xref: /openbmc/linux/drivers/usb/core/hub.c (revision 643d1f7f)
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/kthread.h>
23 #include <linux/mutex.h>
24 #include <linux/freezer.h>
25 
26 #include <asm/semaphore.h>
27 #include <asm/uaccess.h>
28 #include <asm/byteorder.h>
29 
30 #include "usb.h"
31 #include "hcd.h"
32 #include "hub.h"
33 
34 #ifdef	CONFIG_USB_PERSIST
35 #define	USB_PERSIST	1
36 #else
37 #define	USB_PERSIST	0
38 #endif
39 
40 /* if we are in debug mode, always announce new devices */
41 #ifdef DEBUG
42 #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
43 #define CONFIG_USB_ANNOUNCE_NEW_DEVICES
44 #endif
45 #endif
46 
47 struct usb_hub {
48 	struct device		*intfdev;	/* the "interface" device */
49 	struct usb_device	*hdev;
50 	struct kref		kref;
51 	struct urb		*urb;		/* for interrupt polling pipe */
52 
53 	/* buffer for urb ... with extra space in case of babble */
54 	char			(*buffer)[8];
55 	dma_addr_t		buffer_dma;	/* DMA address for buffer */
56 	union {
57 		struct usb_hub_status	hub;
58 		struct usb_port_status	port;
59 	}			*status;	/* buffer for status reports */
60 	struct mutex		status_mutex;	/* for the status buffer */
61 
62 	int			error;		/* last reported error */
63 	int			nerrors;	/* track consecutive errors */
64 
65 	struct list_head	event_list;	/* hubs w/data or errs ready */
66 	unsigned long		event_bits[1];	/* status change bitmask */
67 	unsigned long		change_bits[1];	/* ports with logical connect
68 							status change */
69 	unsigned long		busy_bits[1];	/* ports being reset or
70 							resumed */
71 #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */
72 #error event_bits[] is too short!
73 #endif
74 
75 	struct usb_hub_descriptor *descriptor;	/* class descriptor */
76 	struct usb_tt		tt;		/* Transaction Translator */
77 
78 	unsigned		mA_per_port;	/* current for each child */
79 
80 	unsigned		limited_power:1;
81 	unsigned		quiescing:1;
82 	unsigned		activating:1;
83 	unsigned		disconnected:1;
84 
85 	unsigned		has_indicators:1;
86 	u8			indicator[USB_MAXCHILDREN];
87 	struct delayed_work	leds;
88 };
89 
90 
91 /* Protect struct usb_device->state and ->children members
92  * Note: Both are also protected by ->dev.sem, except that ->state can
93  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
94 static DEFINE_SPINLOCK(device_state_lock);
95 
96 /* khubd's worklist and its lock */
97 static DEFINE_SPINLOCK(hub_event_lock);
98 static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */
99 
100 /* Wakes up khubd */
101 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
102 
103 static struct task_struct *khubd_task;
104 
105 /* cycle leds on hubs that aren't blinking for attention */
106 static int blinkenlights = 0;
107 module_param (blinkenlights, bool, S_IRUGO);
108 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
109 
110 /*
111  * As of 2.6.10 we introduce a new USB device initialization scheme which
112  * closely resembles the way Windows works.  Hopefully it will be compatible
113  * with a wider range of devices than the old scheme.  However some previously
114  * working devices may start giving rise to "device not accepting address"
115  * errors; if that happens the user can try the old scheme by adjusting the
116  * following module parameters.
117  *
118  * For maximum flexibility there are two boolean parameters to control the
119  * hub driver's behavior.  On the first initialization attempt, if the
120  * "old_scheme_first" parameter is set then the old scheme will be used,
121  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
122  * is set, then the driver will make another attempt, using the other scheme.
123  */
124 static int old_scheme_first = 0;
125 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
126 MODULE_PARM_DESC(old_scheme_first,
127 		 "start with the old device initialization scheme");
128 
129 static int use_both_schemes = 1;
130 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
131 MODULE_PARM_DESC(use_both_schemes,
132 		"try the other device initialization scheme if the "
133 		"first one fails");
134 
135 /* Mutual exclusion for EHCI CF initialization.  This interferes with
136  * port reset on some companion controllers.
137  */
138 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
139 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
140 
141 
142 static inline char *portspeed(int portstatus)
143 {
144 	if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
145     		return "480 Mb/s";
146 	else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
147 		return "1.5 Mb/s";
148 	else
149 		return "12 Mb/s";
150 }
151 
152 /* Note that hdev or one of its children must be locked! */
153 static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
154 {
155 	return usb_get_intfdata(hdev->actconfig->interface[0]);
156 }
157 
158 /* USB 2.0 spec Section 11.24.4.5 */
159 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
160 {
161 	int i, ret;
162 
163 	for (i = 0; i < 3; i++) {
164 		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
165 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
166 			USB_DT_HUB << 8, 0, data, size,
167 			USB_CTRL_GET_TIMEOUT);
168 		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
169 			return ret;
170 	}
171 	return -EINVAL;
172 }
173 
174 /*
175  * USB 2.0 spec Section 11.24.2.1
176  */
177 static int clear_hub_feature(struct usb_device *hdev, int feature)
178 {
179 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
180 		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
181 }
182 
183 /*
184  * USB 2.0 spec Section 11.24.2.2
185  */
186 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
187 {
188 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
189 		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
190 		NULL, 0, 1000);
191 }
192 
193 /*
194  * USB 2.0 spec Section 11.24.2.13
195  */
196 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
197 {
198 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
199 		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
200 		NULL, 0, 1000);
201 }
202 
203 /*
204  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
205  * for info about using port indicators
206  */
207 static void set_port_led(
208 	struct usb_hub *hub,
209 	int port1,
210 	int selector
211 )
212 {
213 	int status = set_port_feature(hub->hdev, (selector << 8) | port1,
214 			USB_PORT_FEAT_INDICATOR);
215 	if (status < 0)
216 		dev_dbg (hub->intfdev,
217 			"port %d indicator %s status %d\n",
218 			port1,
219 			({ char *s; switch (selector) {
220 			case HUB_LED_AMBER: s = "amber"; break;
221 			case HUB_LED_GREEN: s = "green"; break;
222 			case HUB_LED_OFF: s = "off"; break;
223 			case HUB_LED_AUTO: s = "auto"; break;
224 			default: s = "??"; break;
225 			}; s; }),
226 			status);
227 }
228 
229 #define	LED_CYCLE_PERIOD	((2*HZ)/3)
230 
231 static void led_work (struct work_struct *work)
232 {
233 	struct usb_hub		*hub =
234 		container_of(work, struct usb_hub, leds.work);
235 	struct usb_device	*hdev = hub->hdev;
236 	unsigned		i;
237 	unsigned		changed = 0;
238 	int			cursor = -1;
239 
240 	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
241 		return;
242 
243 	for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
244 		unsigned	selector, mode;
245 
246 		/* 30%-50% duty cycle */
247 
248 		switch (hub->indicator[i]) {
249 		/* cycle marker */
250 		case INDICATOR_CYCLE:
251 			cursor = i;
252 			selector = HUB_LED_AUTO;
253 			mode = INDICATOR_AUTO;
254 			break;
255 		/* blinking green = sw attention */
256 		case INDICATOR_GREEN_BLINK:
257 			selector = HUB_LED_GREEN;
258 			mode = INDICATOR_GREEN_BLINK_OFF;
259 			break;
260 		case INDICATOR_GREEN_BLINK_OFF:
261 			selector = HUB_LED_OFF;
262 			mode = INDICATOR_GREEN_BLINK;
263 			break;
264 		/* blinking amber = hw attention */
265 		case INDICATOR_AMBER_BLINK:
266 			selector = HUB_LED_AMBER;
267 			mode = INDICATOR_AMBER_BLINK_OFF;
268 			break;
269 		case INDICATOR_AMBER_BLINK_OFF:
270 			selector = HUB_LED_OFF;
271 			mode = INDICATOR_AMBER_BLINK;
272 			break;
273 		/* blink green/amber = reserved */
274 		case INDICATOR_ALT_BLINK:
275 			selector = HUB_LED_GREEN;
276 			mode = INDICATOR_ALT_BLINK_OFF;
277 			break;
278 		case INDICATOR_ALT_BLINK_OFF:
279 			selector = HUB_LED_AMBER;
280 			mode = INDICATOR_ALT_BLINK;
281 			break;
282 		default:
283 			continue;
284 		}
285 		if (selector != HUB_LED_AUTO)
286 			changed = 1;
287 		set_port_led(hub, i + 1, selector);
288 		hub->indicator[i] = mode;
289 	}
290 	if (!changed && blinkenlights) {
291 		cursor++;
292 		cursor %= hub->descriptor->bNbrPorts;
293 		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
294 		hub->indicator[cursor] = INDICATOR_CYCLE;
295 		changed++;
296 	}
297 	if (changed)
298 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
299 }
300 
301 /* use a short timeout for hub/port status fetches */
302 #define	USB_STS_TIMEOUT		1000
303 #define	USB_STS_RETRIES		5
304 
305 /*
306  * USB 2.0 spec Section 11.24.2.6
307  */
308 static int get_hub_status(struct usb_device *hdev,
309 		struct usb_hub_status *data)
310 {
311 	int i, status = -ETIMEDOUT;
312 
313 	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
314 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
315 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
316 			data, sizeof(*data), USB_STS_TIMEOUT);
317 	}
318 	return status;
319 }
320 
321 /*
322  * USB 2.0 spec Section 11.24.2.7
323  */
324 static int get_port_status(struct usb_device *hdev, int port1,
325 		struct usb_port_status *data)
326 {
327 	int i, status = -ETIMEDOUT;
328 
329 	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
330 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
331 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
332 			data, sizeof(*data), USB_STS_TIMEOUT);
333 	}
334 	return status;
335 }
336 
337 static void kick_khubd(struct usb_hub *hub)
338 {
339 	unsigned long	flags;
340 
341 	/* Suppress autosuspend until khubd runs */
342 	to_usb_interface(hub->intfdev)->pm_usage_cnt = 1;
343 
344 	spin_lock_irqsave(&hub_event_lock, flags);
345 	if (!hub->disconnected && list_empty(&hub->event_list)) {
346 		list_add_tail(&hub->event_list, &hub_event_list);
347 		wake_up(&khubd_wait);
348 	}
349 	spin_unlock_irqrestore(&hub_event_lock, flags);
350 }
351 
352 void usb_kick_khubd(struct usb_device *hdev)
353 {
354 	/* FIXME: What if hdev isn't bound to the hub driver? */
355 	kick_khubd(hdev_to_hub(hdev));
356 }
357 
358 
359 /* completion function, fires on port status changes and various faults */
360 static void hub_irq(struct urb *urb)
361 {
362 	struct usb_hub *hub = urb->context;
363 	int status = urb->status;
364 	int i;
365 	unsigned long bits;
366 
367 	switch (status) {
368 	case -ENOENT:		/* synchronous unlink */
369 	case -ECONNRESET:	/* async unlink */
370 	case -ESHUTDOWN:	/* hardware going away */
371 		return;
372 
373 	default:		/* presumably an error */
374 		/* Cause a hub reset after 10 consecutive errors */
375 		dev_dbg (hub->intfdev, "transfer --> %d\n", status);
376 		if ((++hub->nerrors < 10) || hub->error)
377 			goto resubmit;
378 		hub->error = status;
379 		/* FALL THROUGH */
380 
381 	/* let khubd handle things */
382 	case 0:			/* we got data:  port status changed */
383 		bits = 0;
384 		for (i = 0; i < urb->actual_length; ++i)
385 			bits |= ((unsigned long) ((*hub->buffer)[i]))
386 					<< (i*8);
387 		hub->event_bits[0] = bits;
388 		break;
389 	}
390 
391 	hub->nerrors = 0;
392 
393 	/* Something happened, let khubd figure it out */
394 	kick_khubd(hub);
395 
396 resubmit:
397 	if (hub->quiescing)
398 		return;
399 
400 	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
401 			&& status != -ENODEV && status != -EPERM)
402 		dev_err (hub->intfdev, "resubmit --> %d\n", status);
403 }
404 
405 /* USB 2.0 spec Section 11.24.2.3 */
406 static inline int
407 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
408 {
409 	return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
410 			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
411 			       tt, NULL, 0, 1000);
412 }
413 
414 /*
415  * enumeration blocks khubd for a long time. we use keventd instead, since
416  * long blocking there is the exception, not the rule.  accordingly, HCDs
417  * talking to TTs must queue control transfers (not just bulk and iso), so
418  * both can talk to the same hub concurrently.
419  */
420 static void hub_tt_kevent (struct work_struct *work)
421 {
422 	struct usb_hub		*hub =
423 		container_of(work, struct usb_hub, tt.kevent);
424 	unsigned long		flags;
425 	int			limit = 100;
426 
427 	spin_lock_irqsave (&hub->tt.lock, flags);
428 	while (--limit && !list_empty (&hub->tt.clear_list)) {
429 		struct list_head	*temp;
430 		struct usb_tt_clear	*clear;
431 		struct usb_device	*hdev = hub->hdev;
432 		int			status;
433 
434 		temp = hub->tt.clear_list.next;
435 		clear = list_entry (temp, struct usb_tt_clear, clear_list);
436 		list_del (&clear->clear_list);
437 
438 		/* drop lock so HCD can concurrently report other TT errors */
439 		spin_unlock_irqrestore (&hub->tt.lock, flags);
440 		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
441 		spin_lock_irqsave (&hub->tt.lock, flags);
442 
443 		if (status)
444 			dev_err (&hdev->dev,
445 				"clear tt %d (%04x) error %d\n",
446 				clear->tt, clear->devinfo, status);
447 		kfree(clear);
448 	}
449 	spin_unlock_irqrestore (&hub->tt.lock, flags);
450 }
451 
452 /**
453  * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
454  * @udev: the device whose split transaction failed
455  * @pipe: identifies the endpoint of the failed transaction
456  *
457  * High speed HCDs use this to tell the hub driver that some split control or
458  * bulk transaction failed in a way that requires clearing internal state of
459  * a transaction translator.  This is normally detected (and reported) from
460  * interrupt context.
461  *
462  * It may not be possible for that hub to handle additional full (or low)
463  * speed transactions until that state is fully cleared out.
464  */
465 void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
466 {
467 	struct usb_tt		*tt = udev->tt;
468 	unsigned long		flags;
469 	struct usb_tt_clear	*clear;
470 
471 	/* we've got to cope with an arbitrary number of pending TT clears,
472 	 * since each TT has "at least two" buffers that can need it (and
473 	 * there can be many TTs per hub).  even if they're uncommon.
474 	 */
475 	if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
476 		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
477 		/* FIXME recover somehow ... RESET_TT? */
478 		return;
479 	}
480 
481 	/* info that CLEAR_TT_BUFFER needs */
482 	clear->tt = tt->multi ? udev->ttport : 1;
483 	clear->devinfo = usb_pipeendpoint (pipe);
484 	clear->devinfo |= udev->devnum << 4;
485 	clear->devinfo |= usb_pipecontrol (pipe)
486 			? (USB_ENDPOINT_XFER_CONTROL << 11)
487 			: (USB_ENDPOINT_XFER_BULK << 11);
488 	if (usb_pipein (pipe))
489 		clear->devinfo |= 1 << 15;
490 
491 	/* tell keventd to clear state for this TT */
492 	spin_lock_irqsave (&tt->lock, flags);
493 	list_add_tail (&clear->clear_list, &tt->clear_list);
494 	schedule_work (&tt->kevent);
495 	spin_unlock_irqrestore (&tt->lock, flags);
496 }
497 EXPORT_SYMBOL_GPL(usb_hub_tt_clear_buffer);
498 
499 static void hub_power_on(struct usb_hub *hub)
500 {
501 	int port1;
502 	unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
503 	u16 wHubCharacteristics =
504 			le16_to_cpu(hub->descriptor->wHubCharacteristics);
505 
506 	/* Enable power on each port.  Some hubs have reserved values
507 	 * of LPSM (> 2) in their descriptors, even though they are
508 	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
509 	 * but only emulate it.  In all cases, the ports won't work
510 	 * unless we send these messages to the hub.
511 	 */
512 	if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
513 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
514 	else
515 		dev_dbg(hub->intfdev, "trying to enable port power on "
516 				"non-switchable hub\n");
517 	for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
518 		set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
519 
520 	/* Wait at least 100 msec for power to become stable */
521 	msleep(max(pgood_delay, (unsigned) 100));
522 }
523 
524 static void hub_quiesce(struct usb_hub *hub)
525 {
526 	/* (nonblocking) khubd and related activity won't re-trigger */
527 	hub->quiescing = 1;
528 	hub->activating = 0;
529 
530 	/* (blocking) stop khubd and related activity */
531 	usb_kill_urb(hub->urb);
532 	if (hub->has_indicators)
533 		cancel_delayed_work_sync(&hub->leds);
534 	if (hub->tt.hub)
535 		cancel_work_sync(&hub->tt.kevent);
536 }
537 
538 static void hub_activate(struct usb_hub *hub)
539 {
540 	int	status;
541 
542 	hub->quiescing = 0;
543 	hub->activating = 1;
544 
545 	status = usb_submit_urb(hub->urb, GFP_NOIO);
546 	if (status < 0)
547 		dev_err(hub->intfdev, "activate --> %d\n", status);
548 	if (hub->has_indicators && blinkenlights)
549 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
550 
551 	/* scan all ports ASAP */
552 	kick_khubd(hub);
553 }
554 
555 static int hub_hub_status(struct usb_hub *hub,
556 		u16 *status, u16 *change)
557 {
558 	int ret;
559 
560 	mutex_lock(&hub->status_mutex);
561 	ret = get_hub_status(hub->hdev, &hub->status->hub);
562 	if (ret < 0)
563 		dev_err (hub->intfdev,
564 			"%s failed (err = %d)\n", __FUNCTION__, ret);
565 	else {
566 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
567 		*change = le16_to_cpu(hub->status->hub.wHubChange);
568 		ret = 0;
569 	}
570 	mutex_unlock(&hub->status_mutex);
571 	return ret;
572 }
573 
574 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
575 {
576 	struct usb_device *hdev = hub->hdev;
577 	int ret = 0;
578 
579 	if (hdev->children[port1-1] && set_state)
580 		usb_set_device_state(hdev->children[port1-1],
581 				USB_STATE_NOTATTACHED);
582 	if (!hub->error)
583 		ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
584 	if (ret)
585 		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
586 				port1, ret);
587 	return ret;
588 }
589 
590 /*
591  * Disable a port and mark a logical connnect-change event, so that some
592  * time later khubd will disconnect() any existing usb_device on the port
593  * and will re-enumerate if there actually is a device attached.
594  */
595 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
596 {
597 	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
598 	hub_port_disable(hub, port1, 1);
599 
600 	/* FIXME let caller ask to power down the port:
601 	 *  - some devices won't enumerate without a VBUS power cycle
602 	 *  - SRP saves power that way
603 	 *  - ... new call, TBD ...
604 	 * That's easy if this hub can switch power per-port, and
605 	 * khubd reactivates the port later (timer, SRP, etc).
606 	 * Powerdown must be optional, because of reset/DFU.
607 	 */
608 
609 	set_bit(port1, hub->change_bits);
610  	kick_khubd(hub);
611 }
612 
613 /* caller has locked the hub device */
614 static int hub_pre_reset(struct usb_interface *intf)
615 {
616 	struct usb_hub *hub = usb_get_intfdata(intf);
617 	struct usb_device *hdev = hub->hdev;
618 	int i;
619 
620 	/* Disconnect all the children */
621 	for (i = 0; i < hdev->maxchild; ++i) {
622 		if (hdev->children[i])
623 			usb_disconnect(&hdev->children[i]);
624 	}
625 	hub_quiesce(hub);
626 	return 0;
627 }
628 
629 /* caller has locked the hub device */
630 static int hub_post_reset(struct usb_interface *intf)
631 {
632 	struct usb_hub *hub = usb_get_intfdata(intf);
633 
634 	hub_power_on(hub);
635 	hub_activate(hub);
636 	return 0;
637 }
638 
639 static int hub_configure(struct usb_hub *hub,
640 	struct usb_endpoint_descriptor *endpoint)
641 {
642 	struct usb_device *hdev = hub->hdev;
643 	struct device *hub_dev = hub->intfdev;
644 	u16 hubstatus, hubchange;
645 	u16 wHubCharacteristics;
646 	unsigned int pipe;
647 	int maxp, ret;
648 	char *message;
649 
650 	hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
651 			&hub->buffer_dma);
652 	if (!hub->buffer) {
653 		message = "can't allocate hub irq buffer";
654 		ret = -ENOMEM;
655 		goto fail;
656 	}
657 
658 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
659 	if (!hub->status) {
660 		message = "can't kmalloc hub status buffer";
661 		ret = -ENOMEM;
662 		goto fail;
663 	}
664 	mutex_init(&hub->status_mutex);
665 
666 	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
667 	if (!hub->descriptor) {
668 		message = "can't kmalloc hub descriptor";
669 		ret = -ENOMEM;
670 		goto fail;
671 	}
672 
673 	/* Request the entire hub descriptor.
674 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
675 	 * but the hub can/will return fewer bytes here.
676 	 */
677 	ret = get_hub_descriptor(hdev, hub->descriptor,
678 			sizeof(*hub->descriptor));
679 	if (ret < 0) {
680 		message = "can't read hub descriptor";
681 		goto fail;
682 	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
683 		message = "hub has too many ports!";
684 		ret = -ENODEV;
685 		goto fail;
686 	}
687 
688 	hdev->maxchild = hub->descriptor->bNbrPorts;
689 	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
690 		(hdev->maxchild == 1) ? "" : "s");
691 
692 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
693 
694 	if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
695 		int	i;
696 		char	portstr [USB_MAXCHILDREN + 1];
697 
698 		for (i = 0; i < hdev->maxchild; i++)
699 			portstr[i] = hub->descriptor->DeviceRemovable
700 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
701 				? 'F' : 'R';
702 		portstr[hdev->maxchild] = 0;
703 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
704 	} else
705 		dev_dbg(hub_dev, "standalone hub\n");
706 
707 	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
708 		case 0x00:
709 			dev_dbg(hub_dev, "ganged power switching\n");
710 			break;
711 		case 0x01:
712 			dev_dbg(hub_dev, "individual port power switching\n");
713 			break;
714 		case 0x02:
715 		case 0x03:
716 			dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
717 			break;
718 	}
719 
720 	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
721 		case 0x00:
722 			dev_dbg(hub_dev, "global over-current protection\n");
723 			break;
724 		case 0x08:
725 			dev_dbg(hub_dev, "individual port over-current protection\n");
726 			break;
727 		case 0x10:
728 		case 0x18:
729 			dev_dbg(hub_dev, "no over-current protection\n");
730                         break;
731 	}
732 
733 	spin_lock_init (&hub->tt.lock);
734 	INIT_LIST_HEAD (&hub->tt.clear_list);
735 	INIT_WORK (&hub->tt.kevent, hub_tt_kevent);
736 	switch (hdev->descriptor.bDeviceProtocol) {
737 		case 0:
738 			break;
739 		case 1:
740 			dev_dbg(hub_dev, "Single TT\n");
741 			hub->tt.hub = hdev;
742 			break;
743 		case 2:
744 			ret = usb_set_interface(hdev, 0, 1);
745 			if (ret == 0) {
746 				dev_dbg(hub_dev, "TT per port\n");
747 				hub->tt.multi = 1;
748 			} else
749 				dev_err(hub_dev, "Using single TT (err %d)\n",
750 					ret);
751 			hub->tt.hub = hdev;
752 			break;
753 		default:
754 			dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
755 				hdev->descriptor.bDeviceProtocol);
756 			break;
757 	}
758 
759 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
760 	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
761 		case HUB_TTTT_8_BITS:
762 			if (hdev->descriptor.bDeviceProtocol != 0) {
763 				hub->tt.think_time = 666;
764 				dev_dbg(hub_dev, "TT requires at most %d "
765 						"FS bit times (%d ns)\n",
766 					8, hub->tt.think_time);
767 			}
768 			break;
769 		case HUB_TTTT_16_BITS:
770 			hub->tt.think_time = 666 * 2;
771 			dev_dbg(hub_dev, "TT requires at most %d "
772 					"FS bit times (%d ns)\n",
773 				16, hub->tt.think_time);
774 			break;
775 		case HUB_TTTT_24_BITS:
776 			hub->tt.think_time = 666 * 3;
777 			dev_dbg(hub_dev, "TT requires at most %d "
778 					"FS bit times (%d ns)\n",
779 				24, hub->tt.think_time);
780 			break;
781 		case HUB_TTTT_32_BITS:
782 			hub->tt.think_time = 666 * 4;
783 			dev_dbg(hub_dev, "TT requires at most %d "
784 					"FS bit times (%d ns)\n",
785 				32, hub->tt.think_time);
786 			break;
787 	}
788 
789 	/* probe() zeroes hub->indicator[] */
790 	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
791 		hub->has_indicators = 1;
792 		dev_dbg(hub_dev, "Port indicators are supported\n");
793 	}
794 
795 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
796 		hub->descriptor->bPwrOn2PwrGood * 2);
797 
798 	/* power budgeting mostly matters with bus-powered hubs,
799 	 * and battery-powered root hubs (may provide just 8 mA).
800 	 */
801 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
802 	if (ret < 2) {
803 		message = "can't get hub status";
804 		goto fail;
805 	}
806 	le16_to_cpus(&hubstatus);
807 	if (hdev == hdev->bus->root_hub) {
808 		if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
809 			hub->mA_per_port = 500;
810 		else {
811 			hub->mA_per_port = hdev->bus_mA;
812 			hub->limited_power = 1;
813 		}
814 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
815 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
816 			hub->descriptor->bHubContrCurrent);
817 		hub->limited_power = 1;
818 		if (hdev->maxchild > 0) {
819 			int remaining = hdev->bus_mA -
820 					hub->descriptor->bHubContrCurrent;
821 
822 			if (remaining < hdev->maxchild * 100)
823 				dev_warn(hub_dev,
824 					"insufficient power available "
825 					"to use all downstream ports\n");
826 			hub->mA_per_port = 100;		/* 7.2.1.1 */
827 		}
828 	} else {	/* Self-powered external hub */
829 		/* FIXME: What about battery-powered external hubs that
830 		 * provide less current per port? */
831 		hub->mA_per_port = 500;
832 	}
833 	if (hub->mA_per_port < 500)
834 		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
835 				hub->mA_per_port);
836 
837 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
838 	if (ret < 0) {
839 		message = "can't get hub status";
840 		goto fail;
841 	}
842 
843 	/* local power status reports aren't always correct */
844 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
845 		dev_dbg(hub_dev, "local power source is %s\n",
846 			(hubstatus & HUB_STATUS_LOCAL_POWER)
847 			? "lost (inactive)" : "good");
848 
849 	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
850 		dev_dbg(hub_dev, "%sover-current condition exists\n",
851 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
852 
853 	/* set up the interrupt endpoint
854 	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
855 	 * bytes as USB2.0[11.12.3] says because some hubs are known
856 	 * to send more data (and thus cause overflow). For root hubs,
857 	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
858 	 * to be big enough for at least USB_MAXCHILDREN ports. */
859 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
860 	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
861 
862 	if (maxp > sizeof(*hub->buffer))
863 		maxp = sizeof(*hub->buffer);
864 
865 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
866 	if (!hub->urb) {
867 		message = "couldn't allocate interrupt urb";
868 		ret = -ENOMEM;
869 		goto fail;
870 	}
871 
872 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
873 		hub, endpoint->bInterval);
874 	hub->urb->transfer_dma = hub->buffer_dma;
875 	hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
876 
877 	/* maybe cycle the hub leds */
878 	if (hub->has_indicators && blinkenlights)
879 		hub->indicator [0] = INDICATOR_CYCLE;
880 
881 	hub_power_on(hub);
882 	hub_activate(hub);
883 	return 0;
884 
885 fail:
886 	dev_err (hub_dev, "config failed, %s (err %d)\n",
887 			message, ret);
888 	/* hub_disconnect() frees urb and descriptor */
889 	return ret;
890 }
891 
892 static void hub_release(struct kref *kref)
893 {
894 	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
895 
896 	usb_put_intf(to_usb_interface(hub->intfdev));
897 	kfree(hub);
898 }
899 
900 static unsigned highspeed_hubs;
901 
902 static void hub_disconnect(struct usb_interface *intf)
903 {
904 	struct usb_hub *hub = usb_get_intfdata (intf);
905 
906 	/* Take the hub off the event list and don't let it be added again */
907 	spin_lock_irq(&hub_event_lock);
908 	list_del_init(&hub->event_list);
909 	hub->disconnected = 1;
910 	spin_unlock_irq(&hub_event_lock);
911 
912 	/* Disconnect all children and quiesce the hub */
913 	hub->error = 0;
914 	hub_pre_reset(intf);
915 
916 	usb_set_intfdata (intf, NULL);
917 
918 	if (hub->hdev->speed == USB_SPEED_HIGH)
919 		highspeed_hubs--;
920 
921 	usb_free_urb(hub->urb);
922 	kfree(hub->descriptor);
923 	kfree(hub->status);
924 	usb_buffer_free(hub->hdev, sizeof(*hub->buffer), hub->buffer,
925 			hub->buffer_dma);
926 
927 	kref_put(&hub->kref, hub_release);
928 }
929 
930 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
931 {
932 	struct usb_host_interface *desc;
933 	struct usb_endpoint_descriptor *endpoint;
934 	struct usb_device *hdev;
935 	struct usb_hub *hub;
936 
937 	desc = intf->cur_altsetting;
938 	hdev = interface_to_usbdev(intf);
939 
940 #ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
941 	if (hdev->parent) {
942 		dev_warn(&intf->dev, "ignoring external hub\n");
943 		return -ENODEV;
944 	}
945 #endif
946 
947 	/* Some hubs have a subclass of 1, which AFAICT according to the */
948 	/*  specs is not defined, but it works */
949 	if ((desc->desc.bInterfaceSubClass != 0) &&
950 	    (desc->desc.bInterfaceSubClass != 1)) {
951 descriptor_error:
952 		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
953 		return -EIO;
954 	}
955 
956 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
957 	if (desc->desc.bNumEndpoints != 1)
958 		goto descriptor_error;
959 
960 	endpoint = &desc->endpoint[0].desc;
961 
962 	/* If it's not an interrupt in endpoint, we'd better punt! */
963 	if (!usb_endpoint_is_int_in(endpoint))
964 		goto descriptor_error;
965 
966 	/* We found a hub */
967 	dev_info (&intf->dev, "USB hub found\n");
968 
969 	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
970 	if (!hub) {
971 		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
972 		return -ENOMEM;
973 	}
974 
975 	kref_init(&hub->kref);
976 	INIT_LIST_HEAD(&hub->event_list);
977 	hub->intfdev = &intf->dev;
978 	hub->hdev = hdev;
979 	INIT_DELAYED_WORK(&hub->leds, led_work);
980 	usb_get_intf(intf);
981 
982 	usb_set_intfdata (intf, hub);
983 	intf->needs_remote_wakeup = 1;
984 
985 	if (hdev->speed == USB_SPEED_HIGH)
986 		highspeed_hubs++;
987 
988 	if (hub_configure(hub, endpoint) >= 0)
989 		return 0;
990 
991 	hub_disconnect (intf);
992 	return -ENODEV;
993 }
994 
995 static int
996 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
997 {
998 	struct usb_device *hdev = interface_to_usbdev (intf);
999 
1000 	/* assert ifno == 0 (part of hub spec) */
1001 	switch (code) {
1002 	case USBDEVFS_HUB_PORTINFO: {
1003 		struct usbdevfs_hub_portinfo *info = user_data;
1004 		int i;
1005 
1006 		spin_lock_irq(&device_state_lock);
1007 		if (hdev->devnum <= 0)
1008 			info->nports = 0;
1009 		else {
1010 			info->nports = hdev->maxchild;
1011 			for (i = 0; i < info->nports; i++) {
1012 				if (hdev->children[i] == NULL)
1013 					info->port[i] = 0;
1014 				else
1015 					info->port[i] =
1016 						hdev->children[i]->devnum;
1017 			}
1018 		}
1019 		spin_unlock_irq(&device_state_lock);
1020 
1021 		return info->nports + 1;
1022 		}
1023 
1024 	default:
1025 		return -ENOSYS;
1026 	}
1027 }
1028 
1029 
1030 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1031 {
1032 	int i;
1033 
1034 	for (i = 0; i < udev->maxchild; ++i) {
1035 		if (udev->children[i])
1036 			recursively_mark_NOTATTACHED(udev->children[i]);
1037 	}
1038 	if (udev->state == USB_STATE_SUSPENDED) {
1039 		udev->discon_suspended = 1;
1040 		udev->active_duration -= jiffies;
1041 	}
1042 	udev->state = USB_STATE_NOTATTACHED;
1043 }
1044 
1045 /**
1046  * usb_set_device_state - change a device's current state (usbcore, hcds)
1047  * @udev: pointer to device whose state should be changed
1048  * @new_state: new state value to be stored
1049  *
1050  * udev->state is _not_ fully protected by the device lock.  Although
1051  * most transitions are made only while holding the lock, the state can
1052  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1053  * is so that devices can be marked as disconnected as soon as possible,
1054  * without having to wait for any semaphores to be released.  As a result,
1055  * all changes to any device's state must be protected by the
1056  * device_state_lock spinlock.
1057  *
1058  * Once a device has been added to the device tree, all changes to its state
1059  * should be made using this routine.  The state should _not_ be set directly.
1060  *
1061  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1062  * Otherwise udev->state is set to new_state, and if new_state is
1063  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1064  * to USB_STATE_NOTATTACHED.
1065  */
1066 void usb_set_device_state(struct usb_device *udev,
1067 		enum usb_device_state new_state)
1068 {
1069 	unsigned long flags;
1070 
1071 	spin_lock_irqsave(&device_state_lock, flags);
1072 	if (udev->state == USB_STATE_NOTATTACHED)
1073 		;	/* do nothing */
1074 	else if (new_state != USB_STATE_NOTATTACHED) {
1075 
1076 		/* root hub wakeup capabilities are managed out-of-band
1077 		 * and may involve silicon errata ... ignore them here.
1078 		 */
1079 		if (udev->parent) {
1080 			if (udev->state == USB_STATE_SUSPENDED
1081 					|| new_state == USB_STATE_SUSPENDED)
1082 				;	/* No change to wakeup settings */
1083 			else if (new_state == USB_STATE_CONFIGURED)
1084 				device_init_wakeup(&udev->dev,
1085 					(udev->actconfig->desc.bmAttributes
1086 					 & USB_CONFIG_ATT_WAKEUP));
1087 			else
1088 				device_init_wakeup(&udev->dev, 0);
1089 		}
1090 		if (udev->state == USB_STATE_SUSPENDED &&
1091 			new_state != USB_STATE_SUSPENDED)
1092 			udev->active_duration -= jiffies;
1093 		else if (new_state == USB_STATE_SUSPENDED &&
1094 				udev->state != USB_STATE_SUSPENDED)
1095 			udev->active_duration += jiffies;
1096 		udev->state = new_state;
1097 	} else
1098 		recursively_mark_NOTATTACHED(udev);
1099 	spin_unlock_irqrestore(&device_state_lock, flags);
1100 }
1101 
1102 static void choose_address(struct usb_device *udev)
1103 {
1104 	int		devnum;
1105 	struct usb_bus	*bus = udev->bus;
1106 
1107 	/* If khubd ever becomes multithreaded, this will need a lock */
1108 
1109 	/* Try to allocate the next devnum beginning at bus->devnum_next. */
1110 	devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1111 			bus->devnum_next);
1112 	if (devnum >= 128)
1113 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
1114 
1115 	bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1116 
1117 	if (devnum < 128) {
1118 		set_bit(devnum, bus->devmap.devicemap);
1119 		udev->devnum = devnum;
1120 	}
1121 }
1122 
1123 static void release_address(struct usb_device *udev)
1124 {
1125 	if (udev->devnum > 0) {
1126 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1127 		udev->devnum = -1;
1128 	}
1129 }
1130 
1131 #ifdef	CONFIG_USB_SUSPEND
1132 
1133 static void usb_stop_pm(struct usb_device *udev)
1134 {
1135 	/* Synchronize with the ksuspend thread to prevent any more
1136 	 * autosuspend requests from being submitted, and decrement
1137 	 * the parent's count of unsuspended children.
1138 	 */
1139 	usb_pm_lock(udev);
1140 	if (udev->parent && !udev->discon_suspended)
1141 		usb_autosuspend_device(udev->parent);
1142 	usb_pm_unlock(udev);
1143 
1144 	/* Stop any autosuspend requests already submitted */
1145 	cancel_rearming_delayed_work(&udev->autosuspend);
1146 }
1147 
1148 #else
1149 
1150 static inline void usb_stop_pm(struct usb_device *udev)
1151 { }
1152 
1153 #endif
1154 
1155 /**
1156  * usb_disconnect - disconnect a device (usbcore-internal)
1157  * @pdev: pointer to device being disconnected
1158  * Context: !in_interrupt ()
1159  *
1160  * Something got disconnected. Get rid of it and all of its children.
1161  *
1162  * If *pdev is a normal device then the parent hub must already be locked.
1163  * If *pdev is a root hub then this routine will acquire the
1164  * usb_bus_list_lock on behalf of the caller.
1165  *
1166  * Only hub drivers (including virtual root hub drivers for host
1167  * controllers) should ever call this.
1168  *
1169  * This call is synchronous, and may not be used in an interrupt context.
1170  */
1171 void usb_disconnect(struct usb_device **pdev)
1172 {
1173 	struct usb_device	*udev = *pdev;
1174 	int			i;
1175 
1176 	if (!udev) {
1177 		pr_debug ("%s nodev\n", __FUNCTION__);
1178 		return;
1179 	}
1180 
1181 	/* mark the device as inactive, so any further urb submissions for
1182 	 * this device (and any of its children) will fail immediately.
1183 	 * this quiesces everyting except pending urbs.
1184 	 */
1185 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1186 	dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1187 
1188 	usb_lock_device(udev);
1189 
1190 	/* Free up all the children before we remove this device */
1191 	for (i = 0; i < USB_MAXCHILDREN; i++) {
1192 		if (udev->children[i])
1193 			usb_disconnect(&udev->children[i]);
1194 	}
1195 
1196 	/* deallocate hcd/hardware state ... nuking all pending urbs and
1197 	 * cleaning up all state associated with the current configuration
1198 	 * so that the hardware is now fully quiesced.
1199 	 */
1200 	dev_dbg (&udev->dev, "unregistering device\n");
1201 	usb_disable_device(udev, 0);
1202 
1203 	usb_unlock_device(udev);
1204 
1205 	/* Unregister the device.  The device driver is responsible
1206 	 * for removing the device files from usbfs and sysfs and for
1207 	 * de-configuring the device.
1208 	 */
1209 	device_del(&udev->dev);
1210 
1211 	/* Free the device number and delete the parent's children[]
1212 	 * (or root_hub) pointer.
1213 	 */
1214 	release_address(udev);
1215 
1216 	/* Avoid races with recursively_mark_NOTATTACHED() */
1217 	spin_lock_irq(&device_state_lock);
1218 	*pdev = NULL;
1219 	spin_unlock_irq(&device_state_lock);
1220 
1221 	usb_stop_pm(udev);
1222 
1223 	put_device(&udev->dev);
1224 }
1225 
1226 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
1227 static void show_string(struct usb_device *udev, char *id, char *string)
1228 {
1229 	if (!string)
1230 		return;
1231 	dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1232 }
1233 
1234 static void announce_device(struct usb_device *udev)
1235 {
1236 	dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
1237 		le16_to_cpu(udev->descriptor.idVendor),
1238 		le16_to_cpu(udev->descriptor.idProduct));
1239 	dev_info(&udev->dev, "New USB device strings: Mfr=%d, Product=%d, "
1240 		"SerialNumber=%d\n",
1241 		udev->descriptor.iManufacturer,
1242 		udev->descriptor.iProduct,
1243 		udev->descriptor.iSerialNumber);
1244 	show_string(udev, "Product", udev->product);
1245 	show_string(udev, "Manufacturer", udev->manufacturer);
1246 	show_string(udev, "SerialNumber", udev->serial);
1247 }
1248 #else
1249 static inline void announce_device(struct usb_device *udev) { }
1250 #endif
1251 
1252 #ifdef	CONFIG_USB_OTG
1253 #include "otg_whitelist.h"
1254 #endif
1255 
1256 /**
1257  * usb_configure_device_otg - FIXME (usbcore-internal)
1258  * @udev: newly addressed device (in ADDRESS state)
1259  *
1260  * Do configuration for On-The-Go devices
1261  */
1262 static int usb_configure_device_otg(struct usb_device *udev)
1263 {
1264 	int err = 0;
1265 
1266 #ifdef	CONFIG_USB_OTG
1267 	/*
1268 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1269 	 * to wake us after we've powered off VBUS; and HNP, switching roles
1270 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
1271 	 */
1272 	if (!udev->bus->is_b_host
1273 			&& udev->config
1274 			&& udev->parent == udev->bus->root_hub) {
1275 		struct usb_otg_descriptor	*desc = 0;
1276 		struct usb_bus			*bus = udev->bus;
1277 
1278 		/* descriptor may appear anywhere in config */
1279 		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1280 					le16_to_cpu(udev->config[0].desc.wTotalLength),
1281 					USB_DT_OTG, (void **) &desc) == 0) {
1282 			if (desc->bmAttributes & USB_OTG_HNP) {
1283 				unsigned		port1 = udev->portnum;
1284 
1285 				dev_info(&udev->dev,
1286 					"Dual-Role OTG device on %sHNP port\n",
1287 					(port1 == bus->otg_port)
1288 						? "" : "non-");
1289 
1290 				/* enable HNP before suspend, it's simpler */
1291 				if (port1 == bus->otg_port)
1292 					bus->b_hnp_enable = 1;
1293 				err = usb_control_msg(udev,
1294 					usb_sndctrlpipe(udev, 0),
1295 					USB_REQ_SET_FEATURE, 0,
1296 					bus->b_hnp_enable
1297 						? USB_DEVICE_B_HNP_ENABLE
1298 						: USB_DEVICE_A_ALT_HNP_SUPPORT,
1299 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1300 				if (err < 0) {
1301 					/* OTG MESSAGE: report errors here,
1302 					 * customize to match your product.
1303 					 */
1304 					dev_info(&udev->dev,
1305 						"can't set HNP mode; %d\n",
1306 						err);
1307 					bus->b_hnp_enable = 0;
1308 				}
1309 			}
1310 		}
1311 	}
1312 
1313 	if (!is_targeted(udev)) {
1314 
1315 		/* Maybe it can talk to us, though we can't talk to it.
1316 		 * (Includes HNP test device.)
1317 		 */
1318 		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1319 			err = usb_port_suspend(udev);
1320 			if (err < 0)
1321 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1322 		}
1323 		err = -ENOTSUPP;
1324 		goto fail;
1325 	}
1326 fail:
1327 #endif
1328 	return err;
1329 }
1330 
1331 
1332 /**
1333  * usb_configure_device - Detect and probe device intfs/otg (usbcore-internal)
1334  * @udev: newly addressed device (in ADDRESS state)
1335  *
1336  * This is only called by usb_new_device() and usb_authorize_device()
1337  * and FIXME -- all comments that apply to them apply here wrt to
1338  * environment.
1339  *
1340  * If the device is WUSB and not authorized, we don't attempt to read
1341  * the string descriptors, as they will be errored out by the device
1342  * until it has been authorized.
1343  */
1344 static int usb_configure_device(struct usb_device *udev)
1345 {
1346 	int err;
1347 
1348 	if (udev->config == NULL) {
1349 		err = usb_get_configuration(udev);
1350 		if (err < 0) {
1351 			dev_err(&udev->dev, "can't read configurations, error %d\n",
1352 				err);
1353 			goto fail;
1354 		}
1355 	}
1356 	if (udev->wusb == 1 && udev->authorized == 0) {
1357 		udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1358 		udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1359 		udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1360 	}
1361 	else {
1362 		/* read the standard strings and cache them if present */
1363 		udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
1364 		udev->manufacturer = usb_cache_string(udev,
1365 						      udev->descriptor.iManufacturer);
1366 		udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
1367 	}
1368 	err = usb_configure_device_otg(udev);
1369 fail:
1370 	return err;
1371 }
1372 
1373 
1374 /**
1375  * usb_new_device - perform initial device setup (usbcore-internal)
1376  * @udev: newly addressed device (in ADDRESS state)
1377  *
1378  * This is called with devices which have been enumerated, but not yet
1379  * configured.  The device descriptor is available, but not descriptors
1380  * for any device configuration.  The caller must have locked either
1381  * the parent hub (if udev is a normal device) or else the
1382  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
1383  * udev has already been installed, but udev is not yet visible through
1384  * sysfs or other filesystem code.
1385  *
1386  * It will return if the device is configured properly or not.  Zero if
1387  * the interface was registered with the driver core; else a negative
1388  * errno value.
1389  *
1390  * This call is synchronous, and may not be used in an interrupt context.
1391  *
1392  * Only the hub driver or root-hub registrar should ever call this.
1393  */
1394 int usb_new_device(struct usb_device *udev)
1395 {
1396 	int err;
1397 
1398 	usb_detect_quirks(udev);		/* Determine quirks */
1399 	err = usb_configure_device(udev);	/* detect & probe dev/intfs */
1400 	if (err < 0)
1401 		goto fail;
1402 	/* export the usbdev device-node for libusb */
1403 	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
1404 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
1405 
1406 	/* Increment the parent's count of unsuspended children */
1407 	if (udev->parent)
1408 		usb_autoresume_device(udev->parent);
1409 
1410 	/* Register the device.  The device driver is responsible
1411 	 * for adding the device files to sysfs and for configuring
1412 	 * the device.
1413 	 */
1414 	err = device_add(&udev->dev);
1415 	if (err) {
1416 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
1417 		goto fail;
1418 	}
1419 
1420 	/* Tell the world! */
1421 	announce_device(udev);
1422 	return err;
1423 
1424 fail:
1425 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1426 	return err;
1427 }
1428 
1429 
1430 /**
1431  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
1432  * @usb_dev: USB device
1433  *
1434  * Move the USB device to a very basic state where interfaces are disabled
1435  * and the device is in fact unconfigured and unusable.
1436  *
1437  * We share a lock (that we have) with device_del(), so we need to
1438  * defer its call.
1439  */
1440 int usb_deauthorize_device(struct usb_device *usb_dev)
1441 {
1442 	unsigned cnt;
1443 	usb_lock_device(usb_dev);
1444 	if (usb_dev->authorized == 0)
1445 		goto out_unauthorized;
1446 	usb_dev->authorized = 0;
1447 	usb_set_configuration(usb_dev, -1);
1448 	usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1449 	usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1450 	usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1451 	kfree(usb_dev->config);
1452 	usb_dev->config = NULL;
1453 	for (cnt = 0; cnt < usb_dev->descriptor.bNumConfigurations; cnt++)
1454 		kfree(usb_dev->rawdescriptors[cnt]);
1455 	usb_dev->descriptor.bNumConfigurations = 0;
1456 	kfree(usb_dev->rawdescriptors);
1457 out_unauthorized:
1458 	usb_unlock_device(usb_dev);
1459 	return 0;
1460 }
1461 
1462 
1463 int usb_authorize_device(struct usb_device *usb_dev)
1464 {
1465 	int result = 0, c;
1466 	usb_lock_device(usb_dev);
1467 	if (usb_dev->authorized == 1)
1468 		goto out_authorized;
1469 	kfree(usb_dev->product);
1470 	usb_dev->product = NULL;
1471 	kfree(usb_dev->manufacturer);
1472 	usb_dev->manufacturer = NULL;
1473 	kfree(usb_dev->serial);
1474 	usb_dev->serial = NULL;
1475 	result = usb_autoresume_device(usb_dev);
1476 	if (result < 0) {
1477 		dev_err(&usb_dev->dev,
1478 			"can't autoresume for authorization: %d\n", result);
1479 		goto error_autoresume;
1480 	}
1481 	result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
1482 	if (result < 0) {
1483 		dev_err(&usb_dev->dev, "can't re-read device descriptor for "
1484 			"authorization: %d\n", result);
1485 		goto error_device_descriptor;
1486 	}
1487 	usb_dev->authorized = 1;
1488 	result = usb_configure_device(usb_dev);
1489 	if (result < 0)
1490 		goto error_configure;
1491 	/* Choose and set the configuration.  This registers the interfaces
1492 	 * with the driver core and lets interface drivers bind to them.
1493 	 */
1494 	c = usb_choose_configuration(usb_dev);
1495 	if (c >= 0) {
1496 		result = usb_set_configuration(usb_dev, c);
1497 		if (result) {
1498 			dev_err(&usb_dev->dev,
1499 				"can't set config #%d, error %d\n", c, result);
1500 			/* This need not be fatal.  The user can try to
1501 			 * set other configurations. */
1502 		}
1503 	}
1504 	dev_info(&usb_dev->dev, "authorized to connect\n");
1505 error_configure:
1506 error_device_descriptor:
1507 error_autoresume:
1508 out_authorized:
1509 	usb_unlock_device(usb_dev);	// complements locktree
1510 	return result;
1511 }
1512 
1513 
1514 static int hub_port_status(struct usb_hub *hub, int port1,
1515 			       u16 *status, u16 *change)
1516 {
1517 	int ret;
1518 
1519 	mutex_lock(&hub->status_mutex);
1520 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
1521 	if (ret < 4) {
1522 		dev_err (hub->intfdev,
1523 			"%s failed (err = %d)\n", __FUNCTION__, ret);
1524 		if (ret >= 0)
1525 			ret = -EIO;
1526 	} else {
1527 		*status = le16_to_cpu(hub->status->port.wPortStatus);
1528 		*change = le16_to_cpu(hub->status->port.wPortChange);
1529 		ret = 0;
1530 	}
1531 	mutex_unlock(&hub->status_mutex);
1532 	return ret;
1533 }
1534 
1535 
1536 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
1537 static unsigned hub_is_wusb(struct usb_hub *hub)
1538 {
1539 	struct usb_hcd *hcd;
1540 	if (hub->hdev->parent != NULL)  /* not a root hub? */
1541 		return 0;
1542 	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
1543 	return hcd->wireless;
1544 }
1545 
1546 
1547 #define PORT_RESET_TRIES	5
1548 #define SET_ADDRESS_TRIES	2
1549 #define GET_DESCRIPTOR_TRIES	2
1550 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
1551 #define USE_NEW_SCHEME(i)	((i) / 2 == old_scheme_first)
1552 
1553 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
1554 #define HUB_SHORT_RESET_TIME	10
1555 #define HUB_LONG_RESET_TIME	200
1556 #define HUB_RESET_TIMEOUT	500
1557 
1558 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1559 				struct usb_device *udev, unsigned int delay)
1560 {
1561 	int delay_time, ret;
1562 	u16 portstatus;
1563 	u16 portchange;
1564 
1565 	for (delay_time = 0;
1566 			delay_time < HUB_RESET_TIMEOUT;
1567 			delay_time += delay) {
1568 		/* wait to give the device a chance to reset */
1569 		msleep(delay);
1570 
1571 		/* read and decode port status */
1572 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
1573 		if (ret < 0)
1574 			return ret;
1575 
1576 		/* Device went away? */
1577 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
1578 			return -ENOTCONN;
1579 
1580 		/* bomb out completely if the connection bounced */
1581 		if ((portchange & USB_PORT_STAT_C_CONNECTION))
1582 			return -ENOTCONN;
1583 
1584 		/* if we`ve finished resetting, then break out of the loop */
1585 		if (!(portstatus & USB_PORT_STAT_RESET) &&
1586 		    (portstatus & USB_PORT_STAT_ENABLE)) {
1587 			if (hub_is_wusb(hub))
1588 				udev->speed = USB_SPEED_VARIABLE;
1589 			else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1590 				udev->speed = USB_SPEED_HIGH;
1591 			else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1592 				udev->speed = USB_SPEED_LOW;
1593 			else
1594 				udev->speed = USB_SPEED_FULL;
1595 			return 0;
1596 		}
1597 
1598 		/* switch to the long delay after two short delay failures */
1599 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1600 			delay = HUB_LONG_RESET_TIME;
1601 
1602 		dev_dbg (hub->intfdev,
1603 			"port %d not reset yet, waiting %dms\n",
1604 			port1, delay);
1605 	}
1606 
1607 	return -EBUSY;
1608 }
1609 
1610 static int hub_port_reset(struct usb_hub *hub, int port1,
1611 				struct usb_device *udev, unsigned int delay)
1612 {
1613 	int i, status;
1614 
1615 	/* Block EHCI CF initialization during the port reset.
1616 	 * Some companion controllers don't like it when they mix.
1617 	 */
1618 	down_read(&ehci_cf_port_reset_rwsem);
1619 
1620 	/* Reset the port */
1621 	for (i = 0; i < PORT_RESET_TRIES; i++) {
1622 		status = set_port_feature(hub->hdev,
1623 				port1, USB_PORT_FEAT_RESET);
1624 		if (status)
1625 			dev_err(hub->intfdev,
1626 					"cannot reset port %d (err = %d)\n",
1627 					port1, status);
1628 		else {
1629 			status = hub_port_wait_reset(hub, port1, udev, delay);
1630 			if (status && status != -ENOTCONN)
1631 				dev_dbg(hub->intfdev,
1632 						"port_wait_reset: err = %d\n",
1633 						status);
1634 		}
1635 
1636 		/* return on disconnect or reset */
1637 		switch (status) {
1638 		case 0:
1639 			/* TRSTRCY = 10 ms; plus some extra */
1640 			msleep(10 + 40);
1641 		  	udev->devnum = 0;	/* Device now at address 0 */
1642 			/* FALL THROUGH */
1643 		case -ENOTCONN:
1644 		case -ENODEV:
1645 			clear_port_feature(hub->hdev,
1646 				port1, USB_PORT_FEAT_C_RESET);
1647 			/* FIXME need disconnect() for NOTATTACHED device */
1648 			usb_set_device_state(udev, status
1649 					? USB_STATE_NOTATTACHED
1650 					: USB_STATE_DEFAULT);
1651 			goto done;
1652 		}
1653 
1654 		dev_dbg (hub->intfdev,
1655 			"port %d not enabled, trying reset again...\n",
1656 			port1);
1657 		delay = HUB_LONG_RESET_TIME;
1658 	}
1659 
1660 	dev_err (hub->intfdev,
1661 		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
1662 		port1);
1663 
1664  done:
1665 	up_read(&ehci_cf_port_reset_rwsem);
1666 	return status;
1667 }
1668 
1669 #ifdef	CONFIG_PM
1670 
1671 #ifdef	CONFIG_USB_SUSPEND
1672 
1673 /*
1674  * usb_port_suspend - suspend a usb device's upstream port
1675  * @udev: device that's no longer in active use, not a root hub
1676  * Context: must be able to sleep; device not locked; pm locks held
1677  *
1678  * Suspends a USB device that isn't in active use, conserving power.
1679  * Devices may wake out of a suspend, if anything important happens,
1680  * using the remote wakeup mechanism.  They may also be taken out of
1681  * suspend by the host, using usb_port_resume().  It's also routine
1682  * to disconnect devices while they are suspended.
1683  *
1684  * This only affects the USB hardware for a device; its interfaces
1685  * (and, for hubs, child devices) must already have been suspended.
1686  *
1687  * Selective port suspend reduces power; most suspended devices draw
1688  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1689  * All devices below the suspended port are also suspended.
1690  *
1691  * Devices leave suspend state when the host wakes them up.  Some devices
1692  * also support "remote wakeup", where the device can activate the USB
1693  * tree above them to deliver data, such as a keypress or packet.  In
1694  * some cases, this wakes the USB host.
1695  *
1696  * Suspending OTG devices may trigger HNP, if that's been enabled
1697  * between a pair of dual-role devices.  That will change roles, such
1698  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1699  *
1700  * Devices on USB hub ports have only one "suspend" state, corresponding
1701  * to ACPI D2, "may cause the device to lose some context".
1702  * State transitions include:
1703  *
1704  *   - suspend, resume ... when the VBUS power link stays live
1705  *   - suspend, disconnect ... VBUS lost
1706  *
1707  * Once VBUS drop breaks the circuit, the port it's using has to go through
1708  * normal re-enumeration procedures, starting with enabling VBUS power.
1709  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1710  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1711  * timer, no SRP, no requests through sysfs.
1712  *
1713  * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
1714  * the root hub for their bus goes into global suspend ... so we don't
1715  * (falsely) update the device power state to say it suspended.
1716  *
1717  * Returns 0 on success, else negative errno.
1718  */
1719 int usb_port_suspend(struct usb_device *udev)
1720 {
1721 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
1722 	int		port1 = udev->portnum;
1723 	int		status;
1724 
1725 	// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1726 
1727 	/* enable remote wakeup when appropriate; this lets the device
1728 	 * wake up the upstream hub (including maybe the root hub).
1729 	 *
1730 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1731 	 * we don't explicitly enable it here.
1732 	 */
1733 	if (udev->do_remote_wakeup) {
1734 		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1735 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1736 				USB_DEVICE_REMOTE_WAKEUP, 0,
1737 				NULL, 0,
1738 				USB_CTRL_SET_TIMEOUT);
1739 		if (status)
1740 			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
1741 					status);
1742 	}
1743 
1744 	/* see 7.1.7.6 */
1745 	status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1746 	if (status) {
1747 		dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
1748 				port1, status);
1749 		/* paranoia:  "should not happen" */
1750 		(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1751 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1752 				USB_DEVICE_REMOTE_WAKEUP, 0,
1753 				NULL, 0,
1754 				USB_CTRL_SET_TIMEOUT);
1755 	} else {
1756 		/* device has up to 10 msec to fully suspend */
1757 		dev_dbg(&udev->dev, "usb %ssuspend\n",
1758 				udev->auto_pm ? "auto-" : "");
1759 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
1760 		msleep(10);
1761 	}
1762 	return status;
1763 }
1764 
1765 /*
1766  * If the USB "suspend" state is in use (rather than "global suspend"),
1767  * many devices will be individually taken out of suspend state using
1768  * special "resume" signaling.  This routine kicks in shortly after
1769  * hardware resume signaling is finished, either because of selective
1770  * resume (by host) or remote wakeup (by device) ... now see what changed
1771  * in the tree that's rooted at this device.
1772  *
1773  * If @udev->reset_resume is set then the device is reset before the
1774  * status check is done.
1775  */
1776 static int finish_port_resume(struct usb_device *udev)
1777 {
1778 	int	status = 0;
1779 	u16	devstatus;
1780 
1781 	/* caller owns the udev device lock */
1782 	dev_dbg(&udev->dev, "finish %sresume\n",
1783 			udev->reset_resume ? "reset-" : "");
1784 
1785 	/* usb ch9 identifies four variants of SUSPENDED, based on what
1786 	 * state the device resumes to.  Linux currently won't see the
1787 	 * first two on the host side; they'd be inside hub_port_init()
1788 	 * during many timeouts, but khubd can't suspend until later.
1789 	 */
1790 	usb_set_device_state(udev, udev->actconfig
1791 			? USB_STATE_CONFIGURED
1792 			: USB_STATE_ADDRESS);
1793 
1794 	/* 10.5.4.5 says not to reset a suspended port if the attached
1795 	 * device is enabled for remote wakeup.  Hence the reset
1796 	 * operation is carried out here, after the port has been
1797 	 * resumed.
1798 	 */
1799 	if (udev->reset_resume)
1800 		status = usb_reset_device(udev);
1801 
1802  	/* 10.5.4.5 says be sure devices in the tree are still there.
1803  	 * For now let's assume the device didn't go crazy on resume,
1804 	 * and device drivers will know about any resume quirks.
1805 	 */
1806 	if (status == 0) {
1807 		devstatus = 0;
1808 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1809 		if (status >= 0)
1810 			status = (status > 0 ? 0 : -ENODEV);
1811 	}
1812 
1813 	if (status) {
1814 		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
1815 				status);
1816 	} else if (udev->actconfig) {
1817 		le16_to_cpus(&devstatus);
1818 		if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
1819 			status = usb_control_msg(udev,
1820 					usb_sndctrlpipe(udev, 0),
1821 					USB_REQ_CLEAR_FEATURE,
1822 						USB_RECIP_DEVICE,
1823 					USB_DEVICE_REMOTE_WAKEUP, 0,
1824 					NULL, 0,
1825 					USB_CTRL_SET_TIMEOUT);
1826 			if (status)
1827 				dev_dbg(&udev->dev, "disable remote "
1828 					"wakeup, status %d\n", status);
1829 		}
1830 		status = 0;
1831 	}
1832 	return status;
1833 }
1834 
1835 /*
1836  * usb_port_resume - re-activate a suspended usb device's upstream port
1837  * @udev: device to re-activate, not a root hub
1838  * Context: must be able to sleep; device not locked; pm locks held
1839  *
1840  * This will re-activate the suspended device, increasing power usage
1841  * while letting drivers communicate again with its endpoints.
1842  * USB resume explicitly guarantees that the power session between
1843  * the host and the device is the same as it was when the device
1844  * suspended.
1845  *
1846  * If CONFIG_USB_PERSIST and @udev->reset_resume are both set then this
1847  * routine won't check that the port is still enabled.  Furthermore,
1848  * if @udev->reset_resume is set then finish_port_resume() above will
1849  * reset @udev.  The end result is that a broken power session can be
1850  * recovered and @udev will appear to persist across a loss of VBUS power.
1851  *
1852  * For example, if a host controller doesn't maintain VBUS suspend current
1853  * during a system sleep or is reset when the system wakes up, all the USB
1854  * power sessions below it will be broken.  This is especially troublesome
1855  * for mass-storage devices containing mounted filesystems, since the
1856  * device will appear to have disconnected and all the memory mappings
1857  * to it will be lost.  Using the USB_PERSIST facility, the device can be
1858  * made to appear as if it had not disconnected.
1859  *
1860  * This facility is inherently dangerous.  Although usb_reset_device()
1861  * makes every effort to insure that the same device is present after the
1862  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
1863  * quite possible for a device to remain unaltered but its media to be
1864  * changed.  If the user replaces a flash memory card while the system is
1865  * asleep, he will have only himself to blame when the filesystem on the
1866  * new card is corrupted and the system crashes.
1867  *
1868  * Returns 0 on success, else negative errno.
1869  */
1870 int usb_port_resume(struct usb_device *udev)
1871 {
1872 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
1873 	int		port1 = udev->portnum;
1874 	int		status;
1875 	u16		portchange, portstatus;
1876 	unsigned	mask_flags, want_flags;
1877 
1878 	/* Skip the initial Clear-Suspend step for a remote wakeup */
1879 	status = hub_port_status(hub, port1, &portstatus, &portchange);
1880 	if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
1881 		goto SuspendCleared;
1882 
1883 	// dev_dbg(hub->intfdev, "resume port %d\n", port1);
1884 
1885 	set_bit(port1, hub->busy_bits);
1886 
1887 	/* see 7.1.7.7; affects power usage, but not budgeting */
1888 	status = clear_port_feature(hub->hdev,
1889 			port1, USB_PORT_FEAT_SUSPEND);
1890 	if (status) {
1891 		dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
1892 				port1, status);
1893 	} else {
1894 		/* drive resume for at least 20 msec */
1895 		dev_dbg(&udev->dev, "usb %sresume\n",
1896 				udev->auto_pm ? "auto-" : "");
1897 		msleep(25);
1898 
1899 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
1900 		 * stop resume signaling.  Then finish the resume
1901 		 * sequence.
1902 		 */
1903 		status = hub_port_status(hub, port1, &portstatus, &portchange);
1904 
1905  SuspendCleared:
1906 		if (USB_PERSIST && udev->reset_resume)
1907 			want_flags = USB_PORT_STAT_POWER
1908 					| USB_PORT_STAT_CONNECTION;
1909 		else
1910 			want_flags = USB_PORT_STAT_POWER
1911 					| USB_PORT_STAT_CONNECTION
1912 					| USB_PORT_STAT_ENABLE;
1913 		mask_flags = want_flags | USB_PORT_STAT_SUSPEND;
1914 
1915 		if (status < 0 || (portstatus & mask_flags) != want_flags) {
1916 			dev_dbg(hub->intfdev,
1917 				"port %d status %04x.%04x after resume, %d\n",
1918 				port1, portchange, portstatus, status);
1919 			if (status >= 0)
1920 				status = -ENODEV;
1921 		} else {
1922 			if (portchange & USB_PORT_STAT_C_SUSPEND)
1923 				clear_port_feature(hub->hdev, port1,
1924 						USB_PORT_FEAT_C_SUSPEND);
1925 			/* TRSMRCY = 10 msec */
1926 			msleep(10);
1927 		}
1928 	}
1929 
1930 	clear_bit(port1, hub->busy_bits);
1931 	if (!hub->hdev->parent && !hub->busy_bits[0])
1932 		usb_enable_root_hub_irq(hub->hdev->bus);
1933 
1934 	if (status == 0)
1935 		status = finish_port_resume(udev);
1936 	if (status < 0) {
1937 		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
1938 		hub_port_logical_disconnect(hub, port1);
1939 	}
1940 	return status;
1941 }
1942 
1943 static int remote_wakeup(struct usb_device *udev)
1944 {
1945 	int	status = 0;
1946 
1947 	usb_lock_device(udev);
1948 	if (udev->state == USB_STATE_SUSPENDED) {
1949 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
1950 		usb_mark_last_busy(udev);
1951 		status = usb_external_resume_device(udev);
1952 	}
1953 	usb_unlock_device(udev);
1954 	return status;
1955 }
1956 
1957 #else	/* CONFIG_USB_SUSPEND */
1958 
1959 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
1960 
1961 int usb_port_suspend(struct usb_device *udev)
1962 {
1963 	return 0;
1964 }
1965 
1966 int usb_port_resume(struct usb_device *udev)
1967 {
1968 	int status = 0;
1969 
1970 	/* However we may need to do a reset-resume */
1971 	if (udev->reset_resume) {
1972 		dev_dbg(&udev->dev, "reset-resume\n");
1973 		status = usb_reset_device(udev);
1974 	}
1975 	return status;
1976 }
1977 
1978 static inline int remote_wakeup(struct usb_device *udev)
1979 {
1980 	return 0;
1981 }
1982 
1983 #endif
1984 
1985 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
1986 {
1987 	struct usb_hub		*hub = usb_get_intfdata (intf);
1988 	struct usb_device	*hdev = hub->hdev;
1989 	unsigned		port1;
1990 
1991 	/* fail if children aren't already suspended */
1992 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1993 		struct usb_device	*udev;
1994 
1995 		udev = hdev->children [port1-1];
1996 		if (udev && udev->can_submit) {
1997 			if (!hdev->auto_pm)
1998 				dev_dbg(&intf->dev, "port %d nyet suspended\n",
1999 						port1);
2000 			return -EBUSY;
2001 		}
2002 	}
2003 
2004 	dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
2005 
2006 	/* stop khubd and related activity */
2007 	hub_quiesce(hub);
2008 	return 0;
2009 }
2010 
2011 static int hub_resume(struct usb_interface *intf)
2012 {
2013 	struct usb_hub		*hub = usb_get_intfdata (intf);
2014 
2015 	dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
2016 
2017 	/* tell khubd to look for changes on this hub */
2018 	hub_activate(hub);
2019 	return 0;
2020 }
2021 
2022 static int hub_reset_resume(struct usb_interface *intf)
2023 {
2024 	struct usb_hub *hub = usb_get_intfdata(intf);
2025 	struct usb_device *hdev = hub->hdev;
2026 	int port1;
2027 
2028 	hub_power_on(hub);
2029 
2030 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2031 		struct usb_device *child = hdev->children[port1-1];
2032 
2033 		if (child) {
2034 
2035 			/* For "USB_PERSIST"-enabled children we must
2036 			 * mark the child device for reset-resume and
2037 			 * turn off the connect-change status to prevent
2038 			 * khubd from disconnecting it later.
2039 			 */
2040 			if (USB_PERSIST && child->persist_enabled) {
2041 				child->reset_resume = 1;
2042 				clear_port_feature(hdev, port1,
2043 						USB_PORT_FEAT_C_CONNECTION);
2044 
2045 			/* Otherwise we must disconnect the child,
2046 			 * but as we may not lock the child device here
2047 			 * we have to do a "logical" disconnect.
2048 			 */
2049 			} else {
2050 				hub_port_logical_disconnect(hub, port1);
2051 			}
2052 		}
2053 	}
2054 
2055 	hub_activate(hub);
2056 	return 0;
2057 }
2058 
2059 /**
2060  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
2061  * @rhdev: struct usb_device for the root hub
2062  *
2063  * The USB host controller driver calls this function when its root hub
2064  * is resumed and Vbus power has been interrupted or the controller
2065  * has been reset.  The routine marks @rhdev as having lost power.  When
2066  * the hub driver is resumed it will take notice; if CONFIG_USB_PERSIST
2067  * is enabled then it will carry out power-session recovery, otherwise
2068  * it will disconnect all the child devices.
2069  */
2070 void usb_root_hub_lost_power(struct usb_device *rhdev)
2071 {
2072 	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
2073 	rhdev->reset_resume = 1;
2074 }
2075 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
2076 
2077 #else	/* CONFIG_PM */
2078 
2079 static inline int remote_wakeup(struct usb_device *udev)
2080 {
2081 	return 0;
2082 }
2083 
2084 #define hub_suspend		NULL
2085 #define hub_resume		NULL
2086 #define hub_reset_resume	NULL
2087 #endif
2088 
2089 
2090 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2091  *
2092  * Between connect detection and reset signaling there must be a delay
2093  * of 100ms at least for debounce and power-settling.  The corresponding
2094  * timer shall restart whenever the downstream port detects a disconnect.
2095  *
2096  * Apparently there are some bluetooth and irda-dongles and a number of
2097  * low-speed devices for which this debounce period may last over a second.
2098  * Not covered by the spec - but easy to deal with.
2099  *
2100  * This implementation uses a 1500ms total debounce timeout; if the
2101  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
2102  * every 25ms for transient disconnects.  When the port status has been
2103  * unchanged for 100ms it returns the port status.
2104  */
2105 
2106 #define HUB_DEBOUNCE_TIMEOUT	1500
2107 #define HUB_DEBOUNCE_STEP	  25
2108 #define HUB_DEBOUNCE_STABLE	 100
2109 
2110 static int hub_port_debounce(struct usb_hub *hub, int port1)
2111 {
2112 	int ret;
2113 	int total_time, stable_time = 0;
2114 	u16 portchange, portstatus;
2115 	unsigned connection = 0xffff;
2116 
2117 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2118 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
2119 		if (ret < 0)
2120 			return ret;
2121 
2122 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2123 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2124 			stable_time += HUB_DEBOUNCE_STEP;
2125 			if (stable_time >= HUB_DEBOUNCE_STABLE)
2126 				break;
2127 		} else {
2128 			stable_time = 0;
2129 			connection = portstatus & USB_PORT_STAT_CONNECTION;
2130 		}
2131 
2132 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
2133 			clear_port_feature(hub->hdev, port1,
2134 					USB_PORT_FEAT_C_CONNECTION);
2135 		}
2136 
2137 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2138 			break;
2139 		msleep(HUB_DEBOUNCE_STEP);
2140 	}
2141 
2142 	dev_dbg (hub->intfdev,
2143 		"debounce: port %d: total %dms stable %dms status 0x%x\n",
2144 		port1, total_time, stable_time, portstatus);
2145 
2146 	if (stable_time < HUB_DEBOUNCE_STABLE)
2147 		return -ETIMEDOUT;
2148 	return portstatus;
2149 }
2150 
2151 static void ep0_reinit(struct usb_device *udev)
2152 {
2153 	usb_disable_endpoint(udev, 0 + USB_DIR_IN);
2154 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
2155 	usb_enable_endpoint(udev, &udev->ep0);
2156 }
2157 
2158 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
2159 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
2160 
2161 static int hub_set_address(struct usb_device *udev, int devnum)
2162 {
2163 	int retval;
2164 
2165 	if (devnum <= 1)
2166 		return -EINVAL;
2167 	if (udev->state == USB_STATE_ADDRESS)
2168 		return 0;
2169 	if (udev->state != USB_STATE_DEFAULT)
2170 		return -EINVAL;
2171 	retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2172 		USB_REQ_SET_ADDRESS, 0, devnum, 0,
2173 		NULL, 0, USB_CTRL_SET_TIMEOUT);
2174 	if (retval == 0) {
2175 		udev->devnum = devnum;	/* Device now using proper address */
2176 		usb_set_device_state(udev, USB_STATE_ADDRESS);
2177 		ep0_reinit(udev);
2178 	}
2179 	return retval;
2180 }
2181 
2182 /* Reset device, (re)assign address, get device descriptor.
2183  * Device connection must be stable, no more debouncing needed.
2184  * Returns device in USB_STATE_ADDRESS, except on error.
2185  *
2186  * If this is called for an already-existing device (as part of
2187  * usb_reset_device), the caller must own the device lock.  For a
2188  * newly detected device that is not accessible through any global
2189  * pointers, it's not necessary to lock the device.
2190  */
2191 static int
2192 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2193 		int retry_counter)
2194 {
2195 	static DEFINE_MUTEX(usb_address0_mutex);
2196 
2197 	struct usb_device	*hdev = hub->hdev;
2198 	int			i, j, retval;
2199 	unsigned		delay = HUB_SHORT_RESET_TIME;
2200 	enum usb_device_speed	oldspeed = udev->speed;
2201 	char 			*speed, *type;
2202 	int			devnum = udev->devnum;
2203 
2204 	/* root hub ports have a slightly longer reset period
2205 	 * (from USB 2.0 spec, section 7.1.7.5)
2206 	 */
2207 	if (!hdev->parent) {
2208 		delay = HUB_ROOT_RESET_TIME;
2209 		if (port1 == hdev->bus->otg_port)
2210 			hdev->bus->b_hnp_enable = 0;
2211 	}
2212 
2213 	/* Some low speed devices have problems with the quick delay, so */
2214 	/*  be a bit pessimistic with those devices. RHbug #23670 */
2215 	if (oldspeed == USB_SPEED_LOW)
2216 		delay = HUB_LONG_RESET_TIME;
2217 
2218 	mutex_lock(&usb_address0_mutex);
2219 
2220 	/* Reset the device; full speed may morph to high speed */
2221 	retval = hub_port_reset(hub, port1, udev, delay);
2222 	if (retval < 0)		/* error or disconnect */
2223 		goto fail;
2224 				/* success, speed is known */
2225 	retval = -ENODEV;
2226 
2227 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2228 		dev_dbg(&udev->dev, "device reset changed speed!\n");
2229 		goto fail;
2230 	}
2231 	oldspeed = udev->speed;
2232 
2233 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2234 	 * it's fixed size except for full speed devices.
2235 	 * For Wireless USB devices, ep0 max packet is always 512 (tho
2236 	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
2237 	 */
2238 	switch (udev->speed) {
2239 	case USB_SPEED_VARIABLE:	/* fixed at 512 */
2240 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(512);
2241 		break;
2242 	case USB_SPEED_HIGH:		/* fixed at 64 */
2243 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2244 		break;
2245 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
2246 		/* to determine the ep0 maxpacket size, try to read
2247 		 * the device descriptor to get bMaxPacketSize0 and
2248 		 * then correct our initial guess.
2249 		 */
2250 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2251 		break;
2252 	case USB_SPEED_LOW:		/* fixed at 8 */
2253 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2254 		break;
2255 	default:
2256 		goto fail;
2257 	}
2258 
2259 	type = "";
2260 	switch (udev->speed) {
2261 	case USB_SPEED_LOW:	speed = "low";	break;
2262 	case USB_SPEED_FULL:	speed = "full";	break;
2263 	case USB_SPEED_HIGH:	speed = "high";	break;
2264 	case USB_SPEED_VARIABLE:
2265 				speed = "variable";
2266 				type = "Wireless ";
2267 				break;
2268 	default: 		speed = "?";	break;
2269 	}
2270 	dev_info (&udev->dev,
2271 		  "%s %s speed %sUSB device using %s and address %d\n",
2272 		  (udev->config) ? "reset" : "new", speed, type,
2273 		  udev->bus->controller->driver->name, devnum);
2274 
2275 	/* Set up TT records, if needed  */
2276 	if (hdev->tt) {
2277 		udev->tt = hdev->tt;
2278 		udev->ttport = hdev->ttport;
2279 	} else if (udev->speed != USB_SPEED_HIGH
2280 			&& hdev->speed == USB_SPEED_HIGH) {
2281 		udev->tt = &hub->tt;
2282 		udev->ttport = port1;
2283 	}
2284 
2285 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2286 	 * Because device hardware and firmware is sometimes buggy in
2287 	 * this area, and this is how Linux has done it for ages.
2288 	 * Change it cautiously.
2289 	 *
2290 	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2291 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2292 	 * so it may help with some non-standards-compliant devices.
2293 	 * Otherwise we start with SET_ADDRESS and then try to read the
2294 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2295 	 * value.
2296 	 */
2297 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2298 		if (USE_NEW_SCHEME(retry_counter)) {
2299 			struct usb_device_descriptor *buf;
2300 			int r = 0;
2301 
2302 #define GET_DESCRIPTOR_BUFSIZE	64
2303 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2304 			if (!buf) {
2305 				retval = -ENOMEM;
2306 				continue;
2307 			}
2308 
2309 			/* Retry on all errors; some devices are flakey.
2310 			 * 255 is for WUSB devices, we actually need to use
2311 			 * 512 (WUSB1.0[4.8.1]).
2312 			 */
2313 			for (j = 0; j < 3; ++j) {
2314 				buf->bMaxPacketSize0 = 0;
2315 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2316 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2317 					USB_DT_DEVICE << 8, 0,
2318 					buf, GET_DESCRIPTOR_BUFSIZE,
2319 					USB_CTRL_GET_TIMEOUT);
2320 				switch (buf->bMaxPacketSize0) {
2321 				case 8: case 16: case 32: case 64: case 255:
2322 					if (buf->bDescriptorType ==
2323 							USB_DT_DEVICE) {
2324 						r = 0;
2325 						break;
2326 					}
2327 					/* FALL THROUGH */
2328 				default:
2329 					if (r == 0)
2330 						r = -EPROTO;
2331 					break;
2332 				}
2333 				if (r == 0)
2334 					break;
2335 			}
2336 			udev->descriptor.bMaxPacketSize0 =
2337 					buf->bMaxPacketSize0;
2338 			kfree(buf);
2339 
2340 			retval = hub_port_reset(hub, port1, udev, delay);
2341 			if (retval < 0)		/* error or disconnect */
2342 				goto fail;
2343 			if (oldspeed != udev->speed) {
2344 				dev_dbg(&udev->dev,
2345 					"device reset changed speed!\n");
2346 				retval = -ENODEV;
2347 				goto fail;
2348 			}
2349 			if (r) {
2350 				dev_err(&udev->dev, "device descriptor "
2351 						"read/%s, error %d\n",
2352 						"64", r);
2353 				retval = -EMSGSIZE;
2354 				continue;
2355 			}
2356 #undef GET_DESCRIPTOR_BUFSIZE
2357 		}
2358 
2359 		for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2360 			retval = hub_set_address(udev, devnum);
2361 			if (retval >= 0)
2362 				break;
2363 			msleep(200);
2364 		}
2365 		if (retval < 0) {
2366 			dev_err(&udev->dev,
2367 				"device not accepting address %d, error %d\n",
2368 				devnum, retval);
2369 			goto fail;
2370 		}
2371 
2372 		/* cope with hardware quirkiness:
2373 		 *  - let SET_ADDRESS settle, some device hardware wants it
2374 		 *  - read ep0 maxpacket even for high and low speed,
2375   		 */
2376 		msleep(10);
2377 		if (USE_NEW_SCHEME(retry_counter))
2378 			break;
2379 
2380 		retval = usb_get_device_descriptor(udev, 8);
2381 		if (retval < 8) {
2382 			dev_err(&udev->dev, "device descriptor "
2383 					"read/%s, error %d\n",
2384 					"8", retval);
2385 			if (retval >= 0)
2386 				retval = -EMSGSIZE;
2387 		} else {
2388 			retval = 0;
2389 			break;
2390 		}
2391 	}
2392 	if (retval)
2393 		goto fail;
2394 
2395 	i = udev->descriptor.bMaxPacketSize0 == 0xff?
2396 	    512 : udev->descriptor.bMaxPacketSize0;
2397 	if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2398 		if (udev->speed != USB_SPEED_FULL ||
2399 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
2400 			dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2401 			retval = -EMSGSIZE;
2402 			goto fail;
2403 		}
2404 		dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2405 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2406 		ep0_reinit(udev);
2407 	}
2408 
2409 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2410 	if (retval < (signed)sizeof(udev->descriptor)) {
2411 		dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2412 			"all", retval);
2413 		if (retval >= 0)
2414 			retval = -ENOMSG;
2415 		goto fail;
2416 	}
2417 
2418 	retval = 0;
2419 
2420 fail:
2421 	if (retval) {
2422 		hub_port_disable(hub, port1, 0);
2423 		udev->devnum = devnum;	/* for disconnect processing */
2424 	}
2425 	mutex_unlock(&usb_address0_mutex);
2426 	return retval;
2427 }
2428 
2429 static void
2430 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2431 {
2432 	struct usb_qualifier_descriptor	*qual;
2433 	int				status;
2434 
2435 	qual = kmalloc (sizeof *qual, GFP_KERNEL);
2436 	if (qual == NULL)
2437 		return;
2438 
2439 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2440 			qual, sizeof *qual);
2441 	if (status == sizeof *qual) {
2442 		dev_info(&udev->dev, "not running at top speed; "
2443 			"connect to a high speed hub\n");
2444 		/* hub LEDs are probably harder to miss than syslog */
2445 		if (hub->has_indicators) {
2446 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2447 			schedule_delayed_work (&hub->leds, 0);
2448 		}
2449 	}
2450 	kfree(qual);
2451 }
2452 
2453 static unsigned
2454 hub_power_remaining (struct usb_hub *hub)
2455 {
2456 	struct usb_device *hdev = hub->hdev;
2457 	int remaining;
2458 	int port1;
2459 
2460 	if (!hub->limited_power)
2461 		return 0;
2462 
2463 	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
2464 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2465 		struct usb_device	*udev = hdev->children[port1 - 1];
2466 		int			delta;
2467 
2468 		if (!udev)
2469 			continue;
2470 
2471 		/* Unconfigured devices may not use more than 100mA,
2472 		 * or 8mA for OTG ports */
2473 		if (udev->actconfig)
2474 			delta = udev->actconfig->desc.bMaxPower * 2;
2475 		else if (port1 != udev->bus->otg_port || hdev->parent)
2476 			delta = 100;
2477 		else
2478 			delta = 8;
2479 		if (delta > hub->mA_per_port)
2480 			dev_warn(&udev->dev, "%dmA is over %umA budget "
2481 					"for port %d!\n",
2482 					delta, hub->mA_per_port, port1);
2483 		remaining -= delta;
2484 	}
2485 	if (remaining < 0) {
2486 		dev_warn(hub->intfdev, "%dmA over power budget!\n",
2487 			- remaining);
2488 		remaining = 0;
2489 	}
2490 	return remaining;
2491 }
2492 
2493 /* Handle physical or logical connection change events.
2494  * This routine is called when:
2495  * 	a port connection-change occurs;
2496  *	a port enable-change occurs (often caused by EMI);
2497  *	usb_reset_device() encounters changed descriptors (as from
2498  *		a firmware download)
2499  * caller already locked the hub
2500  */
2501 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2502 					u16 portstatus, u16 portchange)
2503 {
2504 	struct usb_device *hdev = hub->hdev;
2505 	struct device *hub_dev = hub->intfdev;
2506 	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
2507 	u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2508 	int status, i;
2509 
2510 	dev_dbg (hub_dev,
2511 		"port %d, status %04x, change %04x, %s\n",
2512 		port1, portstatus, portchange, portspeed (portstatus));
2513 
2514 	if (hub->has_indicators) {
2515 		set_port_led(hub, port1, HUB_LED_AUTO);
2516 		hub->indicator[port1-1] = INDICATOR_AUTO;
2517 	}
2518 
2519 	/* Disconnect any existing devices under this port */
2520 	if (hdev->children[port1-1])
2521 		usb_disconnect(&hdev->children[port1-1]);
2522 	clear_bit(port1, hub->change_bits);
2523 
2524 #ifdef	CONFIG_USB_OTG
2525 	/* during HNP, don't repeat the debounce */
2526 	if (hdev->bus->is_b_host)
2527 		portchange &= ~USB_PORT_STAT_C_CONNECTION;
2528 #endif
2529 
2530 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
2531 		status = hub_port_debounce(hub, port1);
2532 		if (status < 0) {
2533 			if (printk_ratelimit())
2534 				dev_err (hub_dev, "connect-debounce failed, "
2535 						"port %d disabled\n", port1);
2536 			goto done;
2537 		}
2538 		portstatus = status;
2539 	}
2540 
2541 	/* Return now if nothing is connected */
2542 	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2543 
2544 		/* maybe switch power back on (e.g. root hub was reset) */
2545 		if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
2546 				&& !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2547 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2548 
2549 		if (portstatus & USB_PORT_STAT_ENABLE)
2550   			goto done;
2551 		return;
2552 	}
2553 
2554 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
2555 		struct usb_device *udev;
2556 
2557 		/* reallocate for each attempt, since references
2558 		 * to the previous one can escape in various ways
2559 		 */
2560 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
2561 		if (!udev) {
2562 			dev_err (hub_dev,
2563 				"couldn't allocate port %d usb_device\n",
2564 				port1);
2565 			goto done;
2566 		}
2567 
2568 		usb_set_device_state(udev, USB_STATE_POWERED);
2569 		udev->speed = USB_SPEED_UNKNOWN;
2570  		udev->bus_mA = hub->mA_per_port;
2571 		udev->level = hdev->level + 1;
2572 
2573 		/* set the address */
2574 		choose_address(udev);
2575 		if (udev->devnum <= 0) {
2576 			status = -ENOTCONN;	/* Don't retry */
2577 			goto loop;
2578 		}
2579 
2580 		/* reset and get descriptor */
2581 		status = hub_port_init(hub, udev, port1, i);
2582 		if (status < 0)
2583 			goto loop;
2584 
2585 		/* consecutive bus-powered hubs aren't reliable; they can
2586 		 * violate the voltage drop budget.  if the new child has
2587 		 * a "powered" LED, users should notice we didn't enable it
2588 		 * (without reading syslog), even without per-port LEDs
2589 		 * on the parent.
2590 		 */
2591 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2592 				&& udev->bus_mA <= 100) {
2593 			u16	devstat;
2594 
2595 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2596 					&devstat);
2597 			if (status < 2) {
2598 				dev_dbg(&udev->dev, "get status %d ?\n", status);
2599 				goto loop_disable;
2600 			}
2601 			le16_to_cpus(&devstat);
2602 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2603 				dev_err(&udev->dev,
2604 					"can't connect bus-powered hub "
2605 					"to this port\n");
2606 				if (hub->has_indicators) {
2607 					hub->indicator[port1-1] =
2608 						INDICATOR_AMBER_BLINK;
2609 					schedule_delayed_work (&hub->leds, 0);
2610 				}
2611 				status = -ENOTCONN;	/* Don't retry */
2612 				goto loop_disable;
2613 			}
2614 		}
2615 
2616 		/* check for devices running slower than they could */
2617 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2618 				&& udev->speed == USB_SPEED_FULL
2619 				&& highspeed_hubs != 0)
2620 			check_highspeed (hub, udev, port1);
2621 
2622 		/* Store the parent's children[] pointer.  At this point
2623 		 * udev becomes globally accessible, although presumably
2624 		 * no one will look at it until hdev is unlocked.
2625 		 */
2626 		status = 0;
2627 
2628 		/* We mustn't add new devices if the parent hub has
2629 		 * been disconnected; we would race with the
2630 		 * recursively_mark_NOTATTACHED() routine.
2631 		 */
2632 		spin_lock_irq(&device_state_lock);
2633 		if (hdev->state == USB_STATE_NOTATTACHED)
2634 			status = -ENOTCONN;
2635 		else
2636 			hdev->children[port1-1] = udev;
2637 		spin_unlock_irq(&device_state_lock);
2638 
2639 		/* Run it through the hoops (find a driver, etc) */
2640 		if (!status) {
2641 			status = usb_new_device(udev);
2642 			if (status) {
2643 				spin_lock_irq(&device_state_lock);
2644 				hdev->children[port1-1] = NULL;
2645 				spin_unlock_irq(&device_state_lock);
2646 			}
2647 		}
2648 
2649 		if (status)
2650 			goto loop_disable;
2651 
2652 		status = hub_power_remaining(hub);
2653 		if (status)
2654 			dev_dbg(hub_dev, "%dmA power budget left\n", status);
2655 
2656 		return;
2657 
2658 loop_disable:
2659 		hub_port_disable(hub, port1, 1);
2660 loop:
2661 		ep0_reinit(udev);
2662 		release_address(udev);
2663 		usb_put_dev(udev);
2664 		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
2665 			break;
2666 	}
2667 
2668 done:
2669 	hub_port_disable(hub, port1, 1);
2670 	if (hcd->driver->relinquish_port && !hub->hdev->parent)
2671 		hcd->driver->relinquish_port(hcd, port1);
2672 }
2673 
2674 static void hub_events(void)
2675 {
2676 	struct list_head *tmp;
2677 	struct usb_device *hdev;
2678 	struct usb_interface *intf;
2679 	struct usb_hub *hub;
2680 	struct device *hub_dev;
2681 	u16 hubstatus;
2682 	u16 hubchange;
2683 	u16 portstatus;
2684 	u16 portchange;
2685 	int i, ret;
2686 	int connect_change;
2687 
2688 	/*
2689 	 *  We restart the list every time to avoid a deadlock with
2690 	 * deleting hubs downstream from this one. This should be
2691 	 * safe since we delete the hub from the event list.
2692 	 * Not the most efficient, but avoids deadlocks.
2693 	 */
2694 	while (1) {
2695 
2696 		/* Grab the first entry at the beginning of the list */
2697 		spin_lock_irq(&hub_event_lock);
2698 		if (list_empty(&hub_event_list)) {
2699 			spin_unlock_irq(&hub_event_lock);
2700 			break;
2701 		}
2702 
2703 		tmp = hub_event_list.next;
2704 		list_del_init(tmp);
2705 
2706 		hub = list_entry(tmp, struct usb_hub, event_list);
2707 		kref_get(&hub->kref);
2708 		spin_unlock_irq(&hub_event_lock);
2709 
2710 		hdev = hub->hdev;
2711 		hub_dev = hub->intfdev;
2712 		intf = to_usb_interface(hub_dev);
2713 		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
2714 				hdev->state, hub->descriptor
2715 					? hub->descriptor->bNbrPorts
2716 					: 0,
2717 				/* NOTE: expects max 15 ports... */
2718 				(u16) hub->change_bits[0],
2719 				(u16) hub->event_bits[0]);
2720 
2721 		/* Lock the device, then check to see if we were
2722 		 * disconnected while waiting for the lock to succeed. */
2723 		usb_lock_device(hdev);
2724 		if (unlikely(hub->disconnected))
2725 			goto loop;
2726 
2727 		/* If the hub has died, clean up after it */
2728 		if (hdev->state == USB_STATE_NOTATTACHED) {
2729 			hub->error = -ENODEV;
2730 			hub_pre_reset(intf);
2731 			goto loop;
2732 		}
2733 
2734 		/* Autoresume */
2735 		ret = usb_autopm_get_interface(intf);
2736 		if (ret) {
2737 			dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
2738 			goto loop;
2739 		}
2740 
2741 		/* If this is an inactive hub, do nothing */
2742 		if (hub->quiescing)
2743 			goto loop_autopm;
2744 
2745 		if (hub->error) {
2746 			dev_dbg (hub_dev, "resetting for error %d\n",
2747 				hub->error);
2748 
2749 			ret = usb_reset_composite_device(hdev, intf);
2750 			if (ret) {
2751 				dev_dbg (hub_dev,
2752 					"error resetting hub: %d\n", ret);
2753 				goto loop_autopm;
2754 			}
2755 
2756 			hub->nerrors = 0;
2757 			hub->error = 0;
2758 		}
2759 
2760 		/* deal with port status changes */
2761 		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2762 			if (test_bit(i, hub->busy_bits))
2763 				continue;
2764 			connect_change = test_bit(i, hub->change_bits);
2765 			if (!test_and_clear_bit(i, hub->event_bits) &&
2766 					!connect_change && !hub->activating)
2767 				continue;
2768 
2769 			ret = hub_port_status(hub, i,
2770 					&portstatus, &portchange);
2771 			if (ret < 0)
2772 				continue;
2773 
2774 			if (hub->activating && !hdev->children[i-1] &&
2775 					(portstatus &
2776 						USB_PORT_STAT_CONNECTION))
2777 				connect_change = 1;
2778 
2779 			if (portchange & USB_PORT_STAT_C_CONNECTION) {
2780 				clear_port_feature(hdev, i,
2781 					USB_PORT_FEAT_C_CONNECTION);
2782 				connect_change = 1;
2783 			}
2784 
2785 			if (portchange & USB_PORT_STAT_C_ENABLE) {
2786 				if (!connect_change)
2787 					dev_dbg (hub_dev,
2788 						"port %d enable change, "
2789 						"status %08x\n",
2790 						i, portstatus);
2791 				clear_port_feature(hdev, i,
2792 					USB_PORT_FEAT_C_ENABLE);
2793 
2794 				/*
2795 				 * EM interference sometimes causes badly
2796 				 * shielded USB devices to be shutdown by
2797 				 * the hub, this hack enables them again.
2798 				 * Works at least with mouse driver.
2799 				 */
2800 				if (!(portstatus & USB_PORT_STAT_ENABLE)
2801 				    && !connect_change
2802 				    && hdev->children[i-1]) {
2803 					dev_err (hub_dev,
2804 					    "port %i "
2805 					    "disabled by hub (EMI?), "
2806 					    "re-enabling...\n",
2807 						i);
2808 					connect_change = 1;
2809 				}
2810 			}
2811 
2812 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
2813 				clear_port_feature(hdev, i,
2814 					USB_PORT_FEAT_C_SUSPEND);
2815 				if (hdev->children[i-1]) {
2816 					ret = remote_wakeup(hdev->
2817 							children[i-1]);
2818 					if (ret < 0)
2819 						connect_change = 1;
2820 				} else {
2821 					ret = -ENODEV;
2822 					hub_port_disable(hub, i, 1);
2823 				}
2824 				dev_dbg (hub_dev,
2825 					"resume on port %d, status %d\n",
2826 					i, ret);
2827 			}
2828 
2829 			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2830 				dev_err (hub_dev,
2831 					"over-current change on port %d\n",
2832 					i);
2833 				clear_port_feature(hdev, i,
2834 					USB_PORT_FEAT_C_OVER_CURRENT);
2835 				hub_power_on(hub);
2836 			}
2837 
2838 			if (portchange & USB_PORT_STAT_C_RESET) {
2839 				dev_dbg (hub_dev,
2840 					"reset change on port %d\n",
2841 					i);
2842 				clear_port_feature(hdev, i,
2843 					USB_PORT_FEAT_C_RESET);
2844 			}
2845 
2846 			if (connect_change)
2847 				hub_port_connect_change(hub, i,
2848 						portstatus, portchange);
2849 		} /* end for i */
2850 
2851 		/* deal with hub status changes */
2852 		if (test_and_clear_bit(0, hub->event_bits) == 0)
2853 			;	/* do nothing */
2854 		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2855 			dev_err (hub_dev, "get_hub_status failed\n");
2856 		else {
2857 			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2858 				dev_dbg (hub_dev, "power change\n");
2859 				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2860 				if (hubstatus & HUB_STATUS_LOCAL_POWER)
2861 					/* FIXME: Is this always true? */
2862 					hub->limited_power = 1;
2863 				else
2864 					hub->limited_power = 0;
2865 			}
2866 			if (hubchange & HUB_CHANGE_OVERCURRENT) {
2867 				dev_dbg (hub_dev, "overcurrent change\n");
2868 				msleep(500);	/* Cool down */
2869 				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2870                         	hub_power_on(hub);
2871 			}
2872 		}
2873 
2874 		hub->activating = 0;
2875 
2876 		/* If this is a root hub, tell the HCD it's okay to
2877 		 * re-enable port-change interrupts now. */
2878 		if (!hdev->parent && !hub->busy_bits[0])
2879 			usb_enable_root_hub_irq(hdev->bus);
2880 
2881 loop_autopm:
2882 		/* Allow autosuspend if we're not going to run again */
2883 		if (list_empty(&hub->event_list))
2884 			usb_autopm_enable(intf);
2885 loop:
2886 		usb_unlock_device(hdev);
2887 		kref_put(&hub->kref, hub_release);
2888 
2889         } /* end while (1) */
2890 }
2891 
2892 static int hub_thread(void *__unused)
2893 {
2894 	set_freezable();
2895 	do {
2896 		hub_events();
2897 		wait_event_freezable(khubd_wait,
2898 				!list_empty(&hub_event_list) ||
2899 				kthread_should_stop());
2900 	} while (!kthread_should_stop() || !list_empty(&hub_event_list));
2901 
2902 	pr_debug("%s: khubd exiting\n", usbcore_name);
2903 	return 0;
2904 }
2905 
2906 static struct usb_device_id hub_id_table [] = {
2907     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2908       .bDeviceClass = USB_CLASS_HUB},
2909     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2910       .bInterfaceClass = USB_CLASS_HUB},
2911     { }						/* Terminating entry */
2912 };
2913 
2914 MODULE_DEVICE_TABLE (usb, hub_id_table);
2915 
2916 static struct usb_driver hub_driver = {
2917 	.name =		"hub",
2918 	.probe =	hub_probe,
2919 	.disconnect =	hub_disconnect,
2920 	.suspend =	hub_suspend,
2921 	.resume =	hub_resume,
2922 	.reset_resume =	hub_reset_resume,
2923 	.pre_reset =	hub_pre_reset,
2924 	.post_reset =	hub_post_reset,
2925 	.ioctl =	hub_ioctl,
2926 	.id_table =	hub_id_table,
2927 	.supports_autosuspend =	1,
2928 };
2929 
2930 int usb_hub_init(void)
2931 {
2932 	if (usb_register(&hub_driver) < 0) {
2933 		printk(KERN_ERR "%s: can't register hub driver\n",
2934 			usbcore_name);
2935 		return -1;
2936 	}
2937 
2938 	khubd_task = kthread_run(hub_thread, NULL, "khubd");
2939 	if (!IS_ERR(khubd_task))
2940 		return 0;
2941 
2942 	/* Fall through if kernel_thread failed */
2943 	usb_deregister(&hub_driver);
2944 	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2945 
2946 	return -1;
2947 }
2948 
2949 void usb_hub_cleanup(void)
2950 {
2951 	kthread_stop(khubd_task);
2952 
2953 	/*
2954 	 * Hub resources are freed for us by usb_deregister. It calls
2955 	 * usb_driver_purge on every device which in turn calls that
2956 	 * devices disconnect function if it is using this driver.
2957 	 * The hub_disconnect function takes care of releasing the
2958 	 * individual hub resources. -greg
2959 	 */
2960 	usb_deregister(&hub_driver);
2961 } /* usb_hub_cleanup() */
2962 
2963 static int config_descriptors_changed(struct usb_device *udev)
2964 {
2965 	unsigned			index;
2966 	unsigned			len = 0;
2967 	struct usb_config_descriptor	*buf;
2968 
2969 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2970 		if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2971 			len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2972 	}
2973 	buf = kmalloc(len, GFP_NOIO);
2974 	if (buf == NULL) {
2975 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2976 		/* assume the worst */
2977 		return 1;
2978 	}
2979 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2980 		int length;
2981 		int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2982 
2983 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2984 				old_length);
2985 		if (length < old_length) {
2986 			dev_dbg(&udev->dev, "config index %d, error %d\n",
2987 					index, length);
2988 			break;
2989 		}
2990 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
2991 				!= 0) {
2992 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2993 				index, buf->bConfigurationValue);
2994 			break;
2995 		}
2996 	}
2997 	kfree(buf);
2998 	return index != udev->descriptor.bNumConfigurations;
2999 }
3000 
3001 /**
3002  * usb_reset_device - perform a USB port reset to reinitialize a device
3003  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3004  *
3005  * WARNING - don't use this routine to reset a composite device
3006  * (one with multiple interfaces owned by separate drivers)!
3007  * Use usb_reset_composite_device() instead.
3008  *
3009  * Do a port reset, reassign the device's address, and establish its
3010  * former operating configuration.  If the reset fails, or the device's
3011  * descriptors change from their values before the reset, or the original
3012  * configuration and altsettings cannot be restored, a flag will be set
3013  * telling khubd to pretend the device has been disconnected and then
3014  * re-connected.  All drivers will be unbound, and the device will be
3015  * re-enumerated and probed all over again.
3016  *
3017  * Returns 0 if the reset succeeded, -ENODEV if the device has been
3018  * flagged for logical disconnection, or some other negative error code
3019  * if the reset wasn't even attempted.
3020  *
3021  * The caller must own the device lock.  For example, it's safe to use
3022  * this from a driver probe() routine after downloading new firmware.
3023  * For calls that might not occur during probe(), drivers should lock
3024  * the device using usb_lock_device_for_reset().
3025  *
3026  * Locking exception: This routine may also be called from within an
3027  * autoresume handler.  Such usage won't conflict with other tasks
3028  * holding the device lock because these tasks should always call
3029  * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
3030  */
3031 int usb_reset_device(struct usb_device *udev)
3032 {
3033 	struct usb_device		*parent_hdev = udev->parent;
3034 	struct usb_hub			*parent_hub;
3035 	struct usb_device_descriptor	descriptor = udev->descriptor;
3036 	int 				i, ret = 0;
3037 	int				port1 = udev->portnum;
3038 
3039 	if (udev->state == USB_STATE_NOTATTACHED ||
3040 			udev->state == USB_STATE_SUSPENDED) {
3041 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3042 				udev->state);
3043 		return -EINVAL;
3044 	}
3045 
3046 	if (!parent_hdev) {
3047 		/* this requires hcd-specific logic; see OHCI hc_restart() */
3048 		dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
3049 		return -EISDIR;
3050 	}
3051 	parent_hub = hdev_to_hub(parent_hdev);
3052 
3053 	set_bit(port1, parent_hub->busy_bits);
3054 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
3055 
3056 		/* ep0 maxpacket size may change; let the HCD know about it.
3057 		 * Other endpoints will be handled by re-enumeration. */
3058 		ep0_reinit(udev);
3059 		ret = hub_port_init(parent_hub, udev, port1, i);
3060 		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
3061 			break;
3062 	}
3063 	clear_bit(port1, parent_hub->busy_bits);
3064 	if (!parent_hdev->parent && !parent_hub->busy_bits[0])
3065 		usb_enable_root_hub_irq(parent_hdev->bus);
3066 
3067 	if (ret < 0)
3068 		goto re_enumerate;
3069 
3070 	/* Device might have changed firmware (DFU or similar) */
3071 	if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
3072 			|| config_descriptors_changed (udev)) {
3073 		dev_info(&udev->dev, "device firmware changed\n");
3074 		udev->descriptor = descriptor;	/* for disconnect() calls */
3075 		goto re_enumerate;
3076   	}
3077 
3078 	if (!udev->actconfig)
3079 		goto done;
3080 
3081 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3082 			USB_REQ_SET_CONFIGURATION, 0,
3083 			udev->actconfig->desc.bConfigurationValue, 0,
3084 			NULL, 0, USB_CTRL_SET_TIMEOUT);
3085 	if (ret < 0) {
3086 		dev_err(&udev->dev,
3087 			"can't restore configuration #%d (error=%d)\n",
3088 			udev->actconfig->desc.bConfigurationValue, ret);
3089 		goto re_enumerate;
3090   	}
3091 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
3092 
3093 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3094 		struct usb_interface *intf = udev->actconfig->interface[i];
3095 		struct usb_interface_descriptor *desc;
3096 
3097 		/* set_interface resets host side toggle even
3098 		 * for altsetting zero.  the interface may have no driver.
3099 		 */
3100 		desc = &intf->cur_altsetting->desc;
3101 		ret = usb_set_interface(udev, desc->bInterfaceNumber,
3102 			desc->bAlternateSetting);
3103 		if (ret < 0) {
3104 			dev_err(&udev->dev, "failed to restore interface %d "
3105 				"altsetting %d (error=%d)\n",
3106 				desc->bInterfaceNumber,
3107 				desc->bAlternateSetting,
3108 				ret);
3109 			goto re_enumerate;
3110 		}
3111 	}
3112 
3113 done:
3114 	return 0;
3115 
3116 re_enumerate:
3117 	hub_port_logical_disconnect(parent_hub, port1);
3118 	return -ENODEV;
3119 }
3120 EXPORT_SYMBOL_GPL(usb_reset_device);
3121 
3122 /**
3123  * usb_reset_composite_device - warn interface drivers and perform a USB port reset
3124  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3125  * @iface: interface bound to the driver making the request (optional)
3126  *
3127  * Warns all drivers bound to registered interfaces (using their pre_reset
3128  * method), performs the port reset, and then lets the drivers know that
3129  * the reset is over (using their post_reset method).
3130  *
3131  * Return value is the same as for usb_reset_device().
3132  *
3133  * The caller must own the device lock.  For example, it's safe to use
3134  * this from a driver probe() routine after downloading new firmware.
3135  * For calls that might not occur during probe(), drivers should lock
3136  * the device using usb_lock_device_for_reset().
3137  */
3138 int usb_reset_composite_device(struct usb_device *udev,
3139 		struct usb_interface *iface)
3140 {
3141 	int ret;
3142 	int i;
3143 	struct usb_host_config *config = udev->actconfig;
3144 
3145 	if (udev->state == USB_STATE_NOTATTACHED ||
3146 			udev->state == USB_STATE_SUSPENDED) {
3147 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3148 				udev->state);
3149 		return -EINVAL;
3150 	}
3151 
3152 	/* Prevent autosuspend during the reset */
3153 	usb_autoresume_device(udev);
3154 
3155 	if (iface && iface->condition != USB_INTERFACE_BINDING)
3156 		iface = NULL;
3157 
3158 	if (config) {
3159 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
3160 			struct usb_interface *cintf = config->interface[i];
3161 			struct usb_driver *drv;
3162 
3163 			if (cintf->dev.driver) {
3164 				drv = to_usb_driver(cintf->dev.driver);
3165 				if (drv->pre_reset)
3166 					(drv->pre_reset)(cintf);
3167 	/* FIXME: Unbind if pre_reset returns an error or isn't defined */
3168 			}
3169 		}
3170 	}
3171 
3172 	ret = usb_reset_device(udev);
3173 
3174 	if (config) {
3175 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
3176 			struct usb_interface *cintf = config->interface[i];
3177 			struct usb_driver *drv;
3178 
3179 			if (cintf->dev.driver) {
3180 				drv = to_usb_driver(cintf->dev.driver);
3181 				if (drv->post_reset)
3182 					(drv->post_reset)(cintf);
3183 	/* FIXME: Unbind if post_reset returns an error or isn't defined */
3184 			}
3185 		}
3186 	}
3187 
3188 	usb_autosuspend_device(udev);
3189 	return ret;
3190 }
3191 EXPORT_SYMBOL_GPL(usb_reset_composite_device);
3192