by @port1.
5561  * @hdev: USB device belonging to the usb hub
5562  * @port1: port num to indicate which port the child device
5563  *	is attached to.
5564  *
5565  * USB drivers call this function to get hub's child device
5566  * pointer.
5567  *
5568  * Return: %NULL if input param is invalid and
5569  * child's usb_device pointer if non-NULL.
5570  */
5571 struct usb_device *usb_hub_find_child(struct usb_device *hdev,
5572 		int port1)
5573 {
5574 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5575 
5576 	if (port1 < 1 || port1 > hdev->maxchild)
5577 		return NULL;
5578 	return hub->ports[port1 - 1]->child;
5579 }
5580 EXPORT_SYMBOL_GPL(usb_hub_find_child);
5581 
5582 void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
5583 		struct usb_hub_descriptor *desc)
5584 {
5585 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5586 	enum usb_port_connect_type connect_type;
5587 	int i;
5588 
5589 	if (!hub)
5590 		return;
5591 
5592 	if (!hub_is_superspeed(hdev)) {
5593 		for (i = 1; i <= hdev->maxchild; i++) {
5594 			struct usb_port *port_dev = hub->ports[i - 1];
5595 
5596 			connect_type = port_dev->connect_type;
5597 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5598 				u8 mask = 1 << (i%8);
5599 
5600 				if (!(desc->u.hs.DeviceRemovable[i/8] & mask)) {
5601 					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
5602 					desc->u.hs.DeviceRemovable[i/8]	|= mask;
5603 				}
5604 			}
5605 		}
5606 	} else {
5607 		u16 port_removable = le16_to_cpu(desc->u.ss.DeviceRemovable);
5608 
5609 		for (i = 1; i <= hdev->maxchild; i++) {
5610 			struct usb_port *port_dev = hub->ports[i - 1];
5611 
5612 			connect_type = port_dev->connect_type;
5613 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5614 				u16 mask = 1 << i;
5615 
5616 				if (!(port_removable & mask)) {
5617 					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
5618 					port_removable |= mask;
5619 				}
5620 			}
5621 		}
5622 
5623 		desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
5624 	}
5625 }
5626 
5627 #ifdef CONFIG_ACPI
5628 /**
5629  * usb_get_hub_port_acpi_handle - Get the usb port's acpi handle
5630  * @hdev: USB device belonging to the usb hub
5631  * @port1: port num of the port
5632  *
5633  * Return: Port's acpi handle if successful, %NULL if params are
5634  * invalid.
5635  */
5636 acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
5637 	int port1)
5638 {
5639 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5640 
5641 	if (!hub)
5642 		return NULL;
5643 
5644 	return ACPI_HANDLE(&hub->ports[port1 - 1]->dev);
5645 }
5646 #endif
5647