xref: /linux/drivers/usb/core/hub.c (revision 2624f124b3b5d550ab2fbef7ee3bc0e1fed09722)
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 
439 	/* if hub supports power switching, enable power on each port */
440 	if ((hub->descriptor->wHubCharacteristics & HUB_CHAR_LPSM) < 2) {
441 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
442 		for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
443 			set_port_feature(hub->hdev, port1,
444 					USB_PORT_FEAT_POWER);
445 	}
446 
447 	/* Wait for power to be enabled */
448 	msleep(hub->descriptor->bPwrOn2PwrGood * 2);
449 }
450 
451 static void hub_quiesce(struct usb_hub *hub)
452 {
453 	/* stop khubd and related activity */
454 	hub->quiescing = 1;
455 	usb_kill_urb(hub->urb);
456 	if (hub->has_indicators)
457 		cancel_delayed_work(&hub->leds);
458 	if (hub->has_indicators || hub->tt.hub)
459 		flush_scheduled_work();
460 }
461 
462 static void hub_activate(struct usb_hub *hub)
463 {
464 	int	status;
465 
466 	hub->quiescing = 0;
467 	hub->activating = 1;
468 	status = usb_submit_urb(hub->urb, GFP_NOIO);
469 	if (status < 0)
470 		dev_err(hub->intfdev, "activate --> %d\n", status);
471 	if (hub->has_indicators && blinkenlights)
472 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
473 
474 	/* scan all ports ASAP */
475 	kick_khubd(hub);
476 }
477 
478 static int hub_hub_status(struct usb_hub *hub,
479 		u16 *status, u16 *change)
480 {
481 	int ret;
482 
483 	ret = get_hub_status(hub->hdev, &hub->status->hub);
484 	if (ret < 0)
485 		dev_err (hub->intfdev,
486 			"%s failed (err = %d)\n", __FUNCTION__, ret);
487 	else {
488 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
489 		*change = le16_to_cpu(hub->status->hub.wHubChange);
490 		ret = 0;
491 	}
492 	return ret;
493 }
494 
495 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
496 {
497 	struct usb_device *hdev = hub->hdev;
498 	int ret;
499 
500 	if (hdev->children[port1-1] && set_state) {
501 		usb_set_device_state(hdev->children[port1-1],
502 				USB_STATE_NOTATTACHED);
503 	}
504 	ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
505 	if (ret)
506 		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
507 			port1, ret);
508 
509 	return ret;
510 }
511 
512 static int hub_configure(struct usb_hub *hub,
513 	struct usb_endpoint_descriptor *endpoint)
514 {
515 	struct usb_device *hdev = hub->hdev;
516 	struct device *hub_dev = hub->intfdev;
517 	u16 hubstatus, hubchange;
518 	unsigned int pipe;
519 	int maxp, ret;
520 	char *message;
521 
522 	hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
523 			&hub->buffer_dma);
524 	if (!hub->buffer) {
525 		message = "can't allocate hub irq buffer";
526 		ret = -ENOMEM;
527 		goto fail;
528 	}
529 
530 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
531 	if (!hub->status) {
532 		message = "can't kmalloc hub status buffer";
533 		ret = -ENOMEM;
534 		goto fail;
535 	}
536 
537 	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
538 	if (!hub->descriptor) {
539 		message = "can't kmalloc hub descriptor";
540 		ret = -ENOMEM;
541 		goto fail;
542 	}
543 
544 	/* Request the entire hub descriptor.
545 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
546 	 * but the hub can/will return fewer bytes here.
547 	 */
548 	ret = get_hub_descriptor(hdev, hub->descriptor,
549 			sizeof(*hub->descriptor));
550 	if (ret < 0) {
551 		message = "can't read hub descriptor";
552 		goto fail;
553 	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
554 		message = "hub has too many ports!";
555 		ret = -ENODEV;
556 		goto fail;
557 	}
558 
559 	hdev->maxchild = hub->descriptor->bNbrPorts;
560 	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
561 		(hdev->maxchild == 1) ? "" : "s");
562 
563 	le16_to_cpus(&hub->descriptor->wHubCharacteristics);
564 
565 	if (hub->descriptor->wHubCharacteristics & HUB_CHAR_COMPOUND) {
566 		int	i;
567 		char	portstr [USB_MAXCHILDREN + 1];
568 
569 		for (i = 0; i < hdev->maxchild; i++)
570 			portstr[i] = hub->descriptor->DeviceRemovable
571 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
572 				? 'F' : 'R';
573 		portstr[hdev->maxchild] = 0;
574 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
575 	} else
576 		dev_dbg(hub_dev, "standalone hub\n");
577 
578 	switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_LPSM) {
579 		case 0x00:
580 			dev_dbg(hub_dev, "ganged power switching\n");
581 			break;
582 		case 0x01:
583 			dev_dbg(hub_dev, "individual port power switching\n");
584 			break;
585 		case 0x02:
586 		case 0x03:
587 			dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
588 			break;
589 	}
590 
591 	switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_OCPM) {
592 		case 0x00:
593 			dev_dbg(hub_dev, "global over-current protection\n");
594 			break;
595 		case 0x08:
596 			dev_dbg(hub_dev, "individual port over-current protection\n");
597 			break;
598 		case 0x10:
599 		case 0x18:
600 			dev_dbg(hub_dev, "no over-current protection\n");
601                         break;
602 	}
603 
604 	spin_lock_init (&hub->tt.lock);
605 	INIT_LIST_HEAD (&hub->tt.clear_list);
606 	INIT_WORK (&hub->tt.kevent, hub_tt_kevent, hub);
607 	switch (hdev->descriptor.bDeviceProtocol) {
608 		case 0:
609 			break;
610 		case 1:
611 			dev_dbg(hub_dev, "Single TT\n");
612 			hub->tt.hub = hdev;
613 			break;
614 		case 2:
615 			ret = usb_set_interface(hdev, 0, 1);
616 			if (ret == 0) {
617 				dev_dbg(hub_dev, "TT per port\n");
618 				hub->tt.multi = 1;
619 			} else
620 				dev_err(hub_dev, "Using single TT (err %d)\n",
621 					ret);
622 			hub->tt.hub = hdev;
623 			break;
624 		default:
625 			dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
626 				hdev->descriptor.bDeviceProtocol);
627 			break;
628 	}
629 
630 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
631 	switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_TTTT) {
632 		case HUB_TTTT_8_BITS:
633 			if (hdev->descriptor.bDeviceProtocol != 0) {
634 				hub->tt.think_time = 666;
635 				dev_dbg(hub_dev, "TT requires at most %d "
636 						"FS bit times (%d ns)\n",
637 					8, hub->tt.think_time);
638 			}
639 			break;
640 		case HUB_TTTT_16_BITS:
641 			hub->tt.think_time = 666 * 2;
642 			dev_dbg(hub_dev, "TT requires at most %d "
643 					"FS bit times (%d ns)\n",
644 				16, hub->tt.think_time);
645 			break;
646 		case HUB_TTTT_24_BITS:
647 			hub->tt.think_time = 666 * 3;
648 			dev_dbg(hub_dev, "TT requires at most %d "
649 					"FS bit times (%d ns)\n",
650 				24, hub->tt.think_time);
651 			break;
652 		case HUB_TTTT_32_BITS:
653 			hub->tt.think_time = 666 * 4;
654 			dev_dbg(hub_dev, "TT requires at most %d "
655 					"FS bit times (%d ns)\n",
656 				32, hub->tt.think_time);
657 			break;
658 	}
659 
660 	/* probe() zeroes hub->indicator[] */
661 	if (hub->descriptor->wHubCharacteristics & HUB_CHAR_PORTIND) {
662 		hub->has_indicators = 1;
663 		dev_dbg(hub_dev, "Port indicators are supported\n");
664 	}
665 
666 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
667 		hub->descriptor->bPwrOn2PwrGood * 2);
668 
669 	/* power budgeting mostly matters with bus-powered hubs,
670 	 * and battery-powered root hubs (may provide just 8 mA).
671 	 */
672 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
673 	if (ret < 0) {
674 		message = "can't get hub status";
675 		goto fail;
676 	}
677 	le16_to_cpus(&hubstatus);
678 	if (hdev == hdev->bus->root_hub) {
679 		struct usb_hcd *hcd =
680 				container_of(hdev->bus, struct usb_hcd, self);
681 
682 		hub->power_budget = min(500u, hcd->power_budget) / 2;
683 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
684 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
685 			hub->descriptor->bHubContrCurrent);
686 		hub->power_budget = (501 - hub->descriptor->bHubContrCurrent)
687 					/ 2;
688 	}
689 	if (hub->power_budget)
690 		dev_dbg(hub_dev, "%dmA bus power budget for children\n",
691 			hub->power_budget * 2);
692 
693 
694 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
695 	if (ret < 0) {
696 		message = "can't get hub status";
697 		goto fail;
698 	}
699 
700 	/* local power status reports aren't always correct */
701 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
702 		dev_dbg(hub_dev, "local power source is %s\n",
703 			(hubstatus & HUB_STATUS_LOCAL_POWER)
704 			? "lost (inactive)" : "good");
705 
706 	if ((hub->descriptor->wHubCharacteristics & HUB_CHAR_OCPM) == 0)
707 		dev_dbg(hub_dev, "%sover-current condition exists\n",
708 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
709 
710 	/* set up the interrupt endpoint */
711 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
712 	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
713 
714 	if (maxp > sizeof(*hub->buffer))
715 		maxp = sizeof(*hub->buffer);
716 
717 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
718 	if (!hub->urb) {
719 		message = "couldn't allocate interrupt urb";
720 		ret = -ENOMEM;
721 		goto fail;
722 	}
723 
724 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
725 		hub, endpoint->bInterval);
726 	hub->urb->transfer_dma = hub->buffer_dma;
727 	hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
728 
729 	/* maybe cycle the hub leds */
730 	if (hub->has_indicators && blinkenlights)
731 		hub->indicator [0] = INDICATOR_CYCLE;
732 
733 	hub_power_on(hub);
734 	hub_activate(hub);
735 	return 0;
736 
737 fail:
738 	dev_err (hub_dev, "config failed, %s (err %d)\n",
739 			message, ret);
740 	/* hub_disconnect() frees urb and descriptor */
741 	return ret;
742 }
743 
744 static unsigned highspeed_hubs;
745 
746 /* Called after the hub driver is unbound from a hub with children */
747 static void hub_remove_children_work(void *__hub)
748 {
749 	struct usb_hub		*hub = __hub;
750 	struct usb_device	*hdev = hub->hdev;
751 	int			i;
752 
753 	kfree(hub);
754 
755 	usb_lock_device(hdev);
756 	for (i = 0; i < hdev->maxchild; ++i) {
757 		if (hdev->children[i])
758 			usb_disconnect(&hdev->children[i]);
759 	}
760 	usb_unlock_device(hdev);
761 	usb_put_dev(hdev);
762 }
763 
764 static void hub_disconnect(struct usb_interface *intf)
765 {
766 	struct usb_hub *hub = usb_get_intfdata (intf);
767 	struct usb_device *hdev;
768 	int n, port1;
769 
770 	usb_set_intfdata (intf, NULL);
771 	hdev = hub->hdev;
772 
773 	if (hdev->speed == USB_SPEED_HIGH)
774 		highspeed_hubs--;
775 
776 	hub_quiesce(hub);
777 	usb_free_urb(hub->urb);
778 	hub->urb = NULL;
779 
780 	spin_lock_irq(&hub_event_lock);
781 	list_del_init(&hub->event_list);
782 	spin_unlock_irq(&hub_event_lock);
783 
784 	kfree(hub->descriptor);
785 	hub->descriptor = NULL;
786 
787 	kfree(hub->status);
788 	hub->status = NULL;
789 
790 	if (hub->buffer) {
791 		usb_buffer_free(hdev, sizeof(*hub->buffer), hub->buffer,
792 				hub->buffer_dma);
793 		hub->buffer = NULL;
794 	}
795 
796 	/* If there are any children then this is an unbind only, not a
797 	 * physical disconnection.  The active ports must be disabled
798 	 * and later on we must call usb_disconnect().  We can't call
799 	 * it now because we may not hold the hub's device lock.
800 	 */
801 	n = 0;
802 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
803 		if (hdev->children[port1 - 1]) {
804 			++n;
805 			hub_port_disable(hub, port1, 1);
806 		}
807 	}
808 
809 	if (n == 0)
810 		kfree(hub);
811 	else {
812 		/* Reuse the hub->leds work_struct for our own purposes */
813 		INIT_WORK(&hub->leds, hub_remove_children_work, hub);
814 		schedule_work(&hub->leds);
815 		usb_get_dev(hdev);
816 	}
817 }
818 
819 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
820 {
821 	struct usb_host_interface *desc;
822 	struct usb_endpoint_descriptor *endpoint;
823 	struct usb_device *hdev;
824 	struct usb_hub *hub;
825 
826 	desc = intf->cur_altsetting;
827 	hdev = interface_to_usbdev(intf);
828 
829 	/* Some hubs have a subclass of 1, which AFAICT according to the */
830 	/*  specs is not defined, but it works */
831 	if ((desc->desc.bInterfaceSubClass != 0) &&
832 	    (desc->desc.bInterfaceSubClass != 1)) {
833 descriptor_error:
834 		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
835 		return -EIO;
836 	}
837 
838 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
839 	if (desc->desc.bNumEndpoints != 1)
840 		goto descriptor_error;
841 
842 	endpoint = &desc->endpoint[0].desc;
843 
844 	/* Output endpoint? Curiouser and curiouser.. */
845 	if (!(endpoint->bEndpointAddress & USB_DIR_IN))
846 		goto descriptor_error;
847 
848 	/* If it's not an interrupt endpoint, we'd better punt! */
849 	if ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
850 			!= USB_ENDPOINT_XFER_INT)
851 		goto descriptor_error;
852 
853 	/* We found a hub */
854 	dev_info (&intf->dev, "USB hub found\n");
855 
856 	hub = kmalloc(sizeof(*hub), GFP_KERNEL);
857 	if (!hub) {
858 		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
859 		return -ENOMEM;
860 	}
861 
862 	memset(hub, 0, sizeof(*hub));
863 
864 	INIT_LIST_HEAD(&hub->event_list);
865 	hub->intfdev = &intf->dev;
866 	hub->hdev = hdev;
867 	INIT_WORK(&hub->leds, led_work, hub);
868 
869 	usb_set_intfdata (intf, hub);
870 
871 	if (hdev->speed == USB_SPEED_HIGH)
872 		highspeed_hubs++;
873 
874 	if (hub_configure(hub, endpoint) >= 0)
875 		return 0;
876 
877 	hub_disconnect (intf);
878 	return -ENODEV;
879 }
880 
881 static int
882 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
883 {
884 	struct usb_device *hdev = interface_to_usbdev (intf);
885 
886 	/* assert ifno == 0 (part of hub spec) */
887 	switch (code) {
888 	case USBDEVFS_HUB_PORTINFO: {
889 		struct usbdevfs_hub_portinfo *info = user_data;
890 		int i;
891 
892 		spin_lock_irq(&device_state_lock);
893 		if (hdev->devnum <= 0)
894 			info->nports = 0;
895 		else {
896 			info->nports = hdev->maxchild;
897 			for (i = 0; i < info->nports; i++) {
898 				if (hdev->children[i] == NULL)
899 					info->port[i] = 0;
900 				else
901 					info->port[i] =
902 						hdev->children[i]->devnum;
903 			}
904 		}
905 		spin_unlock_irq(&device_state_lock);
906 
907 		return info->nports + 1;
908 		}
909 
910 	default:
911 		return -ENOSYS;
912 	}
913 }
914 
915 /* caller has locked the hub device */
916 static void hub_pre_reset(struct usb_hub *hub)
917 {
918 	struct usb_device *hdev = hub->hdev;
919 	int i;
920 
921 	for (i = 0; i < hdev->maxchild; ++i) {
922 		if (hdev->children[i])
923 			usb_disconnect(&hdev->children[i]);
924 	}
925 	hub_quiesce(hub);
926 }
927 
928 /* caller has locked the hub device */
929 static void hub_post_reset(struct usb_hub *hub)
930 {
931 	hub_activate(hub);
932 	hub_power_on(hub);
933 }
934 
935 
936 /* grab device/port lock, returning index of that port (zero based).
937  * protects the upstream link used by this device from concurrent
938  * tree operations like suspend, resume, reset, and disconnect, which
939  * apply to everything downstream of a given port.
940  */
941 static int locktree(struct usb_device *udev)
942 {
943 	int			t;
944 	struct usb_device	*hdev;
945 
946 	if (!udev)
947 		return -ENODEV;
948 
949 	/* root hub is always the first lock in the series */
950 	hdev = udev->parent;
951 	if (!hdev) {
952 		usb_lock_device(udev);
953 		return 0;
954 	}
955 
956 	/* on the path from root to us, lock everything from
957 	 * top down, dropping parent locks when not needed
958 	 */
959 	t = locktree(hdev);
960 	if (t < 0)
961 		return t;
962 	for (t = 0; t < hdev->maxchild; t++) {
963 		if (hdev->children[t] == udev) {
964 			/* everything is fail-fast once disconnect
965 			 * processing starts
966 			 */
967 			if (udev->state == USB_STATE_NOTATTACHED)
968 				break;
969 
970 			/* when everyone grabs locks top->bottom,
971 			 * non-overlapping work may be concurrent
972 			 */
973 			down(&udev->serialize);
974 			up(&hdev->serialize);
975 			return t + 1;
976 		}
977 	}
978 	usb_unlock_device(hdev);
979 	return -ENODEV;
980 }
981 
982 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
983 {
984 	int i;
985 
986 	for (i = 0; i < udev->maxchild; ++i) {
987 		if (udev->children[i])
988 			recursively_mark_NOTATTACHED(udev->children[i]);
989 	}
990 	udev->state = USB_STATE_NOTATTACHED;
991 }
992 
993 /**
994  * usb_set_device_state - change a device's current state (usbcore, hcds)
995  * @udev: pointer to device whose state should be changed
996  * @new_state: new state value to be stored
997  *
998  * udev->state is _not_ fully protected by the device lock.  Although
999  * most transitions are made only while holding the lock, the state can
1000  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1001  * is so that devices can be marked as disconnected as soon as possible,
1002  * without having to wait for any semaphores to be released.  As a result,
1003  * all changes to any device's state must be protected by the
1004  * device_state_lock spinlock.
1005  *
1006  * Once a device has been added to the device tree, all changes to its state
1007  * should be made using this routine.  The state should _not_ be set directly.
1008  *
1009  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1010  * Otherwise udev->state is set to new_state, and if new_state is
1011  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1012  * to USB_STATE_NOTATTACHED.
1013  */
1014 void usb_set_device_state(struct usb_device *udev,
1015 		enum usb_device_state new_state)
1016 {
1017 	unsigned long flags;
1018 
1019 	spin_lock_irqsave(&device_state_lock, flags);
1020 	if (udev->state == USB_STATE_NOTATTACHED)
1021 		;	/* do nothing */
1022 	else if (new_state != USB_STATE_NOTATTACHED)
1023 		udev->state = new_state;
1024 	else
1025 		recursively_mark_NOTATTACHED(udev);
1026 	spin_unlock_irqrestore(&device_state_lock, flags);
1027 }
1028 EXPORT_SYMBOL(usb_set_device_state);
1029 
1030 
1031 static void choose_address(struct usb_device *udev)
1032 {
1033 	int		devnum;
1034 	struct usb_bus	*bus = udev->bus;
1035 
1036 	/* If khubd ever becomes multithreaded, this will need a lock */
1037 
1038 	/* Try to allocate the next devnum beginning at bus->devnum_next. */
1039 	devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1040 			bus->devnum_next);
1041 	if (devnum >= 128)
1042 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
1043 
1044 	bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1045 
1046 	if (devnum < 128) {
1047 		set_bit(devnum, bus->devmap.devicemap);
1048 		udev->devnum = devnum;
1049 	}
1050 }
1051 
1052 static void release_address(struct usb_device *udev)
1053 {
1054 	if (udev->devnum > 0) {
1055 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1056 		udev->devnum = -1;
1057 	}
1058 }
1059 
1060 /**
1061  * usb_disconnect - disconnect a device (usbcore-internal)
1062  * @pdev: pointer to device being disconnected
1063  * Context: !in_interrupt ()
1064  *
1065  * Something got disconnected. Get rid of it and all of its children.
1066  *
1067  * If *pdev is a normal device then the parent hub must already be locked.
1068  * If *pdev is a root hub then this routine will acquire the
1069  * usb_bus_list_lock on behalf of the caller.
1070  *
1071  * Only hub drivers (including virtual root hub drivers for host
1072  * controllers) should ever call this.
1073  *
1074  * This call is synchronous, and may not be used in an interrupt context.
1075  */
1076 void usb_disconnect(struct usb_device **pdev)
1077 {
1078 	struct usb_device	*udev = *pdev;
1079 	int			i;
1080 
1081 	if (!udev) {
1082 		pr_debug ("%s nodev\n", __FUNCTION__);
1083 		return;
1084 	}
1085 
1086 	/* mark the device as inactive, so any further urb submissions for
1087 	 * this device (and any of its children) will fail immediately.
1088 	 * this quiesces everyting except pending urbs.
1089 	 */
1090 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1091 
1092 	/* lock the bus list on behalf of HCDs unregistering their root hubs */
1093 	if (!udev->parent) {
1094 		down(&usb_bus_list_lock);
1095 		usb_lock_device(udev);
1096 	} else
1097 		down(&udev->serialize);
1098 
1099 	dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1100 
1101 	/* Free up all the children before we remove this device */
1102 	for (i = 0; i < USB_MAXCHILDREN; i++) {
1103 		if (udev->children[i])
1104 			usb_disconnect(&udev->children[i]);
1105 	}
1106 
1107 	/* deallocate hcd/hardware state ... nuking all pending urbs and
1108 	 * cleaning up all state associated with the current configuration
1109 	 * so that the hardware is now fully quiesced.
1110 	 */
1111 	usb_disable_device(udev, 0);
1112 
1113 	/* Free the device number, remove the /proc/bus/usb entry and
1114 	 * the sysfs attributes, and delete the parent's children[]
1115 	 * (or root_hub) pointer.
1116 	 */
1117 	dev_dbg (&udev->dev, "unregistering device\n");
1118 	release_address(udev);
1119 	usbfs_remove_device(udev);
1120 	usbdev_remove(udev);
1121 	usb_remove_sysfs_dev_files(udev);
1122 
1123 	/* Avoid races with recursively_mark_NOTATTACHED() */
1124 	spin_lock_irq(&device_state_lock);
1125 	*pdev = NULL;
1126 	spin_unlock_irq(&device_state_lock);
1127 
1128 	if (!udev->parent) {
1129 		usb_unlock_device(udev);
1130 		up(&usb_bus_list_lock);
1131 	} else
1132 		up(&udev->serialize);
1133 
1134 	device_unregister(&udev->dev);
1135 }
1136 
1137 static int choose_configuration(struct usb_device *udev)
1138 {
1139 	int c, i;
1140 
1141 	/* NOTE: this should interact with hub power budgeting */
1142 
1143 	c = udev->config[0].desc.bConfigurationValue;
1144 	if (udev->descriptor.bNumConfigurations != 1) {
1145 		for (i = 0; i < udev->descriptor.bNumConfigurations; i++) {
1146 			struct usb_interface_descriptor	*desc;
1147 
1148 			/* heuristic:  Linux is more likely to have class
1149 			 * drivers, so avoid vendor-specific interfaces.
1150 			 */
1151 			desc = &udev->config[i].intf_cache[0]
1152 					->altsetting->desc;
1153 			if (desc->bInterfaceClass == USB_CLASS_VENDOR_SPEC)
1154 				continue;
1155 			/* COMM/2/all is CDC ACM, except 0xff is MSFT RNDIS.
1156 			 * MSFT needs this to be the first config; never use
1157 			 * it as the default unless Linux has host-side RNDIS.
1158 			 * A second config would ideally be CDC-Ethernet, but
1159 			 * may instead be the "vendor specific" CDC subset
1160 			 * long used by ARM Linux for sa1100 or pxa255.
1161 			 */
1162 			if (desc->bInterfaceClass == USB_CLASS_COMM
1163 					&& desc->bInterfaceSubClass == 2
1164 					&& desc->bInterfaceProtocol == 0xff) {
1165 				c = udev->config[1].desc.bConfigurationValue;
1166 				continue;
1167 			}
1168 			c = udev->config[i].desc.bConfigurationValue;
1169 			break;
1170 		}
1171 		dev_info(&udev->dev,
1172 			"configuration #%d chosen from %d choices\n",
1173 			c, udev->descriptor.bNumConfigurations);
1174 	}
1175 	return c;
1176 }
1177 
1178 #ifdef DEBUG
1179 static void show_string(struct usb_device *udev, char *id, char *string)
1180 {
1181 	if (!string)
1182 		return;
1183 	dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1184 }
1185 
1186 #else
1187 static inline void show_string(struct usb_device *udev, char *id, char *string)
1188 {}
1189 #endif
1190 
1191 static void get_string(struct usb_device *udev, char **string, int index)
1192 {
1193 	char *buf;
1194 
1195 	if (!index)
1196 		return;
1197 	buf = kmalloc(256, GFP_KERNEL);
1198 	if (!buf)
1199 		return;
1200 	if (usb_string(udev, index, buf, 256) > 0)
1201 		*string = buf;
1202 	else
1203 		kfree(buf);
1204 }
1205 
1206 
1207 #ifdef	CONFIG_USB_OTG
1208 #include "otg_whitelist.h"
1209 #endif
1210 
1211 /**
1212  * usb_new_device - perform initial device setup (usbcore-internal)
1213  * @udev: newly addressed device (in ADDRESS state)
1214  *
1215  * This is called with devices which have been enumerated, but not yet
1216  * configured.  The device descriptor is available, but not descriptors
1217  * for any device configuration.  The caller must have locked udev and
1218  * either the parent hub (if udev is a normal device) or else the
1219  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
1220  * udev has already been installed, but udev is not yet visible through
1221  * sysfs or other filesystem code.
1222  *
1223  * Returns 0 for success (device is configured and listed, with its
1224  * interfaces, in sysfs); else a negative errno value.
1225  *
1226  * This call is synchronous, and may not be used in an interrupt context.
1227  *
1228  * Only the hub driver should ever call this; root hub registration
1229  * uses it indirectly.
1230  */
1231 int usb_new_device(struct usb_device *udev)
1232 {
1233 	int err;
1234 	int c;
1235 
1236 	err = usb_get_configuration(udev);
1237 	if (err < 0) {
1238 		dev_err(&udev->dev, "can't read configurations, error %d\n",
1239 			err);
1240 		goto fail;
1241 	}
1242 
1243 	/* read the standard strings and cache them if present */
1244 	get_string(udev, &udev->product, udev->descriptor.iProduct);
1245 	get_string(udev, &udev->manufacturer, udev->descriptor.iManufacturer);
1246 	get_string(udev, &udev->serial, udev->descriptor.iSerialNumber);
1247 
1248 	/* Tell the world! */
1249 	dev_dbg(&udev->dev, "new device strings: Mfr=%d, Product=%d, "
1250 			"SerialNumber=%d\n",
1251 			udev->descriptor.iManufacturer,
1252 			udev->descriptor.iProduct,
1253 			udev->descriptor.iSerialNumber);
1254 	show_string(udev, "Product", udev->product);
1255 	show_string(udev, "Manufacturer", udev->manufacturer);
1256 	show_string(udev, "SerialNumber", udev->serial);
1257 
1258 #ifdef	CONFIG_USB_OTG
1259 	/*
1260 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1261 	 * to wake us after we've powered off VBUS; and HNP, switching roles
1262 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
1263 	 */
1264 	if (!udev->bus->is_b_host
1265 			&& udev->config
1266 			&& udev->parent == udev->bus->root_hub) {
1267 		struct usb_otg_descriptor	*desc = 0;
1268 		struct usb_bus			*bus = udev->bus;
1269 
1270 		/* descriptor may appear anywhere in config */
1271 		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1272 					le16_to_cpu(udev->config[0].desc.wTotalLength),
1273 					USB_DT_OTG, (void **) &desc) == 0) {
1274 			if (desc->bmAttributes & USB_OTG_HNP) {
1275 				unsigned		port1;
1276 				struct usb_device	*root = udev->parent;
1277 
1278 				for (port1 = 1; port1 <= root->maxchild;
1279 						port1++) {
1280 					if (root->children[port1-1] == udev)
1281 						break;
1282 				}
1283 
1284 				dev_info(&udev->dev,
1285 					"Dual-Role OTG device on %sHNP port\n",
1286 					(port1 == bus->otg_port)
1287 						? "" : "non-");
1288 
1289 				/* enable HNP before suspend, it's simpler */
1290 				if (port1 == bus->otg_port)
1291 					bus->b_hnp_enable = 1;
1292 				err = usb_control_msg(udev,
1293 					usb_sndctrlpipe(udev, 0),
1294 					USB_REQ_SET_FEATURE, 0,
1295 					bus->b_hnp_enable
1296 						? USB_DEVICE_B_HNP_ENABLE
1297 						: USB_DEVICE_A_ALT_HNP_SUPPORT,
1298 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1299 				if (err < 0) {
1300 					/* OTG MESSAGE: report errors here,
1301 					 * customize to match your product.
1302 					 */
1303 					dev_info(&udev->dev,
1304 						"can't set HNP mode; %d\n",
1305 						err);
1306 					bus->b_hnp_enable = 0;
1307 				}
1308 			}
1309 		}
1310 	}
1311 
1312 	if (!is_targeted(udev)) {
1313 
1314 		/* Maybe it can talk to us, though we can't talk to it.
1315 		 * (Includes HNP test device.)
1316 		 */
1317 		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1318 			static int __usb_suspend_device (struct usb_device *,
1319 						int port1, pm_message_t state);
1320 			err = __usb_suspend_device(udev,
1321 					udev->bus->otg_port,
1322 					PMSG_SUSPEND);
1323 			if (err < 0)
1324 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1325 		}
1326 		err = -ENODEV;
1327 		goto fail;
1328 	}
1329 #endif
1330 
1331 	/* put device-specific files into sysfs */
1332 	err = device_add (&udev->dev);
1333 	if (err) {
1334 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
1335 		goto fail;
1336 	}
1337 	usb_create_sysfs_dev_files (udev);
1338 
1339 	/* choose and set the configuration. that registers the interfaces
1340 	 * with the driver core, and lets usb device drivers bind to them.
1341 	 */
1342 	c = choose_configuration(udev);
1343 	if (c < 0)
1344 		dev_warn(&udev->dev,
1345 				"can't choose an initial configuration\n");
1346 	else {
1347 		err = usb_set_configuration(udev, c);
1348 		if (err) {
1349 			dev_err(&udev->dev, "can't set config #%d, error %d\n",
1350 					c, err);
1351 			usb_remove_sysfs_dev_files(udev);
1352 			device_del(&udev->dev);
1353 			goto fail;
1354 		}
1355 	}
1356 
1357 	/* USB device state == configured ... usable */
1358 
1359 	/* add a /proc/bus/usb entry */
1360 	usbdev_add(udev);
1361 	usbfs_add_device(udev);
1362 	return 0;
1363 
1364 fail:
1365 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1366 	return err;
1367 }
1368 
1369 
1370 static int hub_port_status(struct usb_hub *hub, int port1,
1371 			       u16 *status, u16 *change)
1372 {
1373 	int ret;
1374 
1375 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
1376 	if (ret < 0)
1377 		dev_err (hub->intfdev,
1378 			"%s failed (err = %d)\n", __FUNCTION__, ret);
1379 	else {
1380 		*status = le16_to_cpu(hub->status->port.wPortStatus);
1381 		*change = le16_to_cpu(hub->status->port.wPortChange);
1382 		ret = 0;
1383 	}
1384 	return ret;
1385 }
1386 
1387 #define PORT_RESET_TRIES	5
1388 #define SET_ADDRESS_TRIES	2
1389 #define GET_DESCRIPTOR_TRIES	2
1390 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
1391 #define USE_NEW_SCHEME(i)	((i) / 2 == old_scheme_first)
1392 
1393 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
1394 #define HUB_SHORT_RESET_TIME	10
1395 #define HUB_LONG_RESET_TIME	200
1396 #define HUB_RESET_TIMEOUT	500
1397 
1398 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1399 				struct usb_device *udev, unsigned int delay)
1400 {
1401 	int delay_time, ret;
1402 	u16 portstatus;
1403 	u16 portchange;
1404 
1405 	for (delay_time = 0;
1406 			delay_time < HUB_RESET_TIMEOUT;
1407 			delay_time += delay) {
1408 		/* wait to give the device a chance to reset */
1409 		msleep(delay);
1410 
1411 		/* read and decode port status */
1412 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
1413 		if (ret < 0)
1414 			return ret;
1415 
1416 		/* Device went away? */
1417 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
1418 			return -ENOTCONN;
1419 
1420 		/* bomb out completely if something weird happened */
1421 		if ((portchange & USB_PORT_STAT_C_CONNECTION))
1422 			return -EINVAL;
1423 
1424 		/* if we`ve finished resetting, then break out of the loop */
1425 		if (!(portstatus & USB_PORT_STAT_RESET) &&
1426 		    (portstatus & USB_PORT_STAT_ENABLE)) {
1427 			if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1428 				udev->speed = USB_SPEED_HIGH;
1429 			else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1430 				udev->speed = USB_SPEED_LOW;
1431 			else
1432 				udev->speed = USB_SPEED_FULL;
1433 			return 0;
1434 		}
1435 
1436 		/* switch to the long delay after two short delay failures */
1437 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1438 			delay = HUB_LONG_RESET_TIME;
1439 
1440 		dev_dbg (hub->intfdev,
1441 			"port %d not reset yet, waiting %dms\n",
1442 			port1, delay);
1443 	}
1444 
1445 	return -EBUSY;
1446 }
1447 
1448 static int hub_port_reset(struct usb_hub *hub, int port1,
1449 				struct usb_device *udev, unsigned int delay)
1450 {
1451 	int i, status;
1452 
1453 	/* Reset the port */
1454 	for (i = 0; i < PORT_RESET_TRIES; i++) {
1455 		status = set_port_feature(hub->hdev,
1456 				port1, USB_PORT_FEAT_RESET);
1457 		if (status)
1458 			dev_err(hub->intfdev,
1459 					"cannot reset port %d (err = %d)\n",
1460 					port1, status);
1461 		else {
1462 			status = hub_port_wait_reset(hub, port1, udev, delay);
1463 			if (status)
1464 				dev_dbg(hub->intfdev,
1465 						"port_wait_reset: err = %d\n",
1466 						status);
1467 		}
1468 
1469 		/* return on disconnect or reset */
1470 		switch (status) {
1471 		case 0:
1472 			/* TRSTRCY = 10 ms */
1473 			msleep(10);
1474 			/* FALL THROUGH */
1475 		case -ENOTCONN:
1476 		case -ENODEV:
1477 			clear_port_feature(hub->hdev,
1478 				port1, USB_PORT_FEAT_C_RESET);
1479 			/* FIXME need disconnect() for NOTATTACHED device */
1480 			usb_set_device_state(udev, status
1481 					? USB_STATE_NOTATTACHED
1482 					: USB_STATE_DEFAULT);
1483 			return status;
1484 		}
1485 
1486 		dev_dbg (hub->intfdev,
1487 			"port %d not enabled, trying reset again...\n",
1488 			port1);
1489 		delay = HUB_LONG_RESET_TIME;
1490 	}
1491 
1492 	dev_err (hub->intfdev,
1493 		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
1494 		port1);
1495 
1496 	return status;
1497 }
1498 
1499 /*
1500  * Disable a port and mark a logical connnect-change event, so that some
1501  * time later khubd will disconnect() any existing usb_device on the port
1502  * and will re-enumerate if there actually is a device attached.
1503  */
1504 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
1505 {
1506 	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
1507 	hub_port_disable(hub, port1, 1);
1508 
1509 	/* FIXME let caller ask to power down the port:
1510 	 *  - some devices won't enumerate without a VBUS power cycle
1511 	 *  - SRP saves power that way
1512 	 *  - usb_suspend_device(dev, PMSG_SUSPEND)
1513 	 * That's easy if this hub can switch power per-port, and
1514 	 * khubd reactivates the port later (timer, SRP, etc).
1515 	 * Powerdown must be optional, because of reset/DFU.
1516 	 */
1517 
1518 	set_bit(port1, hub->change_bits);
1519  	kick_khubd(hub);
1520 }
1521 
1522 
1523 #ifdef	CONFIG_USB_SUSPEND
1524 
1525 /*
1526  * Selective port suspend reduces power; most suspended devices draw
1527  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1528  * All devices below the suspended port are also suspended.
1529  *
1530  * Devices leave suspend state when the host wakes them up.  Some devices
1531  * also support "remote wakeup", where the device can activate the USB
1532  * tree above them to deliver data, such as a keypress or packet.  In
1533  * some cases, this wakes the USB host.
1534  */
1535 static int hub_port_suspend(struct usb_hub *hub, int port1,
1536 		struct usb_device *udev)
1537 {
1538 	int	status;
1539 
1540 	// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1541 
1542 	/* enable remote wakeup when appropriate; this lets the device
1543 	 * wake up the upstream hub (including maybe the root hub).
1544 	 *
1545 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1546 	 * we don't explicitly enable it here.
1547 	 */
1548 	if (udev->actconfig
1549 			// && FIXME (remote wakeup enabled on this bus)
1550 			// ... currently assuming it's always appropriate
1551 			&& (udev->actconfig->desc.bmAttributes
1552 				& USB_CONFIG_ATT_WAKEUP) != 0) {
1553 		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1554 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1555 				USB_DEVICE_REMOTE_WAKEUP, 0,
1556 				NULL, 0,
1557 				USB_CTRL_SET_TIMEOUT);
1558 		if (status)
1559 			dev_dbg(&udev->dev,
1560 				"won't remote wakeup, status %d\n",
1561 				status);
1562 	}
1563 
1564 	/* see 7.1.7.6 */
1565 	status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1566 	if (status) {
1567 		dev_dbg(hub->intfdev,
1568 			"can't suspend port %d, status %d\n",
1569 			port1, status);
1570 		/* paranoia:  "should not happen" */
1571 		(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1572 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1573 				USB_DEVICE_REMOTE_WAKEUP, 0,
1574 				NULL, 0,
1575 				USB_CTRL_SET_TIMEOUT);
1576 	} else {
1577 		/* device has up to 10 msec to fully suspend */
1578 		dev_dbg(&udev->dev, "usb suspend\n");
1579 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
1580 		msleep(10);
1581 	}
1582 	return status;
1583 }
1584 
1585 /*
1586  * Devices on USB hub ports have only one "suspend" state, corresponding
1587  * to ACPI D2, "may cause the device to lose some context".
1588  * State transitions include:
1589  *
1590  *   - suspend, resume ... when the VBUS power link stays live
1591  *   - suspend, disconnect ... VBUS lost
1592  *
1593  * Once VBUS drop breaks the circuit, the port it's using has to go through
1594  * normal re-enumeration procedures, starting with enabling VBUS power.
1595  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1596  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1597  * timer, no SRP, no requests through sysfs.
1598  */
1599 static int __usb_suspend_device (struct usb_device *udev, int port1,
1600 				 pm_message_t state)
1601 {
1602 	int	status;
1603 
1604 	/* caller owns the udev device lock */
1605 	if (port1 < 0)
1606 		return port1;
1607 
1608 	if (udev->state == USB_STATE_SUSPENDED
1609 			|| udev->state == USB_STATE_NOTATTACHED) {
1610 		return 0;
1611 	}
1612 
1613 	/* suspend interface drivers; if this is a hub, it
1614 	 * suspends the child devices
1615 	 */
1616 	if (udev->actconfig) {
1617 		int	i;
1618 
1619 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1620 			struct usb_interface	*intf;
1621 			struct usb_driver	*driver;
1622 
1623 			intf = udev->actconfig->interface[i];
1624 			if (state.event <= intf->dev.power.power_state.event)
1625 				continue;
1626 			if (!intf->dev.driver)
1627 				continue;
1628 			driver = to_usb_driver(intf->dev.driver);
1629 
1630 			if (driver->suspend) {
1631 				status = driver->suspend(intf, state);
1632 				if (intf->dev.power.power_state.event != state.event
1633 						|| status)
1634 					dev_err(&intf->dev,
1635 						"suspend %d fail, code %d\n",
1636 						state.event, status);
1637 			}
1638 
1639 			/* only drivers with suspend() can ever resume();
1640 			 * and after power loss, even they won't.
1641 			 * bus_rescan_devices() can rebind drivers later.
1642 			 *
1643 			 * FIXME the PM core self-deadlocks when unbinding
1644 			 * drivers during suspend/resume ... everything grabs
1645 			 * dpm_sem (not a spinlock, ugh).  we want to unbind,
1646 			 * since we know every driver's probe/disconnect works
1647 			 * even for drivers that can't suspend.
1648 			 */
1649 			if (!driver->suspend || state.event > PM_EVENT_FREEZE) {
1650 #if 1
1651 				dev_warn(&intf->dev, "resume is unsafe!\n");
1652 #else
1653 				down_write(&usb_bus_type.rwsem);
1654 				device_release_driver(&intf->dev);
1655 				up_write(&usb_bus_type.rwsem);
1656 #endif
1657 			}
1658 		}
1659 	}
1660 
1661 	/*
1662 	 * FIXME this needs port power off call paths too, to help force
1663 	 * USB into the "generic" PM model.  At least for devices on
1664 	 * ports that aren't using ganged switching (usually root hubs).
1665 	 *
1666 	 * NOTE: SRP-capable links should adopt more aggressive poweroff
1667 	 * policies (when HNP doesn't apply) once we have mechanisms to
1668 	 * turn power back on!  (Likely not before 2.7...)
1669 	 */
1670 	if (state.event > PM_EVENT_FREEZE) {
1671 		dev_warn(&udev->dev, "no poweroff yet, suspending instead\n");
1672 	}
1673 
1674 	/* "global suspend" of the HC-to-USB interface (root hub), or
1675 	 * "selective suspend" of just one hub-device link.
1676 	 */
1677 	if (!udev->parent) {
1678 		struct usb_bus	*bus = udev->bus;
1679 		if (bus && bus->op->hub_suspend) {
1680 			status = bus->op->hub_suspend (bus);
1681 			if (status == 0) {
1682 				dev_dbg(&udev->dev, "usb suspend\n");
1683 				usb_set_device_state(udev,
1684 						USB_STATE_SUSPENDED);
1685 			}
1686 		} else
1687 			status = -EOPNOTSUPP;
1688 	} else
1689 		status = hub_port_suspend(hdev_to_hub(udev->parent), port1,
1690 				udev);
1691 
1692 	if (status == 0)
1693 		udev->dev.power.power_state = state;
1694 	return status;
1695 }
1696 
1697 /**
1698  * usb_suspend_device - suspend a usb device
1699  * @udev: device that's no longer in active use
1700  * @state: PMSG_SUSPEND to suspend
1701  * Context: must be able to sleep; device not locked
1702  *
1703  * Suspends a USB device that isn't in active use, conserving power.
1704  * Devices may wake out of a suspend, if anything important happens,
1705  * using the remote wakeup mechanism.  They may also be taken out of
1706  * suspend by the host, using usb_resume_device().  It's also routine
1707  * to disconnect devices while they are suspended.
1708  *
1709  * Suspending OTG devices may trigger HNP, if that's been enabled
1710  * between a pair of dual-role devices.  That will change roles, such
1711  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1712  *
1713  * Returns 0 on success, else negative errno.
1714  */
1715 int usb_suspend_device(struct usb_device *udev, pm_message_t state)
1716 {
1717 	int	port1, status;
1718 
1719 	port1 = locktree(udev);
1720 	if (port1 < 0)
1721 		return port1;
1722 
1723 	status = __usb_suspend_device(udev, port1, state);
1724 	usb_unlock_device(udev);
1725 	return status;
1726 }
1727 
1728 /*
1729  * hardware resume signaling is finished, either because of selective
1730  * resume (by host) or remote wakeup (by device) ... now see what changed
1731  * in the tree that's rooted at this device.
1732  */
1733 static int finish_port_resume(struct usb_device *udev)
1734 {
1735 	int	status;
1736 	u16	devstatus;
1737 
1738 	/* caller owns the udev device lock */
1739 	dev_dbg(&udev->dev, "usb resume\n");
1740 
1741 	/* usb ch9 identifies four variants of SUSPENDED, based on what
1742 	 * state the device resumes to.  Linux currently won't see the
1743 	 * first two on the host side; they'd be inside hub_port_init()
1744 	 * during many timeouts, but khubd can't suspend until later.
1745 	 */
1746 	usb_set_device_state(udev, udev->actconfig
1747 			? USB_STATE_CONFIGURED
1748 			: USB_STATE_ADDRESS);
1749 	udev->dev.power.power_state = PMSG_ON;
1750 
1751  	/* 10.5.4.5 says be sure devices in the tree are still there.
1752  	 * For now let's assume the device didn't go crazy on resume,
1753 	 * and device drivers will know about any resume quirks.
1754 	 */
1755 	status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1756 	if (status < 0)
1757 		dev_dbg(&udev->dev,
1758 			"gone after usb resume? status %d\n",
1759 			status);
1760 	else if (udev->actconfig) {
1761 		unsigned	i;
1762 
1763 		le16_to_cpus(&devstatus);
1764 		if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
1765 			status = usb_control_msg(udev,
1766 					usb_sndctrlpipe(udev, 0),
1767 					USB_REQ_CLEAR_FEATURE,
1768 						USB_RECIP_DEVICE,
1769 					USB_DEVICE_REMOTE_WAKEUP, 0,
1770 					NULL, 0,
1771 					USB_CTRL_SET_TIMEOUT);
1772 			if (status) {
1773 				dev_dbg(&udev->dev, "disable remote "
1774 					"wakeup, status %d\n", status);
1775 				status = 0;
1776 			}
1777 		}
1778 
1779 		/* resume interface drivers; if this is a hub, it
1780 		 * resumes the child devices
1781 		 */
1782 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1783 			struct usb_interface	*intf;
1784 			struct usb_driver	*driver;
1785 
1786 			intf = udev->actconfig->interface[i];
1787 			if (intf->dev.power.power_state.event == PM_EVENT_ON)
1788 				continue;
1789 			if (!intf->dev.driver) {
1790 				/* FIXME maybe force to alt 0 */
1791 				continue;
1792 			}
1793 			driver = to_usb_driver(intf->dev.driver);
1794 
1795 			/* bus_rescan_devices() may rebind drivers */
1796 			if (!driver->resume)
1797 				continue;
1798 
1799 			/* can we do better than just logging errors? */
1800 			status = driver->resume(intf);
1801 			if (intf->dev.power.power_state.event != PM_EVENT_ON
1802 					|| status)
1803 				dev_dbg(&intf->dev,
1804 					"resume fail, state %d code %d\n",
1805 					intf->dev.power.power_state.event, status);
1806 		}
1807 		status = 0;
1808 
1809 	} else if (udev->devnum <= 0) {
1810 		dev_dbg(&udev->dev, "bogus resume!\n");
1811 		status = -EINVAL;
1812 	}
1813 	return status;
1814 }
1815 
1816 static int
1817 hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
1818 {
1819 	int	status;
1820 
1821 	// dev_dbg(hub->intfdev, "resume port %d\n", port1);
1822 
1823 	/* see 7.1.7.7; affects power usage, but not budgeting */
1824 	status = clear_port_feature(hub->hdev,
1825 			port1, USB_PORT_FEAT_SUSPEND);
1826 	if (status) {
1827 		dev_dbg(hub->intfdev,
1828 			"can't resume port %d, status %d\n",
1829 			port1, status);
1830 	} else {
1831 		u16		devstatus;
1832 		u16		portchange;
1833 
1834 		/* drive resume for at least 20 msec */
1835 		if (udev)
1836 			dev_dbg(&udev->dev, "RESUME\n");
1837 		msleep(25);
1838 
1839 #define LIVE_FLAGS	( USB_PORT_STAT_POWER \
1840 			| USB_PORT_STAT_ENABLE \
1841 			| USB_PORT_STAT_CONNECTION)
1842 
1843 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
1844 		 * stop resume signaling.  Then finish the resume
1845 		 * sequence.
1846 		 */
1847 		devstatus = portchange = 0;
1848 		status = hub_port_status(hub, port1,
1849 				&devstatus, &portchange);
1850 		if (status < 0
1851 				|| (devstatus & LIVE_FLAGS) != LIVE_FLAGS
1852 				|| (devstatus & USB_PORT_STAT_SUSPEND) != 0
1853 				) {
1854 			dev_dbg(hub->intfdev,
1855 				"port %d status %04x.%04x after resume, %d\n",
1856 				port1, portchange, devstatus, status);
1857 		} else {
1858 			/* TRSMRCY = 10 msec */
1859 			msleep(10);
1860 			if (udev)
1861 				status = finish_port_resume(udev);
1862 		}
1863 	}
1864 	if (status < 0)
1865 		hub_port_logical_disconnect(hub, port1);
1866 
1867 	return status;
1868 }
1869 
1870 static int hub_resume (struct usb_interface *intf);
1871 
1872 /**
1873  * usb_resume_device - re-activate a suspended usb device
1874  * @udev: device to re-activate
1875  * Context: must be able to sleep; device not locked
1876  *
1877  * This will re-activate the suspended device, increasing power usage
1878  * while letting drivers communicate again with its endpoints.
1879  * USB resume explicitly guarantees that the power session between
1880  * the host and the device is the same as it was when the device
1881  * suspended.
1882  *
1883  * Returns 0 on success, else negative errno.
1884  */
1885 int usb_resume_device(struct usb_device *udev)
1886 {
1887 	int	port1, status;
1888 
1889 	port1 = locktree(udev);
1890 	if (port1 < 0)
1891 		return port1;
1892 
1893 	/* "global resume" of the HC-to-USB interface (root hub), or
1894 	 * selective resume of one hub-to-device port
1895 	 */
1896 	if (!udev->parent) {
1897 		struct usb_bus	*bus = udev->bus;
1898 		if (bus && bus->op->hub_resume) {
1899 			status = bus->op->hub_resume (bus);
1900 		} else
1901 			status = -EOPNOTSUPP;
1902 		if (status == 0) {
1903 			dev_dbg(&udev->dev, "usb resume\n");
1904 			/* TRSMRCY = 10 msec */
1905 			msleep(10);
1906 			usb_set_device_state (udev, USB_STATE_CONFIGURED);
1907 			udev->dev.power.power_state = PMSG_ON;
1908 			status = hub_resume (udev
1909 					->actconfig->interface[0]);
1910 		}
1911 	} else if (udev->state == USB_STATE_SUSPENDED) {
1912 		// NOTE this fails if parent is also suspended...
1913 		status = hub_port_resume(hdev_to_hub(udev->parent),
1914 				port1, udev);
1915 	} else {
1916 		status = 0;
1917 	}
1918 	if (status < 0) {
1919 		dev_dbg(&udev->dev, "can't resume, status %d\n",
1920 			status);
1921 	}
1922 
1923 	usb_unlock_device(udev);
1924 
1925 	/* rebind drivers that had no suspend() */
1926 	if (status == 0) {
1927 		usb_lock_all_devices();
1928 		bus_rescan_devices(&usb_bus_type);
1929 		usb_unlock_all_devices();
1930 	}
1931 	return status;
1932 }
1933 
1934 static int remote_wakeup(struct usb_device *udev)
1935 {
1936 	int	status = 0;
1937 
1938 	/* don't repeat RESUME sequence if this device
1939 	 * was already woken up by some other task
1940 	 */
1941 	down(&udev->serialize);
1942 	if (udev->state == USB_STATE_SUSPENDED) {
1943 		dev_dbg(&udev->dev, "RESUME (wakeup)\n");
1944 		/* TRSMRCY = 10 msec */
1945 		msleep(10);
1946 		status = finish_port_resume(udev);
1947 	}
1948 	up(&udev->serialize);
1949 	return status;
1950 }
1951 
1952 static int hub_suspend(struct usb_interface *intf, pm_message_t state)
1953 {
1954 	struct usb_hub		*hub = usb_get_intfdata (intf);
1955 	struct usb_device	*hdev = hub->hdev;
1956 	unsigned		port1;
1957 	int			status;
1958 
1959 	/* stop khubd and related activity */
1960 	hub_quiesce(hub);
1961 
1962 	/* then suspend every port */
1963 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1964 		struct usb_device	*udev;
1965 
1966 		udev = hdev->children [port1-1];
1967 		if (!udev)
1968 			continue;
1969 		down(&udev->serialize);
1970 		status = __usb_suspend_device(udev, port1, state);
1971 		up(&udev->serialize);
1972 		if (status < 0)
1973 			dev_dbg(&intf->dev, "suspend port %d --> %d\n",
1974 				port1, status);
1975 	}
1976 
1977 	intf->dev.power.power_state = state;
1978 	return 0;
1979 }
1980 
1981 static int hub_resume(struct usb_interface *intf)
1982 {
1983 	struct usb_device	*hdev = interface_to_usbdev(intf);
1984 	struct usb_hub		*hub = usb_get_intfdata (intf);
1985 	unsigned		port1;
1986 	int			status;
1987 
1988 	if (intf->dev.power.power_state.event == PM_EVENT_ON)
1989 		return 0;
1990 
1991 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1992 		struct usb_device	*udev;
1993 		u16			portstat, portchange;
1994 
1995 		udev = hdev->children [port1-1];
1996 		status = hub_port_status(hub, port1, &portstat, &portchange);
1997 		if (status == 0) {
1998 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
1999 				clear_port_feature(hdev, port1,
2000 					USB_PORT_FEAT_C_SUSPEND);
2001 				portchange &= ~USB_PORT_STAT_C_SUSPEND;
2002 			}
2003 
2004 			/* let khubd handle disconnects etc */
2005 			if (portchange)
2006 				continue;
2007 		}
2008 
2009 		if (!udev || status < 0)
2010 			continue;
2011 		down (&udev->serialize);
2012 		if (portstat & USB_PORT_STAT_SUSPEND)
2013 			status = hub_port_resume(hub, port1, udev);
2014 		else {
2015 			status = finish_port_resume(udev);
2016 			if (status < 0) {
2017 				dev_dbg(&intf->dev, "resume port %d --> %d\n",
2018 					port1, status);
2019 				hub_port_logical_disconnect(hub, port1);
2020 			}
2021 		}
2022 		up(&udev->serialize);
2023 	}
2024 	intf->dev.power.power_state = PMSG_ON;
2025 
2026 	hub->resume_root_hub = 0;
2027 	hub_activate(hub);
2028 	return 0;
2029 }
2030 
2031 void usb_resume_root_hub(struct usb_device *hdev)
2032 {
2033 	struct usb_hub *hub = hdev_to_hub(hdev);
2034 
2035 	hub->resume_root_hub = 1;
2036 	kick_khubd(hub);
2037 }
2038 
2039 #else	/* !CONFIG_USB_SUSPEND */
2040 
2041 int usb_suspend_device(struct usb_device *udev, pm_message_t state)
2042 {
2043 	return 0;
2044 }
2045 
2046 int usb_resume_device(struct usb_device *udev)
2047 {
2048 	return 0;
2049 }
2050 
2051 #define	hub_suspend		NULL
2052 #define	hub_resume		NULL
2053 #define	remote_wakeup(x)	0
2054 
2055 #endif	/* CONFIG_USB_SUSPEND */
2056 
2057 EXPORT_SYMBOL(usb_suspend_device);
2058 EXPORT_SYMBOL(usb_resume_device);
2059 
2060 
2061 
2062 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2063  *
2064  * Between connect detection and reset signaling there must be a delay
2065  * of 100ms at least for debounce and power-settling.  The corresponding
2066  * timer shall restart whenever the downstream port detects a disconnect.
2067  *
2068  * Apparently there are some bluetooth and irda-dongles and a number of
2069  * low-speed devices for which this debounce period may last over a second.
2070  * Not covered by the spec - but easy to deal with.
2071  *
2072  * This implementation uses a 1500ms total debounce timeout; if the
2073  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
2074  * every 25ms for transient disconnects.  When the port status has been
2075  * unchanged for 100ms it returns the port status.
2076  */
2077 
2078 #define HUB_DEBOUNCE_TIMEOUT	1500
2079 #define HUB_DEBOUNCE_STEP	  25
2080 #define HUB_DEBOUNCE_STABLE	 100
2081 
2082 static int hub_port_debounce(struct usb_hub *hub, int port1)
2083 {
2084 	int ret;
2085 	int total_time, stable_time = 0;
2086 	u16 portchange, portstatus;
2087 	unsigned connection = 0xffff;
2088 
2089 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2090 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
2091 		if (ret < 0)
2092 			return ret;
2093 
2094 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2095 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2096 			stable_time += HUB_DEBOUNCE_STEP;
2097 			if (stable_time >= HUB_DEBOUNCE_STABLE)
2098 				break;
2099 		} else {
2100 			stable_time = 0;
2101 			connection = portstatus & USB_PORT_STAT_CONNECTION;
2102 		}
2103 
2104 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
2105 			clear_port_feature(hub->hdev, port1,
2106 					USB_PORT_FEAT_C_CONNECTION);
2107 		}
2108 
2109 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2110 			break;
2111 		msleep(HUB_DEBOUNCE_STEP);
2112 	}
2113 
2114 	dev_dbg (hub->intfdev,
2115 		"debounce: port %d: total %dms stable %dms status 0x%x\n",
2116 		port1, total_time, stable_time, portstatus);
2117 
2118 	if (stable_time < HUB_DEBOUNCE_STABLE)
2119 		return -ETIMEDOUT;
2120 	return portstatus;
2121 }
2122 
2123 static void ep0_reinit(struct usb_device *udev)
2124 {
2125 	usb_disable_endpoint(udev, 0 + USB_DIR_IN);
2126 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
2127 	udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
2128 }
2129 
2130 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
2131 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
2132 
2133 static int hub_set_address(struct usb_device *udev)
2134 {
2135 	int retval;
2136 
2137 	if (udev->devnum == 0)
2138 		return -EINVAL;
2139 	if (udev->state == USB_STATE_ADDRESS)
2140 		return 0;
2141 	if (udev->state != USB_STATE_DEFAULT)
2142 		return -EINVAL;
2143 	retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2144 		USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
2145 		NULL, 0, USB_CTRL_SET_TIMEOUT);
2146 	if (retval == 0) {
2147 		usb_set_device_state(udev, USB_STATE_ADDRESS);
2148 		ep0_reinit(udev);
2149 	}
2150 	return retval;
2151 }
2152 
2153 /* Reset device, (re)assign address, get device descriptor.
2154  * Device connection must be stable, no more debouncing needed.
2155  * Returns device in USB_STATE_ADDRESS, except on error.
2156  *
2157  * If this is called for an already-existing device (as part of
2158  * usb_reset_device), the caller must own the device lock.  For a
2159  * newly detected device that is not accessible through any global
2160  * pointers, it's not necessary to lock the device.
2161  */
2162 static int
2163 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2164 		int retry_counter)
2165 {
2166 	static DECLARE_MUTEX(usb_address0_sem);
2167 
2168 	struct usb_device	*hdev = hub->hdev;
2169 	int			i, j, retval;
2170 	unsigned		delay = HUB_SHORT_RESET_TIME;
2171 	enum usb_device_speed	oldspeed = udev->speed;
2172 
2173 	/* root hub ports have a slightly longer reset period
2174 	 * (from USB 2.0 spec, section 7.1.7.5)
2175 	 */
2176 	if (!hdev->parent) {
2177 		delay = HUB_ROOT_RESET_TIME;
2178 		if (port1 == hdev->bus->otg_port)
2179 			hdev->bus->b_hnp_enable = 0;
2180 	}
2181 
2182 	/* Some low speed devices have problems with the quick delay, so */
2183 	/*  be a bit pessimistic with those devices. RHbug #23670 */
2184 	if (oldspeed == USB_SPEED_LOW)
2185 		delay = HUB_LONG_RESET_TIME;
2186 
2187 	down(&usb_address0_sem);
2188 
2189 	/* Reset the device; full speed may morph to high speed */
2190 	retval = hub_port_reset(hub, port1, udev, delay);
2191 	if (retval < 0)		/* error or disconnect */
2192 		goto fail;
2193 				/* success, speed is known */
2194 	retval = -ENODEV;
2195 
2196 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2197 		dev_dbg(&udev->dev, "device reset changed speed!\n");
2198 		goto fail;
2199 	}
2200 	oldspeed = udev->speed;
2201 
2202 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2203 	 * it's fixed size except for full speed devices.
2204 	 */
2205 	switch (udev->speed) {
2206 	case USB_SPEED_HIGH:		/* fixed at 64 */
2207 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2208 		break;
2209 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
2210 		/* to determine the ep0 maxpacket size, try to read
2211 		 * the device descriptor to get bMaxPacketSize0 and
2212 		 * then correct our initial guess.
2213 		 */
2214 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2215 		break;
2216 	case USB_SPEED_LOW:		/* fixed at 8 */
2217 		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2218 		break;
2219 	default:
2220 		goto fail;
2221 	}
2222 
2223 	dev_info (&udev->dev,
2224 			"%s %s speed USB device using %s and address %d\n",
2225 			(udev->config) ? "reset" : "new",
2226 			({ char *speed; switch (udev->speed) {
2227 			case USB_SPEED_LOW:	speed = "low";	break;
2228 			case USB_SPEED_FULL:	speed = "full";	break;
2229 			case USB_SPEED_HIGH:	speed = "high";	break;
2230 			default: 		speed = "?";	break;
2231 			}; speed;}),
2232 			udev->bus->controller->driver->name,
2233 			udev->devnum);
2234 
2235 	/* Set up TT records, if needed  */
2236 	if (hdev->tt) {
2237 		udev->tt = hdev->tt;
2238 		udev->ttport = hdev->ttport;
2239 	} else if (udev->speed != USB_SPEED_HIGH
2240 			&& hdev->speed == USB_SPEED_HIGH) {
2241 		udev->tt = &hub->tt;
2242 		udev->ttport = port1;
2243 	}
2244 
2245 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2246 	 * Because device hardware and firmware is sometimes buggy in
2247 	 * this area, and this is how Linux has done it for ages.
2248 	 * Change it cautiously.
2249 	 *
2250 	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2251 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2252 	 * so it may help with some non-standards-compliant devices.
2253 	 * Otherwise we start with SET_ADDRESS and then try to read the
2254 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2255 	 * value.
2256 	 */
2257 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2258 		if (USE_NEW_SCHEME(retry_counter)) {
2259 			struct usb_device_descriptor *buf;
2260 			int r = 0;
2261 
2262 #define GET_DESCRIPTOR_BUFSIZE	64
2263 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2264 			if (!buf) {
2265 				retval = -ENOMEM;
2266 				continue;
2267 			}
2268 
2269 			/* Use a short timeout the first time through,
2270 			 * so that recalcitrant full-speed devices with
2271 			 * 8- or 16-byte ep0-maxpackets won't slow things
2272 			 * down tremendously by NAKing the unexpectedly
2273 			 * early status stage.  Also, retry on all errors;
2274 			 * some devices are flakey.
2275 			 */
2276 			for (j = 0; j < 3; ++j) {
2277 				buf->bMaxPacketSize0 = 0;
2278 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2279 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2280 					USB_DT_DEVICE << 8, 0,
2281 					buf, GET_DESCRIPTOR_BUFSIZE,
2282 					(i ? USB_CTRL_GET_TIMEOUT : 1000));
2283 				switch (buf->bMaxPacketSize0) {
2284 				case 8: case 16: case 32: case 64:
2285 					if (buf->bDescriptorType ==
2286 							USB_DT_DEVICE) {
2287 						r = 0;
2288 						break;
2289 					}
2290 					/* FALL THROUGH */
2291 				default:
2292 					if (r == 0)
2293 						r = -EPROTO;
2294 					break;
2295 				}
2296 				if (r == 0)
2297 					break;
2298 			}
2299 			udev->descriptor.bMaxPacketSize0 =
2300 					buf->bMaxPacketSize0;
2301 			kfree(buf);
2302 
2303 			retval = hub_port_reset(hub, port1, udev, delay);
2304 			if (retval < 0)		/* error or disconnect */
2305 				goto fail;
2306 			if (oldspeed != udev->speed) {
2307 				dev_dbg(&udev->dev,
2308 					"device reset changed speed!\n");
2309 				retval = -ENODEV;
2310 				goto fail;
2311 			}
2312 			if (r) {
2313 				dev_err(&udev->dev, "device descriptor "
2314 						"read/%s, error %d\n",
2315 						"64", r);
2316 				retval = -EMSGSIZE;
2317 				continue;
2318 			}
2319 #undef GET_DESCRIPTOR_BUFSIZE
2320 		}
2321 
2322 		for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2323 			retval = hub_set_address(udev);
2324 			if (retval >= 0)
2325 				break;
2326 			msleep(200);
2327 		}
2328 		if (retval < 0) {
2329 			dev_err(&udev->dev,
2330 				"device not accepting address %d, error %d\n",
2331 				udev->devnum, retval);
2332 			goto fail;
2333 		}
2334 
2335 		/* cope with hardware quirkiness:
2336 		 *  - let SET_ADDRESS settle, some device hardware wants it
2337 		 *  - read ep0 maxpacket even for high and low speed,
2338   		 */
2339 		msleep(10);
2340 		if (USE_NEW_SCHEME(retry_counter))
2341 			break;
2342 
2343 		retval = usb_get_device_descriptor(udev, 8);
2344 		if (retval < 8) {
2345 			dev_err(&udev->dev, "device descriptor "
2346 					"read/%s, error %d\n",
2347 					"8", retval);
2348 			if (retval >= 0)
2349 				retval = -EMSGSIZE;
2350 		} else {
2351 			retval = 0;
2352 			break;
2353 		}
2354 	}
2355 	if (retval)
2356 		goto fail;
2357 
2358 	i = udev->descriptor.bMaxPacketSize0;
2359 	if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2360 		if (udev->speed != USB_SPEED_FULL ||
2361 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
2362 			dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2363 			retval = -EMSGSIZE;
2364 			goto fail;
2365 		}
2366 		dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2367 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2368 		ep0_reinit(udev);
2369 	}
2370 
2371 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2372 	if (retval < (signed)sizeof(udev->descriptor)) {
2373 		dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2374 			"all", retval);
2375 		if (retval >= 0)
2376 			retval = -ENOMSG;
2377 		goto fail;
2378 	}
2379 
2380 	retval = 0;
2381 
2382 fail:
2383 	if (retval)
2384 		hub_port_disable(hub, port1, 0);
2385 	up(&usb_address0_sem);
2386 	return retval;
2387 }
2388 
2389 static void
2390 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2391 {
2392 	struct usb_qualifier_descriptor	*qual;
2393 	int				status;
2394 
2395 	qual = kmalloc (sizeof *qual, SLAB_KERNEL);
2396 	if (qual == NULL)
2397 		return;
2398 
2399 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2400 			qual, sizeof *qual);
2401 	if (status == sizeof *qual) {
2402 		dev_info(&udev->dev, "not running at top speed; "
2403 			"connect to a high speed hub\n");
2404 		/* hub LEDs are probably harder to miss than syslog */
2405 		if (hub->has_indicators) {
2406 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2407 			schedule_work (&hub->leds);
2408 		}
2409 	}
2410 	kfree(qual);
2411 }
2412 
2413 static unsigned
2414 hub_power_remaining (struct usb_hub *hub)
2415 {
2416 	struct usb_device *hdev = hub->hdev;
2417 	int remaining;
2418 	unsigned i;
2419 
2420 	remaining = hub->power_budget;
2421 	if (!remaining)		/* self-powered */
2422 		return 0;
2423 
2424 	for (i = 0; i < hdev->maxchild; i++) {
2425 		struct usb_device	*udev = hdev->children[i];
2426 		int			delta, ceiling;
2427 
2428 		if (!udev)
2429 			continue;
2430 
2431 		/* 100mA per-port ceiling, or 8mA for OTG ports */
2432 		if (i != (udev->bus->otg_port - 1) || hdev->parent)
2433 			ceiling = 50;
2434 		else
2435 			ceiling = 4;
2436 
2437 		if (udev->actconfig)
2438 			delta = udev->actconfig->desc.bMaxPower;
2439 		else
2440 			delta = ceiling;
2441 		// dev_dbg(&udev->dev, "budgeted %dmA\n", 2 * delta);
2442 		if (delta > ceiling)
2443 			dev_warn(&udev->dev, "%dmA over %dmA budget!\n",
2444 				2 * (delta - ceiling), 2 * ceiling);
2445 		remaining -= delta;
2446 	}
2447 	if (remaining < 0) {
2448 		dev_warn(hub->intfdev,
2449 			"%dmA over power budget!\n",
2450 			-2 * remaining);
2451 		remaining = 0;
2452 	}
2453 	return remaining;
2454 }
2455 
2456 /* Handle physical or logical connection change events.
2457  * This routine is called when:
2458  * 	a port connection-change occurs;
2459  *	a port enable-change occurs (often caused by EMI);
2460  *	usb_reset_device() encounters changed descriptors (as from
2461  *		a firmware download)
2462  * caller already locked the hub
2463  */
2464 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2465 					u16 portstatus, u16 portchange)
2466 {
2467 	struct usb_device *hdev = hub->hdev;
2468 	struct device *hub_dev = hub->intfdev;
2469 	int status, i;
2470 
2471 	dev_dbg (hub_dev,
2472 		"port %d, status %04x, change %04x, %s\n",
2473 		port1, portstatus, portchange, portspeed (portstatus));
2474 
2475 	if (hub->has_indicators) {
2476 		set_port_led(hub, port1, HUB_LED_AUTO);
2477 		hub->indicator[port1-1] = INDICATOR_AUTO;
2478 	}
2479 
2480 	/* Disconnect any existing devices under this port */
2481 	if (hdev->children[port1-1])
2482 		usb_disconnect(&hdev->children[port1-1]);
2483 	clear_bit(port1, hub->change_bits);
2484 
2485 #ifdef	CONFIG_USB_OTG
2486 	/* during HNP, don't repeat the debounce */
2487 	if (hdev->bus->is_b_host)
2488 		portchange &= ~USB_PORT_STAT_C_CONNECTION;
2489 #endif
2490 
2491 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
2492 		status = hub_port_debounce(hub, port1);
2493 		if (status < 0) {
2494 			dev_err (hub_dev,
2495 				"connect-debounce failed, port %d disabled\n",
2496 				port1);
2497 			goto done;
2498 		}
2499 		portstatus = status;
2500 	}
2501 
2502 	/* Return now if nothing is connected */
2503 	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2504 
2505 		/* maybe switch power back on (e.g. root hub was reset) */
2506 		if ((hub->descriptor->wHubCharacteristics
2507 					& HUB_CHAR_LPSM) < 2
2508 				&& !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2509 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2510 
2511 		if (portstatus & USB_PORT_STAT_ENABLE)
2512   			goto done;
2513 		return;
2514 	}
2515 
2516 #ifdef  CONFIG_USB_SUSPEND
2517 	/* If something is connected, but the port is suspended, wake it up. */
2518 	if (portstatus & USB_PORT_STAT_SUSPEND) {
2519 		status = hub_port_resume(hub, port1, NULL);
2520 		if (status < 0) {
2521 			dev_dbg(hub_dev,
2522 				"can't clear suspend on port %d; %d\n",
2523 				port1, status);
2524 			goto done;
2525 		}
2526 	}
2527 #endif
2528 
2529 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
2530 		struct usb_device *udev;
2531 
2532 		/* reallocate for each attempt, since references
2533 		 * to the previous one can escape in various ways
2534 		 */
2535 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
2536 		if (!udev) {
2537 			dev_err (hub_dev,
2538 				"couldn't allocate port %d usb_device\n",
2539 				port1);
2540 			goto done;
2541 		}
2542 
2543 		usb_set_device_state(udev, USB_STATE_POWERED);
2544 		udev->speed = USB_SPEED_UNKNOWN;
2545 
2546 		/* set the address */
2547 		choose_address(udev);
2548 		if (udev->devnum <= 0) {
2549 			status = -ENOTCONN;	/* Don't retry */
2550 			goto loop;
2551 		}
2552 
2553 		/* reset and get descriptor */
2554 		status = hub_port_init(hub, udev, port1, i);
2555 		if (status < 0)
2556 			goto loop;
2557 
2558 		/* consecutive bus-powered hubs aren't reliable; they can
2559 		 * violate the voltage drop budget.  if the new child has
2560 		 * a "powered" LED, users should notice we didn't enable it
2561 		 * (without reading syslog), even without per-port LEDs
2562 		 * on the parent.
2563 		 */
2564 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2565 				&& hub->power_budget) {
2566 			u16	devstat;
2567 
2568 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2569 					&devstat);
2570 			if (status < 0) {
2571 				dev_dbg(&udev->dev, "get status %d ?\n", status);
2572 				goto loop_disable;
2573 			}
2574 			cpu_to_le16s(&devstat);
2575 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2576 				dev_err(&udev->dev,
2577 					"can't connect bus-powered hub "
2578 					"to this port\n");
2579 				if (hub->has_indicators) {
2580 					hub->indicator[port1-1] =
2581 						INDICATOR_AMBER_BLINK;
2582 					schedule_work (&hub->leds);
2583 				}
2584 				status = -ENOTCONN;	/* Don't retry */
2585 				goto loop_disable;
2586 			}
2587 		}
2588 
2589 		/* check for devices running slower than they could */
2590 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2591 				&& udev->speed == USB_SPEED_FULL
2592 				&& highspeed_hubs != 0)
2593 			check_highspeed (hub, udev, port1);
2594 
2595 		/* Store the parent's children[] pointer.  At this point
2596 		 * udev becomes globally accessible, although presumably
2597 		 * no one will look at it until hdev is unlocked.
2598 		 */
2599 		down (&udev->serialize);
2600 		status = 0;
2601 
2602 		/* We mustn't add new devices if the parent hub has
2603 		 * been disconnected; we would race with the
2604 		 * recursively_mark_NOTATTACHED() routine.
2605 		 */
2606 		spin_lock_irq(&device_state_lock);
2607 		if (hdev->state == USB_STATE_NOTATTACHED)
2608 			status = -ENOTCONN;
2609 		else
2610 			hdev->children[port1-1] = udev;
2611 		spin_unlock_irq(&device_state_lock);
2612 
2613 		/* Run it through the hoops (find a driver, etc) */
2614 		if (!status) {
2615 			status = usb_new_device(udev);
2616 			if (status) {
2617 				spin_lock_irq(&device_state_lock);
2618 				hdev->children[port1-1] = NULL;
2619 				spin_unlock_irq(&device_state_lock);
2620 			}
2621 		}
2622 
2623 		up (&udev->serialize);
2624 		if (status)
2625 			goto loop_disable;
2626 
2627 		status = hub_power_remaining(hub);
2628 		if (status)
2629 			dev_dbg(hub_dev,
2630 				"%dmA power budget left\n",
2631 				2 * status);
2632 
2633 		return;
2634 
2635 loop_disable:
2636 		hub_port_disable(hub, port1, 1);
2637 loop:
2638 		ep0_reinit(udev);
2639 		release_address(udev);
2640 		usb_put_dev(udev);
2641 		if (status == -ENOTCONN)
2642 			break;
2643 	}
2644 
2645 done:
2646 	hub_port_disable(hub, port1, 1);
2647 }
2648 
2649 static void hub_events(void)
2650 {
2651 	struct list_head *tmp;
2652 	struct usb_device *hdev;
2653 	struct usb_interface *intf;
2654 	struct usb_hub *hub;
2655 	struct device *hub_dev;
2656 	u16 hubstatus;
2657 	u16 hubchange;
2658 	u16 portstatus;
2659 	u16 portchange;
2660 	int i, ret;
2661 	int connect_change;
2662 
2663 	/*
2664 	 *  We restart the list every time to avoid a deadlock with
2665 	 * deleting hubs downstream from this one. This should be
2666 	 * safe since we delete the hub from the event list.
2667 	 * Not the most efficient, but avoids deadlocks.
2668 	 */
2669 	while (1) {
2670 
2671 		/* Grab the first entry at the beginning of the list */
2672 		spin_lock_irq(&hub_event_lock);
2673 		if (list_empty(&hub_event_list)) {
2674 			spin_unlock_irq(&hub_event_lock);
2675 			break;
2676 		}
2677 
2678 		tmp = hub_event_list.next;
2679 		list_del_init(tmp);
2680 
2681 		hub = list_entry(tmp, struct usb_hub, event_list);
2682 		hdev = hub->hdev;
2683 		intf = to_usb_interface(hub->intfdev);
2684 		hub_dev = &intf->dev;
2685 
2686 		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
2687 				hdev->state, hub->descriptor
2688 					? hub->descriptor->bNbrPorts
2689 					: 0,
2690 				/* NOTE: expects max 15 ports... */
2691 				(u16) hub->change_bits[0],
2692 				(u16) hub->event_bits[0]);
2693 
2694 		usb_get_intf(intf);
2695 		i = hub->resume_root_hub;
2696 		spin_unlock_irq(&hub_event_lock);
2697 
2698 		/* Is this is a root hub wanting to be resumed? */
2699 		if (i)
2700 			usb_resume_device(hdev);
2701 
2702 		/* Lock the device, then check to see if we were
2703 		 * disconnected while waiting for the lock to succeed. */
2704 		if (locktree(hdev) < 0) {
2705 			usb_put_intf(intf);
2706 			continue;
2707 		}
2708 		if (hub != usb_get_intfdata(intf))
2709 			goto loop;
2710 
2711 		/* If the hub has died, clean up after it */
2712 		if (hdev->state == USB_STATE_NOTATTACHED) {
2713 			hub_pre_reset(hub);
2714 			goto loop;
2715 		}
2716 
2717 		/* If this is an inactive or suspended hub, do nothing */
2718 		if (hub->quiescing)
2719 			goto loop;
2720 
2721 		if (hub->error) {
2722 			dev_dbg (hub_dev, "resetting for error %d\n",
2723 				hub->error);
2724 
2725 			ret = usb_reset_device(hdev);
2726 			if (ret) {
2727 				dev_dbg (hub_dev,
2728 					"error resetting hub: %d\n", ret);
2729 				goto loop;
2730 			}
2731 
2732 			hub->nerrors = 0;
2733 			hub->error = 0;
2734 		}
2735 
2736 		/* deal with port status changes */
2737 		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2738 			if (test_bit(i, hub->busy_bits))
2739 				continue;
2740 			connect_change = test_bit(i, hub->change_bits);
2741 			if (!test_and_clear_bit(i, hub->event_bits) &&
2742 					!connect_change && !hub->activating)
2743 				continue;
2744 
2745 			ret = hub_port_status(hub, i,
2746 					&portstatus, &portchange);
2747 			if (ret < 0)
2748 				continue;
2749 
2750 			if (hub->activating && !hdev->children[i-1] &&
2751 					(portstatus &
2752 						USB_PORT_STAT_CONNECTION))
2753 				connect_change = 1;
2754 
2755 			if (portchange & USB_PORT_STAT_C_CONNECTION) {
2756 				clear_port_feature(hdev, i,
2757 					USB_PORT_FEAT_C_CONNECTION);
2758 				connect_change = 1;
2759 			}
2760 
2761 			if (portchange & USB_PORT_STAT_C_ENABLE) {
2762 				if (!connect_change)
2763 					dev_dbg (hub_dev,
2764 						"port %d enable change, "
2765 						"status %08x\n",
2766 						i, portstatus);
2767 				clear_port_feature(hdev, i,
2768 					USB_PORT_FEAT_C_ENABLE);
2769 
2770 				/*
2771 				 * EM interference sometimes causes badly
2772 				 * shielded USB devices to be shutdown by
2773 				 * the hub, this hack enables them again.
2774 				 * Works at least with mouse driver.
2775 				 */
2776 				if (!(portstatus & USB_PORT_STAT_ENABLE)
2777 				    && !connect_change
2778 				    && hdev->children[i-1]) {
2779 					dev_err (hub_dev,
2780 					    "port %i "
2781 					    "disabled by hub (EMI?), "
2782 					    "re-enabling...\n",
2783 						i);
2784 					connect_change = 1;
2785 				}
2786 			}
2787 
2788 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
2789 				clear_port_feature(hdev, i,
2790 					USB_PORT_FEAT_C_SUSPEND);
2791 				if (hdev->children[i-1]) {
2792 					ret = remote_wakeup(hdev->
2793 							children[i-1]);
2794 					if (ret < 0)
2795 						connect_change = 1;
2796 				} else {
2797 					ret = -ENODEV;
2798 					hub_port_disable(hub, i, 1);
2799 				}
2800 				dev_dbg (hub_dev,
2801 					"resume on port %d, status %d\n",
2802 					i, ret);
2803 			}
2804 
2805 			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2806 				dev_err (hub_dev,
2807 					"over-current change on port %d\n",
2808 					i);
2809 				clear_port_feature(hdev, i,
2810 					USB_PORT_FEAT_C_OVER_CURRENT);
2811 				hub_power_on(hub);
2812 			}
2813 
2814 			if (portchange & USB_PORT_STAT_C_RESET) {
2815 				dev_dbg (hub_dev,
2816 					"reset change on port %d\n",
2817 					i);
2818 				clear_port_feature(hdev, i,
2819 					USB_PORT_FEAT_C_RESET);
2820 			}
2821 
2822 			if (connect_change)
2823 				hub_port_connect_change(hub, i,
2824 						portstatus, portchange);
2825 		} /* end for i */
2826 
2827 		/* deal with hub status changes */
2828 		if (test_and_clear_bit(0, hub->event_bits) == 0)
2829 			;	/* do nothing */
2830 		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2831 			dev_err (hub_dev, "get_hub_status failed\n");
2832 		else {
2833 			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2834 				dev_dbg (hub_dev, "power change\n");
2835 				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2836 			}
2837 			if (hubchange & HUB_CHANGE_OVERCURRENT) {
2838 				dev_dbg (hub_dev, "overcurrent change\n");
2839 				msleep(500);	/* Cool down */
2840 				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2841                         	hub_power_on(hub);
2842 			}
2843 		}
2844 
2845 		hub->activating = 0;
2846 
2847 		/* If this is a root hub, tell the HCD it's okay to
2848 		 * re-enable port-change interrupts now. */
2849 		if (!hdev->parent)
2850 			usb_enable_root_hub_irq(hdev->bus);
2851 
2852 loop:
2853 		usb_unlock_device(hdev);
2854 		usb_put_intf(intf);
2855 
2856         } /* end while (1) */
2857 }
2858 
2859 static int hub_thread(void *__unused)
2860 {
2861 	do {
2862 		hub_events();
2863 		wait_event_interruptible(khubd_wait,
2864 				!list_empty(&hub_event_list) ||
2865 				kthread_should_stop());
2866 		try_to_freeze();
2867 	} while (!kthread_should_stop() || !list_empty(&hub_event_list));
2868 
2869 	pr_debug("%s: khubd exiting\n", usbcore_name);
2870 	return 0;
2871 }
2872 
2873 static struct usb_device_id hub_id_table [] = {
2874     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2875       .bDeviceClass = USB_CLASS_HUB},
2876     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2877       .bInterfaceClass = USB_CLASS_HUB},
2878     { }						/* Terminating entry */
2879 };
2880 
2881 MODULE_DEVICE_TABLE (usb, hub_id_table);
2882 
2883 static struct usb_driver hub_driver = {
2884 	.owner =	THIS_MODULE,
2885 	.name =		"hub",
2886 	.probe =	hub_probe,
2887 	.disconnect =	hub_disconnect,
2888 	.suspend =	hub_suspend,
2889 	.resume =	hub_resume,
2890 	.ioctl =	hub_ioctl,
2891 	.id_table =	hub_id_table,
2892 };
2893 
2894 int usb_hub_init(void)
2895 {
2896 	if (usb_register(&hub_driver) < 0) {
2897 		printk(KERN_ERR "%s: can't register hub driver\n",
2898 			usbcore_name);
2899 		return -1;
2900 	}
2901 
2902 	khubd_task = kthread_run(hub_thread, NULL, "khubd");
2903 	if (!IS_ERR(khubd_task))
2904 		return 0;
2905 
2906 	/* Fall through if kernel_thread failed */
2907 	usb_deregister(&hub_driver);
2908 	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2909 
2910 	return -1;
2911 }
2912 
2913 void usb_hub_cleanup(void)
2914 {
2915 	kthread_stop(khubd_task);
2916 
2917 	/*
2918 	 * Hub resources are freed for us by usb_deregister. It calls
2919 	 * usb_driver_purge on every device which in turn calls that
2920 	 * devices disconnect function if it is using this driver.
2921 	 * The hub_disconnect function takes care of releasing the
2922 	 * individual hub resources. -greg
2923 	 */
2924 	usb_deregister(&hub_driver);
2925 } /* usb_hub_cleanup() */
2926 
2927 static int config_descriptors_changed(struct usb_device *udev)
2928 {
2929 	unsigned			index;
2930 	unsigned			len = 0;
2931 	struct usb_config_descriptor	*buf;
2932 
2933 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2934 		if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2935 			len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2936 	}
2937 	buf = kmalloc (len, SLAB_KERNEL);
2938 	if (buf == NULL) {
2939 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2940 		/* assume the worst */
2941 		return 1;
2942 	}
2943 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2944 		int length;
2945 		int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2946 
2947 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2948 				old_length);
2949 		if (length < old_length) {
2950 			dev_dbg(&udev->dev, "config index %d, error %d\n",
2951 					index, length);
2952 			break;
2953 		}
2954 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
2955 				!= 0) {
2956 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2957 				index, buf->bConfigurationValue);
2958 			break;
2959 		}
2960 	}
2961 	kfree(buf);
2962 	return index != udev->descriptor.bNumConfigurations;
2963 }
2964 
2965 /**
2966  * usb_reset_device - perform a USB port reset to reinitialize a device
2967  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2968  *
2969  * WARNING - don't reset any device unless drivers for all of its
2970  * interfaces are expecting that reset!  Maybe some driver->reset()
2971  * method should eventually help ensure sufficient cooperation.
2972  *
2973  * Do a port reset, reassign the device's address, and establish its
2974  * former operating configuration.  If the reset fails, or the device's
2975  * descriptors change from their values before the reset, or the original
2976  * configuration and altsettings cannot be restored, a flag will be set
2977  * telling khubd to pretend the device has been disconnected and then
2978  * re-connected.  All drivers will be unbound, and the device will be
2979  * re-enumerated and probed all over again.
2980  *
2981  * Returns 0 if the reset succeeded, -ENODEV if the device has been
2982  * flagged for logical disconnection, or some other negative error code
2983  * if the reset wasn't even attempted.
2984  *
2985  * The caller must own the device lock.  For example, it's safe to use
2986  * this from a driver probe() routine after downloading new firmware.
2987  * For calls that might not occur during probe(), drivers should lock
2988  * the device using usb_lock_device_for_reset().
2989  */
2990 int usb_reset_device(struct usb_device *udev)
2991 {
2992 	struct usb_device		*parent_hdev = udev->parent;
2993 	struct usb_hub			*parent_hub;
2994 	struct usb_device_descriptor	descriptor = udev->descriptor;
2995 	struct usb_hub			*hub = NULL;
2996 	int 				i, ret = 0, port1 = -1;
2997 
2998 	if (udev->state == USB_STATE_NOTATTACHED ||
2999 			udev->state == USB_STATE_SUSPENDED) {
3000 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3001 				udev->state);
3002 		return -EINVAL;
3003 	}
3004 
3005 	if (!parent_hdev) {
3006 		/* this requires hcd-specific logic; see OHCI hc_restart() */
3007 		dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
3008 		return -EISDIR;
3009 	}
3010 
3011 	for (i = 0; i < parent_hdev->maxchild; i++)
3012 		if (parent_hdev->children[i] == udev) {
3013 			port1 = i + 1;
3014 			break;
3015 		}
3016 
3017 	if (port1 < 0) {
3018 		/* If this ever happens, it's very bad */
3019 		dev_err(&udev->dev, "Can't locate device's port!\n");
3020 		return -ENOENT;
3021 	}
3022 	parent_hub = hdev_to_hub(parent_hdev);
3023 
3024 	/* If we're resetting an active hub, take some special actions */
3025 	if (udev->actconfig &&
3026 			udev->actconfig->interface[0]->dev.driver ==
3027 				&hub_driver.driver &&
3028 			(hub = hdev_to_hub(udev)) != NULL) {
3029 		hub_pre_reset(hub);
3030 	}
3031 
3032 	set_bit(port1, parent_hub->busy_bits);
3033 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
3034 
3035 		/* ep0 maxpacket size may change; let the HCD know about it.
3036 		 * Other endpoints will be handled by re-enumeration. */
3037 		ep0_reinit(udev);
3038 		ret = hub_port_init(parent_hub, udev, port1, i);
3039 		if (ret >= 0)
3040 			break;
3041 	}
3042 	clear_bit(port1, parent_hub->busy_bits);
3043 	if (ret < 0)
3044 		goto re_enumerate;
3045 
3046 	/* Device might have changed firmware (DFU or similar) */
3047 	if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
3048 			|| config_descriptors_changed (udev)) {
3049 		dev_info(&udev->dev, "device firmware changed\n");
3050 		udev->descriptor = descriptor;	/* for disconnect() calls */
3051 		goto re_enumerate;
3052   	}
3053 
3054 	if (!udev->actconfig)
3055 		goto done;
3056 
3057 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3058 			USB_REQ_SET_CONFIGURATION, 0,
3059 			udev->actconfig->desc.bConfigurationValue, 0,
3060 			NULL, 0, USB_CTRL_SET_TIMEOUT);
3061 	if (ret < 0) {
3062 		dev_err(&udev->dev,
3063 			"can't restore configuration #%d (error=%d)\n",
3064 			udev->actconfig->desc.bConfigurationValue, ret);
3065 		goto re_enumerate;
3066   	}
3067 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
3068 
3069 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3070 		struct usb_interface *intf = udev->actconfig->interface[i];
3071 		struct usb_interface_descriptor *desc;
3072 
3073 		/* set_interface resets host side toggle even
3074 		 * for altsetting zero.  the interface may have no driver.
3075 		 */
3076 		desc = &intf->cur_altsetting->desc;
3077 		ret = usb_set_interface(udev, desc->bInterfaceNumber,
3078 			desc->bAlternateSetting);
3079 		if (ret < 0) {
3080 			dev_err(&udev->dev, "failed to restore interface %d "
3081 				"altsetting %d (error=%d)\n",
3082 				desc->bInterfaceNumber,
3083 				desc->bAlternateSetting,
3084 				ret);
3085 			goto re_enumerate;
3086 		}
3087 	}
3088 
3089 done:
3090 	if (hub)
3091 		hub_post_reset(hub);
3092 	return 0;
3093 
3094 re_enumerate:
3095 	hub_port_logical_disconnect(parent_hub, port1);
3096 	return -ENODEV;
3097 }
3098