xref: /linux/drivers/usb/core/hub.c (revision aeb3f46252e26acdc60a1a8e31fb1ca6319d9a07)
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 struct usb_hub {
41 	struct device		*intfdev;	/* the "interface" device */
42 	struct usb_device	*hdev;
43 	struct kref		kref;
44 	struct urb		*urb;		/* for interrupt polling pipe */
45 
46 	/* buffer for urb ... with extra space in case of babble */
47 	char			(*buffer)[8];
48 	dma_addr_t		buffer_dma;	/* DMA address for buffer */
49 	union {
50 		struct usb_hub_status	hub;
51 		struct usb_port_status	port;
52 	}			*status;	/* buffer for status reports */
53 	struct mutex		status_mutex;	/* for the status buffer */
54 
55 	int			error;		/* last reported error */
56 	int			nerrors;	/* track consecutive errors */
57 
58 	struct list_head	event_list;	/* hubs w/data or errs ready */
59 	unsigned long		event_bits[1];	/* status change bitmask */
60 	unsigned long		change_bits[1];	/* ports with logical connect
61 							status change */
62 	unsigned long		busy_bits[1];	/* ports being reset or
63 							resumed */
64 #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */
65 #error event_bits[] is too short!
66 #endif
67 
68 	struct usb_hub_descriptor *descriptor;	/* class descriptor */
69 	struct usb_tt		tt;		/* Transaction Translator */
70 
71 	unsigned		mA_per_port;	/* current for each child */
72 
73 	unsigned		limited_power:1;
74 	unsigned		quiescing:1;
75 	unsigned		activating:1;
76 	unsigned		disconnected:1;
77 
78 	unsigned		has_indicators:1;
79 	u8			indicator[USB_MAXCHILDREN];
80 	struct delayed_work	leds;
81 };
82 
83 
84 /* Protect struct usb_device->state and ->children members
85  * Note: Both are also protected by ->dev.sem, except that ->state can
86  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
87 static DEFINE_SPINLOCK(device_state_lock);
88 
89 /* khubd's worklist and its lock */
90 static DEFINE_SPINLOCK(hub_event_lock);
91 static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */
92 
93 /* Wakes up khubd */
94 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
95 
96 static struct task_struct *khubd_task;
97 
98 /* cycle leds on hubs that aren't blinking for attention */
99 static int blinkenlights = 0;
100 module_param (blinkenlights, bool, S_IRUGO);
101 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
102 
103 /*
104  * As of 2.6.10 we introduce a new USB device initialization scheme which
105  * closely resembles the way Windows works.  Hopefully it will be compatible
106  * with a wider range of devices than the old scheme.  However some previously
107  * working devices may start giving rise to "device not accepting address"
108  * errors; if that happens the user can try the old scheme by adjusting the
109  * following module parameters.
110  *
111  * For maximum flexibility there are two boolean parameters to control the
112  * hub driver's behavior.  On the first initialization attempt, if the
113  * "old_scheme_first" parameter is set then the old scheme will be used,
114  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
115  * is set, then the driver will make another attempt, using the other scheme.
116  */
117 static int old_scheme_first = 0;
118 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
119 MODULE_PARM_DESC(old_scheme_first,
120 		 "start with the old device initialization scheme");
121 
122 static int use_both_schemes = 1;
123 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
124 MODULE_PARM_DESC(use_both_schemes,
125 		"try the other device initialization scheme if the "
126 		"first one fails");
127 
128 
129 static inline char *portspeed(int portstatus)
130 {
131 	if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
132     		return "480 Mb/s";
133 	else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
134 		return "1.5 Mb/s";
135 	else
136 		return "12 Mb/s";
137 }
138 
139 /* Note that hdev or one of its children must be locked! */
140 static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
141 {
142 	return usb_get_intfdata(hdev->actconfig->interface[0]);
143 }
144 
145 /* USB 2.0 spec Section 11.24.4.5 */
146 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
147 {
148 	int i, ret;
149 
150 	for (i = 0; i < 3; i++) {
151 		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
152 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
153 			USB_DT_HUB << 8, 0, data, size,
154 			USB_CTRL_GET_TIMEOUT);
155 		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
156 			return ret;
157 	}
158 	return -EINVAL;
159 }
160 
161 /*
162  * USB 2.0 spec Section 11.24.2.1
163  */
164 static int clear_hub_feature(struct usb_device *hdev, int feature)
165 {
166 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
167 		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
168 }
169 
170 /*
171  * USB 2.0 spec Section 11.24.2.2
172  */
173 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
174 {
175 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
176 		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
177 		NULL, 0, 1000);
178 }
179 
180 /*
181  * USB 2.0 spec Section 11.24.2.13
182  */
183 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
184 {
185 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
186 		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
187 		NULL, 0, 1000);
188 }
189 
190 /*
191  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
192  * for info about using port indicators
193  */
194 static void set_port_led(
195 	struct usb_hub *hub,
196 	int port1,
197 	int selector
198 )
199 {
200 	int status = set_port_feature(hub->hdev, (selector << 8) | port1,
201 			USB_PORT_FEAT_INDICATOR);
202 	if (status < 0)
203 		dev_dbg (hub->intfdev,
204 			"port %d indicator %s status %d\n",
205 			port1,
206 			({ char *s; switch (selector) {
207 			case HUB_LED_AMBER: s = "amber"; break;
208 			case HUB_LED_GREEN: s = "green"; break;
209 			case HUB_LED_OFF: s = "off"; break;
210 			case HUB_LED_AUTO: s = "auto"; break;
211 			default: s = "??"; break;
212 			}; s; }),
213 			status);
214 }
215 
216 #define	LED_CYCLE_PERIOD	((2*HZ)/3)
217 
218 static void led_work (struct work_struct *work)
219 {
220 	struct usb_hub		*hub =
221 		container_of(work, struct usb_hub, leds.work);
222 	struct usb_device	*hdev = hub->hdev;
223 	unsigned		i;
224 	unsigned		changed = 0;
225 	int			cursor = -1;
226 
227 	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
228 		return;
229 
230 	for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
231 		unsigned	selector, mode;
232 
233 		/* 30%-50% duty cycle */
234 
235 		switch (hub->indicator[i]) {
236 		/* cycle marker */
237 		case INDICATOR_CYCLE:
238 			cursor = i;
239 			selector = HUB_LED_AUTO;
240 			mode = INDICATOR_AUTO;
241 			break;
242 		/* blinking green = sw attention */
243 		case INDICATOR_GREEN_BLINK:
244 			selector = HUB_LED_GREEN;
245 			mode = INDICATOR_GREEN_BLINK_OFF;
246 			break;
247 		case INDICATOR_GREEN_BLINK_OFF:
248 			selector = HUB_LED_OFF;
249 			mode = INDICATOR_GREEN_BLINK;
250 			break;
251 		/* blinking amber = hw attention */
252 		case INDICATOR_AMBER_BLINK:
253 			selector = HUB_LED_AMBER;
254 			mode = INDICATOR_AMBER_BLINK_OFF;
255 			break;
256 		case INDICATOR_AMBER_BLINK_OFF:
257 			selector = HUB_LED_OFF;
258 			mode = INDICATOR_AMBER_BLINK;
259 			break;
260 		/* blink green/amber = reserved */
261 		case INDICATOR_ALT_BLINK:
262 			selector = HUB_LED_GREEN;
263 			mode = INDICATOR_ALT_BLINK_OFF;
264 			break;
265 		case INDICATOR_ALT_BLINK_OFF:
266 			selector = HUB_LED_AMBER;
267 			mode = INDICATOR_ALT_BLINK;
268 			break;
269 		default:
270 			continue;
271 		}
272 		if (selector != HUB_LED_AUTO)
273 			changed = 1;
274 		set_port_led(hub, i + 1, selector);
275 		hub->indicator[i] = mode;
276 	}
277 	if (!changed && blinkenlights) {
278 		cursor++;
279 		cursor %= hub->descriptor->bNbrPorts;
280 		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
281 		hub->indicator[cursor] = INDICATOR_CYCLE;
282 		changed++;
283 	}
284 	if (changed)
285 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
286 }
287 
288 /* use a short timeout for hub/port status fetches */
289 #define	USB_STS_TIMEOUT		1000
290 #define	USB_STS_RETRIES		5
291 
292 /*
293  * USB 2.0 spec Section 11.24.2.6
294  */
295 static int get_hub_status(struct usb_device *hdev,
296 		struct usb_hub_status *data)
297 {
298 	int i, status = -ETIMEDOUT;
299 
300 	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
301 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
302 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
303 			data, sizeof(*data), USB_STS_TIMEOUT);
304 	}
305 	return status;
306 }
307 
308 /*
309  * USB 2.0 spec Section 11.24.2.7
310  */
311 static int get_port_status(struct usb_device *hdev, int port1,
312 		struct usb_port_status *data)
313 {
314 	int i, status = -ETIMEDOUT;
315 
316 	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
317 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
318 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
319 			data, sizeof(*data), USB_STS_TIMEOUT);
320 	}
321 	return status;
322 }
323 
324 static void kick_khubd(struct usb_hub *hub)
325 {
326 	unsigned long	flags;
327 
328 	/* Suppress autosuspend until khubd runs */
329 	to_usb_interface(hub->intfdev)->pm_usage_cnt = 1;
330 
331 	spin_lock_irqsave(&hub_event_lock, flags);
332 	if (!hub->disconnected & list_empty(&hub->event_list)) {
333 		list_add_tail(&hub->event_list, &hub_event_list);
334 		wake_up(&khubd_wait);
335 	}
336 	spin_unlock_irqrestore(&hub_event_lock, flags);
337 }
338 
339 void usb_kick_khubd(struct usb_device *hdev)
340 {
341 	/* FIXME: What if hdev isn't bound to the hub driver? */
342 	kick_khubd(hdev_to_hub(hdev));
343 }
344 
345 
346 /* completion function, fires on port status changes and various faults */
347 static void hub_irq(struct urb *urb)
348 {
349 	struct usb_hub *hub = urb->context;
350 	int status;
351 	int i;
352 	unsigned long bits;
353 
354 	switch (urb->status) {
355 	case -ENOENT:		/* synchronous unlink */
356 	case -ECONNRESET:	/* async unlink */
357 	case -ESHUTDOWN:	/* hardware going away */
358 		return;
359 
360 	default:		/* presumably an error */
361 		/* Cause a hub reset after 10 consecutive errors */
362 		dev_dbg (hub->intfdev, "transfer --> %d\n", urb->status);
363 		if ((++hub->nerrors < 10) || hub->error)
364 			goto resubmit;
365 		hub->error = urb->status;
366 		/* FALL THROUGH */
367 
368 	/* let khubd handle things */
369 	case 0:			/* we got data:  port status changed */
370 		bits = 0;
371 		for (i = 0; i < urb->actual_length; ++i)
372 			bits |= ((unsigned long) ((*hub->buffer)[i]))
373 					<< (i*8);
374 		hub->event_bits[0] = bits;
375 		break;
376 	}
377 
378 	hub->nerrors = 0;
379 
380 	/* Something happened, let khubd figure it out */
381 	kick_khubd(hub);
382 
383 resubmit:
384 	if (hub->quiescing)
385 		return;
386 
387 	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
388 			&& status != -ENODEV && status != -EPERM)
389 		dev_err (hub->intfdev, "resubmit --> %d\n", status);
390 }
391 
392 /* USB 2.0 spec Section 11.24.2.3 */
393 static inline int
394 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
395 {
396 	return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
397 			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
398 			       tt, NULL, 0, 1000);
399 }
400 
401 /*
402  * enumeration blocks khubd for a long time. we use keventd instead, since
403  * long blocking there is the exception, not the rule.  accordingly, HCDs
404  * talking to TTs must queue control transfers (not just bulk and iso), so
405  * both can talk to the same hub concurrently.
406  */
407 static void hub_tt_kevent (struct work_struct *work)
408 {
409 	struct usb_hub		*hub =
410 		container_of(work, struct usb_hub, tt.kevent);
411 	unsigned long		flags;
412 	int			limit = 100;
413 
414 	spin_lock_irqsave (&hub->tt.lock, flags);
415 	while (--limit && !list_empty (&hub->tt.clear_list)) {
416 		struct list_head	*temp;
417 		struct usb_tt_clear	*clear;
418 		struct usb_device	*hdev = hub->hdev;
419 		int			status;
420 
421 		temp = hub->tt.clear_list.next;
422 		clear = list_entry (temp, struct usb_tt_clear, clear_list);
423 		list_del (&clear->clear_list);
424 
425 		/* drop lock so HCD can concurrently report other TT errors */
426 		spin_unlock_irqrestore (&hub->tt.lock, flags);
427 		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
428 		spin_lock_irqsave (&hub->tt.lock, flags);
429 
430 		if (status)
431 			dev_err (&hdev->dev,
432 				"clear tt %d (%04x) error %d\n",
433 				clear->tt, clear->devinfo, status);
434 		kfree(clear);
435 	}
436 	spin_unlock_irqrestore (&hub->tt.lock, flags);
437 }
438 
439 /**
440  * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
441  * @udev: the device whose split transaction failed
442  * @pipe: identifies the endpoint of the failed transaction
443  *
444  * High speed HCDs use this to tell the hub driver that some split control or
445  * bulk transaction failed in a way that requires clearing internal state of
446  * a transaction translator.  This is normally detected (and reported) from
447  * interrupt context.
448  *
449  * It may not be possible for that hub to handle additional full (or low)
450  * speed transactions until that state is fully cleared out.
451  */
452 void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
453 {
454 	struct usb_tt		*tt = udev->tt;
455 	unsigned long		flags;
456 	struct usb_tt_clear	*clear;
457 
458 	/* we've got to cope with an arbitrary number of pending TT clears,
459 	 * since each TT has "at least two" buffers that can need it (and
460 	 * there can be many TTs per hub).  even if they're uncommon.
461 	 */
462 	if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
463 		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
464 		/* FIXME recover somehow ... RESET_TT? */
465 		return;
466 	}
467 
468 	/* info that CLEAR_TT_BUFFER needs */
469 	clear->tt = tt->multi ? udev->ttport : 1;
470 	clear->devinfo = usb_pipeendpoint (pipe);
471 	clear->devinfo |= udev->devnum << 4;
472 	clear->devinfo |= usb_pipecontrol (pipe)
473 			? (USB_ENDPOINT_XFER_CONTROL << 11)
474 			: (USB_ENDPOINT_XFER_BULK << 11);
475 	if (usb_pipein (pipe))
476 		clear->devinfo |= 1 << 15;
477 
478 	/* tell keventd to clear state for this TT */
479 	spin_lock_irqsave (&tt->lock, flags);
480 	list_add_tail (&clear->clear_list, &tt->clear_list);
481 	schedule_work (&tt->kevent);
482 	spin_unlock_irqrestore (&tt->lock, flags);
483 }
484 
485 static void hub_power_on(struct usb_hub *hub)
486 {
487 	int port1;
488 	unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
489 	u16 wHubCharacteristics =
490 			le16_to_cpu(hub->descriptor->wHubCharacteristics);
491 
492 	/* Enable power on each port.  Some hubs have reserved values
493 	 * of LPSM (> 2) in their descriptors, even though they are
494 	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
495 	 * but only emulate it.  In all cases, the ports won't work
496 	 * unless we send these messages to the hub.
497 	 */
498 	if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
499 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
500 	else
501 		dev_dbg(hub->intfdev, "trying to enable port power on "
502 				"non-switchable hub\n");
503 	for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
504 		set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
505 
506 	/* Wait at least 100 msec for power to become stable */
507 	msleep(max(pgood_delay, (unsigned) 100));
508 }
509 
510 static void hub_quiesce(struct usb_hub *hub)
511 {
512 	/* (nonblocking) khubd and related activity won't re-trigger */
513 	hub->quiescing = 1;
514 	hub->activating = 0;
515 
516 	/* (blocking) stop khubd and related activity */
517 	usb_kill_urb(hub->urb);
518 	if (hub->has_indicators)
519 		cancel_delayed_work(&hub->leds);
520 	if (hub->has_indicators || hub->tt.hub)
521 		flush_scheduled_work();
522 }
523 
524 static void hub_activate(struct usb_hub *hub)
525 {
526 	int	status;
527 
528 	hub->quiescing = 0;
529 	hub->activating = 1;
530 
531 	status = usb_submit_urb(hub->urb, GFP_NOIO);
532 	if (status < 0)
533 		dev_err(hub->intfdev, "activate --> %d\n", status);
534 	if (hub->has_indicators && blinkenlights)
535 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
536 
537 	/* scan all ports ASAP */
538 	kick_khubd(hub);
539 }
540 
541 static int hub_hub_status(struct usb_hub *hub,
542 		u16 *status, u16 *change)
543 {
544 	int ret;
545 
546 	mutex_lock(&hub->status_mutex);
547 	ret = get_hub_status(hub->hdev, &hub->status->hub);
548 	if (ret < 0)
549 		dev_err (hub->intfdev,
550 			"%s failed (err = %d)\n", __FUNCTION__, ret);
551 	else {
552 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
553 		*change = le16_to_cpu(hub->status->hub.wHubChange);
554 		ret = 0;
555 	}
556 	mutex_unlock(&hub->status_mutex);
557 	return ret;
558 }
559 
560 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
561 {
562 	struct usb_device *hdev = hub->hdev;
563 	int ret = 0;
564 
565 	if (hdev->children[port1-1] && set_state)
566 		usb_set_device_state(hdev->children[port1-1],
567 				USB_STATE_NOTATTACHED);
568 	if (!hub->error)
569 		ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
570 	if (ret)
571 		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
572 				port1, ret);
573 	return ret;
574 }
575 
576 /*
577  * Disable a port and mark a logical connnect-change event, so that some
578  * time later khubd will disconnect() any existing usb_device on the port
579  * and will re-enumerate if there actually is a device attached.
580  */
581 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
582 {
583 	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
584 	hub_port_disable(hub, port1, 1);
585 
586 	/* FIXME let caller ask to power down the port:
587 	 *  - some devices won't enumerate without a VBUS power cycle
588 	 *  - SRP saves power that way
589 	 *  - ... new call, TBD ...
590 	 * That's easy if this hub can switch power per-port, and
591 	 * khubd reactivates the port later (timer, SRP, etc).
592 	 * Powerdown must be optional, because of reset/DFU.
593 	 */
594 
595 	set_bit(port1, hub->change_bits);
596  	kick_khubd(hub);
597 }
598 
599 /* caller has locked the hub device */
600 static int hub_pre_reset(struct usb_interface *intf)
601 {
602 	struct usb_hub *hub = usb_get_intfdata(intf);
603 	struct usb_device *hdev = hub->hdev;
604 	int i;
605 
606 	/* Disconnect all the children */
607 	for (i = 0; i < hdev->maxchild; ++i) {
608 		if (hdev->children[i])
609 			usb_disconnect(&hdev->children[i]);
610 	}
611 	hub_quiesce(hub);
612 	return 0;
613 }
614 
615 /* caller has locked the hub device */
616 static int hub_post_reset(struct usb_interface *intf)
617 {
618 	struct usb_hub *hub = usb_get_intfdata(intf);
619 
620 	hub_power_on(hub);
621 	hub_activate(hub);
622 	return 0;
623 }
624 
625 static int hub_configure(struct usb_hub *hub,
626 	struct usb_endpoint_descriptor *endpoint)
627 {
628 	struct usb_device *hdev = hub->hdev;
629 	struct device *hub_dev = hub->intfdev;
630 	u16 hubstatus, hubchange;
631 	u16 wHubCharacteristics;
632 	unsigned int pipe;
633 	int maxp, ret;
634 	char *message;
635 
636 	hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
637 			&hub->buffer_dma);
638 	if (!hub->buffer) {
639 		message = "can't allocate hub irq buffer";
640 		ret = -ENOMEM;
641 		goto fail;
642 	}
643 
644 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
645 	if (!hub->status) {
646 		message = "can't kmalloc hub status buffer";
647 		ret = -ENOMEM;
648 		goto fail;
649 	}
650 	mutex_init(&hub->status_mutex);
651 
652 	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
653 	if (!hub->descriptor) {
654 		message = "can't kmalloc hub descriptor";
655 		ret = -ENOMEM;
656 		goto fail;
657 	}
658 
659 	/* Request the entire hub descriptor.
660 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
661 	 * but the hub can/will return fewer bytes here.
662 	 */
663 	ret = get_hub_descriptor(hdev, hub->descriptor,
664 			sizeof(*hub->descriptor));
665 	if (ret < 0) {
666 		message = "can't read hub descriptor";
667 		goto fail;
668 	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
669 		message = "hub has too many ports!";
670 		ret = -ENODEV;
671 		goto fail;
672 	}
673 
674 	hdev->maxchild = hub->descriptor->bNbrPorts;
675 	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
676 		(hdev->maxchild == 1) ? "" : "s");
677 
678 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
679 
680 	if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
681 		int	i;
682 		char	portstr [USB_MAXCHILDREN + 1];
683 
684 		for (i = 0; i < hdev->maxchild; i++)
685 			portstr[i] = hub->descriptor->DeviceRemovable
686 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
687 				? 'F' : 'R';
688 		portstr[hdev->maxchild] = 0;
689 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
690 	} else
691 		dev_dbg(hub_dev, "standalone hub\n");
692 
693 	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
694 		case 0x00:
695 			dev_dbg(hub_dev, "ganged power switching\n");
696 			break;
697 		case 0x01:
698 			dev_dbg(hub_dev, "individual port power switching\n");
699 			break;
700 		case 0x02:
701 		case 0x03:
702 			dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
703 			break;
704 	}
705 
706 	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
707 		case 0x00:
708 			dev_dbg(hub_dev, "global over-current protection\n");
709 			break;
710 		case 0x08:
711 			dev_dbg(hub_dev, "individual port over-current protection\n");
712 			break;
713 		case 0x10:
714 		case 0x18:
715 			dev_dbg(hub_dev, "no over-current protection\n");
716                         break;
717 	}
718 
719 	spin_lock_init (&hub->tt.lock);
720 	INIT_LIST_HEAD (&hub->tt.clear_list);
721 	INIT_WORK (&hub->tt.kevent, hub_tt_kevent);
722 	switch (hdev->descriptor.bDeviceProtocol) {
723 		case 0:
724 			break;
725 		case 1:
726 			dev_dbg(hub_dev, "Single TT\n");
727 			hub->tt.hub = hdev;
728 			break;
729 		case 2:
730 			ret = usb_set_interface(hdev, 0, 1);
731 			if (ret == 0) {
732 				dev_dbg(hub_dev, "TT per port\n");
733 				hub->tt.multi = 1;
734 			} else
735 				dev_err(hub_dev, "Using single TT (err %d)\n",
736 					ret);
737 			hub->tt.hub = hdev;
738 			break;
739 		default:
740 			dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
741 				hdev->descriptor.bDeviceProtocol);
742 			break;
743 	}
744 
745 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
746 	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
747 		case HUB_TTTT_8_BITS:
748 			if (hdev->descriptor.bDeviceProtocol != 0) {
749 				hub->tt.think_time = 666;
750 				dev_dbg(hub_dev, "TT requires at most %d "
751 						"FS bit times (%d ns)\n",
752 					8, hub->tt.think_time);
753 			}
754 			break;
755 		case HUB_TTTT_16_BITS:
756 			hub->tt.think_time = 666 * 2;
757 			dev_dbg(hub_dev, "TT requires at most %d "
758 					"FS bit times (%d ns)\n",
759 				16, hub->tt.think_time);
760 			break;
761 		case HUB_TTTT_24_BITS:
762 			hub->tt.think_time = 666 * 3;
763 			dev_dbg(hub_dev, "TT requires at most %d "
764 					"FS bit times (%d ns)\n",
765 				24, hub->tt.think_time);
766 			break;
767 		case HUB_TTTT_32_BITS:
768 			hub->tt.think_time = 666 * 4;
769 			dev_dbg(hub_dev, "TT requires at most %d "
770 					"FS bit times (%d ns)\n",
771 				32, hub->tt.think_time);
772 			break;
773 	}
774 
775 	/* probe() zeroes hub->indicator[] */
776 	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
777 		hub->has_indicators = 1;
778 		dev_dbg(hub_dev, "Port indicators are supported\n");
779 	}
780 
781 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
782 		hub->descriptor->bPwrOn2PwrGood * 2);
783 
784 	/* power budgeting mostly matters with bus-powered hubs,
785 	 * and battery-powered root hubs (may provide just 8 mA).
786 	 */
787 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
788 	if (ret < 2) {
789 		message = "can't get hub status";
790 		goto fail;
791 	}
792 	le16_to_cpus(&hubstatus);
793 	if (hdev == hdev->bus->root_hub) {
794 		if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
795 			hub->mA_per_port = 500;
796 		else {
797 			hub->mA_per_port = hdev->bus_mA;
798 			hub->limited_power = 1;
799 		}
800 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
801 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
802 			hub->descriptor->bHubContrCurrent);
803 		hub->limited_power = 1;
804 		if (hdev->maxchild > 0) {
805 			int remaining = hdev->bus_mA -
806 					hub->descriptor->bHubContrCurrent;
807 
808 			if (remaining < hdev->maxchild * 100)
809 				dev_warn(hub_dev,
810 					"insufficient power available "
811 					"to use all downstream ports\n");
812 			hub->mA_per_port = 100;		/* 7.2.1.1 */
813 		}
814 	} else {	/* Self-powered external hub */
815 		/* FIXME: What about battery-powered external hubs that
816 		 * provide less current per port? */
817 		hub->mA_per_port = 500;
818 	}
819 	if (hub->mA_per_port < 500)
820 		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
821 				hub->mA_per_port);
822 
823 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
824 	if (ret < 0) {
825 		message = "can't get hub status";
826 		goto fail;
827 	}
828 
829 	/* local power status reports aren't always correct */
830 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
831 		dev_dbg(hub_dev, "local power source is %s\n",
832 			(hubstatus & HUB_STATUS_LOCAL_POWER)
833 			? "lost (inactive)" : "good");
834 
835 	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
836 		dev_dbg(hub_dev, "%sover-current condition exists\n",
837 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
838 
839 	/* set up the interrupt endpoint
840 	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
841 	 * bytes as USB2.0[11.12.3] says because some hubs are known
842 	 * to send more data (and thus cause overflow). For root hubs,
843 	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
844 	 * to be big enough for at least USB_MAXCHILDREN ports. */
845 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
846 	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
847 
848 	if (maxp > sizeof(*hub->buffer))
849 		maxp = sizeof(*hub->buffer);
850 
851 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
852 	if (!hub->urb) {
853 		message = "couldn't allocate interrupt urb";
854 		ret = -ENOMEM;
855 		goto fail;
856 	}
857 
858 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
859 		hub, endpoint->bInterval);
860 	hub->urb->transfer_dma = hub->buffer_dma;
861 	hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
862 
863 	/* maybe cycle the hub leds */
864 	if (hub->has_indicators && blinkenlights)
865 		hub->indicator [0] = INDICATOR_CYCLE;
866 
867 	hub_power_on(hub);
868 	hub_activate(hub);
869 	return 0;
870 
871 fail:
872 	dev_err (hub_dev, "config failed, %s (err %d)\n",
873 			message, ret);
874 	/* hub_disconnect() frees urb and descriptor */
875 	return ret;
876 }
877 
878 static void hub_release(struct kref *kref)
879 {
880 	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
881 
882 	usb_put_intf(to_usb_interface(hub->intfdev));
883 	kfree(hub);
884 }
885 
886 static unsigned highspeed_hubs;
887 
888 static void hub_disconnect(struct usb_interface *intf)
889 {
890 	struct usb_hub *hub = usb_get_intfdata (intf);
891 
892 	/* Take the hub off the event list and don't let it be added again */
893 	spin_lock_irq(&hub_event_lock);
894 	list_del_init(&hub->event_list);
895 	hub->disconnected = 1;
896 	spin_unlock_irq(&hub_event_lock);
897 
898 	/* Disconnect all children and quiesce the hub */
899 	hub->error = 0;
900 	hub_pre_reset(intf);
901 
902 	usb_set_intfdata (intf, NULL);
903 
904 	if (hub->hdev->speed == USB_SPEED_HIGH)
905 		highspeed_hubs--;
906 
907 	usb_free_urb(hub->urb);
908 	kfree(hub->descriptor);
909 	kfree(hub->status);
910 	usb_buffer_free(hub->hdev, sizeof(*hub->buffer), hub->buffer,
911 			hub->buffer_dma);
912 
913 	kref_put(&hub->kref, hub_release);
914 }
915 
916 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
917 {
918 	struct usb_host_interface *desc;
919 	struct usb_endpoint_descriptor *endpoint;
920 	struct usb_device *hdev;
921 	struct usb_hub *hub;
922 
923 	desc = intf->cur_altsetting;
924 	hdev = interface_to_usbdev(intf);
925 
926 #ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
927 	if (hdev->parent) {
928 		dev_warn(&intf->dev, "ignoring external hub\n");
929 		return -ENODEV;
930 	}
931 #endif
932 
933 	/* Some hubs have a subclass of 1, which AFAICT according to the */
934 	/*  specs is not defined, but it works */
935 	if ((desc->desc.bInterfaceSubClass != 0) &&
936 	    (desc->desc.bInterfaceSubClass != 1)) {
937 descriptor_error:
938 		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
939 		return -EIO;
940 	}
941 
942 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
943 	if (desc->desc.bNumEndpoints != 1)
944 		goto descriptor_error;
945 
946 	endpoint = &desc->endpoint[0].desc;
947 
948 	/* If it's not an interrupt in endpoint, we'd better punt! */
949 	if (!usb_endpoint_is_int_in(endpoint))
950 		goto descriptor_error;
951 
952 	/* We found a hub */
953 	dev_info (&intf->dev, "USB hub found\n");
954 
955 	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
956 	if (!hub) {
957 		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
958 		return -ENOMEM;
959 	}
960 
961 	kref_init(&hub->kref);
962 	INIT_LIST_HEAD(&hub->event_list);
963 	hub->intfdev = &intf->dev;
964 	hub->hdev = hdev;
965 	INIT_DELAYED_WORK(&hub->leds, led_work);
966 	usb_get_intf(intf);
967 
968 	usb_set_intfdata (intf, hub);
969 	intf->needs_remote_wakeup = 1;
970 
971 	if (hdev->speed == USB_SPEED_HIGH)
972 		highspeed_hubs++;
973 
974 	if (hub_configure(hub, endpoint) >= 0)
975 		return 0;
976 
977 	hub_disconnect (intf);
978 	return -ENODEV;
979 }
980 
981 static int
982 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
983 {
984 	struct usb_device *hdev = interface_to_usbdev (intf);
985 
986 	/* assert ifno == 0 (part of hub spec) */
987 	switch (code) {
988 	case USBDEVFS_HUB_PORTINFO: {
989 		struct usbdevfs_hub_portinfo *info = user_data;
990 		int i;
991 
992 		spin_lock_irq(&device_state_lock);
993 		if (hdev->devnum <= 0)
994 			info->nports = 0;
995 		else {
996 			info->nports = hdev->maxchild;
997 			for (i = 0; i < info->nports; i++) {
998 				if (hdev->children[i] == NULL)
999 					info->port[i] = 0;
1000 				else
1001 					info->port[i] =
1002 						hdev->children[i]->devnum;
1003 			}
1004 		}
1005 		spin_unlock_irq(&device_state_lock);
1006 
1007 		return info->nports + 1;
1008 		}
1009 
1010 	default:
1011 		return -ENOSYS;
1012 	}
1013 }
1014 
1015 
1016 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1017 {
1018 	int i;
1019 
1020 	for (i = 0; i < udev->maxchild; ++i) {
1021 		if (udev->children[i])
1022 			recursively_mark_NOTATTACHED(udev->children[i]);
1023 	}
1024 	if (udev->state == USB_STATE_SUSPENDED)
1025 		udev->discon_suspended = 1;
1026 	udev->state = USB_STATE_NOTATTACHED;
1027 }
1028 
1029 /**
1030  * usb_set_device_state - change a device's current state (usbcore, hcds)
1031  * @udev: pointer to device whose state should be changed
1032  * @new_state: new state value to be stored
1033  *
1034  * udev->state is _not_ fully protected by the device lock.  Although
1035  * most transitions are made only while holding the lock, the state can
1036  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1037  * is so that devices can be marked as disconnected as soon as possible,
1038  * without having to wait for any semaphores to be released.  As a result,
1039  * all changes to any device's state must be protected by the
1040  * device_state_lock spinlock.
1041  *
1042  * Once a device has been added to the device tree, all changes to its state
1043  * should be made using this routine.  The state should _not_ be set directly.
1044  *
1045  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1046  * Otherwise udev->state is set to new_state, and if new_state is
1047  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1048  * to USB_STATE_NOTATTACHED.
1049  */
1050 void usb_set_device_state(struct usb_device *udev,
1051 		enum usb_device_state new_state)
1052 {
1053 	unsigned long flags;
1054 
1055 	spin_lock_irqsave(&device_state_lock, flags);
1056 	if (udev->state == USB_STATE_NOTATTACHED)
1057 		;	/* do nothing */
1058 	else if (new_state != USB_STATE_NOTATTACHED) {
1059 
1060 		/* root hub wakeup capabilities are managed out-of-band
1061 		 * and may involve silicon errata ... ignore them here.
1062 		 */
1063 		if (udev->parent) {
1064 			if (udev->state == USB_STATE_SUSPENDED
1065 					|| new_state == USB_STATE_SUSPENDED)
1066 				;	/* No change to wakeup settings */
1067 			else if (new_state == USB_STATE_CONFIGURED)
1068 				device_init_wakeup(&udev->dev,
1069 					(udev->actconfig->desc.bmAttributes
1070 					 & USB_CONFIG_ATT_WAKEUP));
1071 			else
1072 				device_init_wakeup(&udev->dev, 0);
1073 		}
1074 		udev->state = new_state;
1075 	} else
1076 		recursively_mark_NOTATTACHED(udev);
1077 	spin_unlock_irqrestore(&device_state_lock, flags);
1078 }
1079 
1080 static void choose_address(struct usb_device *udev)
1081 {
1082 	int		devnum;
1083 	struct usb_bus	*bus = udev->bus;
1084 
1085 	/* If khubd ever becomes multithreaded, this will need a lock */
1086 
1087 	/* Try to allocate the next devnum beginning at bus->devnum_next. */
1088 	devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1089 			bus->devnum_next);
1090 	if (devnum >= 128)
1091 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
1092 
1093 	bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1094 
1095 	if (devnum < 128) {
1096 		set_bit(devnum, bus->devmap.devicemap);
1097 		udev->devnum = devnum;
1098 	}
1099 }
1100 
1101 static void release_address(struct usb_device *udev)
1102 {
1103 	if (udev->devnum > 0) {
1104 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1105 		udev->devnum = -1;
1106 	}
1107 }
1108 
1109 #ifdef	CONFIG_USB_SUSPEND
1110 
1111 static void usb_stop_pm(struct usb_device *udev)
1112 {
1113 	/* Synchronize with the ksuspend thread to prevent any more
1114 	 * autosuspend requests from being submitted, and decrement
1115 	 * the parent's count of unsuspended children.
1116 	 */
1117 	usb_pm_lock(udev);
1118 	if (udev->parent && !udev->discon_suspended)
1119 		usb_autosuspend_device(udev->parent);
1120 	usb_pm_unlock(udev);
1121 
1122 	/* Stop any autosuspend requests already submitted */
1123 	cancel_rearming_delayed_work(&udev->autosuspend);
1124 }
1125 
1126 #else
1127 
1128 static inline void usb_stop_pm(struct usb_device *udev)
1129 { }
1130 
1131 #endif
1132 
1133 /**
1134  * usb_disconnect - disconnect a device (usbcore-internal)
1135  * @pdev: pointer to device being disconnected
1136  * Context: !in_interrupt ()
1137  *
1138  * Something got disconnected. Get rid of it and all of its children.
1139  *
1140  * If *pdev is a normal device then the parent hub must already be locked.
1141  * If *pdev is a root hub then this routine will acquire the
1142  * usb_bus_list_lock on behalf of the caller.
1143  *
1144  * Only hub drivers (including virtual root hub drivers for host
1145  * controllers) should ever call this.
1146  *
1147  * This call is synchronous, and may not be used in an interrupt context.
1148  */
1149 void usb_disconnect(struct usb_device **pdev)
1150 {
1151 	struct usb_device	*udev = *pdev;
1152 	int			i;
1153 
1154 	if (!udev) {
1155 		pr_debug ("%s nodev\n", __FUNCTION__);
1156 		return;
1157 	}
1158 
1159 	/* mark the device as inactive, so any further urb submissions for
1160 	 * this device (and any of its children) will fail immediately.
1161 	 * this quiesces everyting except pending urbs.
1162 	 */
1163 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1164 	dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1165 
1166 	usb_lock_device(udev);
1167 
1168 	/* Free up all the children before we remove this device */
1169 	for (i = 0; i < USB_MAXCHILDREN; i++) {
1170 		if (udev->children[i])
1171 			usb_disconnect(&udev->children[i]);
1172 	}
1173 
1174 	/* deallocate hcd/hardware state ... nuking all pending urbs and
1175 	 * cleaning up all state associated with the current configuration
1176 	 * so that the hardware is now fully quiesced.
1177 	 */
1178 	dev_dbg (&udev->dev, "unregistering device\n");
1179 	usb_disable_device(udev, 0);
1180 
1181 	usb_unlock_device(udev);
1182 
1183 	/* Unregister the device.  The device driver is responsible
1184 	 * for removing the device files from usbfs and sysfs and for
1185 	 * de-configuring the device.
1186 	 */
1187 	device_del(&udev->dev);
1188 
1189 	/* Free the device number and delete the parent's children[]
1190 	 * (or root_hub) pointer.
1191 	 */
1192 	release_address(udev);
1193 
1194 	/* Avoid races with recursively_mark_NOTATTACHED() */
1195 	spin_lock_irq(&device_state_lock);
1196 	*pdev = NULL;
1197 	spin_unlock_irq(&device_state_lock);
1198 
1199 	usb_stop_pm(udev);
1200 
1201 	put_device(&udev->dev);
1202 }
1203 
1204 #ifdef DEBUG
1205 static void show_string(struct usb_device *udev, char *id, char *string)
1206 {
1207 	if (!string)
1208 		return;
1209 	dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1210 }
1211 
1212 #else
1213 static inline void show_string(struct usb_device *udev, char *id, char *string)
1214 {}
1215 #endif
1216 
1217 
1218 #ifdef	CONFIG_USB_OTG
1219 #include "otg_whitelist.h"
1220 #endif
1221 
1222 /**
1223  * usb_new_device - perform initial device setup (usbcore-internal)
1224  * @udev: newly addressed device (in ADDRESS state)
1225  *
1226  * This is called with devices which have been enumerated, but not yet
1227  * configured.  The device descriptor is available, but not descriptors
1228  * for any device configuration.  The caller must have locked either
1229  * the parent hub (if udev is a normal device) or else the
1230  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
1231  * udev has already been installed, but udev is not yet visible through
1232  * sysfs or other filesystem code.
1233  *
1234  * It will return if the device is configured properly or not.  Zero if
1235  * the interface was registered with the driver core; else a negative
1236  * errno value.
1237  *
1238  * This call is synchronous, and may not be used in an interrupt context.
1239  *
1240  * Only the hub driver or root-hub registrar should ever call this.
1241  */
1242 int usb_new_device(struct usb_device *udev)
1243 {
1244 	int err;
1245 
1246 	/* Determine quirks */
1247 	usb_detect_quirks(udev);
1248 
1249 	err = usb_get_configuration(udev);
1250 	if (err < 0) {
1251 		dev_err(&udev->dev, "can't read configurations, error %d\n",
1252 			err);
1253 		goto fail;
1254 	}
1255 
1256 	/* read the standard strings and cache them if present */
1257 	udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
1258 	udev->manufacturer = usb_cache_string(udev,
1259 			udev->descriptor.iManufacturer);
1260 	udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
1261 
1262 	/* Tell the world! */
1263 	dev_dbg(&udev->dev, "new device strings: Mfr=%d, Product=%d, "
1264 			"SerialNumber=%d\n",
1265 			udev->descriptor.iManufacturer,
1266 			udev->descriptor.iProduct,
1267 			udev->descriptor.iSerialNumber);
1268 	show_string(udev, "Product", udev->product);
1269 	show_string(udev, "Manufacturer", udev->manufacturer);
1270 	show_string(udev, "SerialNumber", udev->serial);
1271 
1272 #ifdef	CONFIG_USB_OTG
1273 	/*
1274 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1275 	 * to wake us after we've powered off VBUS; and HNP, switching roles
1276 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
1277 	 */
1278 	if (!udev->bus->is_b_host
1279 			&& udev->config
1280 			&& udev->parent == udev->bus->root_hub) {
1281 		struct usb_otg_descriptor	*desc = 0;
1282 		struct usb_bus			*bus = udev->bus;
1283 
1284 		/* descriptor may appear anywhere in config */
1285 		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1286 					le16_to_cpu(udev->config[0].desc.wTotalLength),
1287 					USB_DT_OTG, (void **) &desc) == 0) {
1288 			if (desc->bmAttributes & USB_OTG_HNP) {
1289 				unsigned		port1 = udev->portnum;
1290 
1291 				dev_info(&udev->dev,
1292 					"Dual-Role OTG device on %sHNP port\n",
1293 					(port1 == bus->otg_port)
1294 						? "" : "non-");
1295 
1296 				/* enable HNP before suspend, it's simpler */
1297 				if (port1 == bus->otg_port)
1298 					bus->b_hnp_enable = 1;
1299 				err = usb_control_msg(udev,
1300 					usb_sndctrlpipe(udev, 0),
1301 					USB_REQ_SET_FEATURE, 0,
1302 					bus->b_hnp_enable
1303 						? USB_DEVICE_B_HNP_ENABLE
1304 						: USB_DEVICE_A_ALT_HNP_SUPPORT,
1305 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1306 				if (err < 0) {
1307 					/* OTG MESSAGE: report errors here,
1308 					 * customize to match your product.
1309 					 */
1310 					dev_info(&udev->dev,
1311 						"can't set HNP mode; %d\n",
1312 						err);
1313 					bus->b_hnp_enable = 0;
1314 				}
1315 			}
1316 		}
1317 	}
1318 
1319 	if (!is_targeted(udev)) {
1320 
1321 		/* Maybe it can talk to us, though we can't talk to it.
1322 		 * (Includes HNP test device.)
1323 		 */
1324 		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1325 			err = usb_port_suspend(udev);
1326 			if (err < 0)
1327 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1328 		}
1329 		err = -ENOTSUPP;
1330 		goto fail;
1331 	}
1332 #endif
1333 
1334 	/* export the usbdev device-node for libusb */
1335 	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
1336 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
1337 
1338 	/* Increment the parent's count of unsuspended children */
1339 	if (udev->parent)
1340 		usb_autoresume_device(udev->parent);
1341 
1342 	/* Register the device.  The device driver is responsible
1343 	 * for adding the device files to sysfs and for configuring
1344 	 * the device.
1345 	 */
1346 	err = device_add(&udev->dev);
1347 	if (err) {
1348 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
1349 		if (udev->parent)
1350 			usb_autosuspend_device(udev->parent);
1351 		goto fail;
1352 	}
1353 
1354 exit:
1355 	return err;
1356 
1357 fail:
1358 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1359 	goto exit;
1360 }
1361 
1362 static int hub_port_status(struct usb_hub *hub, int port1,
1363 			       u16 *status, u16 *change)
1364 {
1365 	int ret;
1366 
1367 	mutex_lock(&hub->status_mutex);
1368 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
1369 	if (ret < 4) {
1370 		dev_err (hub->intfdev,
1371 			"%s failed (err = %d)\n", __FUNCTION__, ret);
1372 		if (ret >= 0)
1373 			ret = -EIO;
1374 	} else {
1375 		*status = le16_to_cpu(hub->status->port.wPortStatus);
1376 		*change = le16_to_cpu(hub->status->port.wPortChange);
1377 		ret = 0;
1378 	}
1379 	mutex_unlock(&hub->status_mutex);
1380 	return ret;
1381 }
1382 
1383 
1384 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
1385 static unsigned hub_is_wusb(struct usb_hub *hub)
1386 {
1387 	struct usb_hcd *hcd;
1388 	if (hub->hdev->parent != NULL)  /* not a root hub? */
1389 		return 0;
1390 	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
1391 	return hcd->wireless;
1392 }
1393 
1394 
1395 #define PORT_RESET_TRIES	5
1396 #define SET_ADDRESS_TRIES	2
1397 #define GET_DESCRIPTOR_TRIES	2
1398 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
1399 #define USE_NEW_SCHEME(i)	((i) / 2 == old_scheme_first)
1400 
1401 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
1402 #define HUB_SHORT_RESET_TIME	10
1403 #define HUB_LONG_RESET_TIME	200
1404 #define HUB_RESET_TIMEOUT	500
1405 
1406 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1407 				struct usb_device *udev, unsigned int delay)
1408 {
1409 	int delay_time, ret;
1410 	u16 portstatus;
1411 	u16 portchange;
1412 
1413 	for (delay_time = 0;
1414 			delay_time < HUB_RESET_TIMEOUT;
1415 			delay_time += delay) {
1416 		/* wait to give the device a chance to reset */
1417 		msleep(delay);
1418 
1419 		/* read and decode port status */
1420 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
1421 		if (ret < 0)
1422 			return ret;
1423 
1424 		/* Device went away? */
1425 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
1426 			return -ENOTCONN;
1427 
1428 		/* bomb out completely if the connection bounced */
1429 		if ((portchange & USB_PORT_STAT_C_CONNECTION))
1430 			return -ENOTCONN;
1431 
1432 		/* if we`ve finished resetting, then break out of the loop */
1433 		if (!(portstatus & USB_PORT_STAT_RESET) &&
1434 		    (portstatus & USB_PORT_STAT_ENABLE)) {
1435 			if (hub_is_wusb(hub))
1436 				udev->speed = USB_SPEED_VARIABLE;
1437 			else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1438 				udev->speed = USB_SPEED_HIGH;
1439 			else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1440 				udev->speed = USB_SPEED_LOW;
1441 			else
1442 				udev->speed = USB_SPEED_FULL;
1443 			return 0;
1444 		}
1445 
1446 		/* switch to the long delay after two short delay failures */
1447 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1448 			delay = HUB_LONG_RESET_TIME;
1449 
1450 		dev_dbg (hub->intfdev,
1451 			"port %d not reset yet, waiting %dms\n",
1452 			port1, delay);
1453 	}
1454 
1455 	return -EBUSY;
1456 }
1457 
1458 static int hub_port_reset(struct usb_hub *hub, int port1,
1459 				struct usb_device *udev, unsigned int delay)
1460 {
1461 	int i, status;
1462 
1463 	/* Reset the port */
1464 	for (i = 0; i < PORT_RESET_TRIES; i++) {
1465 		status = set_port_feature(hub->hdev,
1466 				port1, USB_PORT_FEAT_RESET);
1467 		if (status)
1468 			dev_err(hub->intfdev,
1469 					"cannot reset port %d (err = %d)\n",
1470 					port1, status);
1471 		else {
1472 			status = hub_port_wait_reset(hub, port1, udev, delay);
1473 			if (status && status != -ENOTCONN)
1474 				dev_dbg(hub->intfdev,
1475 						"port_wait_reset: err = %d\n",
1476 						status);
1477 		}
1478 
1479 		/* return on disconnect or reset */
1480 		switch (status) {
1481 		case 0:
1482 			/* TRSTRCY = 10 ms; plus some extra */
1483 			msleep(10 + 40);
1484 			/* FALL THROUGH */
1485 		case -ENOTCONN:
1486 		case -ENODEV:
1487 			clear_port_feature(hub->hdev,
1488 				port1, USB_PORT_FEAT_C_RESET);
1489 			/* FIXME need disconnect() for NOTATTACHED device */
1490 			usb_set_device_state(udev, status
1491 					? USB_STATE_NOTATTACHED
1492 					: USB_STATE_DEFAULT);
1493 			return status;
1494 		}
1495 
1496 		dev_dbg (hub->intfdev,
1497 			"port %d not enabled, trying reset again...\n",
1498 			port1);
1499 		delay = HUB_LONG_RESET_TIME;
1500 	}
1501 
1502 	dev_err (hub->intfdev,
1503 		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
1504 		port1);
1505 
1506 	return status;
1507 }
1508 
1509 #ifdef	CONFIG_PM
1510 
1511 #ifdef	CONFIG_USB_SUSPEND
1512 
1513 /*
1514  * usb_port_suspend - suspend a usb device's upstream port
1515  * @udev: device that's no longer in active use, not a root hub
1516  * Context: must be able to sleep; device not locked; pm locks held
1517  *
1518  * Suspends a USB device that isn't in active use, conserving power.
1519  * Devices may wake out of a suspend, if anything important happens,
1520  * using the remote wakeup mechanism.  They may also be taken out of
1521  * suspend by the host, using usb_port_resume().  It's also routine
1522  * to disconnect devices while they are suspended.
1523  *
1524  * This only affects the USB hardware for a device; its interfaces
1525  * (and, for hubs, child devices) must already have been suspended.
1526  *
1527  * Selective port suspend reduces power; most suspended devices draw
1528  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1529  * All devices below the suspended port are also suspended.
1530  *
1531  * Devices leave suspend state when the host wakes them up.  Some devices
1532  * also support "remote wakeup", where the device can activate the USB
1533  * tree above them to deliver data, such as a keypress or packet.  In
1534  * some cases, this wakes the USB host.
1535  *
1536  * Suspending OTG devices may trigger HNP, if that's been enabled
1537  * between a pair of dual-role devices.  That will change roles, such
1538  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1539  *
1540  * Devices on USB hub ports have only one "suspend" state, corresponding
1541  * to ACPI D2, "may cause the device to lose some context".
1542  * State transitions include:
1543  *
1544  *   - suspend, resume ... when the VBUS power link stays live
1545  *   - suspend, disconnect ... VBUS lost
1546  *
1547  * Once VBUS drop breaks the circuit, the port it's using has to go through
1548  * normal re-enumeration procedures, starting with enabling VBUS power.
1549  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1550  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1551  * timer, no SRP, no requests through sysfs.
1552  *
1553  * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
1554  * the root hub for their bus goes into global suspend ... so we don't
1555  * (falsely) update the device power state to say it suspended.
1556  *
1557  * Returns 0 on success, else negative errno.
1558  */
1559 int usb_port_suspend(struct usb_device *udev)
1560 {
1561 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
1562 	int		port1 = udev->portnum;
1563 	int		status;
1564 
1565 	// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1566 
1567 	/* enable remote wakeup when appropriate; this lets the device
1568 	 * wake up the upstream hub (including maybe the root hub).
1569 	 *
1570 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1571 	 * we don't explicitly enable it here.
1572 	 */
1573 	if (udev->do_remote_wakeup) {
1574 		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1575 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1576 				USB_DEVICE_REMOTE_WAKEUP, 0,
1577 				NULL, 0,
1578 				USB_CTRL_SET_TIMEOUT);
1579 		if (status)
1580 			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
1581 					status);
1582 	}
1583 
1584 	/* see 7.1.7.6 */
1585 	status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1586 	if (status) {
1587 		dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
1588 				port1, status);
1589 		/* paranoia:  "should not happen" */
1590 		(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1591 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1592 				USB_DEVICE_REMOTE_WAKEUP, 0,
1593 				NULL, 0,
1594 				USB_CTRL_SET_TIMEOUT);
1595 	} else {
1596 		/* device has up to 10 msec to fully suspend */
1597 		dev_dbg(&udev->dev, "usb %ssuspend\n",
1598 				udev->auto_pm ? "auto-" : "");
1599 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
1600 		msleep(10);
1601 	}
1602 	return status;
1603 }
1604 
1605 /*
1606  * If the USB "suspend" state is in use (rather than "global suspend"),
1607  * many devices will be individually taken out of suspend state using
1608  * special "resume" signaling.  This routine kicks in shortly after
1609  * hardware resume signaling is finished, either because of selective
1610  * resume (by host) or remote wakeup (by device) ... now see what changed
1611  * in the tree that's rooted at this device.
1612  *
1613  * If @udev->reset_resume is set then the device is reset before the
1614  * status check is done.
1615  */
1616 static int finish_port_resume(struct usb_device *udev)
1617 {
1618 	int	status = 0;
1619 	u16	devstatus;
1620 
1621 	/* caller owns the udev device lock */
1622 	dev_dbg(&udev->dev, "finish %sresume\n",
1623 			udev->reset_resume ? "reset-" : "");
1624 
1625 	/* usb ch9 identifies four variants of SUSPENDED, based on what
1626 	 * state the device resumes to.  Linux currently won't see the
1627 	 * first two on the host side; they'd be inside hub_port_init()
1628 	 * during many timeouts, but khubd can't suspend until later.
1629 	 */
1630 	usb_set_device_state(udev, udev->actconfig
1631 			? USB_STATE_CONFIGURED
1632 			: USB_STATE_ADDRESS);
1633 
1634 	/* 10.5.4.5 says not to reset a suspended port if the attached
1635 	 * device is enabled for remote wakeup.  Hence the reset
1636 	 * operation is carried out here, after the port has been
1637 	 * resumed.
1638 	 */
1639 	if (udev->reset_resume)
1640 		status = usb_reset_device(udev);
1641 
1642  	/* 10.5.4.5 says be sure devices in the tree are still there.
1643  	 * For now let's assume the device didn't go crazy on resume,
1644 	 * and device drivers will know about any resume quirks.
1645 	 */
1646 	if (status == 0) {
1647 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1648 		if (status >= 0)
1649 			status = (status == 2 ? 0 : -ENODEV);
1650 	}
1651 
1652 	if (status) {
1653 		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
1654 				status);
1655 	} else if (udev->actconfig) {
1656 		le16_to_cpus(&devstatus);
1657 		if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
1658 			status = usb_control_msg(udev,
1659 					usb_sndctrlpipe(udev, 0),
1660 					USB_REQ_CLEAR_FEATURE,
1661 						USB_RECIP_DEVICE,
1662 					USB_DEVICE_REMOTE_WAKEUP, 0,
1663 					NULL, 0,
1664 					USB_CTRL_SET_TIMEOUT);
1665 			if (status)
1666 				dev_dbg(&udev->dev, "disable remote "
1667 					"wakeup, status %d\n", status);
1668 		}
1669 		status = 0;
1670 	}
1671 	return status;
1672 }
1673 
1674 /*
1675  * usb_port_resume - re-activate a suspended usb device's upstream port
1676  * @udev: device to re-activate, not a root hub
1677  * Context: must be able to sleep; device not locked; pm locks held
1678  *
1679  * This will re-activate the suspended device, increasing power usage
1680  * while letting drivers communicate again with its endpoints.
1681  * USB resume explicitly guarantees that the power session between
1682  * the host and the device is the same as it was when the device
1683  * suspended.
1684  *
1685  * If CONFIG_USB_PERSIST and @udev->reset_resume are both set then this
1686  * routine won't check that the port is still enabled.  Furthermore,
1687  * if @udev->reset_resume is set then finish_port_resume() above will
1688  * reset @udev.  The end result is that a broken power session can be
1689  * recovered and @udev will appear to persist across a loss of VBUS power.
1690  *
1691  * For example, if a host controller doesn't maintain VBUS suspend current
1692  * during a system sleep or is reset when the system wakes up, all the USB
1693  * power sessions below it will be broken.  This is especially troublesome
1694  * for mass-storage devices containing mounted filesystems, since the
1695  * device will appear to have disconnected and all the memory mappings
1696  * to it will be lost.  Using the USB_PERSIST facility, the device can be
1697  * made to appear as if it had not disconnected.
1698  *
1699  * This facility is inherently dangerous.  Although usb_reset_device()
1700  * makes every effort to insure that the same device is present after the
1701  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
1702  * quite possible for a device to remain unaltered but its media to be
1703  * changed.  If the user replaces a flash memory card while the system is
1704  * asleep, he will have only himself to blame when the filesystem on the
1705  * new card is corrupted and the system crashes.
1706  *
1707  * Returns 0 on success, else negative errno.
1708  */
1709 int usb_port_resume(struct usb_device *udev)
1710 {
1711 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
1712 	int		port1 = udev->portnum;
1713 	int		status;
1714 	u16		portchange, portstatus;
1715 	unsigned	mask_flags, want_flags;
1716 
1717 	/* Skip the initial Clear-Suspend step for a remote wakeup */
1718 	status = hub_port_status(hub, port1, &portstatus, &portchange);
1719 	if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
1720 		goto SuspendCleared;
1721 
1722 	// dev_dbg(hub->intfdev, "resume port %d\n", port1);
1723 
1724 	set_bit(port1, hub->busy_bits);
1725 
1726 	/* see 7.1.7.7; affects power usage, but not budgeting */
1727 	status = clear_port_feature(hub->hdev,
1728 			port1, USB_PORT_FEAT_SUSPEND);
1729 	if (status) {
1730 		dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
1731 				port1, status);
1732 	} else {
1733 		/* drive resume for at least 20 msec */
1734 		dev_dbg(&udev->dev, "usb %sresume\n",
1735 				udev->auto_pm ? "auto-" : "");
1736 		msleep(25);
1737 
1738 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
1739 		 * stop resume signaling.  Then finish the resume
1740 		 * sequence.
1741 		 */
1742 		status = hub_port_status(hub, port1, &portstatus, &portchange);
1743 
1744  SuspendCleared:
1745 		if (USB_PERSIST && udev->reset_resume)
1746 			want_flags = USB_PORT_STAT_POWER
1747 					| USB_PORT_STAT_CONNECTION;
1748 		else
1749 			want_flags = USB_PORT_STAT_POWER
1750 					| USB_PORT_STAT_CONNECTION
1751 					| USB_PORT_STAT_ENABLE;
1752 		mask_flags = want_flags | USB_PORT_STAT_SUSPEND;
1753 
1754 		if (status < 0 || (portstatus & mask_flags) != want_flags) {
1755 			dev_dbg(hub->intfdev,
1756 				"port %d status %04x.%04x after resume, %d\n",
1757 				port1, portchange, portstatus, status);
1758 			if (status >= 0)
1759 				status = -ENODEV;
1760 		} else {
1761 			if (portchange & USB_PORT_STAT_C_SUSPEND)
1762 				clear_port_feature(hub->hdev, port1,
1763 						USB_PORT_FEAT_C_SUSPEND);
1764 			/* TRSMRCY = 10 msec */
1765 			msleep(10);
1766 		}
1767 	}
1768 
1769 	clear_bit(port1, hub->busy_bits);
1770 	if (!hub->hdev->parent && !hub->busy_bits[0])
1771 		usb_enable_root_hub_irq(hub->hdev->bus);
1772 
1773 	if (status == 0)
1774 		status = finish_port_resume(udev);
1775 	if (status < 0) {
1776 		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
1777 		hub_port_logical_disconnect(hub, port1);
1778 	}
1779 	return status;
1780 }
1781 
1782 static int remote_wakeup(struct usb_device *udev)
1783 {
1784 	int	status = 0;
1785 
1786 	usb_lock_device(udev);
1787 	if (udev->state == USB_STATE_SUSPENDED) {
1788 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
1789 		usb_mark_last_busy(udev);
1790 		status = usb_external_resume_device(udev);
1791 	}
1792 	usb_unlock_device(udev);
1793 	return status;
1794 }
1795 
1796 #else	/* CONFIG_USB_SUSPEND */
1797 
1798 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
1799 
1800 int usb_port_suspend(struct usb_device *udev)
1801 {
1802 	return 0;
1803 }
1804 
1805 int usb_port_resume(struct usb_device *udev)
1806 {
1807 	int status = 0;
1808 
1809 	/* However we may need to do a reset-resume */
1810 	if (udev->reset_resume) {
1811 		dev_dbg(&udev->dev, "reset-resume\n");
1812 		status = usb_reset_device(udev);
1813 	}
1814 	return status;
1815 }
1816 
1817 static inline int remote_wakeup(struct usb_device *udev)
1818 {
1819 	return 0;
1820 }
1821 
1822 #endif
1823 
1824 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
1825 {
1826 	struct usb_hub		*hub = usb_get_intfdata (intf);
1827 	struct usb_device	*hdev = hub->hdev;
1828 	unsigned		port1;
1829 
1830 	/* fail if children aren't already suspended */
1831 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1832 		struct usb_device	*udev;
1833 
1834 		udev = hdev->children [port1-1];
1835 		if (udev && msg.event == PM_EVENT_SUSPEND &&
1836 #ifdef	CONFIG_USB_SUSPEND
1837 				udev->state != USB_STATE_SUSPENDED
1838 #else
1839 				udev->dev.power.power_state.event
1840 					== PM_EVENT_ON
1841 #endif
1842 				) {
1843 			if (!hdev->auto_pm)
1844 				dev_dbg(&intf->dev, "port %d nyet suspended\n",
1845 						port1);
1846 			return -EBUSY;
1847 		}
1848 	}
1849 
1850 	dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
1851 
1852 	/* stop khubd and related activity */
1853 	hub_quiesce(hub);
1854 	return 0;
1855 }
1856 
1857 static int hub_resume(struct usb_interface *intf)
1858 {
1859 	struct usb_hub		*hub = usb_get_intfdata (intf);
1860 
1861 	dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
1862 
1863 	/* tell khubd to look for changes on this hub */
1864 	hub_activate(hub);
1865 	return 0;
1866 }
1867 
1868 static int hub_reset_resume(struct usb_interface *intf)
1869 {
1870 	struct usb_hub *hub = usb_get_intfdata(intf);
1871 	struct usb_device *hdev = hub->hdev;
1872 	int port1;
1873 
1874 	hub_power_on(hub);
1875 
1876 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1877 		struct usb_device *child = hdev->children[port1-1];
1878 
1879 		if (child) {
1880 
1881 			/* For "USB_PERSIST"-enabled children we must
1882 			 * mark the child device for reset-resume and
1883 			 * turn off the connect-change status to prevent
1884 			 * khubd from disconnecting it later.
1885 			 */
1886 			if (USB_PERSIST && child->persist_enabled) {
1887 				child->reset_resume = 1;
1888 				clear_port_feature(hdev, port1,
1889 						USB_PORT_FEAT_C_CONNECTION);
1890 
1891 			/* Otherwise we must disconnect the child,
1892 			 * but as we may not lock the child device here
1893 			 * we have to do a "logical" disconnect.
1894 			 */
1895 			} else {
1896 				hub_port_logical_disconnect(hub, port1);
1897 			}
1898 		}
1899 	}
1900 
1901 	hub_activate(hub);
1902 	return 0;
1903 }
1904 
1905 /**
1906  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
1907  * @rhdev: struct usb_device for the root hub
1908  *
1909  * The USB host controller driver calls this function when its root hub
1910  * is resumed and Vbus power has been interrupted or the controller
1911  * has been reset.  The routine marks @rhdev as having lost power.  When
1912  * the hub driver is resumed it will take notice; if CONFIG_USB_PERSIST
1913  * is enabled then it will carry out power-session recovery, otherwise
1914  * it will disconnect all the child devices.
1915  */
1916 void usb_root_hub_lost_power(struct usb_device *rhdev)
1917 {
1918 	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
1919 	rhdev->reset_resume = 1;
1920 }
1921 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
1922 
1923 #else	/* CONFIG_PM */
1924 
1925 static inline int remote_wakeup(struct usb_device *udev)
1926 {
1927 	return 0;
1928 }
1929 
1930 #define hub_suspend		NULL
1931 #define hub_resume		NULL
1932 #define hub_reset_resume	NULL
1933 #endif
1934 
1935 
1936 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
1937  *
1938  * Between connect detection and reset signaling there must be a delay
1939  * of 100ms at least for debounce and power-settling.  The corresponding
1940  * timer shall restart whenever the downstream port detects a disconnect.
1941  *
1942  * Apparently there are some bluetooth and irda-dongles and a number of
1943  * low-speed devices for which this debounce period may last over a second.
1944  * Not covered by the spec - but easy to deal with.
1945  *
1946  * This implementation uses a 1500ms total debounce timeout; if the
1947  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
1948  * every 25ms for transient disconnects.  When the port status has been
1949  * unchanged for 100ms it returns the port status.
1950  */
1951 
1952 #define HUB_DEBOUNCE_TIMEOUT	1500
1953 #define HUB_DEBOUNCE_STEP	  25
1954 #define HUB_DEBOUNCE_STABLE	 100
1955 
1956 static int hub_port_debounce(struct usb_hub *hub, int port1)
1957 {
1958 	int ret;
1959 	int total_time, stable_time = 0;
1960 	u16 portchange, portstatus;
1961 	unsigned connection = 0xffff;
1962 
1963 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
1964 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
1965 		if (ret < 0)
1966 			return ret;
1967 
1968 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
1969 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
1970 			stable_time += HUB_DEBOUNCE_STEP;
1971 			if (stable_time >= HUB_DEBOUNCE_STABLE)
1972 				break;
1973 		} else {
1974 			stable_time = 0;
1975 			connection = portstatus & USB_PORT_STAT_CONNECTION;
1976 		}
1977 
1978 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
1979 			clear_port_feature(hub->hdev, port1,
1980 					USB_PORT_FEAT_C_CONNECTION);
1981 		}
1982 
1983 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
1984 			break;
1985 		msleep(HUB_DEBOUNCE_STEP);
1986 	}
1987 
1988 	dev_dbg (hub->intfdev,
1989 		"debounce: port %d: total %dms stable %dms status 0x%x\n",
1990 		port1, total_time, stable_time, portstatus);
1991 
1992 	if (stable_time < HUB_DEBOUNCE_STABLE)
1993 		return -ETIMEDOUT;
1994 	return portstatus;
1995 }
1996 
1997 static void ep0_reinit(struct usb_device *udev)
1998 {
1999 	usb_disable_endpoint(udev, 0 + USB_DIR_IN);
2000 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
2001 	udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
2002 }
2003 
2004 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
2005 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
2006 
2007 static int hub_set_address(struct usb_device *udev)
2008 {
2009 	int retval;
2010 
2011 	if (udev->devnum == 0)
2012 		return -EINVAL;
2013 	if (udev->state == USB_STATE_ADDRESS)
2014 		return 0;
2015 	if (udev->state != USB_STATE_DEFAULT)
2016 		return -EINVAL;
2017 	retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2018 		USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
2019 		NULL, 0, USB_CTRL_SET_TIMEOUT);
2020 	if (retval == 0) {
2021 		usb_set_device_state(udev, USB_STATE_ADDRESS);
2022 		ep0_reinit(udev);
2023 	}
2024 	return retval;
2025 }
2026 
2027 /* Reset device, (re)assign address, get device descriptor.
2028  * Device connection must be stable, no more debouncing needed.
2029  * Returns device in USB_STATE_ADDRESS, except on error.
2030  *
2031  * If this is called for an already-existing device (as part of
2032  * usb_reset_device), the caller must own the device lock.  For a
2033  * newly detected device that is not accessible through any global
2034  * pointers, it's not necessary to lock the device.
2035  */
2036 static int
2037 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2038 		int retry_counter)
2039 {
2040 	static DEFINE_MUTEX(usb_address0_mutex);
2041 
2042 	struct usb_device	*hdev = hub->hdev;
2043 	int			i, j, retval;
2044 	unsigned		delay = HUB_SHORT_RESET_TIME;
2045 	enum usb_device_speed	oldspeed = udev->speed;
2046 	char 			*speed, *type;
2047 
2048 	/* root hub ports have a slightly longer reset period
2049 	 * (from USB 2.0 spec, section 7.1.7.5)
2050 	 */
2051 	if (!hdev->parent) {
2052 		delay = HUB_ROOT_RESET_TIME;
2053 		if (port1 == hdev->bus->otg_port)
2054 			hdev->bus->b_hnp_enable = 0;
2055 	}
2056 
2057 	/* Some low speed devices have problems with the quick delay, so */
2058 	/*  be a bit pessimistic with those devices. RHbug #23670 */
2059 	if (oldspeed == USB_SPEED_LOW)
2060 		delay = HUB_LONG_RESET_TIME;
2061 
2062 	mutex_lock(&usb_address0_mutex);
2063 
2064 	/* Reset the device; full speed may morph to high speed */
2065 	retval = hub_port_reset(hub, port1, udev, delay);
2066 	if (retval < 0)		/* error or disconnect */
2067 		goto fail;
2068 				/* success, speed is known */
2069 	retval = -ENODEV;
2070 
2071 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2072 		dev_dbg(&udev->dev, "device reset changed speed!\n");
2073 		goto fail;
2074 	}
2075 	oldspeed = udev->speed;
2076 
2077 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2078 	 * it's fixed size except for full speed devices.
2079 	 * For Wireless USB devices, ep0 max packet is always 512 (tho
2080 	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
2081 	 */
2082 	switch (udev->speed) {
2083 	case USB_SPEED_VARIABLE:	/* fixed at 512 */
2084 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(512);
2085 		break;
2086 	case USB_SPEED_HIGH:		/* fixed at 64 */
2087 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2088 		break;
2089 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
2090 		/* to determine the ep0 maxpacket size, try to read
2091 		 * the device descriptor to get bMaxPacketSize0 and
2092 		 * then correct our initial guess.
2093 		 */
2094 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2095 		break;
2096 	case USB_SPEED_LOW:		/* fixed at 8 */
2097 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2098 		break;
2099 	default:
2100 		goto fail;
2101 	}
2102 
2103 	type = "";
2104 	switch (udev->speed) {
2105 	case USB_SPEED_LOW:	speed = "low";	break;
2106 	case USB_SPEED_FULL:	speed = "full";	break;
2107 	case USB_SPEED_HIGH:	speed = "high";	break;
2108 	case USB_SPEED_VARIABLE:
2109 				speed = "variable";
2110 				type = "Wireless ";
2111 				break;
2112 	default: 		speed = "?";	break;
2113 	}
2114 	dev_info (&udev->dev,
2115 		  "%s %s speed %sUSB device using %s and address %d\n",
2116 		  (udev->config) ? "reset" : "new", speed, type,
2117 		  udev->bus->controller->driver->name, udev->devnum);
2118 
2119 	/* Set up TT records, if needed  */
2120 	if (hdev->tt) {
2121 		udev->tt = hdev->tt;
2122 		udev->ttport = hdev->ttport;
2123 	} else if (udev->speed != USB_SPEED_HIGH
2124 			&& hdev->speed == USB_SPEED_HIGH) {
2125 		udev->tt = &hub->tt;
2126 		udev->ttport = port1;
2127 	}
2128 
2129 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2130 	 * Because device hardware and firmware is sometimes buggy in
2131 	 * this area, and this is how Linux has done it for ages.
2132 	 * Change it cautiously.
2133 	 *
2134 	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2135 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2136 	 * so it may help with some non-standards-compliant devices.
2137 	 * Otherwise we start with SET_ADDRESS and then try to read the
2138 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2139 	 * value.
2140 	 */
2141 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2142 		if (USE_NEW_SCHEME(retry_counter)) {
2143 			struct usb_device_descriptor *buf;
2144 			int r = 0;
2145 
2146 #define GET_DESCRIPTOR_BUFSIZE	64
2147 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2148 			if (!buf) {
2149 				retval = -ENOMEM;
2150 				continue;
2151 			}
2152 
2153 			/* Retry on all errors; some devices are flakey.
2154 			 * 255 is for WUSB devices, we actually need to use
2155 			 * 512 (WUSB1.0[4.8.1]).
2156 			 */
2157 			for (j = 0; j < 3; ++j) {
2158 				buf->bMaxPacketSize0 = 0;
2159 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2160 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2161 					USB_DT_DEVICE << 8, 0,
2162 					buf, GET_DESCRIPTOR_BUFSIZE,
2163 					USB_CTRL_GET_TIMEOUT);
2164 				switch (buf->bMaxPacketSize0) {
2165 				case 8: case 16: case 32: case 64: case 255:
2166 					if (buf->bDescriptorType ==
2167 							USB_DT_DEVICE) {
2168 						r = 0;
2169 						break;
2170 					}
2171 					/* FALL THROUGH */
2172 				default:
2173 					if (r == 0)
2174 						r = -EPROTO;
2175 					break;
2176 				}
2177 				if (r == 0)
2178 					break;
2179 			}
2180 			udev->descriptor.bMaxPacketSize0 =
2181 					buf->bMaxPacketSize0;
2182 			kfree(buf);
2183 
2184 			retval = hub_port_reset(hub, port1, udev, delay);
2185 			if (retval < 0)		/* error or disconnect */
2186 				goto fail;
2187 			if (oldspeed != udev->speed) {
2188 				dev_dbg(&udev->dev,
2189 					"device reset changed speed!\n");
2190 				retval = -ENODEV;
2191 				goto fail;
2192 			}
2193 			if (r) {
2194 				dev_err(&udev->dev, "device descriptor "
2195 						"read/%s, error %d\n",
2196 						"64", r);
2197 				retval = -EMSGSIZE;
2198 				continue;
2199 			}
2200 #undef GET_DESCRIPTOR_BUFSIZE
2201 		}
2202 
2203 		for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2204 			retval = hub_set_address(udev);
2205 			if (retval >= 0)
2206 				break;
2207 			msleep(200);
2208 		}
2209 		if (retval < 0) {
2210 			dev_err(&udev->dev,
2211 				"device not accepting address %d, error %d\n",
2212 				udev->devnum, retval);
2213 			goto fail;
2214 		}
2215 
2216 		/* cope with hardware quirkiness:
2217 		 *  - let SET_ADDRESS settle, some device hardware wants it
2218 		 *  - read ep0 maxpacket even for high and low speed,
2219   		 */
2220 		msleep(10);
2221 		if (USE_NEW_SCHEME(retry_counter))
2222 			break;
2223 
2224 		retval = usb_get_device_descriptor(udev, 8);
2225 		if (retval < 8) {
2226 			dev_err(&udev->dev, "device descriptor "
2227 					"read/%s, error %d\n",
2228 					"8", retval);
2229 			if (retval >= 0)
2230 				retval = -EMSGSIZE;
2231 		} else {
2232 			retval = 0;
2233 			break;
2234 		}
2235 	}
2236 	if (retval)
2237 		goto fail;
2238 
2239 	i = udev->descriptor.bMaxPacketSize0 == 0xff?
2240 	    512 : udev->descriptor.bMaxPacketSize0;
2241 	if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2242 		if (udev->speed != USB_SPEED_FULL ||
2243 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
2244 			dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2245 			retval = -EMSGSIZE;
2246 			goto fail;
2247 		}
2248 		dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2249 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2250 		ep0_reinit(udev);
2251 	}
2252 
2253 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2254 	if (retval < (signed)sizeof(udev->descriptor)) {
2255 		dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2256 			"all", retval);
2257 		if (retval >= 0)
2258 			retval = -ENOMSG;
2259 		goto fail;
2260 	}
2261 
2262 	retval = 0;
2263 
2264 fail:
2265 	if (retval)
2266 		hub_port_disable(hub, port1, 0);
2267 	mutex_unlock(&usb_address0_mutex);
2268 	return retval;
2269 }
2270 
2271 static void
2272 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2273 {
2274 	struct usb_qualifier_descriptor	*qual;
2275 	int				status;
2276 
2277 	qual = kmalloc (sizeof *qual, GFP_KERNEL);
2278 	if (qual == NULL)
2279 		return;
2280 
2281 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2282 			qual, sizeof *qual);
2283 	if (status == sizeof *qual) {
2284 		dev_info(&udev->dev, "not running at top speed; "
2285 			"connect to a high speed hub\n");
2286 		/* hub LEDs are probably harder to miss than syslog */
2287 		if (hub->has_indicators) {
2288 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2289 			schedule_delayed_work (&hub->leds, 0);
2290 		}
2291 	}
2292 	kfree(qual);
2293 }
2294 
2295 static unsigned
2296 hub_power_remaining (struct usb_hub *hub)
2297 {
2298 	struct usb_device *hdev = hub->hdev;
2299 	int remaining;
2300 	int port1;
2301 
2302 	if (!hub->limited_power)
2303 		return 0;
2304 
2305 	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
2306 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2307 		struct usb_device	*udev = hdev->children[port1 - 1];
2308 		int			delta;
2309 
2310 		if (!udev)
2311 			continue;
2312 
2313 		/* Unconfigured devices may not use more than 100mA,
2314 		 * or 8mA for OTG ports */
2315 		if (udev->actconfig)
2316 			delta = udev->actconfig->desc.bMaxPower * 2;
2317 		else if (port1 != udev->bus->otg_port || hdev->parent)
2318 			delta = 100;
2319 		else
2320 			delta = 8;
2321 		if (delta > hub->mA_per_port)
2322 			dev_warn(&udev->dev, "%dmA is over %umA budget "
2323 					"for port %d!\n",
2324 					delta, hub->mA_per_port, port1);
2325 		remaining -= delta;
2326 	}
2327 	if (remaining < 0) {
2328 		dev_warn(hub->intfdev, "%dmA over power budget!\n",
2329 			- remaining);
2330 		remaining = 0;
2331 	}
2332 	return remaining;
2333 }
2334 
2335 /* Handle physical or logical connection change events.
2336  * This routine is called when:
2337  * 	a port connection-change occurs;
2338  *	a port enable-change occurs (often caused by EMI);
2339  *	usb_reset_device() encounters changed descriptors (as from
2340  *		a firmware download)
2341  * caller already locked the hub
2342  */
2343 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2344 					u16 portstatus, u16 portchange)
2345 {
2346 	struct usb_device *hdev = hub->hdev;
2347 	struct device *hub_dev = hub->intfdev;
2348 	u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2349 	int status, i;
2350 
2351 	dev_dbg (hub_dev,
2352 		"port %d, status %04x, change %04x, %s\n",
2353 		port1, portstatus, portchange, portspeed (portstatus));
2354 
2355 	if (hub->has_indicators) {
2356 		set_port_led(hub, port1, HUB_LED_AUTO);
2357 		hub->indicator[port1-1] = INDICATOR_AUTO;
2358 	}
2359 
2360 	/* Disconnect any existing devices under this port */
2361 	if (hdev->children[port1-1])
2362 		usb_disconnect(&hdev->children[port1-1]);
2363 	clear_bit(port1, hub->change_bits);
2364 
2365 #ifdef	CONFIG_USB_OTG
2366 	/* during HNP, don't repeat the debounce */
2367 	if (hdev->bus->is_b_host)
2368 		portchange &= ~USB_PORT_STAT_C_CONNECTION;
2369 #endif
2370 
2371 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
2372 		status = hub_port_debounce(hub, port1);
2373 		if (status < 0) {
2374 			if (printk_ratelimit())
2375 				dev_err (hub_dev, "connect-debounce failed, "
2376 						"port %d disabled\n", port1);
2377 			goto done;
2378 		}
2379 		portstatus = status;
2380 	}
2381 
2382 	/* Return now if nothing is connected */
2383 	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2384 
2385 		/* maybe switch power back on (e.g. root hub was reset) */
2386 		if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
2387 				&& !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2388 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2389 
2390 		if (portstatus & USB_PORT_STAT_ENABLE)
2391   			goto done;
2392 		return;
2393 	}
2394 
2395 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
2396 		struct usb_device *udev;
2397 
2398 		/* reallocate for each attempt, since references
2399 		 * to the previous one can escape in various ways
2400 		 */
2401 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
2402 		if (!udev) {
2403 			dev_err (hub_dev,
2404 				"couldn't allocate port %d usb_device\n",
2405 				port1);
2406 			goto done;
2407 		}
2408 
2409 		usb_set_device_state(udev, USB_STATE_POWERED);
2410 		udev->speed = USB_SPEED_UNKNOWN;
2411  		udev->bus_mA = hub->mA_per_port;
2412 		udev->level = hdev->level + 1;
2413 
2414 		/* set the address */
2415 		choose_address(udev);
2416 		if (udev->devnum <= 0) {
2417 			status = -ENOTCONN;	/* Don't retry */
2418 			goto loop;
2419 		}
2420 
2421 		/* reset and get descriptor */
2422 		status = hub_port_init(hub, udev, port1, i);
2423 		if (status < 0)
2424 			goto loop;
2425 
2426 		/* consecutive bus-powered hubs aren't reliable; they can
2427 		 * violate the voltage drop budget.  if the new child has
2428 		 * a "powered" LED, users should notice we didn't enable it
2429 		 * (without reading syslog), even without per-port LEDs
2430 		 * on the parent.
2431 		 */
2432 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2433 				&& udev->bus_mA <= 100) {
2434 			u16	devstat;
2435 
2436 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2437 					&devstat);
2438 			if (status < 2) {
2439 				dev_dbg(&udev->dev, "get status %d ?\n", status);
2440 				goto loop_disable;
2441 			}
2442 			le16_to_cpus(&devstat);
2443 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2444 				dev_err(&udev->dev,
2445 					"can't connect bus-powered hub "
2446 					"to this port\n");
2447 				if (hub->has_indicators) {
2448 					hub->indicator[port1-1] =
2449 						INDICATOR_AMBER_BLINK;
2450 					schedule_delayed_work (&hub->leds, 0);
2451 				}
2452 				status = -ENOTCONN;	/* Don't retry */
2453 				goto loop_disable;
2454 			}
2455 		}
2456 
2457 		/* check for devices running slower than they could */
2458 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2459 				&& udev->speed == USB_SPEED_FULL
2460 				&& highspeed_hubs != 0)
2461 			check_highspeed (hub, udev, port1);
2462 
2463 		/* Store the parent's children[] pointer.  At this point
2464 		 * udev becomes globally accessible, although presumably
2465 		 * no one will look at it until hdev is unlocked.
2466 		 */
2467 		status = 0;
2468 
2469 		/* We mustn't add new devices if the parent hub has
2470 		 * been disconnected; we would race with the
2471 		 * recursively_mark_NOTATTACHED() routine.
2472 		 */
2473 		spin_lock_irq(&device_state_lock);
2474 		if (hdev->state == USB_STATE_NOTATTACHED)
2475 			status = -ENOTCONN;
2476 		else
2477 			hdev->children[port1-1] = udev;
2478 		spin_unlock_irq(&device_state_lock);
2479 
2480 		/* Run it through the hoops (find a driver, etc) */
2481 		if (!status) {
2482 			status = usb_new_device(udev);
2483 			if (status) {
2484 				spin_lock_irq(&device_state_lock);
2485 				hdev->children[port1-1] = NULL;
2486 				spin_unlock_irq(&device_state_lock);
2487 			}
2488 		}
2489 
2490 		if (status)
2491 			goto loop_disable;
2492 
2493 		status = hub_power_remaining(hub);
2494 		if (status)
2495 			dev_dbg(hub_dev, "%dmA power budget left\n", status);
2496 
2497 		return;
2498 
2499 loop_disable:
2500 		hub_port_disable(hub, port1, 1);
2501 loop:
2502 		ep0_reinit(udev);
2503 		release_address(udev);
2504 		usb_put_dev(udev);
2505 		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
2506 			break;
2507 	}
2508 
2509 done:
2510 	hub_port_disable(hub, port1, 1);
2511 }
2512 
2513 static void hub_events(void)
2514 {
2515 	struct list_head *tmp;
2516 	struct usb_device *hdev;
2517 	struct usb_interface *intf;
2518 	struct usb_hub *hub;
2519 	struct device *hub_dev;
2520 	u16 hubstatus;
2521 	u16 hubchange;
2522 	u16 portstatus;
2523 	u16 portchange;
2524 	int i, ret;
2525 	int connect_change;
2526 
2527 	/*
2528 	 *  We restart the list every time to avoid a deadlock with
2529 	 * deleting hubs downstream from this one. This should be
2530 	 * safe since we delete the hub from the event list.
2531 	 * Not the most efficient, but avoids deadlocks.
2532 	 */
2533 	while (1) {
2534 
2535 		/* Grab the first entry at the beginning of the list */
2536 		spin_lock_irq(&hub_event_lock);
2537 		if (list_empty(&hub_event_list)) {
2538 			spin_unlock_irq(&hub_event_lock);
2539 			break;
2540 		}
2541 
2542 		tmp = hub_event_list.next;
2543 		list_del_init(tmp);
2544 
2545 		hub = list_entry(tmp, struct usb_hub, event_list);
2546 		kref_get(&hub->kref);
2547 		spin_unlock_irq(&hub_event_lock);
2548 
2549 		hdev = hub->hdev;
2550 		hub_dev = hub->intfdev;
2551 		intf = to_usb_interface(hub_dev);
2552 		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
2553 				hdev->state, hub->descriptor
2554 					? hub->descriptor->bNbrPorts
2555 					: 0,
2556 				/* NOTE: expects max 15 ports... */
2557 				(u16) hub->change_bits[0],
2558 				(u16) hub->event_bits[0]);
2559 
2560 		/* Lock the device, then check to see if we were
2561 		 * disconnected while waiting for the lock to succeed. */
2562 		usb_lock_device(hdev);
2563 		if (unlikely(hub->disconnected))
2564 			goto loop;
2565 
2566 		/* If the hub has died, clean up after it */
2567 		if (hdev->state == USB_STATE_NOTATTACHED) {
2568 			hub->error = -ENODEV;
2569 			hub_pre_reset(intf);
2570 			goto loop;
2571 		}
2572 
2573 		/* Autoresume */
2574 		ret = usb_autopm_get_interface(intf);
2575 		if (ret) {
2576 			dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
2577 			goto loop;
2578 		}
2579 
2580 		/* If this is an inactive hub, do nothing */
2581 		if (hub->quiescing)
2582 			goto loop_autopm;
2583 
2584 		if (hub->error) {
2585 			dev_dbg (hub_dev, "resetting for error %d\n",
2586 				hub->error);
2587 
2588 			ret = usb_reset_composite_device(hdev, intf);
2589 			if (ret) {
2590 				dev_dbg (hub_dev,
2591 					"error resetting hub: %d\n", ret);
2592 				goto loop_autopm;
2593 			}
2594 
2595 			hub->nerrors = 0;
2596 			hub->error = 0;
2597 		}
2598 
2599 		/* deal with port status changes */
2600 		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2601 			if (test_bit(i, hub->busy_bits))
2602 				continue;
2603 			connect_change = test_bit(i, hub->change_bits);
2604 			if (!test_and_clear_bit(i, hub->event_bits) &&
2605 					!connect_change && !hub->activating)
2606 				continue;
2607 
2608 			ret = hub_port_status(hub, i,
2609 					&portstatus, &portchange);
2610 			if (ret < 0)
2611 				continue;
2612 
2613 			if (hub->activating && !hdev->children[i-1] &&
2614 					(portstatus &
2615 						USB_PORT_STAT_CONNECTION))
2616 				connect_change = 1;
2617 
2618 			if (portchange & USB_PORT_STAT_C_CONNECTION) {
2619 				clear_port_feature(hdev, i,
2620 					USB_PORT_FEAT_C_CONNECTION);
2621 				connect_change = 1;
2622 			}
2623 
2624 			if (portchange & USB_PORT_STAT_C_ENABLE) {
2625 				if (!connect_change)
2626 					dev_dbg (hub_dev,
2627 						"port %d enable change, "
2628 						"status %08x\n",
2629 						i, portstatus);
2630 				clear_port_feature(hdev, i,
2631 					USB_PORT_FEAT_C_ENABLE);
2632 
2633 				/*
2634 				 * EM interference sometimes causes badly
2635 				 * shielded USB devices to be shutdown by
2636 				 * the hub, this hack enables them again.
2637 				 * Works at least with mouse driver.
2638 				 */
2639 				if (!(portstatus & USB_PORT_STAT_ENABLE)
2640 				    && !connect_change
2641 				    && hdev->children[i-1]) {
2642 					dev_err (hub_dev,
2643 					    "port %i "
2644 					    "disabled by hub (EMI?), "
2645 					    "re-enabling...\n",
2646 						i);
2647 					connect_change = 1;
2648 				}
2649 			}
2650 
2651 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
2652 				clear_port_feature(hdev, i,
2653 					USB_PORT_FEAT_C_SUSPEND);
2654 				if (hdev->children[i-1]) {
2655 					ret = remote_wakeup(hdev->
2656 							children[i-1]);
2657 					if (ret < 0)
2658 						connect_change = 1;
2659 				} else {
2660 					ret = -ENODEV;
2661 					hub_port_disable(hub, i, 1);
2662 				}
2663 				dev_dbg (hub_dev,
2664 					"resume on port %d, status %d\n",
2665 					i, ret);
2666 			}
2667 
2668 			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2669 				dev_err (hub_dev,
2670 					"over-current change on port %d\n",
2671 					i);
2672 				clear_port_feature(hdev, i,
2673 					USB_PORT_FEAT_C_OVER_CURRENT);
2674 				hub_power_on(hub);
2675 			}
2676 
2677 			if (portchange & USB_PORT_STAT_C_RESET) {
2678 				dev_dbg (hub_dev,
2679 					"reset change on port %d\n",
2680 					i);
2681 				clear_port_feature(hdev, i,
2682 					USB_PORT_FEAT_C_RESET);
2683 			}
2684 
2685 			if (connect_change)
2686 				hub_port_connect_change(hub, i,
2687 						portstatus, portchange);
2688 		} /* end for i */
2689 
2690 		/* deal with hub status changes */
2691 		if (test_and_clear_bit(0, hub->event_bits) == 0)
2692 			;	/* do nothing */
2693 		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2694 			dev_err (hub_dev, "get_hub_status failed\n");
2695 		else {
2696 			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2697 				dev_dbg (hub_dev, "power change\n");
2698 				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2699 				if (hubstatus & HUB_STATUS_LOCAL_POWER)
2700 					/* FIXME: Is this always true? */
2701 					hub->limited_power = 0;
2702 				else
2703 					hub->limited_power = 1;
2704 			}
2705 			if (hubchange & HUB_CHANGE_OVERCURRENT) {
2706 				dev_dbg (hub_dev, "overcurrent change\n");
2707 				msleep(500);	/* Cool down */
2708 				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2709                         	hub_power_on(hub);
2710 			}
2711 		}
2712 
2713 		hub->activating = 0;
2714 
2715 		/* If this is a root hub, tell the HCD it's okay to
2716 		 * re-enable port-change interrupts now. */
2717 		if (!hdev->parent && !hub->busy_bits[0])
2718 			usb_enable_root_hub_irq(hdev->bus);
2719 
2720 loop_autopm:
2721 		/* Allow autosuspend if we're not going to run again */
2722 		if (list_empty(&hub->event_list))
2723 			usb_autopm_enable(intf);
2724 loop:
2725 		usb_unlock_device(hdev);
2726 		kref_put(&hub->kref, hub_release);
2727 
2728         } /* end while (1) */
2729 }
2730 
2731 static int hub_thread(void *__unused)
2732 {
2733 	set_freezable();
2734 	do {
2735 		hub_events();
2736 		wait_event_interruptible(khubd_wait,
2737 				!list_empty(&hub_event_list) ||
2738 				kthread_should_stop());
2739 		try_to_freeze();
2740 	} while (!kthread_should_stop() || !list_empty(&hub_event_list));
2741 
2742 	pr_debug("%s: khubd exiting\n", usbcore_name);
2743 	return 0;
2744 }
2745 
2746 static struct usb_device_id hub_id_table [] = {
2747     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2748       .bDeviceClass = USB_CLASS_HUB},
2749     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2750       .bInterfaceClass = USB_CLASS_HUB},
2751     { }						/* Terminating entry */
2752 };
2753 
2754 MODULE_DEVICE_TABLE (usb, hub_id_table);
2755 
2756 static struct usb_driver hub_driver = {
2757 	.name =		"hub",
2758 	.probe =	hub_probe,
2759 	.disconnect =	hub_disconnect,
2760 	.suspend =	hub_suspend,
2761 	.resume =	hub_resume,
2762 	.reset_resume =	hub_reset_resume,
2763 	.pre_reset =	hub_pre_reset,
2764 	.post_reset =	hub_post_reset,
2765 	.ioctl =	hub_ioctl,
2766 	.id_table =	hub_id_table,
2767 	.supports_autosuspend =	1,
2768 };
2769 
2770 int usb_hub_init(void)
2771 {
2772 	if (usb_register(&hub_driver) < 0) {
2773 		printk(KERN_ERR "%s: can't register hub driver\n",
2774 			usbcore_name);
2775 		return -1;
2776 	}
2777 
2778 	khubd_task = kthread_run(hub_thread, NULL, "khubd");
2779 	if (!IS_ERR(khubd_task))
2780 		return 0;
2781 
2782 	/* Fall through if kernel_thread failed */
2783 	usb_deregister(&hub_driver);
2784 	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2785 
2786 	return -1;
2787 }
2788 
2789 void usb_hub_cleanup(void)
2790 {
2791 	kthread_stop(khubd_task);
2792 
2793 	/*
2794 	 * Hub resources are freed for us by usb_deregister. It calls
2795 	 * usb_driver_purge on every device which in turn calls that
2796 	 * devices disconnect function if it is using this driver.
2797 	 * The hub_disconnect function takes care of releasing the
2798 	 * individual hub resources. -greg
2799 	 */
2800 	usb_deregister(&hub_driver);
2801 } /* usb_hub_cleanup() */
2802 
2803 static int config_descriptors_changed(struct usb_device *udev)
2804 {
2805 	unsigned			index;
2806 	unsigned			len = 0;
2807 	struct usb_config_descriptor	*buf;
2808 
2809 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2810 		if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2811 			len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2812 	}
2813 	buf = kmalloc (len, GFP_KERNEL);
2814 	if (buf == NULL) {
2815 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2816 		/* assume the worst */
2817 		return 1;
2818 	}
2819 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2820 		int length;
2821 		int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2822 
2823 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2824 				old_length);
2825 		if (length < old_length) {
2826 			dev_dbg(&udev->dev, "config index %d, error %d\n",
2827 					index, length);
2828 			break;
2829 		}
2830 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
2831 				!= 0) {
2832 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2833 				index, buf->bConfigurationValue);
2834 			break;
2835 		}
2836 	}
2837 	kfree(buf);
2838 	return index != udev->descriptor.bNumConfigurations;
2839 }
2840 
2841 /**
2842  * usb_reset_device - perform a USB port reset to reinitialize a device
2843  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2844  *
2845  * WARNING - don't use this routine to reset a composite device
2846  * (one with multiple interfaces owned by separate drivers)!
2847  * Use usb_reset_composite_device() instead.
2848  *
2849  * Do a port reset, reassign the device's address, and establish its
2850  * former operating configuration.  If the reset fails, or the device's
2851  * descriptors change from their values before the reset, or the original
2852  * configuration and altsettings cannot be restored, a flag will be set
2853  * telling khubd to pretend the device has been disconnected and then
2854  * re-connected.  All drivers will be unbound, and the device will be
2855  * re-enumerated and probed all over again.
2856  *
2857  * Returns 0 if the reset succeeded, -ENODEV if the device has been
2858  * flagged for logical disconnection, or some other negative error code
2859  * if the reset wasn't even attempted.
2860  *
2861  * The caller must own the device lock.  For example, it's safe to use
2862  * this from a driver probe() routine after downloading new firmware.
2863  * For calls that might not occur during probe(), drivers should lock
2864  * the device using usb_lock_device_for_reset().
2865  *
2866  * Locking exception: This routine may also be called from within an
2867  * autoresume handler.  Such usage won't conflict with other tasks
2868  * holding the device lock because these tasks should always call
2869  * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
2870  */
2871 int usb_reset_device(struct usb_device *udev)
2872 {
2873 	struct usb_device		*parent_hdev = udev->parent;
2874 	struct usb_hub			*parent_hub;
2875 	struct usb_device_descriptor	descriptor = udev->descriptor;
2876 	int 				i, ret = 0;
2877 	int				port1 = udev->portnum;
2878 
2879 	if (udev->state == USB_STATE_NOTATTACHED ||
2880 			udev->state == USB_STATE_SUSPENDED) {
2881 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2882 				udev->state);
2883 		return -EINVAL;
2884 	}
2885 
2886 	if (!parent_hdev) {
2887 		/* this requires hcd-specific logic; see OHCI hc_restart() */
2888 		dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
2889 		return -EISDIR;
2890 	}
2891 	parent_hub = hdev_to_hub(parent_hdev);
2892 
2893 	set_bit(port1, parent_hub->busy_bits);
2894 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
2895 
2896 		/* ep0 maxpacket size may change; let the HCD know about it.
2897 		 * Other endpoints will be handled by re-enumeration. */
2898 		ep0_reinit(udev);
2899 		ret = hub_port_init(parent_hub, udev, port1, i);
2900 		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
2901 			break;
2902 	}
2903 	clear_bit(port1, parent_hub->busy_bits);
2904 	if (!parent_hdev->parent && !parent_hub->busy_bits[0])
2905 		usb_enable_root_hub_irq(parent_hdev->bus);
2906 
2907 	if (ret < 0)
2908 		goto re_enumerate;
2909 
2910 	/* Device might have changed firmware (DFU or similar) */
2911 	if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
2912 			|| config_descriptors_changed (udev)) {
2913 		dev_info(&udev->dev, "device firmware changed\n");
2914 		udev->descriptor = descriptor;	/* for disconnect() calls */
2915 		goto re_enumerate;
2916   	}
2917 
2918 	if (!udev->actconfig)
2919 		goto done;
2920 
2921 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2922 			USB_REQ_SET_CONFIGURATION, 0,
2923 			udev->actconfig->desc.bConfigurationValue, 0,
2924 			NULL, 0, USB_CTRL_SET_TIMEOUT);
2925 	if (ret < 0) {
2926 		dev_err(&udev->dev,
2927 			"can't restore configuration #%d (error=%d)\n",
2928 			udev->actconfig->desc.bConfigurationValue, ret);
2929 		goto re_enumerate;
2930   	}
2931 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
2932 
2933 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
2934 		struct usb_interface *intf = udev->actconfig->interface[i];
2935 		struct usb_interface_descriptor *desc;
2936 
2937 		/* set_interface resets host side toggle even
2938 		 * for altsetting zero.  the interface may have no driver.
2939 		 */
2940 		desc = &intf->cur_altsetting->desc;
2941 		ret = usb_set_interface(udev, desc->bInterfaceNumber,
2942 			desc->bAlternateSetting);
2943 		if (ret < 0) {
2944 			dev_err(&udev->dev, "failed to restore interface %d "
2945 				"altsetting %d (error=%d)\n",
2946 				desc->bInterfaceNumber,
2947 				desc->bAlternateSetting,
2948 				ret);
2949 			goto re_enumerate;
2950 		}
2951 	}
2952 
2953 done:
2954 	return 0;
2955 
2956 re_enumerate:
2957 	hub_port_logical_disconnect(parent_hub, port1);
2958 	return -ENODEV;
2959 }
2960 EXPORT_SYMBOL(usb_reset_device);
2961 
2962 /**
2963  * usb_reset_composite_device - warn interface drivers and perform a USB port reset
2964  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2965  * @iface: interface bound to the driver making the request (optional)
2966  *
2967  * Warns all drivers bound to registered interfaces (using their pre_reset
2968  * method), performs the port reset, and then lets the drivers know that
2969  * the reset is over (using their post_reset method).
2970  *
2971  * Return value is the same as for usb_reset_device().
2972  *
2973  * The caller must own the device lock.  For example, it's safe to use
2974  * this from a driver probe() routine after downloading new firmware.
2975  * For calls that might not occur during probe(), drivers should lock
2976  * the device using usb_lock_device_for_reset().
2977  *
2978  * The interface locks are acquired during the pre_reset stage and released
2979  * during the post_reset stage.  However if iface is not NULL and is
2980  * currently being probed, we assume that the caller already owns its
2981  * lock.
2982  */
2983 int usb_reset_composite_device(struct usb_device *udev,
2984 		struct usb_interface *iface)
2985 {
2986 	int ret;
2987 	struct usb_host_config *config = udev->actconfig;
2988 
2989 	if (udev->state == USB_STATE_NOTATTACHED ||
2990 			udev->state == USB_STATE_SUSPENDED) {
2991 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2992 				udev->state);
2993 		return -EINVAL;
2994 	}
2995 
2996 	/* Prevent autosuspend during the reset */
2997 	usb_autoresume_device(udev);
2998 
2999 	if (iface && iface->condition != USB_INTERFACE_BINDING)
3000 		iface = NULL;
3001 
3002 	if (config) {
3003 		int i;
3004 		struct usb_interface *cintf;
3005 		struct usb_driver *drv;
3006 
3007 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
3008 			cintf = config->interface[i];
3009 			if (cintf != iface)
3010 				down(&cintf->dev.sem);
3011 			if (device_is_registered(&cintf->dev) &&
3012 					cintf->dev.driver) {
3013 				drv = to_usb_driver(cintf->dev.driver);
3014 				if (drv->pre_reset)
3015 					(drv->pre_reset)(cintf);
3016 	/* FIXME: Unbind if pre_reset returns an error or isn't defined */
3017 			}
3018 		}
3019 	}
3020 
3021 	ret = usb_reset_device(udev);
3022 
3023 	if (config) {
3024 		int i;
3025 		struct usb_interface *cintf;
3026 		struct usb_driver *drv;
3027 
3028 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
3029 			cintf = config->interface[i];
3030 			if (device_is_registered(&cintf->dev) &&
3031 					cintf->dev.driver) {
3032 				drv = to_usb_driver(cintf->dev.driver);
3033 				if (drv->post_reset)
3034 					(drv->post_reset)(cintf);
3035 	/* FIXME: Unbind if post_reset returns an error or isn't defined */
3036 			}
3037 			if (cintf != iface)
3038 				up(&cintf->dev.sem);
3039 		}
3040 	}
3041 
3042 	usb_autosuspend_device(udev);
3043 	return ret;
3044 }
3045 EXPORT_SYMBOL(usb_reset_composite_device);
3046