xref: /linux/drivers/usb/core/hub.c (revision 54a8a2220c936a47840c9a3d74910c5a56fae2ed)
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/config.h>
12 #ifdef CONFIG_USB_DEBUG
13 	#define DEBUG
14 #else
15 	#undef DEBUG
16 #endif
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/completion.h>
22 #include <linux/sched.h>
23 #include <linux/list.h>
24 #include <linux/slab.h>
25 #include <linux/smp_lock.h>
26 #include <linux/ioctl.h>
27 #include <linux/usb.h>
28 #include <linux/usbdevice_fs.h>
29 #include <linux/kthread.h>
30 
31 #include <asm/semaphore.h>
32 #include <asm/uaccess.h>
33 #include <asm/byteorder.h>
34 
35 #include "usb.h"
36 #include "hcd.h"
37 #include "hub.h"
38 
39 /* Protect struct usb_device->state and ->children members
40  * Note: Both are also protected by ->serialize, except that ->state can
41  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
42 static DEFINE_SPINLOCK(device_state_lock);
43 
44 /* khubd's worklist and its lock */
45 static DEFINE_SPINLOCK(hub_event_lock);
46 static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */
47 
48 /* Wakes up khubd */
49 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
50 
51 static struct task_struct *khubd_task;
52 
53 /* cycle leds on hubs that aren't blinking for attention */
54 static int blinkenlights = 0;
55 module_param (blinkenlights, bool, S_IRUGO);
56 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
57 
58 /*
59  * As of 2.6.10 we introduce a new USB device initialization scheme which
60  * closely resembles the way Windows works.  Hopefully it will be compatible
61  * with a wider range of devices than the old scheme.  However some previously
62  * working devices may start giving rise to "device not accepting address"
63  * errors; if that happens the user can try the old scheme by adjusting the
64  * following module parameters.
65  *
66  * For maximum flexibility there are two boolean parameters to control the
67  * hub driver's behavior.  On the first initialization attempt, if the
68  * "old_scheme_first" parameter is set then the old scheme will be used,
69  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
70  * is set, then the driver will make another attempt, using the other scheme.
71  */
72 static int old_scheme_first = 0;
73 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
74 MODULE_PARM_DESC(old_scheme_first,
75 		 "start with the old device initialization scheme");
76 
77 static int use_both_schemes = 1;
78 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
79 MODULE_PARM_DESC(use_both_schemes,
80 		"try the other device initialization scheme if the "
81 		"first one fails");
82 
83 
84 #ifdef	DEBUG
85 static inline char *portspeed (int portstatus)
86 {
87 	if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
88     		return "480 Mb/s";
89 	else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
90 		return "1.5 Mb/s";
91 	else
92 		return "12 Mb/s";
93 }
94 #endif
95 
96 /* Note that hdev or one of its children must be locked! */
97 static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
98 {
99 	return usb_get_intfdata(hdev->actconfig->interface[0]);
100 }
101 
102 /* USB 2.0 spec Section 11.24.4.5 */
103 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
104 {
105 	int i, ret;
106 
107 	for (i = 0; i < 3; i++) {
108 		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
109 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
110 			USB_DT_HUB << 8, 0, data, size,
111 			USB_CTRL_GET_TIMEOUT);
112 		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
113 			return ret;
114 	}
115 	return -EINVAL;
116 }
117 
118 /*
119  * USB 2.0 spec Section 11.24.2.1
120  */
121 static int clear_hub_feature(struct usb_device *hdev, int feature)
122 {
123 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
124 		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
125 }
126 
127 /*
128  * USB 2.0 spec Section 11.24.2.2
129  */
130 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
131 {
132 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
133 		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
134 		NULL, 0, 1000);
135 }
136 
137 /*
138  * USB 2.0 spec Section 11.24.2.13
139  */
140 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
141 {
142 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
143 		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
144 		NULL, 0, 1000);
145 }
146 
147 /*
148  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
149  * for info about using port indicators
150  */
151 static void set_port_led(
152 	struct usb_hub *hub,
153 	int port1,
154 	int selector
155 )
156 {
157 	int status = set_port_feature(hub->hdev, (selector << 8) | port1,
158 			USB_PORT_FEAT_INDICATOR);
159 	if (status < 0)
160 		dev_dbg (hub->intfdev,
161 			"port %d indicator %s status %d\n",
162 			port1,
163 			({ char *s; switch (selector) {
164 			case HUB_LED_AMBER: s = "amber"; break;
165 			case HUB_LED_GREEN: s = "green"; break;
166 			case HUB_LED_OFF: s = "off"; break;
167 			case HUB_LED_AUTO: s = "auto"; break;
168 			default: s = "??"; break;
169 			}; s; }),
170 			status);
171 }
172 
173 #define	LED_CYCLE_PERIOD	((2*HZ)/3)
174 
175 static void led_work (void *__hub)
176 {
177 	struct usb_hub		*hub = __hub;
178 	struct usb_device	*hdev = hub->hdev;
179 	unsigned		i;
180 	unsigned		changed = 0;
181 	int			cursor = -1;
182 
183 	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
184 		return;
185 
186 	for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
187 		unsigned	selector, mode;
188 
189 		/* 30%-50% duty cycle */
190 
191 		switch (hub->indicator[i]) {
192 		/* cycle marker */
193 		case INDICATOR_CYCLE:
194 			cursor = i;
195 			selector = HUB_LED_AUTO;
196 			mode = INDICATOR_AUTO;
197 			break;
198 		/* blinking green = sw attention */
199 		case INDICATOR_GREEN_BLINK:
200 			selector = HUB_LED_GREEN;
201 			mode = INDICATOR_GREEN_BLINK_OFF;
202 			break;
203 		case INDICATOR_GREEN_BLINK_OFF:
204 			selector = HUB_LED_OFF;
205 			mode = INDICATOR_GREEN_BLINK;
206 			break;
207 		/* blinking amber = hw attention */
208 		case INDICATOR_AMBER_BLINK:
209 			selector = HUB_LED_AMBER;
210 			mode = INDICATOR_AMBER_BLINK_OFF;
211 			break;
212 		case INDICATOR_AMBER_BLINK_OFF:
213 			selector = HUB_LED_OFF;
214 			mode = INDICATOR_AMBER_BLINK;
215 			break;
216 		/* blink green/amber = reserved */
217 		case INDICATOR_ALT_BLINK:
218 			selector = HUB_LED_GREEN;
219 			mode = INDICATOR_ALT_BLINK_OFF;
220 			break;
221 		case INDICATOR_ALT_BLINK_OFF:
222 			selector = HUB_LED_AMBER;
223 			mode = INDICATOR_ALT_BLINK;
224 			break;
225 		default:
226 			continue;
227 		}
228 		if (selector != HUB_LED_AUTO)
229 			changed = 1;
230 		set_port_led(hub, i + 1, selector);
231 		hub->indicator[i] = mode;
232 	}
233 	if (!changed && blinkenlights) {
234 		cursor++;
235 		cursor %= hub->descriptor->bNbrPorts;
236 		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
237 		hub->indicator[cursor] = INDICATOR_CYCLE;
238 		changed++;
239 	}
240 	if (changed)
241 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
242 }
243 
244 /* use a short timeout for hub/port status fetches */
245 #define	USB_STS_TIMEOUT		1000
246 #define	USB_STS_RETRIES		5
247 
248 /*
249  * USB 2.0 spec Section 11.24.2.6
250  */
251 static int get_hub_status(struct usb_device *hdev,
252 		struct usb_hub_status *data)
253 {
254 	int i, status = -ETIMEDOUT;
255 
256 	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
257 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
258 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
259 			data, sizeof(*data), USB_STS_TIMEOUT);
260 	}
261 	return status;
262 }
263 
264 /*
265  * USB 2.0 spec Section 11.24.2.7
266  */
267 static int get_port_status(struct usb_device *hdev, int port1,
268 		struct usb_port_status *data)
269 {
270 	int i, status = -ETIMEDOUT;
271 
272 	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
273 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
274 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
275 			data, sizeof(*data), USB_STS_TIMEOUT);
276 	}
277 	return status;
278 }
279 
280 static void kick_khubd(struct usb_hub *hub)
281 {
282 	unsigned long	flags;
283 
284 	spin_lock_irqsave(&hub_event_lock, flags);
285 	if (list_empty(&hub->event_list)) {
286 		list_add_tail(&hub->event_list, &hub_event_list);
287 		wake_up(&khubd_wait);
288 	}
289 	spin_unlock_irqrestore(&hub_event_lock, flags);
290 }
291 
292 void usb_kick_khubd(struct usb_device *hdev)
293 {
294 	kick_khubd(hdev_to_hub(hdev));
295 }
296 
297 
298 /* completion function, fires on port status changes and various faults */
299 static void hub_irq(struct urb *urb, struct pt_regs *regs)
300 {
301 	struct usb_hub *hub = (struct usb_hub *)urb->context;
302 	int status;
303 	int i;
304 	unsigned long bits;
305 
306 	switch (urb->status) {
307 	case -ENOENT:		/* synchronous unlink */
308 	case -ECONNRESET:	/* async unlink */
309 	case -ESHUTDOWN:	/* hardware going away */
310 		return;
311 
312 	default:		/* presumably an error */
313 		/* Cause a hub reset after 10 consecutive errors */
314 		dev_dbg (hub->intfdev, "transfer --> %d\n", urb->status);
315 		if ((++hub->nerrors < 10) || hub->error)
316 			goto resubmit;
317 		hub->error = urb->status;
318 		/* FALL THROUGH */
319 
320 	/* let khubd handle things */
321 	case 0:			/* we got data:  port status changed */
322 		bits = 0;
323 		for (i = 0; i < urb->actual_length; ++i)
324 			bits |= ((unsigned long) ((*hub->buffer)[i]))
325 					<< (i*8);
326 		hub->event_bits[0] = bits;
327 		break;
328 	}
329 
330 	hub->nerrors = 0;
331 
332 	/* Something happened, let khubd figure it out */
333 	kick_khubd(hub);
334 
335 resubmit:
336 	if (hub->quiescing)
337 		return;
338 
339 	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
340 			&& status != -ENODEV && status != -EPERM)
341 		dev_err (hub->intfdev, "resubmit --> %d\n", status);
342 }
343 
344 /* USB 2.0 spec Section 11.24.2.3 */
345 static inline int
346 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
347 {
348 	return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
349 			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
350 			       tt, NULL, 0, 1000);
351 }
352 
353 /*
354  * enumeration blocks khubd for a long time. we use keventd instead, since
355  * long blocking there is the exception, not the rule.  accordingly, HCDs
356  * talking to TTs must queue control transfers (not just bulk and iso), so
357  * both can talk to the same hub concurrently.
358  */
359 static void hub_tt_kevent (void *arg)
360 {
361 	struct usb_hub		*hub = arg;
362 	unsigned long		flags;
363 
364 	spin_lock_irqsave (&hub->tt.lock, flags);
365 	while (!list_empty (&hub->tt.clear_list)) {
366 		struct list_head	*temp;
367 		struct usb_tt_clear	*clear;
368 		struct usb_device	*hdev = hub->hdev;
369 		int			status;
370 
371 		temp = hub->tt.clear_list.next;
372 		clear = list_entry (temp, struct usb_tt_clear, clear_list);
373 		list_del (&clear->clear_list);
374 
375 		/* drop lock so HCD can concurrently report other TT errors */
376 		spin_unlock_irqrestore (&hub->tt.lock, flags);
377 		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
378 		spin_lock_irqsave (&hub->tt.lock, flags);
379 
380 		if (status)
381 			dev_err (&hdev->dev,
382 				"clear tt %d (%04x) error %d\n",
383 				clear->tt, clear->devinfo, status);
384 		kfree(clear);
385 	}
386 	spin_unlock_irqrestore (&hub->tt.lock, flags);
387 }
388 
389 /**
390  * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
391  * @udev: the device whose split transaction failed
392  * @pipe: identifies the endpoint of the failed transaction
393  *
394  * High speed HCDs use this to tell the hub driver that some split control or
395  * bulk transaction failed in a way that requires clearing internal state of
396  * a transaction translator.  This is normally detected (and reported) from
397  * interrupt context.
398  *
399  * It may not be possible for that hub to handle additional full (or low)
400  * speed transactions until that state is fully cleared out.
401  */
402 void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
403 {
404 	struct usb_tt		*tt = udev->tt;
405 	unsigned long		flags;
406 	struct usb_tt_clear	*clear;
407 
408 	/* we've got to cope with an arbitrary number of pending TT clears,
409 	 * since each TT has "at least two" buffers that can need it (and
410 	 * there can be many TTs per hub).  even if they're uncommon.
411 	 */
412 	if ((clear = kmalloc (sizeof *clear, SLAB_ATOMIC)) == NULL) {
413 		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
414 		/* FIXME recover somehow ... RESET_TT? */
415 		return;
416 	}
417 
418 	/* info that CLEAR_TT_BUFFER needs */
419 	clear->tt = tt->multi ? udev->ttport : 1;
420 	clear->devinfo = usb_pipeendpoint (pipe);
421 	clear->devinfo |= udev->devnum << 4;
422 	clear->devinfo |= usb_pipecontrol (pipe)
423 			? (USB_ENDPOINT_XFER_CONTROL << 11)
424 			: (USB_ENDPOINT_XFER_BULK << 11);
425 	if (usb_pipein (pipe))
426 		clear->devinfo |= 1 << 15;
427 
428 	/* tell keventd to clear state for this TT */
429 	spin_lock_irqsave (&tt->lock, flags);
430 	list_add_tail (&clear->clear_list, &tt->clear_list);
431 	schedule_work (&tt->kevent);
432 	spin_unlock_irqrestore (&tt->lock, flags);
433 }
434 
435 static void hub_power_on(struct usb_hub *hub)
436 {
437 	int port1;
438 	unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
439 
440 	/* if hub supports power switching, enable power on each port */
441 	if ((hub->descriptor->wHubCharacteristics & HUB_CHAR_LPSM) < 2) {
442 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
443 		for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
444 			set_port_feature(hub->hdev, port1,
445 					USB_PORT_FEAT_POWER);
446 	}
447 
448 	/* Wait at least 100 msec for power to become stable */
449 	msleep(max(pgood_delay, (unsigned) 100));
450 }
451 
452 static void hub_quiesce(struct usb_hub *hub)
453 {
454 	/* stop khubd and related activity */
455 	hub->quiescing = 1;
456 	usb_kill_urb(hub->urb);
457 	if (hub->has_indicators)
458 		cancel_delayed_work(&hub->leds);
459 	if (hub->has_indicators || hub->tt.hub)
460 		flush_scheduled_work();
461 }
462 
463 static void hub_activate(struct usb_hub *hub)
464 {
465 	int	status;
466 
467 	hub->quiescing = 0;
468 	hub->activating = 1;
469 	status = usb_submit_urb(hub->urb, GFP_NOIO);
470 	if (status < 0)
471 		dev_err(hub->intfdev, "activate --> %d\n", status);
472 	if (hub->has_indicators && blinkenlights)
473 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
474 
475 	/* scan all ports ASAP */
476 	kick_khubd(hub);
477 }
478 
479 static int hub_hub_status(struct usb_hub *hub,
480 		u16 *status, u16 *change)
481 {
482 	int ret;
483 
484 	ret = get_hub_status(hub->hdev, &hub->status->hub);
485 	if (ret < 0)
486 		dev_err (hub->intfdev,
487 			"%s failed (err = %d)\n", __FUNCTION__, ret);
488 	else {
489 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
490 		*change = le16_to_cpu(hub->status->hub.wHubChange);
491 		ret = 0;
492 	}
493 	return ret;
494 }
495 
496 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
497 {
498 	struct usb_device *hdev = hub->hdev;
499 	int ret;
500 
501 	if (hdev->children[port1-1] && set_state) {
502 		usb_set_device_state(hdev->children[port1-1],
503 				USB_STATE_NOTATTACHED);
504 	}
505 	ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
506 	if (ret)
507 		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
508 			port1, ret);
509 
510 	return ret;
511 }
512 
513 static int hub_configure(struct usb_hub *hub,
514 	struct usb_endpoint_descriptor *endpoint)
515 {
516 	struct usb_device *hdev = hub->hdev;
517 	struct device *hub_dev = hub->intfdev;
518 	u16 hubstatus, hubchange;
519 	unsigned int pipe;
520 	int maxp, ret;
521 	char *message;
522 
523 	hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
524 			&hub->buffer_dma);
525 	if (!hub->buffer) {
526 		message = "can't allocate hub irq buffer";
527 		ret = -ENOMEM;
528 		goto fail;
529 	}
530 
531 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
532 	if (!hub->status) {
533 		message = "can't kmalloc hub status buffer";
534 		ret = -ENOMEM;
535 		goto fail;
536 	}
537 
538 	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
539 	if (!hub->descriptor) {
540 		message = "can't kmalloc hub descriptor";
541 		ret = -ENOMEM;
542 		goto fail;
543 	}
544 
545 	/* Request the entire hub descriptor.
546 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
547 	 * but the hub can/will return fewer bytes here.
548 	 */
549 	ret = get_hub_descriptor(hdev, hub->descriptor,
550 			sizeof(*hub->descriptor));
551 	if (ret < 0) {
552 		message = "can't read hub descriptor";
553 		goto fail;
554 	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
555 		message = "hub has too many ports!";
556 		ret = -ENODEV;
557 		goto fail;
558 	}
559 
560 	hdev->maxchild = hub->descriptor->bNbrPorts;
561 	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
562 		(hdev->maxchild == 1) ? "" : "s");
563 
564 	le16_to_cpus(&hub->descriptor->wHubCharacteristics);
565 
566 	if (hub->descriptor->wHubCharacteristics & HUB_CHAR_COMPOUND) {
567 		int	i;
568 		char	portstr [USB_MAXCHILDREN + 1];
569 
570 		for (i = 0; i < hdev->maxchild; i++)
571 			portstr[i] = hub->descriptor->DeviceRemovable
572 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
573 				? 'F' : 'R';
574 		portstr[hdev->maxchild] = 0;
575 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
576 	} else
577 		dev_dbg(hub_dev, "standalone hub\n");
578 
579 	switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_LPSM) {
580 		case 0x00:
581 			dev_dbg(hub_dev, "ganged power switching\n");
582 			break;
583 		case 0x01:
584 			dev_dbg(hub_dev, "individual port power switching\n");
585 			break;
586 		case 0x02:
587 		case 0x03:
588 			dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
589 			break;
590 	}
591 
592 	switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_OCPM) {
593 		case 0x00:
594 			dev_dbg(hub_dev, "global over-current protection\n");
595 			break;
596 		case 0x08:
597 			dev_dbg(hub_dev, "individual port over-current protection\n");
598 			break;
599 		case 0x10:
600 		case 0x18:
601 			dev_dbg(hub_dev, "no over-current protection\n");
602                         break;
603 	}
604 
605 	spin_lock_init (&hub->tt.lock);
606 	INIT_LIST_HEAD (&hub->tt.clear_list);
607 	INIT_WORK (&hub->tt.kevent, hub_tt_kevent, hub);
608 	switch (hdev->descriptor.bDeviceProtocol) {
609 		case 0:
610 			break;
611 		case 1:
612 			dev_dbg(hub_dev, "Single TT\n");
613 			hub->tt.hub = hdev;
614 			break;
615 		case 2:
616 			ret = usb_set_interface(hdev, 0, 1);
617 			if (ret == 0) {
618 				dev_dbg(hub_dev, "TT per port\n");
619 				hub->tt.multi = 1;
620 			} else
621 				dev_err(hub_dev, "Using single TT (err %d)\n",
622 					ret);
623 			hub->tt.hub = hdev;
624 			break;
625 		default:
626 			dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
627 				hdev->descriptor.bDeviceProtocol);
628 			break;
629 	}
630 
631 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
632 	switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_TTTT) {
633 		case HUB_TTTT_8_BITS:
634 			if (hdev->descriptor.bDeviceProtocol != 0) {
635 				hub->tt.think_time = 666;
636 				dev_dbg(hub_dev, "TT requires at most %d "
637 						"FS bit times (%d ns)\n",
638 					8, hub->tt.think_time);
639 			}
640 			break;
641 		case HUB_TTTT_16_BITS:
642 			hub->tt.think_time = 666 * 2;
643 			dev_dbg(hub_dev, "TT requires at most %d "
644 					"FS bit times (%d ns)\n",
645 				16, hub->tt.think_time);
646 			break;
647 		case HUB_TTTT_24_BITS:
648 			hub->tt.think_time = 666 * 3;
649 			dev_dbg(hub_dev, "TT requires at most %d "
650 					"FS bit times (%d ns)\n",
651 				24, hub->tt.think_time);
652 			break;
653 		case HUB_TTTT_32_BITS:
654 			hub->tt.think_time = 666 * 4;
655 			dev_dbg(hub_dev, "TT requires at most %d "
656 					"FS bit times (%d ns)\n",
657 				32, hub->tt.think_time);
658 			break;
659 	}
660 
661 	/* probe() zeroes hub->indicator[] */
662 	if (hub->descriptor->wHubCharacteristics & HUB_CHAR_PORTIND) {
663 		hub->has_indicators = 1;
664 		dev_dbg(hub_dev, "Port indicators are supported\n");
665 	}
666 
667 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
668 		hub->descriptor->bPwrOn2PwrGood * 2);
669 
670 	/* power budgeting mostly matters with bus-powered hubs,
671 	 * and battery-powered root hubs (may provide just 8 mA).
672 	 */
673 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
674 	if (ret < 0) {
675 		message = "can't get hub status";
676 		goto fail;
677 	}
678 	le16_to_cpus(&hubstatus);
679 	if (hdev == hdev->bus->root_hub) {
680 		struct usb_hcd *hcd =
681 				container_of(hdev->bus, struct usb_hcd, self);
682 
683 		hub->power_budget = min(500u, hcd->power_budget) / 2;
684 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
685 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
686 			hub->descriptor->bHubContrCurrent);
687 		hub->power_budget = (501 - hub->descriptor->bHubContrCurrent)
688 					/ 2;
689 	}
690 	if (hub->power_budget)
691 		dev_dbg(hub_dev, "%dmA bus power budget for children\n",
692 			hub->power_budget * 2);
693 
694 
695 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
696 	if (ret < 0) {
697 		message = "can't get hub status";
698 		goto fail;
699 	}
700 
701 	/* local power status reports aren't always correct */
702 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
703 		dev_dbg(hub_dev, "local power source is %s\n",
704 			(hubstatus & HUB_STATUS_LOCAL_POWER)
705 			? "lost (inactive)" : "good");
706 
707 	if ((hub->descriptor->wHubCharacteristics & HUB_CHAR_OCPM) == 0)
708 		dev_dbg(hub_dev, "%sover-current condition exists\n",
709 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
710 
711 	/* set up the interrupt endpoint */
712 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
713 	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
714 
715 	if (maxp > sizeof(*hub->buffer))
716 		maxp = sizeof(*hub->buffer);
717 
718 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
719 	if (!hub->urb) {
720 		message = "couldn't allocate interrupt urb";
721 		ret = -ENOMEM;
722 		goto fail;
723 	}
724 
725 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
726 		hub, endpoint->bInterval);
727 	hub->urb->transfer_dma = hub->buffer_dma;
728 	hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
729 
730 	/* maybe cycle the hub leds */
731 	if (hub->has_indicators && blinkenlights)
732 		hub->indicator [0] = INDICATOR_CYCLE;
733 
734 	hub_power_on(hub);
735 	hub_activate(hub);
736 	return 0;
737 
738 fail:
739 	dev_err (hub_dev, "config failed, %s (err %d)\n",
740 			message, ret);
741 	/* hub_disconnect() frees urb and descriptor */
742 	return ret;
743 }
744 
745 static unsigned highspeed_hubs;
746 
747 /* Called after the hub driver is unbound from a hub with children */
748 static void hub_remove_children_work(void *__hub)
749 {
750 	struct usb_hub		*hub = __hub;
751 	struct usb_device	*hdev = hub->hdev;
752 	int			i;
753 
754 	kfree(hub);
755 
756 	usb_lock_device(hdev);
757 	for (i = 0; i < hdev->maxchild; ++i) {
758 		if (hdev->children[i])
759 			usb_disconnect(&hdev->children[i]);
760 	}
761 	usb_unlock_device(hdev);
762 	usb_put_dev(hdev);
763 }
764 
765 static void hub_disconnect(struct usb_interface *intf)
766 {
767 	struct usb_hub *hub = usb_get_intfdata (intf);
768 	struct usb_device *hdev;
769 	int n, port1;
770 
771 	usb_set_intfdata (intf, NULL);
772 	hdev = hub->hdev;
773 
774 	if (hdev->speed == USB_SPEED_HIGH)
775 		highspeed_hubs--;
776 
777 	hub_quiesce(hub);
778 	usb_free_urb(hub->urb);
779 	hub->urb = NULL;
780 
781 	spin_lock_irq(&hub_event_lock);
782 	list_del_init(&hub->event_list);
783 	spin_unlock_irq(&hub_event_lock);
784 
785 	kfree(hub->descriptor);
786 	hub->descriptor = NULL;
787 
788 	kfree(hub->status);
789 	hub->status = NULL;
790 
791 	if (hub->buffer) {
792 		usb_buffer_free(hdev, sizeof(*hub->buffer), hub->buffer,
793 				hub->buffer_dma);
794 		hub->buffer = NULL;
795 	}
796 
797 	/* If there are any children then this is an unbind only, not a
798 	 * physical disconnection.  The active ports must be disabled
799 	 * and later on we must call usb_disconnect().  We can't call
800 	 * it now because we may not hold the hub's device lock.
801 	 */
802 	n = 0;
803 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
804 		if (hdev->children[port1 - 1]) {
805 			++n;
806 			hub_port_disable(hub, port1, 1);
807 		}
808 	}
809 
810 	if (n == 0)
811 		kfree(hub);
812 	else {
813 		/* Reuse the hub->leds work_struct for our own purposes */
814 		INIT_WORK(&hub->leds, hub_remove_children_work, hub);
815 		schedule_work(&hub->leds);
816 		usb_get_dev(hdev);
817 	}
818 }
819 
820 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
821 {
822 	struct usb_host_interface *desc;
823 	struct usb_endpoint_descriptor *endpoint;
824 	struct usb_device *hdev;
825 	struct usb_hub *hub;
826 
827 	desc = intf->cur_altsetting;
828 	hdev = interface_to_usbdev(intf);
829 
830 	/* Some hubs have a subclass of 1, which AFAICT according to the */
831 	/*  specs is not defined, but it works */
832 	if ((desc->desc.bInterfaceSubClass != 0) &&
833 	    (desc->desc.bInterfaceSubClass != 1)) {
834 descriptor_error:
835 		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
836 		return -EIO;
837 	}
838 
839 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
840 	if (desc->desc.bNumEndpoints != 1)
841 		goto descriptor_error;
842 
843 	endpoint = &desc->endpoint[0].desc;
844 
845 	/* Output endpoint? Curiouser and curiouser.. */
846 	if (!(endpoint->bEndpointAddress & USB_DIR_IN))
847 		goto descriptor_error;
848 
849 	/* If it's not an interrupt endpoint, we'd better punt! */
850 	if ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
851 			!= USB_ENDPOINT_XFER_INT)
852 		goto descriptor_error;
853 
854 	/* We found a hub */
855 	dev_info (&intf->dev, "USB hub found\n");
856 
857 	hub = kmalloc(sizeof(*hub), GFP_KERNEL);
858 	if (!hub) {
859 		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
860 		return -ENOMEM;
861 	}
862 
863 	memset(hub, 0, sizeof(*hub));
864 
865 	INIT_LIST_HEAD(&hub->event_list);
866 	hub->intfdev = &intf->dev;
867 	hub->hdev = hdev;
868 	INIT_WORK(&hub->leds, led_work, hub);
869 
870 	usb_set_intfdata (intf, hub);
871 
872 	if (hdev->speed == USB_SPEED_HIGH)
873 		highspeed_hubs++;
874 
875 	if (hub_configure(hub, endpoint) >= 0)
876 		return 0;
877 
878 	hub_disconnect (intf);
879 	return -ENODEV;
880 }
881 
882 static int
883 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
884 {
885 	struct usb_device *hdev = interface_to_usbdev (intf);
886 
887 	/* assert ifno == 0 (part of hub spec) */
888 	switch (code) {
889 	case USBDEVFS_HUB_PORTINFO: {
890 		struct usbdevfs_hub_portinfo *info = user_data;
891 		int i;
892 
893 		spin_lock_irq(&device_state_lock);
894 		if (hdev->devnum <= 0)
895 			info->nports = 0;
896 		else {
897 			info->nports = hdev->maxchild;
898 			for (i = 0; i < info->nports; i++) {
899 				if (hdev->children[i] == NULL)
900 					info->port[i] = 0;
901 				else
902 					info->port[i] =
903 						hdev->children[i]->devnum;
904 			}
905 		}
906 		spin_unlock_irq(&device_state_lock);
907 
908 		return info->nports + 1;
909 		}
910 
911 	default:
912 		return -ENOSYS;
913 	}
914 }
915 
916 /* caller has locked the hub device */
917 static void hub_pre_reset(struct usb_hub *hub)
918 {
919 	struct usb_device *hdev = hub->hdev;
920 	int i;
921 
922 	for (i = 0; i < hdev->maxchild; ++i) {
923 		if (hdev->children[i])
924 			usb_disconnect(&hdev->children[i]);
925 	}
926 	hub_quiesce(hub);
927 }
928 
929 /* caller has locked the hub device */
930 static void hub_post_reset(struct usb_hub *hub)
931 {
932 	hub_activate(hub);
933 	hub_power_on(hub);
934 }
935 
936 
937 /* grab device/port lock, returning index of that port (zero based).
938  * protects the upstream link used by this device from concurrent
939  * tree operations like suspend, resume, reset, and disconnect, which
940  * apply to everything downstream of a given port.
941  */
942 static int locktree(struct usb_device *udev)
943 {
944 	int			t;
945 	struct usb_device	*hdev;
946 
947 	if (!udev)
948 		return -ENODEV;
949 
950 	/* root hub is always the first lock in the series */
951 	hdev = udev->parent;
952 	if (!hdev) {
953 		usb_lock_device(udev);
954 		return 0;
955 	}
956 
957 	/* on the path from root to us, lock everything from
958 	 * top down, dropping parent locks when not needed
959 	 */
960 	t = locktree(hdev);
961 	if (t < 0)
962 		return t;
963 	for (t = 0; t < hdev->maxchild; t++) {
964 		if (hdev->children[t] == udev) {
965 			/* everything is fail-fast once disconnect
966 			 * processing starts
967 			 */
968 			if (udev->state == USB_STATE_NOTATTACHED)
969 				break;
970 
971 			/* when everyone grabs locks top->bottom,
972 			 * non-overlapping work may be concurrent
973 			 */
974 			down(&udev->serialize);
975 			up(&hdev->serialize);
976 			return t + 1;
977 		}
978 	}
979 	usb_unlock_device(hdev);
980 	return -ENODEV;
981 }
982 
983 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
984 {
985 	int i;
986 
987 	for (i = 0; i < udev->maxchild; ++i) {
988 		if (udev->children[i])
989 			recursively_mark_NOTATTACHED(udev->children[i]);
990 	}
991 	udev->state = USB_STATE_NOTATTACHED;
992 }
993 
994 /**
995  * usb_set_device_state - change a device's current state (usbcore, hcds)
996  * @udev: pointer to device whose state should be changed
997  * @new_state: new state value to be stored
998  *
999  * udev->state is _not_ fully protected by the device lock.  Although
1000  * most transitions are made only while holding the lock, the state can
1001  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1002  * is so that devices can be marked as disconnected as soon as possible,
1003  * without having to wait for any semaphores to be released.  As a result,
1004  * all changes to any device's state must be protected by the
1005  * device_state_lock spinlock.
1006  *
1007  * Once a device has been added to the device tree, all changes to its state
1008  * should be made using this routine.  The state should _not_ be set directly.
1009  *
1010  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1011  * Otherwise udev->state is set to new_state, and if new_state is
1012  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1013  * to USB_STATE_NOTATTACHED.
1014  */
1015 void usb_set_device_state(struct usb_device *udev,
1016 		enum usb_device_state new_state)
1017 {
1018 	unsigned long flags;
1019 
1020 	spin_lock_irqsave(&device_state_lock, flags);
1021 	if (udev->state == USB_STATE_NOTATTACHED)
1022 		;	/* do nothing */
1023 	else if (new_state != USB_STATE_NOTATTACHED)
1024 		udev->state = new_state;
1025 	else
1026 		recursively_mark_NOTATTACHED(udev);
1027 	spin_unlock_irqrestore(&device_state_lock, flags);
1028 }
1029 EXPORT_SYMBOL(usb_set_device_state);
1030 
1031 
1032 static void choose_address(struct usb_device *udev)
1033 {
1034 	int		devnum;
1035 	struct usb_bus	*bus = udev->bus;
1036 
1037 	/* If khubd ever becomes multithreaded, this will need a lock */
1038 
1039 	/* Try to allocate the next devnum beginning at bus->devnum_next. */
1040 	devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1041 			bus->devnum_next);
1042 	if (devnum >= 128)
1043 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
1044 
1045 	bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1046 
1047 	if (devnum < 128) {
1048 		set_bit(devnum, bus->devmap.devicemap);
1049 		udev->devnum = devnum;
1050 	}
1051 }
1052 
1053 static void release_address(struct usb_device *udev)
1054 {
1055 	if (udev->devnum > 0) {
1056 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1057 		udev->devnum = -1;
1058 	}
1059 }
1060 
1061 /**
1062  * usb_disconnect - disconnect a device (usbcore-internal)
1063  * @pdev: pointer to device being disconnected
1064  * Context: !in_interrupt ()
1065  *
1066  * Something got disconnected. Get rid of it and all of its children.
1067  *
1068  * If *pdev is a normal device then the parent hub must already be locked.
1069  * If *pdev is a root hub then this routine will acquire the
1070  * usb_bus_list_lock on behalf of the caller.
1071  *
1072  * Only hub drivers (including virtual root hub drivers for host
1073  * controllers) should ever call this.
1074  *
1075  * This call is synchronous, and may not be used in an interrupt context.
1076  */
1077 void usb_disconnect(struct usb_device **pdev)
1078 {
1079 	struct usb_device	*udev = *pdev;
1080 	int			i;
1081 
1082 	if (!udev) {
1083 		pr_debug ("%s nodev\n", __FUNCTION__);
1084 		return;
1085 	}
1086 
1087 	/* mark the device as inactive, so any further urb submissions for
1088 	 * this device (and any of its children) will fail immediately.
1089 	 * this quiesces everyting except pending urbs.
1090 	 */
1091 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1092 
1093 	/* lock the bus list on behalf of HCDs unregistering their root hubs */
1094 	if (!udev->parent) {
1095 		down(&usb_bus_list_lock);
1096 		usb_lock_device(udev);
1097 	} else
1098 		down(&udev->serialize);
1099 
1100 	dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1101 
1102 	/* Free up all the children before we remove this device */
1103 	for (i = 0; i < USB_MAXCHILDREN; i++) {
1104 		if (udev->children[i])
1105 			usb_disconnect(&udev->children[i]);
1106 	}
1107 
1108 	/* deallocate hcd/hardware state ... nuking all pending urbs and
1109 	 * cleaning up all state associated with the current configuration
1110 	 * so that the hardware is now fully quiesced.
1111 	 */
1112 	usb_disable_device(udev, 0);
1113 
1114 	/* Free the device number, remove the /proc/bus/usb entry and
1115 	 * the sysfs attributes, and delete the parent's children[]
1116 	 * (or root_hub) pointer.
1117 	 */
1118 	dev_dbg (&udev->dev, "unregistering device\n");
1119 	release_address(udev);
1120 	usbfs_remove_device(udev);
1121 	usbdev_remove(udev);
1122 	usb_remove_sysfs_dev_files(udev);
1123 
1124 	/* Avoid races with recursively_mark_NOTATTACHED() */
1125 	spin_lock_irq(&device_state_lock);
1126 	*pdev = NULL;
1127 	spin_unlock_irq(&device_state_lock);
1128 
1129 	if (!udev->parent) {
1130 		usb_unlock_device(udev);
1131 		up(&usb_bus_list_lock);
1132 	} else
1133 		up(&udev->serialize);
1134 
1135 	device_unregister(&udev->dev);
1136 }
1137 
1138 static int choose_configuration(struct usb_device *udev)
1139 {
1140 	int c, i;
1141 
1142 	/* NOTE: this should interact with hub power budgeting */
1143 
1144 	c = udev->config[0].desc.bConfigurationValue;
1145 	if (udev->descriptor.bNumConfigurations != 1) {
1146 		for (i = 0; i < udev->descriptor.bNumConfigurations; i++) {
1147 			struct usb_interface_descriptor	*desc;
1148 
1149 			/* heuristic:  Linux is more likely to have class
1150 			 * drivers, so avoid vendor-specific interfaces.
1151 			 */
1152 			desc = &udev->config[i].intf_cache[0]
1153 					->altsetting->desc;
1154 			if (desc->bInterfaceClass == USB_CLASS_VENDOR_SPEC)
1155 				continue;
1156 			/* COMM/2/all is CDC ACM, except 0xff is MSFT RNDIS.
1157 			 * MSFT needs this to be the first config; never use
1158 			 * it as the default unless Linux has host-side RNDIS.
1159 			 * A second config would ideally be CDC-Ethernet, but
1160 			 * may instead be the "vendor specific" CDC subset
1161 			 * long used by ARM Linux for sa1100 or pxa255.
1162 			 */
1163 			if (desc->bInterfaceClass == USB_CLASS_COMM
1164 					&& desc->bInterfaceSubClass == 2
1165 					&& desc->bInterfaceProtocol == 0xff) {
1166 				c = udev->config[1].desc.bConfigurationValue;
1167 				continue;
1168 			}
1169 			c = udev->config[i].desc.bConfigurationValue;
1170 			break;
1171 		}
1172 		dev_info(&udev->dev,
1173 			"configuration #%d chosen from %d choices\n",
1174 			c, udev->descriptor.bNumConfigurations);
1175 	}
1176 	return c;
1177 }
1178 
1179 #ifdef DEBUG
1180 static void show_string(struct usb_device *udev, char *id, char *string)
1181 {
1182 	if (!string)
1183 		return;
1184 	dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1185 }
1186 
1187 #else
1188 static inline void show_string(struct usb_device *udev, char *id, char *string)
1189 {}
1190 #endif
1191 
1192 static void get_string(struct usb_device *udev, char **string, int index)
1193 {
1194 	char *buf;
1195 
1196 	if (!index)
1197 		return;
1198 	buf = kmalloc(256, GFP_KERNEL);
1199 	if (!buf)
1200 		return;
1201 	if (usb_string(udev, index, buf, 256) > 0)
1202 		*string = buf;
1203 	else
1204 		kfree(buf);
1205 }
1206 
1207 
1208 #ifdef	CONFIG_USB_OTG
1209 #include "otg_whitelist.h"
1210 #endif
1211 
1212 /**
1213  * usb_new_device - perform initial device setup (usbcore-internal)
1214  * @udev: newly addressed device (in ADDRESS state)
1215  *
1216  * This is called with devices which have been enumerated, but not yet
1217  * configured.  The device descriptor is available, but not descriptors
1218  * for any device configuration.  The caller must have locked udev and
1219  * either the parent hub (if udev is a normal device) or else the
1220  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
1221  * udev has already been installed, but udev is not yet visible through
1222  * sysfs or other filesystem code.
1223  *
1224  * Returns 0 for success (device is configured and listed, with its
1225  * interfaces, in sysfs); else a negative errno value.
1226  *
1227  * This call is synchronous, and may not be used in an interrupt context.
1228  *
1229  * Only the hub driver should ever call this; root hub registration
1230  * uses it indirectly.
1231  */
1232 int usb_new_device(struct usb_device *udev)
1233 {
1234 	int err;
1235 	int c;
1236 
1237 	err = usb_get_configuration(udev);
1238 	if (err < 0) {
1239 		dev_err(&udev->dev, "can't read configurations, error %d\n",
1240 			err);
1241 		goto fail;
1242 	}
1243 
1244 	/* read the standard strings and cache them if present */
1245 	get_string(udev, &udev->product, udev->descriptor.iProduct);
1246 	get_string(udev, &udev->manufacturer, udev->descriptor.iManufacturer);
1247 	get_string(udev, &udev->serial, udev->descriptor.iSerialNumber);
1248 
1249 	/* Tell the world! */
1250 	dev_dbg(&udev->dev, "new device strings: Mfr=%d, Product=%d, "
1251 			"SerialNumber=%d\n",
1252 			udev->descriptor.iManufacturer,
1253 			udev->descriptor.iProduct,
1254 			udev->descriptor.iSerialNumber);
1255 	show_string(udev, "Product", udev->product);
1256 	show_string(udev, "Manufacturer", udev->manufacturer);
1257 	show_string(udev, "SerialNumber", udev->serial);
1258 
1259 #ifdef	CONFIG_USB_OTG
1260 	/*
1261 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1262 	 * to wake us after we've powered off VBUS; and HNP, switching roles
1263 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
1264 	 */
1265 	if (!udev->bus->is_b_host
1266 			&& udev->config
1267 			&& udev->parent == udev->bus->root_hub) {
1268 		struct usb_otg_descriptor	*desc = 0;
1269 		struct usb_bus			*bus = udev->bus;
1270 
1271 		/* descriptor may appear anywhere in config */
1272 		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1273 					le16_to_cpu(udev->config[0].desc.wTotalLength),
1274 					USB_DT_OTG, (void **) &desc) == 0) {
1275 			if (desc->bmAttributes & USB_OTG_HNP) {
1276 				unsigned		port1;
1277 				struct usb_device	*root = udev->parent;
1278 
1279 				for (port1 = 1; port1 <= root->maxchild;
1280 						port1++) {
1281 					if (root->children[port1-1] == udev)
1282 						break;
1283 				}
1284 
1285 				dev_info(&udev->dev,
1286 					"Dual-Role OTG device on %sHNP port\n",
1287 					(port1 == bus->otg_port)
1288 						? "" : "non-");
1289 
1290 				/* enable HNP before suspend, it's simpler */
1291 				if (port1 == bus->otg_port)
1292 					bus->b_hnp_enable = 1;
1293 				err = usb_control_msg(udev,
1294 					usb_sndctrlpipe(udev, 0),
1295 					USB_REQ_SET_FEATURE, 0,
1296 					bus->b_hnp_enable
1297 						? USB_DEVICE_B_HNP_ENABLE
1298 						: USB_DEVICE_A_ALT_HNP_SUPPORT,
1299 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1300 				if (err < 0) {
1301 					/* OTG MESSAGE: report errors here,
1302 					 * customize to match your product.
1303 					 */
1304 					dev_info(&udev->dev,
1305 						"can't set HNP mode; %d\n",
1306 						err);
1307 					bus->b_hnp_enable = 0;
1308 				}
1309 			}
1310 		}
1311 	}
1312 
1313 	if (!is_targeted(udev)) {
1314 
1315 		/* Maybe it can talk to us, though we can't talk to it.
1316 		 * (Includes HNP test device.)
1317 		 */
1318 		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1319 			static int __usb_suspend_device (struct usb_device *,
1320 						int port1, pm_message_t state);
1321 			err = __usb_suspend_device(udev,
1322 					udev->bus->otg_port,
1323 					PMSG_SUSPEND);
1324 			if (err < 0)
1325 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1326 		}
1327 		err = -ENODEV;
1328 		goto fail;
1329 	}
1330 #endif
1331 
1332 	/* put device-specific files into sysfs */
1333 	err = device_add (&udev->dev);
1334 	if (err) {
1335 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
1336 		goto fail;
1337 	}
1338 	usb_create_sysfs_dev_files (udev);
1339 
1340 	/* choose and set the configuration. that registers the interfaces
1341 	 * with the driver core, and lets usb device drivers bind to them.
1342 	 */
1343 	c = choose_configuration(udev);
1344 	if (c < 0)
1345 		dev_warn(&udev->dev,
1346 				"can't choose an initial configuration\n");
1347 	else {
1348 		err = usb_set_configuration(udev, c);
1349 		if (err) {
1350 			dev_err(&udev->dev, "can't set config #%d, error %d\n",
1351 					c, err);
1352 			usb_remove_sysfs_dev_files(udev);
1353 			device_del(&udev->dev);
1354 			goto fail;
1355 		}
1356 	}
1357 
1358 	/* USB device state == configured ... usable */
1359 
1360 	/* add a /proc/bus/usb entry */
1361 	usbdev_add(udev);
1362 	usbfs_add_device(udev);
1363 	return 0;
1364 
1365 fail:
1366 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1367 	return err;
1368 }
1369 
1370 
1371 static int hub_port_status(struct usb_hub *hub, int port1,
1372 			       u16 *status, u16 *change)
1373 {
1374 	int ret;
1375 
1376 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
1377 	if (ret < 0)
1378 		dev_err (hub->intfdev,
1379 			"%s failed (err = %d)\n", __FUNCTION__, ret);
1380 	else {
1381 		*status = le16_to_cpu(hub->status->port.wPortStatus);
1382 		*change = le16_to_cpu(hub->status->port.wPortChange);
1383 		ret = 0;
1384 	}
1385 	return ret;
1386 }
1387 
1388 #define PORT_RESET_TRIES	5
1389 #define SET_ADDRESS_TRIES	2
1390 #define GET_DESCRIPTOR_TRIES	2
1391 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
1392 #define USE_NEW_SCHEME(i)	((i) / 2 == old_scheme_first)
1393 
1394 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
1395 #define HUB_SHORT_RESET_TIME	10
1396 #define HUB_LONG_RESET_TIME	200
1397 #define HUB_RESET_TIMEOUT	500
1398 
1399 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1400 				struct usb_device *udev, unsigned int delay)
1401 {
1402 	int delay_time, ret;
1403 	u16 portstatus;
1404 	u16 portchange;
1405 
1406 	for (delay_time = 0;
1407 			delay_time < HUB_RESET_TIMEOUT;
1408 			delay_time += delay) {
1409 		/* wait to give the device a chance to reset */
1410 		msleep(delay);
1411 
1412 		/* read and decode port status */
1413 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
1414 		if (ret < 0)
1415 			return ret;
1416 
1417 		/* Device went away? */
1418 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
1419 			return -ENOTCONN;
1420 
1421 		/* bomb out completely if something weird happened */
1422 		if ((portchange & USB_PORT_STAT_C_CONNECTION))
1423 			return -EINVAL;
1424 
1425 		/* if we`ve finished resetting, then break out of the loop */
1426 		if (!(portstatus & USB_PORT_STAT_RESET) &&
1427 		    (portstatus & USB_PORT_STAT_ENABLE)) {
1428 			if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1429 				udev->speed = USB_SPEED_HIGH;
1430 			else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1431 				udev->speed = USB_SPEED_LOW;
1432 			else
1433 				udev->speed = USB_SPEED_FULL;
1434 			return 0;
1435 		}
1436 
1437 		/* switch to the long delay after two short delay failures */
1438 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1439 			delay = HUB_LONG_RESET_TIME;
1440 
1441 		dev_dbg (hub->intfdev,
1442 			"port %d not reset yet, waiting %dms\n",
1443 			port1, delay);
1444 	}
1445 
1446 	return -EBUSY;
1447 }
1448 
1449 static int hub_port_reset(struct usb_hub *hub, int port1,
1450 				struct usb_device *udev, unsigned int delay)
1451 {
1452 	int i, status;
1453 
1454 	/* Reset the port */
1455 	for (i = 0; i < PORT_RESET_TRIES; i++) {
1456 		status = set_port_feature(hub->hdev,
1457 				port1, USB_PORT_FEAT_RESET);
1458 		if (status)
1459 			dev_err(hub->intfdev,
1460 					"cannot reset port %d (err = %d)\n",
1461 					port1, status);
1462 		else {
1463 			status = hub_port_wait_reset(hub, port1, udev, delay);
1464 			if (status && status != -ENOTCONN)
1465 				dev_dbg(hub->intfdev,
1466 						"port_wait_reset: err = %d\n",
1467 						status);
1468 		}
1469 
1470 		/* return on disconnect or reset */
1471 		switch (status) {
1472 		case 0:
1473 			/* TRSTRCY = 10 ms; plus some extra */
1474 			msleep(10 + 40);
1475 			/* FALL THROUGH */
1476 		case -ENOTCONN:
1477 		case -ENODEV:
1478 			clear_port_feature(hub->hdev,
1479 				port1, USB_PORT_FEAT_C_RESET);
1480 			/* FIXME need disconnect() for NOTATTACHED device */
1481 			usb_set_device_state(udev, status
1482 					? USB_STATE_NOTATTACHED
1483 					: USB_STATE_DEFAULT);
1484 			return status;
1485 		}
1486 
1487 		dev_dbg (hub->intfdev,
1488 			"port %d not enabled, trying reset again...\n",
1489 			port1);
1490 		delay = HUB_LONG_RESET_TIME;
1491 	}
1492 
1493 	dev_err (hub->intfdev,
1494 		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
1495 		port1);
1496 
1497 	return status;
1498 }
1499 
1500 /*
1501  * Disable a port and mark a logical connnect-change event, so that some
1502  * time later khubd will disconnect() any existing usb_device on the port
1503  * and will re-enumerate if there actually is a device attached.
1504  */
1505 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
1506 {
1507 	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
1508 	hub_port_disable(hub, port1, 1);
1509 
1510 	/* FIXME let caller ask to power down the port:
1511 	 *  - some devices won't enumerate without a VBUS power cycle
1512 	 *  - SRP saves power that way
1513 	 *  - usb_suspend_device(dev, PMSG_SUSPEND)
1514 	 * That's easy if this hub can switch power per-port, and
1515 	 * khubd reactivates the port later (timer, SRP, etc).
1516 	 * Powerdown must be optional, because of reset/DFU.
1517 	 */
1518 
1519 	set_bit(port1, hub->change_bits);
1520  	kick_khubd(hub);
1521 }
1522 
1523 
1524 #ifdef	CONFIG_USB_SUSPEND
1525 
1526 /*
1527  * Selective port suspend reduces power; most suspended devices draw
1528  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1529  * All devices below the suspended port are also suspended.
1530  *
1531  * Devices leave suspend state when the host wakes them up.  Some devices
1532  * also support "remote wakeup", where the device can activate the USB
1533  * tree above them to deliver data, such as a keypress or packet.  In
1534  * some cases, this wakes the USB host.
1535  */
1536 static int hub_port_suspend(struct usb_hub *hub, int port1,
1537 		struct usb_device *udev)
1538 {
1539 	int	status;
1540 
1541 	// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1542 
1543 	/* enable remote wakeup when appropriate; this lets the device
1544 	 * wake up the upstream hub (including maybe the root hub).
1545 	 *
1546 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1547 	 * we don't explicitly enable it here.
1548 	 */
1549 	if (udev->actconfig
1550 			// && FIXME (remote wakeup enabled on this bus)
1551 			// ... currently assuming it's always appropriate
1552 			&& (udev->actconfig->desc.bmAttributes
1553 				& USB_CONFIG_ATT_WAKEUP) != 0) {
1554 		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1555 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1556 				USB_DEVICE_REMOTE_WAKEUP, 0,
1557 				NULL, 0,
1558 				USB_CTRL_SET_TIMEOUT);
1559 		if (status)
1560 			dev_dbg(&udev->dev,
1561 				"won't remote wakeup, status %d\n",
1562 				status);
1563 	}
1564 
1565 	/* see 7.1.7.6 */
1566 	status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1567 	if (status) {
1568 		dev_dbg(hub->intfdev,
1569 			"can't suspend port %d, status %d\n",
1570 			port1, status);
1571 		/* paranoia:  "should not happen" */
1572 		(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1573 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1574 				USB_DEVICE_REMOTE_WAKEUP, 0,
1575 				NULL, 0,
1576 				USB_CTRL_SET_TIMEOUT);
1577 	} else {
1578 		/* device has up to 10 msec to fully suspend */
1579 		dev_dbg(&udev->dev, "usb suspend\n");
1580 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
1581 		msleep(10);
1582 	}
1583 	return status;
1584 }
1585 
1586 /*
1587  * Devices on USB hub ports have only one "suspend" state, corresponding
1588  * to ACPI D2, "may cause the device to lose some context".
1589  * State transitions include:
1590  *
1591  *   - suspend, resume ... when the VBUS power link stays live
1592  *   - suspend, disconnect ... VBUS lost
1593  *
1594  * Once VBUS drop breaks the circuit, the port it's using has to go through
1595  * normal re-enumeration procedures, starting with enabling VBUS power.
1596  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1597  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1598  * timer, no SRP, no requests through sysfs.
1599  */
1600 static int __usb_suspend_device (struct usb_device *udev, int port1,
1601 				 pm_message_t state)
1602 {
1603 	int	status;
1604 
1605 	/* caller owns the udev device lock */
1606 	if (port1 < 0)
1607 		return port1;
1608 
1609 	if (udev->state == USB_STATE_SUSPENDED
1610 			|| udev->state == USB_STATE_NOTATTACHED) {
1611 		return 0;
1612 	}
1613 
1614 	/* suspend interface drivers; if this is a hub, it
1615 	 * suspends the child devices
1616 	 */
1617 	if (udev->actconfig) {
1618 		int	i;
1619 
1620 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1621 			struct usb_interface	*intf;
1622 			struct usb_driver	*driver;
1623 
1624 			intf = udev->actconfig->interface[i];
1625 			if (state.event <= intf->dev.power.power_state.event)
1626 				continue;
1627 			if (!intf->dev.driver)
1628 				continue;
1629 			driver = to_usb_driver(intf->dev.driver);
1630 
1631 			if (driver->suspend) {
1632 				status = driver->suspend(intf, state);
1633 				if (intf->dev.power.power_state.event != state.event
1634 						|| status)
1635 					dev_err(&intf->dev,
1636 						"suspend %d fail, code %d\n",
1637 						state.event, status);
1638 			}
1639 
1640 			/* only drivers with suspend() can ever resume();
1641 			 * and after power loss, even they won't.
1642 			 * bus_rescan_devices() can rebind drivers later.
1643 			 *
1644 			 * FIXME the PM core self-deadlocks when unbinding
1645 			 * drivers during suspend/resume ... everything grabs
1646 			 * dpm_sem (not a spinlock, ugh).  we want to unbind,
1647 			 * since we know every driver's probe/disconnect works
1648 			 * even for drivers that can't suspend.
1649 			 */
1650 			if (!driver->suspend || state.event > PM_EVENT_FREEZE) {
1651 #if 1
1652 				dev_warn(&intf->dev, "resume is unsafe!\n");
1653 #else
1654 				down_write(&usb_bus_type.rwsem);
1655 				device_release_driver(&intf->dev);
1656 				up_write(&usb_bus_type.rwsem);
1657 #endif
1658 			}
1659 		}
1660 	}
1661 
1662 	/*
1663 	 * FIXME this needs port power off call paths too, to help force
1664 	 * USB into the "generic" PM model.  At least for devices on
1665 	 * ports that aren't using ganged switching (usually root hubs).
1666 	 *
1667 	 * NOTE: SRP-capable links should adopt more aggressive poweroff
1668 	 * policies (when HNP doesn't apply) once we have mechanisms to
1669 	 * turn power back on!  (Likely not before 2.7...)
1670 	 */
1671 	if (state.event > PM_EVENT_FREEZE) {
1672 		dev_warn(&udev->dev, "no poweroff yet, suspending instead\n");
1673 	}
1674 
1675 	/* "global suspend" of the HC-to-USB interface (root hub), or
1676 	 * "selective suspend" of just one hub-device link.
1677 	 */
1678 	if (!udev->parent) {
1679 		struct usb_bus	*bus = udev->bus;
1680 		if (bus && bus->op->hub_suspend) {
1681 			status = bus->op->hub_suspend (bus);
1682 			if (status == 0) {
1683 				dev_dbg(&udev->dev, "usb suspend\n");
1684 				usb_set_device_state(udev,
1685 						USB_STATE_SUSPENDED);
1686 			}
1687 		} else
1688 			status = -EOPNOTSUPP;
1689 	} else
1690 		status = hub_port_suspend(hdev_to_hub(udev->parent), port1,
1691 				udev);
1692 
1693 	if (status == 0)
1694 		udev->dev.power.power_state = state;
1695 	return status;
1696 }
1697 
1698 /**
1699  * usb_suspend_device - suspend a usb device
1700  * @udev: device that's no longer in active use
1701  * @state: PMSG_SUSPEND to suspend
1702  * Context: must be able to sleep; device not locked
1703  *
1704  * Suspends a USB device that isn't in active use, conserving power.
1705  * Devices may wake out of a suspend, if anything important happens,
1706  * using the remote wakeup mechanism.  They may also be taken out of
1707  * suspend by the host, using usb_resume_device().  It's also routine
1708  * to disconnect devices while they are suspended.
1709  *
1710  * Suspending OTG devices may trigger HNP, if that's been enabled
1711  * between a pair of dual-role devices.  That will change roles, such
1712  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1713  *
1714  * Returns 0 on success, else negative errno.
1715  */
1716 int usb_suspend_device(struct usb_device *udev, pm_message_t state)
1717 {
1718 	int	port1, status;
1719 
1720 	port1 = locktree(udev);
1721 	if (port1 < 0)
1722 		return port1;
1723 
1724 	status = __usb_suspend_device(udev, port1, state);
1725 	usb_unlock_device(udev);
1726 	return status;
1727 }
1728 
1729 /*
1730  * hardware resume signaling is finished, either because of selective
1731  * resume (by host) or remote wakeup (by device) ... now see what changed
1732  * in the tree that's rooted at this device.
1733  */
1734 static int finish_port_resume(struct usb_device *udev)
1735 {
1736 	int	status;
1737 	u16	devstatus;
1738 
1739 	/* caller owns the udev device lock */
1740 	dev_dbg(&udev->dev, "usb resume\n");
1741 
1742 	/* usb ch9 identifies four variants of SUSPENDED, based on what
1743 	 * state the device resumes to.  Linux currently won't see the
1744 	 * first two on the host side; they'd be inside hub_port_init()
1745 	 * during many timeouts, but khubd can't suspend until later.
1746 	 */
1747 	usb_set_device_state(udev, udev->actconfig
1748 			? USB_STATE_CONFIGURED
1749 			: USB_STATE_ADDRESS);
1750 	udev->dev.power.power_state = PMSG_ON;
1751 
1752  	/* 10.5.4.5 says be sure devices in the tree are still there.
1753  	 * For now let's assume the device didn't go crazy on resume,
1754 	 * and device drivers will know about any resume quirks.
1755 	 */
1756 	status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1757 	if (status < 0)
1758 		dev_dbg(&udev->dev,
1759 			"gone after usb resume? status %d\n",
1760 			status);
1761 	else if (udev->actconfig) {
1762 		unsigned	i;
1763 
1764 		le16_to_cpus(&devstatus);
1765 		if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
1766 			status = usb_control_msg(udev,
1767 					usb_sndctrlpipe(udev, 0),
1768 					USB_REQ_CLEAR_FEATURE,
1769 						USB_RECIP_DEVICE,
1770 					USB_DEVICE_REMOTE_WAKEUP, 0,
1771 					NULL, 0,
1772 					USB_CTRL_SET_TIMEOUT);
1773 			if (status) {
1774 				dev_dbg(&udev->dev, "disable remote "
1775 					"wakeup, status %d\n", status);
1776 				status = 0;
1777 			}
1778 		}
1779 
1780 		/* resume interface drivers; if this is a hub, it
1781 		 * resumes the child devices
1782 		 */
1783 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1784 			struct usb_interface	*intf;
1785 			struct usb_driver	*driver;
1786 
1787 			intf = udev->actconfig->interface[i];
1788 			if (intf->dev.power.power_state.event == PM_EVENT_ON)
1789 				continue;
1790 			if (!intf->dev.driver) {
1791 				/* FIXME maybe force to alt 0 */
1792 				continue;
1793 			}
1794 			driver = to_usb_driver(intf->dev.driver);
1795 
1796 			/* bus_rescan_devices() may rebind drivers */
1797 			if (!driver->resume)
1798 				continue;
1799 
1800 			/* can we do better than just logging errors? */
1801 			status = driver->resume(intf);
1802 			if (intf->dev.power.power_state.event != PM_EVENT_ON
1803 					|| status)
1804 				dev_dbg(&intf->dev,
1805 					"resume fail, state %d code %d\n",
1806 					intf->dev.power.power_state.event, status);
1807 		}
1808 		status = 0;
1809 
1810 	} else if (udev->devnum <= 0) {
1811 		dev_dbg(&udev->dev, "bogus resume!\n");
1812 		status = -EINVAL;
1813 	}
1814 	return status;
1815 }
1816 
1817 static int
1818 hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
1819 {
1820 	int	status;
1821 
1822 	// dev_dbg(hub->intfdev, "resume port %d\n", port1);
1823 
1824 	/* see 7.1.7.7; affects power usage, but not budgeting */
1825 	status = clear_port_feature(hub->hdev,
1826 			port1, USB_PORT_FEAT_SUSPEND);
1827 	if (status) {
1828 		dev_dbg(hub->intfdev,
1829 			"can't resume port %d, status %d\n",
1830 			port1, status);
1831 	} else {
1832 		u16		devstatus;
1833 		u16		portchange;
1834 
1835 		/* drive resume for at least 20 msec */
1836 		if (udev)
1837 			dev_dbg(&udev->dev, "RESUME\n");
1838 		msleep(25);
1839 
1840 #define LIVE_FLAGS	( USB_PORT_STAT_POWER \
1841 			| USB_PORT_STAT_ENABLE \
1842 			| USB_PORT_STAT_CONNECTION)
1843 
1844 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
1845 		 * stop resume signaling.  Then finish the resume
1846 		 * sequence.
1847 		 */
1848 		devstatus = portchange = 0;
1849 		status = hub_port_status(hub, port1,
1850 				&devstatus, &portchange);
1851 		if (status < 0
1852 				|| (devstatus & LIVE_FLAGS) != LIVE_FLAGS
1853 				|| (devstatus & USB_PORT_STAT_SUSPEND) != 0
1854 				) {
1855 			dev_dbg(hub->intfdev,
1856 				"port %d status %04x.%04x after resume, %d\n",
1857 				port1, portchange, devstatus, status);
1858 		} else {
1859 			/* TRSMRCY = 10 msec */
1860 			msleep(10);
1861 			if (udev)
1862 				status = finish_port_resume(udev);
1863 		}
1864 	}
1865 	if (status < 0)
1866 		hub_port_logical_disconnect(hub, port1);
1867 
1868 	return status;
1869 }
1870 
1871 static int hub_resume (struct usb_interface *intf);
1872 
1873 /**
1874  * usb_resume_device - re-activate a suspended usb device
1875  * @udev: device to re-activate
1876  * Context: must be able to sleep; device not locked
1877  *
1878  * This will re-activate the suspended device, increasing power usage
1879  * while letting drivers communicate again with its endpoints.
1880  * USB resume explicitly guarantees that the power session between
1881  * the host and the device is the same as it was when the device
1882  * suspended.
1883  *
1884  * Returns 0 on success, else negative errno.
1885  */
1886 int usb_resume_device(struct usb_device *udev)
1887 {
1888 	int	port1, status;
1889 
1890 	port1 = locktree(udev);
1891 	if (port1 < 0)
1892 		return port1;
1893 
1894 	/* "global resume" of the HC-to-USB interface (root hub), or
1895 	 * selective resume of one hub-to-device port
1896 	 */
1897 	if (!udev->parent) {
1898 		struct usb_bus	*bus = udev->bus;
1899 		if (bus && bus->op->hub_resume) {
1900 			status = bus->op->hub_resume (bus);
1901 		} else
1902 			status = -EOPNOTSUPP;
1903 		if (status == 0) {
1904 			dev_dbg(&udev->dev, "usb resume\n");
1905 			/* TRSMRCY = 10 msec */
1906 			msleep(10);
1907 			usb_set_device_state (udev, USB_STATE_CONFIGURED);
1908 			udev->dev.power.power_state = PMSG_ON;
1909 			status = hub_resume (udev
1910 					->actconfig->interface[0]);
1911 		}
1912 	} else if (udev->state == USB_STATE_SUSPENDED) {
1913 		// NOTE this fails if parent is also suspended...
1914 		status = hub_port_resume(hdev_to_hub(udev->parent),
1915 				port1, udev);
1916 	} else {
1917 		status = 0;
1918 	}
1919 	if (status < 0) {
1920 		dev_dbg(&udev->dev, "can't resume, status %d\n",
1921 			status);
1922 	}
1923 
1924 	usb_unlock_device(udev);
1925 
1926 	/* rebind drivers that had no suspend() */
1927 	if (status == 0) {
1928 		usb_lock_all_devices();
1929 		bus_rescan_devices(&usb_bus_type);
1930 		usb_unlock_all_devices();
1931 	}
1932 	return status;
1933 }
1934 
1935 static int remote_wakeup(struct usb_device *udev)
1936 {
1937 	int	status = 0;
1938 
1939 	/* don't repeat RESUME sequence if this device
1940 	 * was already woken up by some other task
1941 	 */
1942 	down(&udev->serialize);
1943 	if (udev->state == USB_STATE_SUSPENDED) {
1944 		dev_dbg(&udev->dev, "RESUME (wakeup)\n");
1945 		/* TRSMRCY = 10 msec */
1946 		msleep(10);
1947 		status = finish_port_resume(udev);
1948 	}
1949 	up(&udev->serialize);
1950 	return status;
1951 }
1952 
1953 static int hub_suspend(struct usb_interface *intf, pm_message_t state)
1954 {
1955 	struct usb_hub		*hub = usb_get_intfdata (intf);
1956 	struct usb_device	*hdev = hub->hdev;
1957 	unsigned		port1;
1958 	int			status;
1959 
1960 	/* stop khubd and related activity */
1961 	hub_quiesce(hub);
1962 
1963 	/* then suspend every port */
1964 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1965 		struct usb_device	*udev;
1966 
1967 		udev = hdev->children [port1-1];
1968 		if (!udev)
1969 			continue;
1970 		down(&udev->serialize);
1971 		status = __usb_suspend_device(udev, port1, state);
1972 		up(&udev->serialize);
1973 		if (status < 0)
1974 			dev_dbg(&intf->dev, "suspend port %d --> %d\n",
1975 				port1, status);
1976 	}
1977 
1978 	intf->dev.power.power_state = state;
1979 	return 0;
1980 }
1981 
1982 static int hub_resume(struct usb_interface *intf)
1983 {
1984 	struct usb_device	*hdev = interface_to_usbdev(intf);
1985 	struct usb_hub		*hub = usb_get_intfdata (intf);
1986 	unsigned		port1;
1987 	int			status;
1988 
1989 	if (intf->dev.power.power_state.event == PM_EVENT_ON)
1990 		return 0;
1991 
1992 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1993 		struct usb_device	*udev;
1994 		u16			portstat, portchange;
1995 
1996 		udev = hdev->children [port1-1];
1997 		status = hub_port_status(hub, port1, &portstat, &portchange);
1998 		if (status == 0) {
1999 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
2000 				clear_port_feature(hdev, port1,
2001 					USB_PORT_FEAT_C_SUSPEND);
2002 				portchange &= ~USB_PORT_STAT_C_SUSPEND;
2003 			}
2004 
2005 			/* let khubd handle disconnects etc */
2006 			if (portchange)
2007 				continue;
2008 		}
2009 
2010 		if (!udev || status < 0)
2011 			continue;
2012 		down (&udev->serialize);
2013 		if (portstat & USB_PORT_STAT_SUSPEND)
2014 			status = hub_port_resume(hub, port1, udev);
2015 		else {
2016 			status = finish_port_resume(udev);
2017 			if (status < 0) {
2018 				dev_dbg(&intf->dev, "resume port %d --> %d\n",
2019 					port1, status);
2020 				hub_port_logical_disconnect(hub, port1);
2021 			}
2022 		}
2023 		up(&udev->serialize);
2024 	}
2025 	intf->dev.power.power_state = PMSG_ON;
2026 
2027 	hub->resume_root_hub = 0;
2028 	hub_activate(hub);
2029 	return 0;
2030 }
2031 
2032 void usb_resume_root_hub(struct usb_device *hdev)
2033 {
2034 	struct usb_hub *hub = hdev_to_hub(hdev);
2035 
2036 	hub->resume_root_hub = 1;
2037 	kick_khubd(hub);
2038 }
2039 
2040 #else	/* !CONFIG_USB_SUSPEND */
2041 
2042 int usb_suspend_device(struct usb_device *udev, pm_message_t state)
2043 {
2044 	return 0;
2045 }
2046 
2047 int usb_resume_device(struct usb_device *udev)
2048 {
2049 	return 0;
2050 }
2051 
2052 #define	hub_suspend		NULL
2053 #define	hub_resume		NULL
2054 #define	remote_wakeup(x)	0
2055 
2056 #endif	/* CONFIG_USB_SUSPEND */
2057 
2058 EXPORT_SYMBOL(usb_suspend_device);
2059 EXPORT_SYMBOL(usb_resume_device);
2060 
2061 
2062 
2063 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2064  *
2065  * Between connect detection and reset signaling there must be a delay
2066  * of 100ms at least for debounce and power-settling.  The corresponding
2067  * timer shall restart whenever the downstream port detects a disconnect.
2068  *
2069  * Apparently there are some bluetooth and irda-dongles and a number of
2070  * low-speed devices for which this debounce period may last over a second.
2071  * Not covered by the spec - but easy to deal with.
2072  *
2073  * This implementation uses a 1500ms total debounce timeout; if the
2074  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
2075  * every 25ms for transient disconnects.  When the port status has been
2076  * unchanged for 100ms it returns the port status.
2077  */
2078 
2079 #define HUB_DEBOUNCE_TIMEOUT	1500
2080 #define HUB_DEBOUNCE_STEP	  25
2081 #define HUB_DEBOUNCE_STABLE	 100
2082 
2083 static int hub_port_debounce(struct usb_hub *hub, int port1)
2084 {
2085 	int ret;
2086 	int total_time, stable_time = 0;
2087 	u16 portchange, portstatus;
2088 	unsigned connection = 0xffff;
2089 
2090 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2091 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
2092 		if (ret < 0)
2093 			return ret;
2094 
2095 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2096 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2097 			stable_time += HUB_DEBOUNCE_STEP;
2098 			if (stable_time >= HUB_DEBOUNCE_STABLE)
2099 				break;
2100 		} else {
2101 			stable_time = 0;
2102 			connection = portstatus & USB_PORT_STAT_CONNECTION;
2103 		}
2104 
2105 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
2106 			clear_port_feature(hub->hdev, port1,
2107 					USB_PORT_FEAT_C_CONNECTION);
2108 		}
2109 
2110 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2111 			break;
2112 		msleep(HUB_DEBOUNCE_STEP);
2113 	}
2114 
2115 	dev_dbg (hub->intfdev,
2116 		"debounce: port %d: total %dms stable %dms status 0x%x\n",
2117 		port1, total_time, stable_time, portstatus);
2118 
2119 	if (stable_time < HUB_DEBOUNCE_STABLE)
2120 		return -ETIMEDOUT;
2121 	return portstatus;
2122 }
2123 
2124 static void ep0_reinit(struct usb_device *udev)
2125 {
2126 	usb_disable_endpoint(udev, 0 + USB_DIR_IN);
2127 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
2128 	udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
2129 }
2130 
2131 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
2132 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
2133 
2134 static int hub_set_address(struct usb_device *udev)
2135 {
2136 	int retval;
2137 
2138 	if (udev->devnum == 0)
2139 		return -EINVAL;
2140 	if (udev->state == USB_STATE_ADDRESS)
2141 		return 0;
2142 	if (udev->state != USB_STATE_DEFAULT)
2143 		return -EINVAL;
2144 	retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2145 		USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
2146 		NULL, 0, USB_CTRL_SET_TIMEOUT);
2147 	if (retval == 0) {
2148 		usb_set_device_state(udev, USB_STATE_ADDRESS);
2149 		ep0_reinit(udev);
2150 	}
2151 	return retval;
2152 }
2153 
2154 /* Reset device, (re)assign address, get device descriptor.
2155  * Device connection must be stable, no more debouncing needed.
2156  * Returns device in USB_STATE_ADDRESS, except on error.
2157  *
2158  * If this is called for an already-existing device (as part of
2159  * usb_reset_device), the caller must own the device lock.  For a
2160  * newly detected device that is not accessible through any global
2161  * pointers, it's not necessary to lock the device.
2162  */
2163 static int
2164 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2165 		int retry_counter)
2166 {
2167 	static DECLARE_MUTEX(usb_address0_sem);
2168 
2169 	struct usb_device	*hdev = hub->hdev;
2170 	int			i, j, retval;
2171 	unsigned		delay = HUB_SHORT_RESET_TIME;
2172 	enum usb_device_speed	oldspeed = udev->speed;
2173 
2174 	/* root hub ports have a slightly longer reset period
2175 	 * (from USB 2.0 spec, section 7.1.7.5)
2176 	 */
2177 	if (!hdev->parent) {
2178 		delay = HUB_ROOT_RESET_TIME;
2179 		if (port1 == hdev->bus->otg_port)
2180 			hdev->bus->b_hnp_enable = 0;
2181 	}
2182 
2183 	/* Some low speed devices have problems with the quick delay, so */
2184 	/*  be a bit pessimistic with those devices. RHbug #23670 */
2185 	if (oldspeed == USB_SPEED_LOW)
2186 		delay = HUB_LONG_RESET_TIME;
2187 
2188 	down(&usb_address0_sem);
2189 
2190 	/* Reset the device; full speed may morph to high speed */
2191 	retval = hub_port_reset(hub, port1, udev, delay);
2192 	if (retval < 0)		/* error or disconnect */
2193 		goto fail;
2194 				/* success, speed is known */
2195 	retval = -ENODEV;
2196 
2197 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2198 		dev_dbg(&udev->dev, "device reset changed speed!\n");
2199 		goto fail;
2200 	}
2201 	oldspeed = udev->speed;
2202 
2203 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2204 	 * it's fixed size except for full speed devices.
2205 	 */
2206 	switch (udev->speed) {
2207 	case USB_SPEED_HIGH:		/* fixed at 64 */
2208 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2209 		break;
2210 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
2211 		/* to determine the ep0 maxpacket size, try to read
2212 		 * the device descriptor to get bMaxPacketSize0 and
2213 		 * then correct our initial guess.
2214 		 */
2215 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2216 		break;
2217 	case USB_SPEED_LOW:		/* fixed at 8 */
2218 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2219 		break;
2220 	default:
2221 		goto fail;
2222 	}
2223 
2224 	dev_info (&udev->dev,
2225 			"%s %s speed USB device using %s and address %d\n",
2226 			(udev->config) ? "reset" : "new",
2227 			({ char *speed; switch (udev->speed) {
2228 			case USB_SPEED_LOW:	speed = "low";	break;
2229 			case USB_SPEED_FULL:	speed = "full";	break;
2230 			case USB_SPEED_HIGH:	speed = "high";	break;
2231 			default: 		speed = "?";	break;
2232 			}; speed;}),
2233 			udev->bus->controller->driver->name,
2234 			udev->devnum);
2235 
2236 	/* Set up TT records, if needed  */
2237 	if (hdev->tt) {
2238 		udev->tt = hdev->tt;
2239 		udev->ttport = hdev->ttport;
2240 	} else if (udev->speed != USB_SPEED_HIGH
2241 			&& hdev->speed == USB_SPEED_HIGH) {
2242 		udev->tt = &hub->tt;
2243 		udev->ttport = port1;
2244 	}
2245 
2246 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2247 	 * Because device hardware and firmware is sometimes buggy in
2248 	 * this area, and this is how Linux has done it for ages.
2249 	 * Change it cautiously.
2250 	 *
2251 	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2252 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2253 	 * so it may help with some non-standards-compliant devices.
2254 	 * Otherwise we start with SET_ADDRESS and then try to read the
2255 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2256 	 * value.
2257 	 */
2258 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2259 		if (USE_NEW_SCHEME(retry_counter)) {
2260 			struct usb_device_descriptor *buf;
2261 			int r = 0;
2262 
2263 #define GET_DESCRIPTOR_BUFSIZE	64
2264 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2265 			if (!buf) {
2266 				retval = -ENOMEM;
2267 				continue;
2268 			}
2269 
2270 			/* Use a short timeout the first time through,
2271 			 * so that recalcitrant full-speed devices with
2272 			 * 8- or 16-byte ep0-maxpackets won't slow things
2273 			 * down tremendously by NAKing the unexpectedly
2274 			 * early status stage.  Also, retry on all errors;
2275 			 * some devices are flakey.
2276 			 */
2277 			for (j = 0; j < 3; ++j) {
2278 				buf->bMaxPacketSize0 = 0;
2279 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2280 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2281 					USB_DT_DEVICE << 8, 0,
2282 					buf, GET_DESCRIPTOR_BUFSIZE,
2283 					(i ? USB_CTRL_GET_TIMEOUT : 1000));
2284 				switch (buf->bMaxPacketSize0) {
2285 				case 8: case 16: case 32: case 64:
2286 					if (buf->bDescriptorType ==
2287 							USB_DT_DEVICE) {
2288 						r = 0;
2289 						break;
2290 					}
2291 					/* FALL THROUGH */
2292 				default:
2293 					if (r == 0)
2294 						r = -EPROTO;
2295 					break;
2296 				}
2297 				if (r == 0)
2298 					break;
2299 			}
2300 			udev->descriptor.bMaxPacketSize0 =
2301 					buf->bMaxPacketSize0;
2302 			kfree(buf);
2303 
2304 			retval = hub_port_reset(hub, port1, udev, delay);
2305 			if (retval < 0)		/* error or disconnect */
2306 				goto fail;
2307 			if (oldspeed != udev->speed) {
2308 				dev_dbg(&udev->dev,
2309 					"device reset changed speed!\n");
2310 				retval = -ENODEV;
2311 				goto fail;
2312 			}
2313 			if (r) {
2314 				dev_err(&udev->dev, "device descriptor "
2315 						"read/%s, error %d\n",
2316 						"64", r);
2317 				retval = -EMSGSIZE;
2318 				continue;
2319 			}
2320 #undef GET_DESCRIPTOR_BUFSIZE
2321 		}
2322 
2323 		for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2324 			retval = hub_set_address(udev);
2325 			if (retval >= 0)
2326 				break;
2327 			msleep(200);
2328 		}
2329 		if (retval < 0) {
2330 			dev_err(&udev->dev,
2331 				"device not accepting address %d, error %d\n",
2332 				udev->devnum, retval);
2333 			goto fail;
2334 		}
2335 
2336 		/* cope with hardware quirkiness:
2337 		 *  - let SET_ADDRESS settle, some device hardware wants it
2338 		 *  - read ep0 maxpacket even for high and low speed,
2339   		 */
2340 		msleep(10);
2341 		if (USE_NEW_SCHEME(retry_counter))
2342 			break;
2343 
2344 		retval = usb_get_device_descriptor(udev, 8);
2345 		if (retval < 8) {
2346 			dev_err(&udev->dev, "device descriptor "
2347 					"read/%s, error %d\n",
2348 					"8", retval);
2349 			if (retval >= 0)
2350 				retval = -EMSGSIZE;
2351 		} else {
2352 			retval = 0;
2353 			break;
2354 		}
2355 	}
2356 	if (retval)
2357 		goto fail;
2358 
2359 	i = udev->descriptor.bMaxPacketSize0;
2360 	if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2361 		if (udev->speed != USB_SPEED_FULL ||
2362 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
2363 			dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2364 			retval = -EMSGSIZE;
2365 			goto fail;
2366 		}
2367 		dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2368 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2369 		ep0_reinit(udev);
2370 	}
2371 
2372 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2373 	if (retval < (signed)sizeof(udev->descriptor)) {
2374 		dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2375 			"all", retval);
2376 		if (retval >= 0)
2377 			retval = -ENOMSG;
2378 		goto fail;
2379 	}
2380 
2381 	retval = 0;
2382 
2383 fail:
2384 	if (retval)
2385 		hub_port_disable(hub, port1, 0);
2386 	up(&usb_address0_sem);
2387 	return retval;
2388 }
2389 
2390 static void
2391 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2392 {
2393 	struct usb_qualifier_descriptor	*qual;
2394 	int				status;
2395 
2396 	qual = kmalloc (sizeof *qual, SLAB_KERNEL);
2397 	if (qual == NULL)
2398 		return;
2399 
2400 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2401 			qual, sizeof *qual);
2402 	if (status == sizeof *qual) {
2403 		dev_info(&udev->dev, "not running at top speed; "
2404 			"connect to a high speed hub\n");
2405 		/* hub LEDs are probably harder to miss than syslog */
2406 		if (hub->has_indicators) {
2407 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2408 			schedule_work (&hub->leds);
2409 		}
2410 	}
2411 	kfree(qual);
2412 }
2413 
2414 static unsigned
2415 hub_power_remaining (struct usb_hub *hub)
2416 {
2417 	struct usb_device *hdev = hub->hdev;
2418 	int remaining;
2419 	unsigned i;
2420 
2421 	remaining = hub->power_budget;
2422 	if (!remaining)		/* self-powered */
2423 		return 0;
2424 
2425 	for (i = 0; i < hdev->maxchild; i++) {
2426 		struct usb_device	*udev = hdev->children[i];
2427 		int			delta, ceiling;
2428 
2429 		if (!udev)
2430 			continue;
2431 
2432 		/* 100mA per-port ceiling, or 8mA for OTG ports */
2433 		if (i != (udev->bus->otg_port - 1) || hdev->parent)
2434 			ceiling = 50;
2435 		else
2436 			ceiling = 4;
2437 
2438 		if (udev->actconfig)
2439 			delta = udev->actconfig->desc.bMaxPower;
2440 		else
2441 			delta = ceiling;
2442 		// dev_dbg(&udev->dev, "budgeted %dmA\n", 2 * delta);
2443 		if (delta > ceiling)
2444 			dev_warn(&udev->dev, "%dmA over %dmA budget!\n",
2445 				2 * (delta - ceiling), 2 * ceiling);
2446 		remaining -= delta;
2447 	}
2448 	if (remaining < 0) {
2449 		dev_warn(hub->intfdev,
2450 			"%dmA over power budget!\n",
2451 			-2 * remaining);
2452 		remaining = 0;
2453 	}
2454 	return remaining;
2455 }
2456 
2457 /* Handle physical or logical connection change events.
2458  * This routine is called when:
2459  * 	a port connection-change occurs;
2460  *	a port enable-change occurs (often caused by EMI);
2461  *	usb_reset_device() encounters changed descriptors (as from
2462  *		a firmware download)
2463  * caller already locked the hub
2464  */
2465 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2466 					u16 portstatus, u16 portchange)
2467 {
2468 	struct usb_device *hdev = hub->hdev;
2469 	struct device *hub_dev = hub->intfdev;
2470 	int status, i;
2471 
2472 	dev_dbg (hub_dev,
2473 		"port %d, status %04x, change %04x, %s\n",
2474 		port1, portstatus, portchange, portspeed (portstatus));
2475 
2476 	if (hub->has_indicators) {
2477 		set_port_led(hub, port1, HUB_LED_AUTO);
2478 		hub->indicator[port1-1] = INDICATOR_AUTO;
2479 	}
2480 
2481 	/* Disconnect any existing devices under this port */
2482 	if (hdev->children[port1-1])
2483 		usb_disconnect(&hdev->children[port1-1]);
2484 	clear_bit(port1, hub->change_bits);
2485 
2486 #ifdef	CONFIG_USB_OTG
2487 	/* during HNP, don't repeat the debounce */
2488 	if (hdev->bus->is_b_host)
2489 		portchange &= ~USB_PORT_STAT_C_CONNECTION;
2490 #endif
2491 
2492 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
2493 		status = hub_port_debounce(hub, port1);
2494 		if (status < 0) {
2495 			dev_err (hub_dev,
2496 				"connect-debounce failed, port %d disabled\n",
2497 				port1);
2498 			goto done;
2499 		}
2500 		portstatus = status;
2501 	}
2502 
2503 	/* Return now if nothing is connected */
2504 	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2505 
2506 		/* maybe switch power back on (e.g. root hub was reset) */
2507 		if ((hub->descriptor->wHubCharacteristics
2508 					& HUB_CHAR_LPSM) < 2
2509 				&& !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2510 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2511 
2512 		if (portstatus & USB_PORT_STAT_ENABLE)
2513   			goto done;
2514 		return;
2515 	}
2516 
2517 #ifdef  CONFIG_USB_SUSPEND
2518 	/* If something is connected, but the port is suspended, wake it up. */
2519 	if (portstatus & USB_PORT_STAT_SUSPEND) {
2520 		status = hub_port_resume(hub, port1, NULL);
2521 		if (status < 0) {
2522 			dev_dbg(hub_dev,
2523 				"can't clear suspend on port %d; %d\n",
2524 				port1, status);
2525 			goto done;
2526 		}
2527 	}
2528 #endif
2529 
2530 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
2531 		struct usb_device *udev;
2532 
2533 		/* reallocate for each attempt, since references
2534 		 * to the previous one can escape in various ways
2535 		 */
2536 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
2537 		if (!udev) {
2538 			dev_err (hub_dev,
2539 				"couldn't allocate port %d usb_device\n",
2540 				port1);
2541 			goto done;
2542 		}
2543 
2544 		usb_set_device_state(udev, USB_STATE_POWERED);
2545 		udev->speed = USB_SPEED_UNKNOWN;
2546 
2547 		/* set the address */
2548 		choose_address(udev);
2549 		if (udev->devnum <= 0) {
2550 			status = -ENOTCONN;	/* Don't retry */
2551 			goto loop;
2552 		}
2553 
2554 		/* reset and get descriptor */
2555 		status = hub_port_init(hub, udev, port1, i);
2556 		if (status < 0)
2557 			goto loop;
2558 
2559 		/* consecutive bus-powered hubs aren't reliable; they can
2560 		 * violate the voltage drop budget.  if the new child has
2561 		 * a "powered" LED, users should notice we didn't enable it
2562 		 * (without reading syslog), even without per-port LEDs
2563 		 * on the parent.
2564 		 */
2565 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2566 				&& hub->power_budget) {
2567 			u16	devstat;
2568 
2569 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2570 					&devstat);
2571 			if (status < 0) {
2572 				dev_dbg(&udev->dev, "get status %d ?\n", status);
2573 				goto loop_disable;
2574 			}
2575 			cpu_to_le16s(&devstat);
2576 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2577 				dev_err(&udev->dev,
2578 					"can't connect bus-powered hub "
2579 					"to this port\n");
2580 				if (hub->has_indicators) {
2581 					hub->indicator[port1-1] =
2582 						INDICATOR_AMBER_BLINK;
2583 					schedule_work (&hub->leds);
2584 				}
2585 				status = -ENOTCONN;	/* Don't retry */
2586 				goto loop_disable;
2587 			}
2588 		}
2589 
2590 		/* check for devices running slower than they could */
2591 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2592 				&& udev->speed == USB_SPEED_FULL
2593 				&& highspeed_hubs != 0)
2594 			check_highspeed (hub, udev, port1);
2595 
2596 		/* Store the parent's children[] pointer.  At this point
2597 		 * udev becomes globally accessible, although presumably
2598 		 * no one will look at it until hdev is unlocked.
2599 		 */
2600 		down (&udev->serialize);
2601 		status = 0;
2602 
2603 		/* We mustn't add new devices if the parent hub has
2604 		 * been disconnected; we would race with the
2605 		 * recursively_mark_NOTATTACHED() routine.
2606 		 */
2607 		spin_lock_irq(&device_state_lock);
2608 		if (hdev->state == USB_STATE_NOTATTACHED)
2609 			status = -ENOTCONN;
2610 		else
2611 			hdev->children[port1-1] = udev;
2612 		spin_unlock_irq(&device_state_lock);
2613 
2614 		/* Run it through the hoops (find a driver, etc) */
2615 		if (!status) {
2616 			status = usb_new_device(udev);
2617 			if (status) {
2618 				spin_lock_irq(&device_state_lock);
2619 				hdev->children[port1-1] = NULL;
2620 				spin_unlock_irq(&device_state_lock);
2621 			}
2622 		}
2623 
2624 		up (&udev->serialize);
2625 		if (status)
2626 			goto loop_disable;
2627 
2628 		status = hub_power_remaining(hub);
2629 		if (status)
2630 			dev_dbg(hub_dev,
2631 				"%dmA power budget left\n",
2632 				2 * status);
2633 
2634 		return;
2635 
2636 loop_disable:
2637 		hub_port_disable(hub, port1, 1);
2638 loop:
2639 		ep0_reinit(udev);
2640 		release_address(udev);
2641 		usb_put_dev(udev);
2642 		if (status == -ENOTCONN)
2643 			break;
2644 	}
2645 
2646 done:
2647 	hub_port_disable(hub, port1, 1);
2648 }
2649 
2650 static void hub_events(void)
2651 {
2652 	struct list_head *tmp;
2653 	struct usb_device *hdev;
2654 	struct usb_interface *intf;
2655 	struct usb_hub *hub;
2656 	struct device *hub_dev;
2657 	u16 hubstatus;
2658 	u16 hubchange;
2659 	u16 portstatus;
2660 	u16 portchange;
2661 	int i, ret;
2662 	int connect_change;
2663 
2664 	/*
2665 	 *  We restart the list every time to avoid a deadlock with
2666 	 * deleting hubs downstream from this one. This should be
2667 	 * safe since we delete the hub from the event list.
2668 	 * Not the most efficient, but avoids deadlocks.
2669 	 */
2670 	while (1) {
2671 
2672 		/* Grab the first entry at the beginning of the list */
2673 		spin_lock_irq(&hub_event_lock);
2674 		if (list_empty(&hub_event_list)) {
2675 			spin_unlock_irq(&hub_event_lock);
2676 			break;
2677 		}
2678 
2679 		tmp = hub_event_list.next;
2680 		list_del_init(tmp);
2681 
2682 		hub = list_entry(tmp, struct usb_hub, event_list);
2683 		hdev = hub->hdev;
2684 		intf = to_usb_interface(hub->intfdev);
2685 		hub_dev = &intf->dev;
2686 
2687 		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
2688 				hdev->state, hub->descriptor
2689 					? hub->descriptor->bNbrPorts
2690 					: 0,
2691 				/* NOTE: expects max 15 ports... */
2692 				(u16) hub->change_bits[0],
2693 				(u16) hub->event_bits[0]);
2694 
2695 		usb_get_intf(intf);
2696 		i = hub->resume_root_hub;
2697 		spin_unlock_irq(&hub_event_lock);
2698 
2699 		/* Is this is a root hub wanting to be resumed? */
2700 		if (i)
2701 			usb_resume_device(hdev);
2702 
2703 		/* Lock the device, then check to see if we were
2704 		 * disconnected while waiting for the lock to succeed. */
2705 		if (locktree(hdev) < 0) {
2706 			usb_put_intf(intf);
2707 			continue;
2708 		}
2709 		if (hub != usb_get_intfdata(intf))
2710 			goto loop;
2711 
2712 		/* If the hub has died, clean up after it */
2713 		if (hdev->state == USB_STATE_NOTATTACHED) {
2714 			hub_pre_reset(hub);
2715 			goto loop;
2716 		}
2717 
2718 		/* If this is an inactive or suspended hub, do nothing */
2719 		if (hub->quiescing)
2720 			goto loop;
2721 
2722 		if (hub->error) {
2723 			dev_dbg (hub_dev, "resetting for error %d\n",
2724 				hub->error);
2725 
2726 			ret = usb_reset_device(hdev);
2727 			if (ret) {
2728 				dev_dbg (hub_dev,
2729 					"error resetting hub: %d\n", ret);
2730 				goto loop;
2731 			}
2732 
2733 			hub->nerrors = 0;
2734 			hub->error = 0;
2735 		}
2736 
2737 		/* deal with port status changes */
2738 		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2739 			if (test_bit(i, hub->busy_bits))
2740 				continue;
2741 			connect_change = test_bit(i, hub->change_bits);
2742 			if (!test_and_clear_bit(i, hub->event_bits) &&
2743 					!connect_change && !hub->activating)
2744 				continue;
2745 
2746 			ret = hub_port_status(hub, i,
2747 					&portstatus, &portchange);
2748 			if (ret < 0)
2749 				continue;
2750 
2751 			if (hub->activating && !hdev->children[i-1] &&
2752 					(portstatus &
2753 						USB_PORT_STAT_CONNECTION))
2754 				connect_change = 1;
2755 
2756 			if (portchange & USB_PORT_STAT_C_CONNECTION) {
2757 				clear_port_feature(hdev, i,
2758 					USB_PORT_FEAT_C_CONNECTION);
2759 				connect_change = 1;
2760 			}
2761 
2762 			if (portchange & USB_PORT_STAT_C_ENABLE) {
2763 				if (!connect_change)
2764 					dev_dbg (hub_dev,
2765 						"port %d enable change, "
2766 						"status %08x\n",
2767 						i, portstatus);
2768 				clear_port_feature(hdev, i,
2769 					USB_PORT_FEAT_C_ENABLE);
2770 
2771 				/*
2772 				 * EM interference sometimes causes badly
2773 				 * shielded USB devices to be shutdown by
2774 				 * the hub, this hack enables them again.
2775 				 * Works at least with mouse driver.
2776 				 */
2777 				if (!(portstatus & USB_PORT_STAT_ENABLE)
2778 				    && !connect_change
2779 				    && hdev->children[i-1]) {
2780 					dev_err (hub_dev,
2781 					    "port %i "
2782 					    "disabled by hub (EMI?), "
2783 					    "re-enabling...\n",
2784 						i);
2785 					connect_change = 1;
2786 				}
2787 			}
2788 
2789 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
2790 				clear_port_feature(hdev, i,
2791 					USB_PORT_FEAT_C_SUSPEND);
2792 				if (hdev->children[i-1]) {
2793 					ret = remote_wakeup(hdev->
2794 							children[i-1]);
2795 					if (ret < 0)
2796 						connect_change = 1;
2797 				} else {
2798 					ret = -ENODEV;
2799 					hub_port_disable(hub, i, 1);
2800 				}
2801 				dev_dbg (hub_dev,
2802 					"resume on port %d, status %d\n",
2803 					i, ret);
2804 			}
2805 
2806 			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2807 				dev_err (hub_dev,
2808 					"over-current change on port %d\n",
2809 					i);
2810 				clear_port_feature(hdev, i,
2811 					USB_PORT_FEAT_C_OVER_CURRENT);
2812 				hub_power_on(hub);
2813 			}
2814 
2815 			if (portchange & USB_PORT_STAT_C_RESET) {
2816 				dev_dbg (hub_dev,
2817 					"reset change on port %d\n",
2818 					i);
2819 				clear_port_feature(hdev, i,
2820 					USB_PORT_FEAT_C_RESET);
2821 			}
2822 
2823 			if (connect_change)
2824 				hub_port_connect_change(hub, i,
2825 						portstatus, portchange);
2826 		} /* end for i */
2827 
2828 		/* deal with hub status changes */
2829 		if (test_and_clear_bit(0, hub->event_bits) == 0)
2830 			;	/* do nothing */
2831 		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2832 			dev_err (hub_dev, "get_hub_status failed\n");
2833 		else {
2834 			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2835 				dev_dbg (hub_dev, "power change\n");
2836 				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2837 			}
2838 			if (hubchange & HUB_CHANGE_OVERCURRENT) {
2839 				dev_dbg (hub_dev, "overcurrent change\n");
2840 				msleep(500);	/* Cool down */
2841 				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2842                         	hub_power_on(hub);
2843 			}
2844 		}
2845 
2846 		hub->activating = 0;
2847 
2848 		/* If this is a root hub, tell the HCD it's okay to
2849 		 * re-enable port-change interrupts now. */
2850 		if (!hdev->parent)
2851 			usb_enable_root_hub_irq(hdev->bus);
2852 
2853 loop:
2854 		usb_unlock_device(hdev);
2855 		usb_put_intf(intf);
2856 
2857         } /* end while (1) */
2858 }
2859 
2860 static int hub_thread(void *__unused)
2861 {
2862 	do {
2863 		hub_events();
2864 		wait_event_interruptible(khubd_wait,
2865 				!list_empty(&hub_event_list) ||
2866 				kthread_should_stop());
2867 		try_to_freeze();
2868 	} while (!kthread_should_stop() || !list_empty(&hub_event_list));
2869 
2870 	pr_debug("%s: khubd exiting\n", usbcore_name);
2871 	return 0;
2872 }
2873 
2874 static struct usb_device_id hub_id_table [] = {
2875     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2876       .bDeviceClass = USB_CLASS_HUB},
2877     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2878       .bInterfaceClass = USB_CLASS_HUB},
2879     { }						/* Terminating entry */
2880 };
2881 
2882 MODULE_DEVICE_TABLE (usb, hub_id_table);
2883 
2884 static struct usb_driver hub_driver = {
2885 	.owner =	THIS_MODULE,
2886 	.name =		"hub",
2887 	.probe =	hub_probe,
2888 	.disconnect =	hub_disconnect,
2889 	.suspend =	hub_suspend,
2890 	.resume =	hub_resume,
2891 	.ioctl =	hub_ioctl,
2892 	.id_table =	hub_id_table,
2893 };
2894 
2895 int usb_hub_init(void)
2896 {
2897 	if (usb_register(&hub_driver) < 0) {
2898 		printk(KERN_ERR "%s: can't register hub driver\n",
2899 			usbcore_name);
2900 		return -1;
2901 	}
2902 
2903 	khubd_task = kthread_run(hub_thread, NULL, "khubd");
2904 	if (!IS_ERR(khubd_task))
2905 		return 0;
2906 
2907 	/* Fall through if kernel_thread failed */
2908 	usb_deregister(&hub_driver);
2909 	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2910 
2911 	return -1;
2912 }
2913 
2914 void usb_hub_cleanup(void)
2915 {
2916 	kthread_stop(khubd_task);
2917 
2918 	/*
2919 	 * Hub resources are freed for us by usb_deregister. It calls
2920 	 * usb_driver_purge on every device which in turn calls that
2921 	 * devices disconnect function if it is using this driver.
2922 	 * The hub_disconnect function takes care of releasing the
2923 	 * individual hub resources. -greg
2924 	 */
2925 	usb_deregister(&hub_driver);
2926 } /* usb_hub_cleanup() */
2927 
2928 static int config_descriptors_changed(struct usb_device *udev)
2929 {
2930 	unsigned			index;
2931 	unsigned			len = 0;
2932 	struct usb_config_descriptor	*buf;
2933 
2934 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2935 		if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2936 			len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2937 	}
2938 	buf = kmalloc (len, SLAB_KERNEL);
2939 	if (buf == NULL) {
2940 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2941 		/* assume the worst */
2942 		return 1;
2943 	}
2944 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2945 		int length;
2946 		int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2947 
2948 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2949 				old_length);
2950 		if (length < old_length) {
2951 			dev_dbg(&udev->dev, "config index %d, error %d\n",
2952 					index, length);
2953 			break;
2954 		}
2955 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
2956 				!= 0) {
2957 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2958 				index, buf->bConfigurationValue);
2959 			break;
2960 		}
2961 	}
2962 	kfree(buf);
2963 	return index != udev->descriptor.bNumConfigurations;
2964 }
2965 
2966 /**
2967  * usb_reset_device - perform a USB port reset to reinitialize a device
2968  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2969  *
2970  * WARNING - don't reset any device unless drivers for all of its
2971  * interfaces are expecting that reset!  Maybe some driver->reset()
2972  * method should eventually help ensure sufficient cooperation.
2973  *
2974  * Do a port reset, reassign the device's address, and establish its
2975  * former operating configuration.  If the reset fails, or the device's
2976  * descriptors change from their values before the reset, or the original
2977  * configuration and altsettings cannot be restored, a flag will be set
2978  * telling khubd to pretend the device has been disconnected and then
2979  * re-connected.  All drivers will be unbound, and the device will be
2980  * re-enumerated and probed all over again.
2981  *
2982  * Returns 0 if the reset succeeded, -ENODEV if the device has been
2983  * flagged for logical disconnection, or some other negative error code
2984  * if the reset wasn't even attempted.
2985  *
2986  * The caller must own the device lock.  For example, it's safe to use
2987  * this from a driver probe() routine after downloading new firmware.
2988  * For calls that might not occur during probe(), drivers should lock
2989  * the device using usb_lock_device_for_reset().
2990  */
2991 int usb_reset_device(struct usb_device *udev)
2992 {
2993 	struct usb_device		*parent_hdev = udev->parent;
2994 	struct usb_hub			*parent_hub;
2995 	struct usb_device_descriptor	descriptor = udev->descriptor;
2996 	struct usb_hub			*hub = NULL;
2997 	int 				i, ret = 0, port1 = -1;
2998 
2999 	if (udev->state == USB_STATE_NOTATTACHED ||
3000 			udev->state == USB_STATE_SUSPENDED) {
3001 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3002 				udev->state);
3003 		return -EINVAL;
3004 	}
3005 
3006 	if (!parent_hdev) {
3007 		/* this requires hcd-specific logic; see OHCI hc_restart() */
3008 		dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
3009 		return -EISDIR;
3010 	}
3011 
3012 	for (i = 0; i < parent_hdev->maxchild; i++)
3013 		if (parent_hdev->children[i] == udev) {
3014 			port1 = i + 1;
3015 			break;
3016 		}
3017 
3018 	if (port1 < 0) {
3019 		/* If this ever happens, it's very bad */
3020 		dev_err(&udev->dev, "Can't locate device's port!\n");
3021 		return -ENOENT;
3022 	}
3023 	parent_hub = hdev_to_hub(parent_hdev);
3024 
3025 	/* If we're resetting an active hub, take some special actions */
3026 	if (udev->actconfig &&
3027 			udev->actconfig->interface[0]->dev.driver ==
3028 				&hub_driver.driver &&
3029 			(hub = hdev_to_hub(udev)) != NULL) {
3030 		hub_pre_reset(hub);
3031 	}
3032 
3033 	set_bit(port1, parent_hub->busy_bits);
3034 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
3035 
3036 		/* ep0 maxpacket size may change; let the HCD know about it.
3037 		 * Other endpoints will be handled by re-enumeration. */
3038 		ep0_reinit(udev);
3039 		ret = hub_port_init(parent_hub, udev, port1, i);
3040 		if (ret >= 0)
3041 			break;
3042 	}
3043 	clear_bit(port1, parent_hub->busy_bits);
3044 	if (ret < 0)
3045 		goto re_enumerate;
3046 
3047 	/* Device might have changed firmware (DFU or similar) */
3048 	if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
3049 			|| config_descriptors_changed (udev)) {
3050 		dev_info(&udev->dev, "device firmware changed\n");
3051 		udev->descriptor = descriptor;	/* for disconnect() calls */
3052 		goto re_enumerate;
3053   	}
3054 
3055 	if (!udev->actconfig)
3056 		goto done;
3057 
3058 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3059 			USB_REQ_SET_CONFIGURATION, 0,
3060 			udev->actconfig->desc.bConfigurationValue, 0,
3061 			NULL, 0, USB_CTRL_SET_TIMEOUT);
3062 	if (ret < 0) {
3063 		dev_err(&udev->dev,
3064 			"can't restore configuration #%d (error=%d)\n",
3065 			udev->actconfig->desc.bConfigurationValue, ret);
3066 		goto re_enumerate;
3067   	}
3068 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
3069 
3070 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3071 		struct usb_interface *intf = udev->actconfig->interface[i];
3072 		struct usb_interface_descriptor *desc;
3073 
3074 		/* set_interface resets host side toggle even
3075 		 * for altsetting zero.  the interface may have no driver.
3076 		 */
3077 		desc = &intf->cur_altsetting->desc;
3078 		ret = usb_set_interface(udev, desc->bInterfaceNumber,
3079 			desc->bAlternateSetting);
3080 		if (ret < 0) {
3081 			dev_err(&udev->dev, "failed to restore interface %d "
3082 				"altsetting %d (error=%d)\n",
3083 				desc->bInterfaceNumber,
3084 				desc->bAlternateSetting,
3085 				ret);
3086 			goto re_enumerate;
3087 		}
3088 	}
3089 
3090 done:
3091 	if (hub)
3092 		hub_post_reset(hub);
3093 	return 0;
3094 
3095 re_enumerate:
3096 	hub_port_logical_disconnect(parent_hub, port1);
3097 	return -ENODEV;
3098 }
3099