xref: /linux/drivers/usb/core/hub.c (revision 8b4a40809e5330c9da5d20107d693d92d73b31dc)
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 	/* Register the device.  The device driver is responsible
1339 	 * for adding the device files to sysfs and for configuring
1340 	 * the device.
1341 	 */
1342 	err = device_add(&udev->dev);
1343 	if (err) {
1344 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
1345 		goto fail;
1346 	}
1347 
1348 	/* Increment the parent's count of unsuspended children */
1349 	if (udev->parent)
1350 		usb_autoresume_device(udev->parent);
1351 
1352 exit:
1353 	return err;
1354 
1355 fail:
1356 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1357 	goto exit;
1358 }
1359 
1360 static int hub_port_status(struct usb_hub *hub, int port1,
1361 			       u16 *status, u16 *change)
1362 {
1363 	int ret;
1364 
1365 	mutex_lock(&hub->status_mutex);
1366 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
1367 	if (ret < 4) {
1368 		dev_err (hub->intfdev,
1369 			"%s failed (err = %d)\n", __FUNCTION__, ret);
1370 		if (ret >= 0)
1371 			ret = -EIO;
1372 	} else {
1373 		*status = le16_to_cpu(hub->status->port.wPortStatus);
1374 		*change = le16_to_cpu(hub->status->port.wPortChange);
1375 		ret = 0;
1376 	}
1377 	mutex_unlock(&hub->status_mutex);
1378 	return ret;
1379 }
1380 
1381 
1382 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
1383 static unsigned hub_is_wusb(struct usb_hub *hub)
1384 {
1385 	struct usb_hcd *hcd;
1386 	if (hub->hdev->parent != NULL)  /* not a root hub? */
1387 		return 0;
1388 	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
1389 	return hcd->wireless;
1390 }
1391 
1392 
1393 #define PORT_RESET_TRIES	5
1394 #define SET_ADDRESS_TRIES	2
1395 #define GET_DESCRIPTOR_TRIES	2
1396 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
1397 #define USE_NEW_SCHEME(i)	((i) / 2 == old_scheme_first)
1398 
1399 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
1400 #define HUB_SHORT_RESET_TIME	10
1401 #define HUB_LONG_RESET_TIME	200
1402 #define HUB_RESET_TIMEOUT	500
1403 
1404 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1405 				struct usb_device *udev, unsigned int delay)
1406 {
1407 	int delay_time, ret;
1408 	u16 portstatus;
1409 	u16 portchange;
1410 
1411 	for (delay_time = 0;
1412 			delay_time < HUB_RESET_TIMEOUT;
1413 			delay_time += delay) {
1414 		/* wait to give the device a chance to reset */
1415 		msleep(delay);
1416 
1417 		/* read and decode port status */
1418 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
1419 		if (ret < 0)
1420 			return ret;
1421 
1422 		/* Device went away? */
1423 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
1424 			return -ENOTCONN;
1425 
1426 		/* bomb out completely if the connection bounced */
1427 		if ((portchange & USB_PORT_STAT_C_CONNECTION))
1428 			return -ENOTCONN;
1429 
1430 		/* if we`ve finished resetting, then break out of the loop */
1431 		if (!(portstatus & USB_PORT_STAT_RESET) &&
1432 		    (portstatus & USB_PORT_STAT_ENABLE)) {
1433 			if (hub_is_wusb(hub))
1434 				udev->speed = USB_SPEED_VARIABLE;
1435 			else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1436 				udev->speed = USB_SPEED_HIGH;
1437 			else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1438 				udev->speed = USB_SPEED_LOW;
1439 			else
1440 				udev->speed = USB_SPEED_FULL;
1441 			return 0;
1442 		}
1443 
1444 		/* switch to the long delay after two short delay failures */
1445 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1446 			delay = HUB_LONG_RESET_TIME;
1447 
1448 		dev_dbg (hub->intfdev,
1449 			"port %d not reset yet, waiting %dms\n",
1450 			port1, delay);
1451 	}
1452 
1453 	return -EBUSY;
1454 }
1455 
1456 static int hub_port_reset(struct usb_hub *hub, int port1,
1457 				struct usb_device *udev, unsigned int delay)
1458 {
1459 	int i, status;
1460 
1461 	/* Reset the port */
1462 	for (i = 0; i < PORT_RESET_TRIES; i++) {
1463 		status = set_port_feature(hub->hdev,
1464 				port1, USB_PORT_FEAT_RESET);
1465 		if (status)
1466 			dev_err(hub->intfdev,
1467 					"cannot reset port %d (err = %d)\n",
1468 					port1, status);
1469 		else {
1470 			status = hub_port_wait_reset(hub, port1, udev, delay);
1471 			if (status && status != -ENOTCONN)
1472 				dev_dbg(hub->intfdev,
1473 						"port_wait_reset: err = %d\n",
1474 						status);
1475 		}
1476 
1477 		/* return on disconnect or reset */
1478 		switch (status) {
1479 		case 0:
1480 			/* TRSTRCY = 10 ms; plus some extra */
1481 			msleep(10 + 40);
1482 			/* FALL THROUGH */
1483 		case -ENOTCONN:
1484 		case -ENODEV:
1485 			clear_port_feature(hub->hdev,
1486 				port1, USB_PORT_FEAT_C_RESET);
1487 			/* FIXME need disconnect() for NOTATTACHED device */
1488 			usb_set_device_state(udev, status
1489 					? USB_STATE_NOTATTACHED
1490 					: USB_STATE_DEFAULT);
1491 			return status;
1492 		}
1493 
1494 		dev_dbg (hub->intfdev,
1495 			"port %d not enabled, trying reset again...\n",
1496 			port1);
1497 		delay = HUB_LONG_RESET_TIME;
1498 	}
1499 
1500 	dev_err (hub->intfdev,
1501 		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
1502 		port1);
1503 
1504 	return status;
1505 }
1506 
1507 #ifdef	CONFIG_PM
1508 
1509 #ifdef	CONFIG_USB_SUSPEND
1510 
1511 /*
1512  * usb_port_suspend - suspend a usb device's upstream port
1513  * @udev: device that's no longer in active use, not a root hub
1514  * Context: must be able to sleep; device not locked; pm locks held
1515  *
1516  * Suspends a USB device that isn't in active use, conserving power.
1517  * Devices may wake out of a suspend, if anything important happens,
1518  * using the remote wakeup mechanism.  They may also be taken out of
1519  * suspend by the host, using usb_port_resume().  It's also routine
1520  * to disconnect devices while they are suspended.
1521  *
1522  * This only affects the USB hardware for a device; its interfaces
1523  * (and, for hubs, child devices) must already have been suspended.
1524  *
1525  * Selective port suspend reduces power; most suspended devices draw
1526  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1527  * All devices below the suspended port are also suspended.
1528  *
1529  * Devices leave suspend state when the host wakes them up.  Some devices
1530  * also support "remote wakeup", where the device can activate the USB
1531  * tree above them to deliver data, such as a keypress or packet.  In
1532  * some cases, this wakes the USB host.
1533  *
1534  * Suspending OTG devices may trigger HNP, if that's been enabled
1535  * between a pair of dual-role devices.  That will change roles, such
1536  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1537  *
1538  * Devices on USB hub ports have only one "suspend" state, corresponding
1539  * to ACPI D2, "may cause the device to lose some context".
1540  * State transitions include:
1541  *
1542  *   - suspend, resume ... when the VBUS power link stays live
1543  *   - suspend, disconnect ... VBUS lost
1544  *
1545  * Once VBUS drop breaks the circuit, the port it's using has to go through
1546  * normal re-enumeration procedures, starting with enabling VBUS power.
1547  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1548  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1549  * timer, no SRP, no requests through sysfs.
1550  *
1551  * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
1552  * the root hub for their bus goes into global suspend ... so we don't
1553  * (falsely) update the device power state to say it suspended.
1554  *
1555  * Returns 0 on success, else negative errno.
1556  */
1557 int usb_port_suspend(struct usb_device *udev)
1558 {
1559 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
1560 	int		port1 = udev->portnum;
1561 	int		status;
1562 
1563 	// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1564 
1565 	/* enable remote wakeup when appropriate; this lets the device
1566 	 * wake up the upstream hub (including maybe the root hub).
1567 	 *
1568 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1569 	 * we don't explicitly enable it here.
1570 	 */
1571 	if (udev->do_remote_wakeup) {
1572 		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1573 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1574 				USB_DEVICE_REMOTE_WAKEUP, 0,
1575 				NULL, 0,
1576 				USB_CTRL_SET_TIMEOUT);
1577 		if (status)
1578 			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
1579 					status);
1580 	}
1581 
1582 	/* see 7.1.7.6 */
1583 	status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1584 	if (status) {
1585 		dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
1586 				port1, status);
1587 		/* paranoia:  "should not happen" */
1588 		(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1589 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1590 				USB_DEVICE_REMOTE_WAKEUP, 0,
1591 				NULL, 0,
1592 				USB_CTRL_SET_TIMEOUT);
1593 	} else {
1594 		/* device has up to 10 msec to fully suspend */
1595 		dev_dbg(&udev->dev, "usb %ssuspend\n",
1596 				udev->auto_pm ? "auto-" : "");
1597 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
1598 		msleep(10);
1599 	}
1600 	return status;
1601 }
1602 
1603 /*
1604  * If the USB "suspend" state is in use (rather than "global suspend"),
1605  * many devices will be individually taken out of suspend state using
1606  * special "resume" signaling.  This routine kicks in shortly after
1607  * hardware resume signaling is finished, either because of selective
1608  * resume (by host) or remote wakeup (by device) ... now see what changed
1609  * in the tree that's rooted at this device.
1610  *
1611  * If @udev->reset_resume is set then the device is reset before the
1612  * status check is done.
1613  */
1614 static int finish_port_resume(struct usb_device *udev)
1615 {
1616 	int	status = 0;
1617 	u16	devstatus;
1618 
1619 	/* caller owns the udev device lock */
1620 	dev_dbg(&udev->dev, "finish %sresume\n",
1621 			udev->reset_resume ? "reset-" : "");
1622 
1623 	/* usb ch9 identifies four variants of SUSPENDED, based on what
1624 	 * state the device resumes to.  Linux currently won't see the
1625 	 * first two on the host side; they'd be inside hub_port_init()
1626 	 * during many timeouts, but khubd can't suspend until later.
1627 	 */
1628 	usb_set_device_state(udev, udev->actconfig
1629 			? USB_STATE_CONFIGURED
1630 			: USB_STATE_ADDRESS);
1631 
1632 	/* 10.5.4.5 says not to reset a suspended port if the attached
1633 	 * device is enabled for remote wakeup.  Hence the reset
1634 	 * operation is carried out here, after the port has been
1635 	 * resumed.
1636 	 */
1637 	if (udev->reset_resume)
1638 		status = usb_reset_device(udev);
1639 
1640  	/* 10.5.4.5 says be sure devices in the tree are still there.
1641  	 * For now let's assume the device didn't go crazy on resume,
1642 	 * and device drivers will know about any resume quirks.
1643 	 */
1644 	if (status == 0) {
1645 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1646 		if (status >= 0)
1647 			status = (status == 2 ? 0 : -ENODEV);
1648 	}
1649 
1650 	if (status) {
1651 		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
1652 				status);
1653 	} else if (udev->actconfig) {
1654 		le16_to_cpus(&devstatus);
1655 		if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
1656 			status = usb_control_msg(udev,
1657 					usb_sndctrlpipe(udev, 0),
1658 					USB_REQ_CLEAR_FEATURE,
1659 						USB_RECIP_DEVICE,
1660 					USB_DEVICE_REMOTE_WAKEUP, 0,
1661 					NULL, 0,
1662 					USB_CTRL_SET_TIMEOUT);
1663 			if (status)
1664 				dev_dbg(&udev->dev, "disable remote "
1665 					"wakeup, status %d\n", status);
1666 		}
1667 		status = 0;
1668 	}
1669 	return status;
1670 }
1671 
1672 /*
1673  * usb_port_resume - re-activate a suspended usb device's upstream port
1674  * @udev: device to re-activate, not a root hub
1675  * Context: must be able to sleep; device not locked; pm locks held
1676  *
1677  * This will re-activate the suspended device, increasing power usage
1678  * while letting drivers communicate again with its endpoints.
1679  * USB resume explicitly guarantees that the power session between
1680  * the host and the device is the same as it was when the device
1681  * suspended.
1682  *
1683  * If CONFIG_USB_PERSIST and @udev->reset_resume are both set then this
1684  * routine won't check that the port is still enabled.  Furthermore,
1685  * if @udev->reset_resume is set then finish_port_resume() above will
1686  * reset @udev.  The end result is that a broken power session can be
1687  * recovered and @udev will appear to persist across a loss of VBUS power.
1688  *
1689  * For example, if a host controller doesn't maintain VBUS suspend current
1690  * during a system sleep or is reset when the system wakes up, all the USB
1691  * power sessions below it will be broken.  This is especially troublesome
1692  * for mass-storage devices containing mounted filesystems, since the
1693  * device will appear to have disconnected and all the memory mappings
1694  * to it will be lost.  Using the USB_PERSIST facility, the device can be
1695  * made to appear as if it had not disconnected.
1696  *
1697  * This facility is inherently dangerous.  Although usb_reset_device()
1698  * makes every effort to insure that the same device is present after the
1699  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
1700  * quite possible for a device to remain unaltered but its media to be
1701  * changed.  If the user replaces a flash memory card while the system is
1702  * asleep, he will have only himself to blame when the filesystem on the
1703  * new card is corrupted and the system crashes.
1704  *
1705  * Returns 0 on success, else negative errno.
1706  */
1707 int usb_port_resume(struct usb_device *udev)
1708 {
1709 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
1710 	int		port1 = udev->portnum;
1711 	int		status;
1712 	u16		portchange, portstatus;
1713 	unsigned	mask_flags, want_flags;
1714 
1715 	/* Skip the initial Clear-Suspend step for a remote wakeup */
1716 	status = hub_port_status(hub, port1, &portstatus, &portchange);
1717 	if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
1718 		goto SuspendCleared;
1719 
1720 	// dev_dbg(hub->intfdev, "resume port %d\n", port1);
1721 
1722 	set_bit(port1, hub->busy_bits);
1723 
1724 	/* see 7.1.7.7; affects power usage, but not budgeting */
1725 	status = clear_port_feature(hub->hdev,
1726 			port1, USB_PORT_FEAT_SUSPEND);
1727 	if (status) {
1728 		dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
1729 				port1, status);
1730 	} else {
1731 		/* drive resume for at least 20 msec */
1732 		dev_dbg(&udev->dev, "usb %sresume\n",
1733 				udev->auto_pm ? "auto-" : "");
1734 		msleep(25);
1735 
1736 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
1737 		 * stop resume signaling.  Then finish the resume
1738 		 * sequence.
1739 		 */
1740 		status = hub_port_status(hub, port1, &portstatus, &portchange);
1741 
1742  SuspendCleared:
1743 		if (USB_PERSIST && udev->reset_resume)
1744 			want_flags = USB_PORT_STAT_POWER
1745 					| USB_PORT_STAT_CONNECTION;
1746 		else
1747 			want_flags = USB_PORT_STAT_POWER
1748 					| USB_PORT_STAT_CONNECTION
1749 					| USB_PORT_STAT_ENABLE;
1750 		mask_flags = want_flags | USB_PORT_STAT_SUSPEND;
1751 
1752 		if (status < 0 || (portstatus & mask_flags) != want_flags) {
1753 			dev_dbg(hub->intfdev,
1754 				"port %d status %04x.%04x after resume, %d\n",
1755 				port1, portchange, portstatus, status);
1756 			if (status >= 0)
1757 				status = -ENODEV;
1758 		} else {
1759 			if (portchange & USB_PORT_STAT_C_SUSPEND)
1760 				clear_port_feature(hub->hdev, port1,
1761 						USB_PORT_FEAT_C_SUSPEND);
1762 			/* TRSMRCY = 10 msec */
1763 			msleep(10);
1764 		}
1765 	}
1766 
1767 	clear_bit(port1, hub->busy_bits);
1768 	if (!hub->hdev->parent && !hub->busy_bits[0])
1769 		usb_enable_root_hub_irq(hub->hdev->bus);
1770 
1771 	if (status == 0)
1772 		status = finish_port_resume(udev);
1773 	if (status < 0) {
1774 		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
1775 		hub_port_logical_disconnect(hub, port1);
1776 	}
1777 	return status;
1778 }
1779 
1780 static int remote_wakeup(struct usb_device *udev)
1781 {
1782 	int	status = 0;
1783 
1784 	usb_lock_device(udev);
1785 	if (udev->state == USB_STATE_SUSPENDED) {
1786 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
1787 		usb_mark_last_busy(udev);
1788 		status = usb_external_resume_device(udev);
1789 	}
1790 	usb_unlock_device(udev);
1791 	return status;
1792 }
1793 
1794 #else	/* CONFIG_USB_SUSPEND */
1795 
1796 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
1797 
1798 int usb_port_suspend(struct usb_device *udev)
1799 {
1800 	return 0;
1801 }
1802 
1803 int usb_port_resume(struct usb_device *udev)
1804 {
1805 	int status = 0;
1806 
1807 	/* However we may need to do a reset-resume */
1808 	if (udev->reset_resume) {
1809 		dev_dbg(&udev->dev, "reset-resume\n");
1810 		status = usb_reset_device(udev);
1811 	}
1812 	return status;
1813 }
1814 
1815 static inline int remote_wakeup(struct usb_device *udev)
1816 {
1817 	return 0;
1818 }
1819 
1820 #endif
1821 
1822 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
1823 {
1824 	struct usb_hub		*hub = usb_get_intfdata (intf);
1825 	struct usb_device	*hdev = hub->hdev;
1826 	unsigned		port1;
1827 
1828 	/* fail if children aren't already suspended */
1829 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1830 		struct usb_device	*udev;
1831 
1832 		udev = hdev->children [port1-1];
1833 		if (udev && msg.event == PM_EVENT_SUSPEND &&
1834 #ifdef	CONFIG_USB_SUSPEND
1835 				udev->state != USB_STATE_SUSPENDED
1836 #else
1837 				udev->dev.power.power_state.event
1838 					== PM_EVENT_ON
1839 #endif
1840 				) {
1841 			if (!hdev->auto_pm)
1842 				dev_dbg(&intf->dev, "port %d nyet suspended\n",
1843 						port1);
1844 			return -EBUSY;
1845 		}
1846 	}
1847 
1848 	dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
1849 
1850 	/* stop khubd and related activity */
1851 	hub_quiesce(hub);
1852 	return 0;
1853 }
1854 
1855 static int hub_resume(struct usb_interface *intf)
1856 {
1857 	struct usb_hub		*hub = usb_get_intfdata (intf);
1858 
1859 	dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
1860 
1861 	/* tell khubd to look for changes on this hub */
1862 	hub_activate(hub);
1863 	return 0;
1864 }
1865 
1866 static int hub_reset_resume(struct usb_interface *intf)
1867 {
1868 	struct usb_hub *hub = usb_get_intfdata(intf);
1869 	struct usb_device *hdev = hub->hdev;
1870 	int port1;
1871 
1872 	hub_power_on(hub);
1873 
1874 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1875 		struct usb_device *child = hdev->children[port1-1];
1876 
1877 		if (child) {
1878 
1879 			/* For "USB_PERSIST"-enabled children we must
1880 			 * mark the child device for reset-resume and
1881 			 * turn off the connect-change status to prevent
1882 			 * khubd from disconnecting it later.
1883 			 */
1884 			if (USB_PERSIST && child->persist_enabled) {
1885 				child->reset_resume = 1;
1886 				clear_port_feature(hdev, port1,
1887 						USB_PORT_FEAT_C_CONNECTION);
1888 
1889 			/* Otherwise we must disconnect the child,
1890 			 * but as we may not lock the child device here
1891 			 * we have to do a "logical" disconnect.
1892 			 */
1893 			} else {
1894 				hub_port_logical_disconnect(hub, port1);
1895 			}
1896 		}
1897 	}
1898 
1899 	hub_activate(hub);
1900 	return 0;
1901 }
1902 
1903 /**
1904  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
1905  * @rhdev: struct usb_device for the root hub
1906  *
1907  * The USB host controller driver calls this function when its root hub
1908  * is resumed and Vbus power has been interrupted or the controller
1909  * has been reset.  The routine marks @rhdev as having lost power.  When
1910  * the hub driver is resumed it will take notice; if CONFIG_USB_PERSIST
1911  * is enabled then it will carry out power-session recovery, otherwise
1912  * it will disconnect all the child devices.
1913  */
1914 void usb_root_hub_lost_power(struct usb_device *rhdev)
1915 {
1916 	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
1917 	rhdev->reset_resume = 1;
1918 }
1919 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
1920 
1921 #else	/* CONFIG_PM */
1922 
1923 static inline int remote_wakeup(struct usb_device *udev)
1924 {
1925 	return 0;
1926 }
1927 
1928 #define hub_suspend		NULL
1929 #define hub_resume		NULL
1930 #define hub_reset_resume	NULL
1931 #endif
1932 
1933 
1934 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
1935  *
1936  * Between connect detection and reset signaling there must be a delay
1937  * of 100ms at least for debounce and power-settling.  The corresponding
1938  * timer shall restart whenever the downstream port detects a disconnect.
1939  *
1940  * Apparently there are some bluetooth and irda-dongles and a number of
1941  * low-speed devices for which this debounce period may last over a second.
1942  * Not covered by the spec - but easy to deal with.
1943  *
1944  * This implementation uses a 1500ms total debounce timeout; if the
1945  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
1946  * every 25ms for transient disconnects.  When the port status has been
1947  * unchanged for 100ms it returns the port status.
1948  */
1949 
1950 #define HUB_DEBOUNCE_TIMEOUT	1500
1951 #define HUB_DEBOUNCE_STEP	  25
1952 #define HUB_DEBOUNCE_STABLE	 100
1953 
1954 static int hub_port_debounce(struct usb_hub *hub, int port1)
1955 {
1956 	int ret;
1957 	int total_time, stable_time = 0;
1958 	u16 portchange, portstatus;
1959 	unsigned connection = 0xffff;
1960 
1961 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
1962 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
1963 		if (ret < 0)
1964 			return ret;
1965 
1966 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
1967 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
1968 			stable_time += HUB_DEBOUNCE_STEP;
1969 			if (stable_time >= HUB_DEBOUNCE_STABLE)
1970 				break;
1971 		} else {
1972 			stable_time = 0;
1973 			connection = portstatus & USB_PORT_STAT_CONNECTION;
1974 		}
1975 
1976 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
1977 			clear_port_feature(hub->hdev, port1,
1978 					USB_PORT_FEAT_C_CONNECTION);
1979 		}
1980 
1981 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
1982 			break;
1983 		msleep(HUB_DEBOUNCE_STEP);
1984 	}
1985 
1986 	dev_dbg (hub->intfdev,
1987 		"debounce: port %d: total %dms stable %dms status 0x%x\n",
1988 		port1, total_time, stable_time, portstatus);
1989 
1990 	if (stable_time < HUB_DEBOUNCE_STABLE)
1991 		return -ETIMEDOUT;
1992 	return portstatus;
1993 }
1994 
1995 static void ep0_reinit(struct usb_device *udev)
1996 {
1997 	usb_disable_endpoint(udev, 0 + USB_DIR_IN);
1998 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
1999 	udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
2000 }
2001 
2002 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
2003 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
2004 
2005 static int hub_set_address(struct usb_device *udev)
2006 {
2007 	int retval;
2008 
2009 	if (udev->devnum == 0)
2010 		return -EINVAL;
2011 	if (udev->state == USB_STATE_ADDRESS)
2012 		return 0;
2013 	if (udev->state != USB_STATE_DEFAULT)
2014 		return -EINVAL;
2015 	retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2016 		USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
2017 		NULL, 0, USB_CTRL_SET_TIMEOUT);
2018 	if (retval == 0) {
2019 		usb_set_device_state(udev, USB_STATE_ADDRESS);
2020 		ep0_reinit(udev);
2021 	}
2022 	return retval;
2023 }
2024 
2025 /* Reset device, (re)assign address, get device descriptor.
2026  * Device connection must be stable, no more debouncing needed.
2027  * Returns device in USB_STATE_ADDRESS, except on error.
2028  *
2029  * If this is called for an already-existing device (as part of
2030  * usb_reset_device), the caller must own the device lock.  For a
2031  * newly detected device that is not accessible through any global
2032  * pointers, it's not necessary to lock the device.
2033  */
2034 static int
2035 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2036 		int retry_counter)
2037 {
2038 	static DEFINE_MUTEX(usb_address0_mutex);
2039 
2040 	struct usb_device	*hdev = hub->hdev;
2041 	int			i, j, retval;
2042 	unsigned		delay = HUB_SHORT_RESET_TIME;
2043 	enum usb_device_speed	oldspeed = udev->speed;
2044 	char 			*speed, *type;
2045 
2046 	/* root hub ports have a slightly longer reset period
2047 	 * (from USB 2.0 spec, section 7.1.7.5)
2048 	 */
2049 	if (!hdev->parent) {
2050 		delay = HUB_ROOT_RESET_TIME;
2051 		if (port1 == hdev->bus->otg_port)
2052 			hdev->bus->b_hnp_enable = 0;
2053 	}
2054 
2055 	/* Some low speed devices have problems with the quick delay, so */
2056 	/*  be a bit pessimistic with those devices. RHbug #23670 */
2057 	if (oldspeed == USB_SPEED_LOW)
2058 		delay = HUB_LONG_RESET_TIME;
2059 
2060 	mutex_lock(&usb_address0_mutex);
2061 
2062 	/* Reset the device; full speed may morph to high speed */
2063 	retval = hub_port_reset(hub, port1, udev, delay);
2064 	if (retval < 0)		/* error or disconnect */
2065 		goto fail;
2066 				/* success, speed is known */
2067 	retval = -ENODEV;
2068 
2069 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2070 		dev_dbg(&udev->dev, "device reset changed speed!\n");
2071 		goto fail;
2072 	}
2073 	oldspeed = udev->speed;
2074 
2075 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2076 	 * it's fixed size except for full speed devices.
2077 	 * For Wireless USB devices, ep0 max packet is always 512 (tho
2078 	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
2079 	 */
2080 	switch (udev->speed) {
2081 	case USB_SPEED_VARIABLE:	/* fixed at 512 */
2082 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(512);
2083 		break;
2084 	case USB_SPEED_HIGH:		/* fixed at 64 */
2085 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2086 		break;
2087 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
2088 		/* to determine the ep0 maxpacket size, try to read
2089 		 * the device descriptor to get bMaxPacketSize0 and
2090 		 * then correct our initial guess.
2091 		 */
2092 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2093 		break;
2094 	case USB_SPEED_LOW:		/* fixed at 8 */
2095 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2096 		break;
2097 	default:
2098 		goto fail;
2099 	}
2100 
2101 	type = "";
2102 	switch (udev->speed) {
2103 	case USB_SPEED_LOW:	speed = "low";	break;
2104 	case USB_SPEED_FULL:	speed = "full";	break;
2105 	case USB_SPEED_HIGH:	speed = "high";	break;
2106 	case USB_SPEED_VARIABLE:
2107 				speed = "variable";
2108 				type = "Wireless ";
2109 				break;
2110 	default: 		speed = "?";	break;
2111 	}
2112 	dev_info (&udev->dev,
2113 		  "%s %s speed %sUSB device using %s and address %d\n",
2114 		  (udev->config) ? "reset" : "new", speed, type,
2115 		  udev->bus->controller->driver->name, udev->devnum);
2116 
2117 	/* Set up TT records, if needed  */
2118 	if (hdev->tt) {
2119 		udev->tt = hdev->tt;
2120 		udev->ttport = hdev->ttport;
2121 	} else if (udev->speed != USB_SPEED_HIGH
2122 			&& hdev->speed == USB_SPEED_HIGH) {
2123 		udev->tt = &hub->tt;
2124 		udev->ttport = port1;
2125 	}
2126 
2127 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2128 	 * Because device hardware and firmware is sometimes buggy in
2129 	 * this area, and this is how Linux has done it for ages.
2130 	 * Change it cautiously.
2131 	 *
2132 	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2133 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2134 	 * so it may help with some non-standards-compliant devices.
2135 	 * Otherwise we start with SET_ADDRESS and then try to read the
2136 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2137 	 * value.
2138 	 */
2139 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2140 		if (USE_NEW_SCHEME(retry_counter)) {
2141 			struct usb_device_descriptor *buf;
2142 			int r = 0;
2143 
2144 #define GET_DESCRIPTOR_BUFSIZE	64
2145 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2146 			if (!buf) {
2147 				retval = -ENOMEM;
2148 				continue;
2149 			}
2150 
2151 			/* Retry on all errors; some devices are flakey.
2152 			 * 255 is for WUSB devices, we actually need to use
2153 			 * 512 (WUSB1.0[4.8.1]).
2154 			 */
2155 			for (j = 0; j < 3; ++j) {
2156 				buf->bMaxPacketSize0 = 0;
2157 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2158 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2159 					USB_DT_DEVICE << 8, 0,
2160 					buf, GET_DESCRIPTOR_BUFSIZE,
2161 					USB_CTRL_GET_TIMEOUT);
2162 				switch (buf->bMaxPacketSize0) {
2163 				case 8: case 16: case 32: case 64: case 255:
2164 					if (buf->bDescriptorType ==
2165 							USB_DT_DEVICE) {
2166 						r = 0;
2167 						break;
2168 					}
2169 					/* FALL THROUGH */
2170 				default:
2171 					if (r == 0)
2172 						r = -EPROTO;
2173 					break;
2174 				}
2175 				if (r == 0)
2176 					break;
2177 			}
2178 			udev->descriptor.bMaxPacketSize0 =
2179 					buf->bMaxPacketSize0;
2180 			kfree(buf);
2181 
2182 			retval = hub_port_reset(hub, port1, udev, delay);
2183 			if (retval < 0)		/* error or disconnect */
2184 				goto fail;
2185 			if (oldspeed != udev->speed) {
2186 				dev_dbg(&udev->dev,
2187 					"device reset changed speed!\n");
2188 				retval = -ENODEV;
2189 				goto fail;
2190 			}
2191 			if (r) {
2192 				dev_err(&udev->dev, "device descriptor "
2193 						"read/%s, error %d\n",
2194 						"64", r);
2195 				retval = -EMSGSIZE;
2196 				continue;
2197 			}
2198 #undef GET_DESCRIPTOR_BUFSIZE
2199 		}
2200 
2201 		for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2202 			retval = hub_set_address(udev);
2203 			if (retval >= 0)
2204 				break;
2205 			msleep(200);
2206 		}
2207 		if (retval < 0) {
2208 			dev_err(&udev->dev,
2209 				"device not accepting address %d, error %d\n",
2210 				udev->devnum, retval);
2211 			goto fail;
2212 		}
2213 
2214 		/* cope with hardware quirkiness:
2215 		 *  - let SET_ADDRESS settle, some device hardware wants it
2216 		 *  - read ep0 maxpacket even for high and low speed,
2217   		 */
2218 		msleep(10);
2219 		if (USE_NEW_SCHEME(retry_counter))
2220 			break;
2221 
2222 		retval = usb_get_device_descriptor(udev, 8);
2223 		if (retval < 8) {
2224 			dev_err(&udev->dev, "device descriptor "
2225 					"read/%s, error %d\n",
2226 					"8", retval);
2227 			if (retval >= 0)
2228 				retval = -EMSGSIZE;
2229 		} else {
2230 			retval = 0;
2231 			break;
2232 		}
2233 	}
2234 	if (retval)
2235 		goto fail;
2236 
2237 	i = udev->descriptor.bMaxPacketSize0 == 0xff?
2238 	    512 : udev->descriptor.bMaxPacketSize0;
2239 	if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2240 		if (udev->speed != USB_SPEED_FULL ||
2241 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
2242 			dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2243 			retval = -EMSGSIZE;
2244 			goto fail;
2245 		}
2246 		dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2247 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2248 		ep0_reinit(udev);
2249 	}
2250 
2251 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2252 	if (retval < (signed)sizeof(udev->descriptor)) {
2253 		dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2254 			"all", retval);
2255 		if (retval >= 0)
2256 			retval = -ENOMSG;
2257 		goto fail;
2258 	}
2259 
2260 	retval = 0;
2261 
2262 fail:
2263 	if (retval)
2264 		hub_port_disable(hub, port1, 0);
2265 	mutex_unlock(&usb_address0_mutex);
2266 	return retval;
2267 }
2268 
2269 static void
2270 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2271 {
2272 	struct usb_qualifier_descriptor	*qual;
2273 	int				status;
2274 
2275 	qual = kmalloc (sizeof *qual, GFP_KERNEL);
2276 	if (qual == NULL)
2277 		return;
2278 
2279 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2280 			qual, sizeof *qual);
2281 	if (status == sizeof *qual) {
2282 		dev_info(&udev->dev, "not running at top speed; "
2283 			"connect to a high speed hub\n");
2284 		/* hub LEDs are probably harder to miss than syslog */
2285 		if (hub->has_indicators) {
2286 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2287 			schedule_delayed_work (&hub->leds, 0);
2288 		}
2289 	}
2290 	kfree(qual);
2291 }
2292 
2293 static unsigned
2294 hub_power_remaining (struct usb_hub *hub)
2295 {
2296 	struct usb_device *hdev = hub->hdev;
2297 	int remaining;
2298 	int port1;
2299 
2300 	if (!hub->limited_power)
2301 		return 0;
2302 
2303 	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
2304 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2305 		struct usb_device	*udev = hdev->children[port1 - 1];
2306 		int			delta;
2307 
2308 		if (!udev)
2309 			continue;
2310 
2311 		/* Unconfigured devices may not use more than 100mA,
2312 		 * or 8mA for OTG ports */
2313 		if (udev->actconfig)
2314 			delta = udev->actconfig->desc.bMaxPower * 2;
2315 		else if (port1 != udev->bus->otg_port || hdev->parent)
2316 			delta = 100;
2317 		else
2318 			delta = 8;
2319 		if (delta > hub->mA_per_port)
2320 			dev_warn(&udev->dev, "%dmA is over %umA budget "
2321 					"for port %d!\n",
2322 					delta, hub->mA_per_port, port1);
2323 		remaining -= delta;
2324 	}
2325 	if (remaining < 0) {
2326 		dev_warn(hub->intfdev, "%dmA over power budget!\n",
2327 			- remaining);
2328 		remaining = 0;
2329 	}
2330 	return remaining;
2331 }
2332 
2333 /* Handle physical or logical connection change events.
2334  * This routine is called when:
2335  * 	a port connection-change occurs;
2336  *	a port enable-change occurs (often caused by EMI);
2337  *	usb_reset_device() encounters changed descriptors (as from
2338  *		a firmware download)
2339  * caller already locked the hub
2340  */
2341 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2342 					u16 portstatus, u16 portchange)
2343 {
2344 	struct usb_device *hdev = hub->hdev;
2345 	struct device *hub_dev = hub->intfdev;
2346 	u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2347 	int status, i;
2348 
2349 	dev_dbg (hub_dev,
2350 		"port %d, status %04x, change %04x, %s\n",
2351 		port1, portstatus, portchange, portspeed (portstatus));
2352 
2353 	if (hub->has_indicators) {
2354 		set_port_led(hub, port1, HUB_LED_AUTO);
2355 		hub->indicator[port1-1] = INDICATOR_AUTO;
2356 	}
2357 
2358 	/* Disconnect any existing devices under this port */
2359 	if (hdev->children[port1-1])
2360 		usb_disconnect(&hdev->children[port1-1]);
2361 	clear_bit(port1, hub->change_bits);
2362 
2363 #ifdef	CONFIG_USB_OTG
2364 	/* during HNP, don't repeat the debounce */
2365 	if (hdev->bus->is_b_host)
2366 		portchange &= ~USB_PORT_STAT_C_CONNECTION;
2367 #endif
2368 
2369 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
2370 		status = hub_port_debounce(hub, port1);
2371 		if (status < 0) {
2372 			if (printk_ratelimit())
2373 				dev_err (hub_dev, "connect-debounce failed, "
2374 						"port %d disabled\n", port1);
2375 			goto done;
2376 		}
2377 		portstatus = status;
2378 	}
2379 
2380 	/* Return now if nothing is connected */
2381 	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2382 
2383 		/* maybe switch power back on (e.g. root hub was reset) */
2384 		if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
2385 				&& !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2386 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2387 
2388 		if (portstatus & USB_PORT_STAT_ENABLE)
2389   			goto done;
2390 		return;
2391 	}
2392 
2393 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
2394 		struct usb_device *udev;
2395 
2396 		/* reallocate for each attempt, since references
2397 		 * to the previous one can escape in various ways
2398 		 */
2399 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
2400 		if (!udev) {
2401 			dev_err (hub_dev,
2402 				"couldn't allocate port %d usb_device\n",
2403 				port1);
2404 			goto done;
2405 		}
2406 
2407 		usb_set_device_state(udev, USB_STATE_POWERED);
2408 		udev->speed = USB_SPEED_UNKNOWN;
2409  		udev->bus_mA = hub->mA_per_port;
2410 		udev->level = hdev->level + 1;
2411 
2412 		/* set the address */
2413 		choose_address(udev);
2414 		if (udev->devnum <= 0) {
2415 			status = -ENOTCONN;	/* Don't retry */
2416 			goto loop;
2417 		}
2418 
2419 		/* reset and get descriptor */
2420 		status = hub_port_init(hub, udev, port1, i);
2421 		if (status < 0)
2422 			goto loop;
2423 
2424 		/* consecutive bus-powered hubs aren't reliable; they can
2425 		 * violate the voltage drop budget.  if the new child has
2426 		 * a "powered" LED, users should notice we didn't enable it
2427 		 * (without reading syslog), even without per-port LEDs
2428 		 * on the parent.
2429 		 */
2430 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2431 				&& udev->bus_mA <= 100) {
2432 			u16	devstat;
2433 
2434 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2435 					&devstat);
2436 			if (status < 2) {
2437 				dev_dbg(&udev->dev, "get status %d ?\n", status);
2438 				goto loop_disable;
2439 			}
2440 			le16_to_cpus(&devstat);
2441 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2442 				dev_err(&udev->dev,
2443 					"can't connect bus-powered hub "
2444 					"to this port\n");
2445 				if (hub->has_indicators) {
2446 					hub->indicator[port1-1] =
2447 						INDICATOR_AMBER_BLINK;
2448 					schedule_delayed_work (&hub->leds, 0);
2449 				}
2450 				status = -ENOTCONN;	/* Don't retry */
2451 				goto loop_disable;
2452 			}
2453 		}
2454 
2455 		/* check for devices running slower than they could */
2456 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2457 				&& udev->speed == USB_SPEED_FULL
2458 				&& highspeed_hubs != 0)
2459 			check_highspeed (hub, udev, port1);
2460 
2461 		/* Store the parent's children[] pointer.  At this point
2462 		 * udev becomes globally accessible, although presumably
2463 		 * no one will look at it until hdev is unlocked.
2464 		 */
2465 		status = 0;
2466 
2467 		/* We mustn't add new devices if the parent hub has
2468 		 * been disconnected; we would race with the
2469 		 * recursively_mark_NOTATTACHED() routine.
2470 		 */
2471 		spin_lock_irq(&device_state_lock);
2472 		if (hdev->state == USB_STATE_NOTATTACHED)
2473 			status = -ENOTCONN;
2474 		else
2475 			hdev->children[port1-1] = udev;
2476 		spin_unlock_irq(&device_state_lock);
2477 
2478 		/* Run it through the hoops (find a driver, etc) */
2479 		if (!status) {
2480 			status = usb_new_device(udev);
2481 			if (status) {
2482 				spin_lock_irq(&device_state_lock);
2483 				hdev->children[port1-1] = NULL;
2484 				spin_unlock_irq(&device_state_lock);
2485 			}
2486 		}
2487 
2488 		if (status)
2489 			goto loop_disable;
2490 
2491 		status = hub_power_remaining(hub);
2492 		if (status)
2493 			dev_dbg(hub_dev, "%dmA power budget left\n", status);
2494 
2495 		return;
2496 
2497 loop_disable:
2498 		hub_port_disable(hub, port1, 1);
2499 loop:
2500 		ep0_reinit(udev);
2501 		release_address(udev);
2502 		usb_put_dev(udev);
2503 		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
2504 			break;
2505 	}
2506 
2507 done:
2508 	hub_port_disable(hub, port1, 1);
2509 }
2510 
2511 static void hub_events(void)
2512 {
2513 	struct list_head *tmp;
2514 	struct usb_device *hdev;
2515 	struct usb_interface *intf;
2516 	struct usb_hub *hub;
2517 	struct device *hub_dev;
2518 	u16 hubstatus;
2519 	u16 hubchange;
2520 	u16 portstatus;
2521 	u16 portchange;
2522 	int i, ret;
2523 	int connect_change;
2524 
2525 	/*
2526 	 *  We restart the list every time to avoid a deadlock with
2527 	 * deleting hubs downstream from this one. This should be
2528 	 * safe since we delete the hub from the event list.
2529 	 * Not the most efficient, but avoids deadlocks.
2530 	 */
2531 	while (1) {
2532 
2533 		/* Grab the first entry at the beginning of the list */
2534 		spin_lock_irq(&hub_event_lock);
2535 		if (list_empty(&hub_event_list)) {
2536 			spin_unlock_irq(&hub_event_lock);
2537 			break;
2538 		}
2539 
2540 		tmp = hub_event_list.next;
2541 		list_del_init(tmp);
2542 
2543 		hub = list_entry(tmp, struct usb_hub, event_list);
2544 		kref_get(&hub->kref);
2545 		spin_unlock_irq(&hub_event_lock);
2546 
2547 		hdev = hub->hdev;
2548 		hub_dev = hub->intfdev;
2549 		intf = to_usb_interface(hub_dev);
2550 		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
2551 				hdev->state, hub->descriptor
2552 					? hub->descriptor->bNbrPorts
2553 					: 0,
2554 				/* NOTE: expects max 15 ports... */
2555 				(u16) hub->change_bits[0],
2556 				(u16) hub->event_bits[0]);
2557 
2558 		/* Lock the device, then check to see if we were
2559 		 * disconnected while waiting for the lock to succeed. */
2560 		usb_lock_device(hdev);
2561 		if (unlikely(hub->disconnected))
2562 			goto loop;
2563 
2564 		/* If the hub has died, clean up after it */
2565 		if (hdev->state == USB_STATE_NOTATTACHED) {
2566 			hub->error = -ENODEV;
2567 			hub_pre_reset(intf);
2568 			goto loop;
2569 		}
2570 
2571 		/* Autoresume */
2572 		ret = usb_autopm_get_interface(intf);
2573 		if (ret) {
2574 			dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
2575 			goto loop;
2576 		}
2577 
2578 		/* If this is an inactive hub, do nothing */
2579 		if (hub->quiescing)
2580 			goto loop_autopm;
2581 
2582 		if (hub->error) {
2583 			dev_dbg (hub_dev, "resetting for error %d\n",
2584 				hub->error);
2585 
2586 			ret = usb_reset_composite_device(hdev, intf);
2587 			if (ret) {
2588 				dev_dbg (hub_dev,
2589 					"error resetting hub: %d\n", ret);
2590 				goto loop_autopm;
2591 			}
2592 
2593 			hub->nerrors = 0;
2594 			hub->error = 0;
2595 		}
2596 
2597 		/* deal with port status changes */
2598 		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2599 			if (test_bit(i, hub->busy_bits))
2600 				continue;
2601 			connect_change = test_bit(i, hub->change_bits);
2602 			if (!test_and_clear_bit(i, hub->event_bits) &&
2603 					!connect_change && !hub->activating)
2604 				continue;
2605 
2606 			ret = hub_port_status(hub, i,
2607 					&portstatus, &portchange);
2608 			if (ret < 0)
2609 				continue;
2610 
2611 			if (hub->activating && !hdev->children[i-1] &&
2612 					(portstatus &
2613 						USB_PORT_STAT_CONNECTION))
2614 				connect_change = 1;
2615 
2616 			if (portchange & USB_PORT_STAT_C_CONNECTION) {
2617 				clear_port_feature(hdev, i,
2618 					USB_PORT_FEAT_C_CONNECTION);
2619 				connect_change = 1;
2620 			}
2621 
2622 			if (portchange & USB_PORT_STAT_C_ENABLE) {
2623 				if (!connect_change)
2624 					dev_dbg (hub_dev,
2625 						"port %d enable change, "
2626 						"status %08x\n",
2627 						i, portstatus);
2628 				clear_port_feature(hdev, i,
2629 					USB_PORT_FEAT_C_ENABLE);
2630 
2631 				/*
2632 				 * EM interference sometimes causes badly
2633 				 * shielded USB devices to be shutdown by
2634 				 * the hub, this hack enables them again.
2635 				 * Works at least with mouse driver.
2636 				 */
2637 				if (!(portstatus & USB_PORT_STAT_ENABLE)
2638 				    && !connect_change
2639 				    && hdev->children[i-1]) {
2640 					dev_err (hub_dev,
2641 					    "port %i "
2642 					    "disabled by hub (EMI?), "
2643 					    "re-enabling...\n",
2644 						i);
2645 					connect_change = 1;
2646 				}
2647 			}
2648 
2649 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
2650 				clear_port_feature(hdev, i,
2651 					USB_PORT_FEAT_C_SUSPEND);
2652 				if (hdev->children[i-1]) {
2653 					ret = remote_wakeup(hdev->
2654 							children[i-1]);
2655 					if (ret < 0)
2656 						connect_change = 1;
2657 				} else {
2658 					ret = -ENODEV;
2659 					hub_port_disable(hub, i, 1);
2660 				}
2661 				dev_dbg (hub_dev,
2662 					"resume on port %d, status %d\n",
2663 					i, ret);
2664 			}
2665 
2666 			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2667 				dev_err (hub_dev,
2668 					"over-current change on port %d\n",
2669 					i);
2670 				clear_port_feature(hdev, i,
2671 					USB_PORT_FEAT_C_OVER_CURRENT);
2672 				hub_power_on(hub);
2673 			}
2674 
2675 			if (portchange & USB_PORT_STAT_C_RESET) {
2676 				dev_dbg (hub_dev,
2677 					"reset change on port %d\n",
2678 					i);
2679 				clear_port_feature(hdev, i,
2680 					USB_PORT_FEAT_C_RESET);
2681 			}
2682 
2683 			if (connect_change)
2684 				hub_port_connect_change(hub, i,
2685 						portstatus, portchange);
2686 		} /* end for i */
2687 
2688 		/* deal with hub status changes */
2689 		if (test_and_clear_bit(0, hub->event_bits) == 0)
2690 			;	/* do nothing */
2691 		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2692 			dev_err (hub_dev, "get_hub_status failed\n");
2693 		else {
2694 			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2695 				dev_dbg (hub_dev, "power change\n");
2696 				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2697 				if (hubstatus & HUB_STATUS_LOCAL_POWER)
2698 					/* FIXME: Is this always true? */
2699 					hub->limited_power = 0;
2700 				else
2701 					hub->limited_power = 1;
2702 			}
2703 			if (hubchange & HUB_CHANGE_OVERCURRENT) {
2704 				dev_dbg (hub_dev, "overcurrent change\n");
2705 				msleep(500);	/* Cool down */
2706 				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2707                         	hub_power_on(hub);
2708 			}
2709 		}
2710 
2711 		hub->activating = 0;
2712 
2713 		/* If this is a root hub, tell the HCD it's okay to
2714 		 * re-enable port-change interrupts now. */
2715 		if (!hdev->parent && !hub->busy_bits[0])
2716 			usb_enable_root_hub_irq(hdev->bus);
2717 
2718 loop_autopm:
2719 		/* Allow autosuspend if we're not going to run again */
2720 		if (list_empty(&hub->event_list))
2721 			usb_autopm_enable(intf);
2722 loop:
2723 		usb_unlock_device(hdev);
2724 		kref_put(&hub->kref, hub_release);
2725 
2726         } /* end while (1) */
2727 }
2728 
2729 static int hub_thread(void *__unused)
2730 {
2731 	set_freezable();
2732 	do {
2733 		hub_events();
2734 		wait_event_interruptible(khubd_wait,
2735 				!list_empty(&hub_event_list) ||
2736 				kthread_should_stop());
2737 		try_to_freeze();
2738 	} while (!kthread_should_stop() || !list_empty(&hub_event_list));
2739 
2740 	pr_debug("%s: khubd exiting\n", usbcore_name);
2741 	return 0;
2742 }
2743 
2744 static struct usb_device_id hub_id_table [] = {
2745     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2746       .bDeviceClass = USB_CLASS_HUB},
2747     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2748       .bInterfaceClass = USB_CLASS_HUB},
2749     { }						/* Terminating entry */
2750 };
2751 
2752 MODULE_DEVICE_TABLE (usb, hub_id_table);
2753 
2754 static struct usb_driver hub_driver = {
2755 	.name =		"hub",
2756 	.probe =	hub_probe,
2757 	.disconnect =	hub_disconnect,
2758 	.suspend =	hub_suspend,
2759 	.resume =	hub_resume,
2760 	.reset_resume =	hub_reset_resume,
2761 	.pre_reset =	hub_pre_reset,
2762 	.post_reset =	hub_post_reset,
2763 	.ioctl =	hub_ioctl,
2764 	.id_table =	hub_id_table,
2765 	.supports_autosuspend =	1,
2766 };
2767 
2768 int usb_hub_init(void)
2769 {
2770 	if (usb_register(&hub_driver) < 0) {
2771 		printk(KERN_ERR "%s: can't register hub driver\n",
2772 			usbcore_name);
2773 		return -1;
2774 	}
2775 
2776 	khubd_task = kthread_run(hub_thread, NULL, "khubd");
2777 	if (!IS_ERR(khubd_task))
2778 		return 0;
2779 
2780 	/* Fall through if kernel_thread failed */
2781 	usb_deregister(&hub_driver);
2782 	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2783 
2784 	return -1;
2785 }
2786 
2787 void usb_hub_cleanup(void)
2788 {
2789 	kthread_stop(khubd_task);
2790 
2791 	/*
2792 	 * Hub resources are freed for us by usb_deregister. It calls
2793 	 * usb_driver_purge on every device which in turn calls that
2794 	 * devices disconnect function if it is using this driver.
2795 	 * The hub_disconnect function takes care of releasing the
2796 	 * individual hub resources. -greg
2797 	 */
2798 	usb_deregister(&hub_driver);
2799 } /* usb_hub_cleanup() */
2800 
2801 static int config_descriptors_changed(struct usb_device *udev)
2802 {
2803 	unsigned			index;
2804 	unsigned			len = 0;
2805 	struct usb_config_descriptor	*buf;
2806 
2807 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2808 		if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2809 			len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2810 	}
2811 	buf = kmalloc (len, GFP_KERNEL);
2812 	if (buf == NULL) {
2813 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2814 		/* assume the worst */
2815 		return 1;
2816 	}
2817 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2818 		int length;
2819 		int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2820 
2821 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2822 				old_length);
2823 		if (length < old_length) {
2824 			dev_dbg(&udev->dev, "config index %d, error %d\n",
2825 					index, length);
2826 			break;
2827 		}
2828 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
2829 				!= 0) {
2830 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2831 				index, buf->bConfigurationValue);
2832 			break;
2833 		}
2834 	}
2835 	kfree(buf);
2836 	return index != udev->descriptor.bNumConfigurations;
2837 }
2838 
2839 /**
2840  * usb_reset_device - perform a USB port reset to reinitialize a device
2841  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2842  *
2843  * WARNING - don't use this routine to reset a composite device
2844  * (one with multiple interfaces owned by separate drivers)!
2845  * Use usb_reset_composite_device() instead.
2846  *
2847  * Do a port reset, reassign the device's address, and establish its
2848  * former operating configuration.  If the reset fails, or the device's
2849  * descriptors change from their values before the reset, or the original
2850  * configuration and altsettings cannot be restored, a flag will be set
2851  * telling khubd to pretend the device has been disconnected and then
2852  * re-connected.  All drivers will be unbound, and the device will be
2853  * re-enumerated and probed all over again.
2854  *
2855  * Returns 0 if the reset succeeded, -ENODEV if the device has been
2856  * flagged for logical disconnection, or some other negative error code
2857  * if the reset wasn't even attempted.
2858  *
2859  * The caller must own the device lock.  For example, it's safe to use
2860  * this from a driver probe() routine after downloading new firmware.
2861  * For calls that might not occur during probe(), drivers should lock
2862  * the device using usb_lock_device_for_reset().
2863  *
2864  * Locking exception: This routine may also be called from within an
2865  * autoresume handler.  Such usage won't conflict with other tasks
2866  * holding the device lock because these tasks should always call
2867  * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
2868  */
2869 int usb_reset_device(struct usb_device *udev)
2870 {
2871 	struct usb_device		*parent_hdev = udev->parent;
2872 	struct usb_hub			*parent_hub;
2873 	struct usb_device_descriptor	descriptor = udev->descriptor;
2874 	int 				i, ret = 0;
2875 	int				port1 = udev->portnum;
2876 
2877 	if (udev->state == USB_STATE_NOTATTACHED ||
2878 			udev->state == USB_STATE_SUSPENDED) {
2879 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2880 				udev->state);
2881 		return -EINVAL;
2882 	}
2883 
2884 	if (!parent_hdev) {
2885 		/* this requires hcd-specific logic; see OHCI hc_restart() */
2886 		dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
2887 		return -EISDIR;
2888 	}
2889 	parent_hub = hdev_to_hub(parent_hdev);
2890 
2891 	set_bit(port1, parent_hub->busy_bits);
2892 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
2893 
2894 		/* ep0 maxpacket size may change; let the HCD know about it.
2895 		 * Other endpoints will be handled by re-enumeration. */
2896 		ep0_reinit(udev);
2897 		ret = hub_port_init(parent_hub, udev, port1, i);
2898 		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
2899 			break;
2900 	}
2901 	clear_bit(port1, parent_hub->busy_bits);
2902 	if (!parent_hdev->parent && !parent_hub->busy_bits[0])
2903 		usb_enable_root_hub_irq(parent_hdev->bus);
2904 
2905 	if (ret < 0)
2906 		goto re_enumerate;
2907 
2908 	/* Device might have changed firmware (DFU or similar) */
2909 	if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
2910 			|| config_descriptors_changed (udev)) {
2911 		dev_info(&udev->dev, "device firmware changed\n");
2912 		udev->descriptor = descriptor;	/* for disconnect() calls */
2913 		goto re_enumerate;
2914   	}
2915 
2916 	if (!udev->actconfig)
2917 		goto done;
2918 
2919 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2920 			USB_REQ_SET_CONFIGURATION, 0,
2921 			udev->actconfig->desc.bConfigurationValue, 0,
2922 			NULL, 0, USB_CTRL_SET_TIMEOUT);
2923 	if (ret < 0) {
2924 		dev_err(&udev->dev,
2925 			"can't restore configuration #%d (error=%d)\n",
2926 			udev->actconfig->desc.bConfigurationValue, ret);
2927 		goto re_enumerate;
2928   	}
2929 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
2930 
2931 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
2932 		struct usb_interface *intf = udev->actconfig->interface[i];
2933 		struct usb_interface_descriptor *desc;
2934 
2935 		/* set_interface resets host side toggle even
2936 		 * for altsetting zero.  the interface may have no driver.
2937 		 */
2938 		desc = &intf->cur_altsetting->desc;
2939 		ret = usb_set_interface(udev, desc->bInterfaceNumber,
2940 			desc->bAlternateSetting);
2941 		if (ret < 0) {
2942 			dev_err(&udev->dev, "failed to restore interface %d "
2943 				"altsetting %d (error=%d)\n",
2944 				desc->bInterfaceNumber,
2945 				desc->bAlternateSetting,
2946 				ret);
2947 			goto re_enumerate;
2948 		}
2949 	}
2950 
2951 done:
2952 	return 0;
2953 
2954 re_enumerate:
2955 	hub_port_logical_disconnect(parent_hub, port1);
2956 	return -ENODEV;
2957 }
2958 EXPORT_SYMBOL(usb_reset_device);
2959 
2960 /**
2961  * usb_reset_composite_device - warn interface drivers and perform a USB port reset
2962  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2963  * @iface: interface bound to the driver making the request (optional)
2964  *
2965  * Warns all drivers bound to registered interfaces (using their pre_reset
2966  * method), performs the port reset, and then lets the drivers know that
2967  * the reset is over (using their post_reset method).
2968  *
2969  * Return value is the same as for usb_reset_device().
2970  *
2971  * The caller must own the device lock.  For example, it's safe to use
2972  * this from a driver probe() routine after downloading new firmware.
2973  * For calls that might not occur during probe(), drivers should lock
2974  * the device using usb_lock_device_for_reset().
2975  *
2976  * The interface locks are acquired during the pre_reset stage and released
2977  * during the post_reset stage.  However if iface is not NULL and is
2978  * currently being probed, we assume that the caller already owns its
2979  * lock.
2980  */
2981 int usb_reset_composite_device(struct usb_device *udev,
2982 		struct usb_interface *iface)
2983 {
2984 	int ret;
2985 	struct usb_host_config *config = udev->actconfig;
2986 
2987 	if (udev->state == USB_STATE_NOTATTACHED ||
2988 			udev->state == USB_STATE_SUSPENDED) {
2989 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2990 				udev->state);
2991 		return -EINVAL;
2992 	}
2993 
2994 	/* Prevent autosuspend during the reset */
2995 	usb_autoresume_device(udev);
2996 
2997 	if (iface && iface->condition != USB_INTERFACE_BINDING)
2998 		iface = NULL;
2999 
3000 	if (config) {
3001 		int i;
3002 		struct usb_interface *cintf;
3003 		struct usb_driver *drv;
3004 
3005 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
3006 			cintf = config->interface[i];
3007 			if (cintf != iface)
3008 				down(&cintf->dev.sem);
3009 			if (device_is_registered(&cintf->dev) &&
3010 					cintf->dev.driver) {
3011 				drv = to_usb_driver(cintf->dev.driver);
3012 				if (drv->pre_reset)
3013 					(drv->pre_reset)(cintf);
3014 	/* FIXME: Unbind if pre_reset returns an error or isn't defined */
3015 			}
3016 		}
3017 	}
3018 
3019 	ret = usb_reset_device(udev);
3020 
3021 	if (config) {
3022 		int i;
3023 		struct usb_interface *cintf;
3024 		struct usb_driver *drv;
3025 
3026 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
3027 			cintf = config->interface[i];
3028 			if (device_is_registered(&cintf->dev) &&
3029 					cintf->dev.driver) {
3030 				drv = to_usb_driver(cintf->dev.driver);
3031 				if (drv->post_reset)
3032 					(drv->post_reset)(cintf);
3033 	/* FIXME: Unbind if post_reset returns an error or isn't defined */
3034 			}
3035 			if (cintf != iface)
3036 				up(&cintf->dev.sem);
3037 		}
3038 	}
3039 
3040 	usb_autosuspend_device(udev);
3041 	return ret;
3042 }
3043 EXPORT_SYMBOL(usb_reset_composite_device);
3044