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[mirror_ubuntu-bionic-kernel.git] / drivers / usb / core / hub.c
1 /*
2 * USB hub driver.
3 *
4 * (C) Copyright 1999 Linus Torvalds
5 * (C) Copyright 1999 Johannes Erdfelt
6 * (C) Copyright 1999 Gregory P. Smith
7 * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
8 *
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/completion.h>
16 #include <linux/sched.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
19 #include <linux/ioctl.h>
20 #include <linux/usb.h>
21 #include <linux/usbdevice_fs.h>
22 #include <linux/usb/hcd.h>
23 #include <linux/usb/quirks.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.h>
26 #include <linux/freezer.h>
27
28 #include <asm/uaccess.h>
29 #include <asm/byteorder.h>
30
31 #include "usb.h"
32
33 /* if we are in debug mode, always announce new devices */
34 #ifdef DEBUG
35 #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
36 #define CONFIG_USB_ANNOUNCE_NEW_DEVICES
37 #endif
38 #endif
39
40 struct usb_hub {
41 struct device *intfdev; /* the "interface" device */
42 struct usb_device *hdev;
43 struct kref kref;
44 struct urb *urb; /* for interrupt polling pipe */
45
46 /* buffer for urb ... with extra space in case of babble */
47 char (*buffer)[8];
48 union {
49 struct usb_hub_status hub;
50 struct usb_port_status port;
51 } *status; /* buffer for status reports */
52 struct mutex status_mutex; /* for the status buffer */
53
54 int error; /* last reported error */
55 int nerrors; /* track consecutive errors */
56
57 struct list_head event_list; /* hubs w/data or errs ready */
58 unsigned long event_bits[1]; /* status change bitmask */
59 unsigned long change_bits[1]; /* ports with logical connect
60 status change */
61 unsigned long busy_bits[1]; /* ports being reset or
62 resumed */
63 unsigned long removed_bits[1]; /* ports with a "removed"
64 device present */
65 #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */
66 #error event_bits[] is too short!
67 #endif
68
69 struct usb_hub_descriptor *descriptor; /* class descriptor */
70 struct usb_tt tt; /* Transaction Translator */
71
72 unsigned mA_per_port; /* current for each child */
73
74 unsigned limited_power:1;
75 unsigned quiescing:1;
76 unsigned disconnected:1;
77
78 unsigned has_indicators:1;
79 u8 indicator[USB_MAXCHILDREN];
80 struct delayed_work leds;
81 struct delayed_work init_work;
82 void **port_owners;
83 };
84
85
86 /* Protect struct usb_device->state and ->children members
87 * Note: Both are also protected by ->dev.sem, except that ->state can
88 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
89 static DEFINE_SPINLOCK(device_state_lock);
90
91 /* khubd's worklist and its lock */
92 static DEFINE_SPINLOCK(hub_event_lock);
93 static LIST_HEAD(hub_event_list); /* List of hubs needing servicing */
94
95 /* Wakes up khubd */
96 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
97
98 static struct task_struct *khubd_task;
99
100 /* cycle leds on hubs that aren't blinking for attention */
101 static int blinkenlights = 0;
102 module_param (blinkenlights, bool, S_IRUGO);
103 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
104
105 /*
106 * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
107 * 10 seconds to send reply for the initial 64-byte descriptor request.
108 */
109 /* define initial 64-byte descriptor request timeout in milliseconds */
110 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
111 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
112 MODULE_PARM_DESC(initial_descriptor_timeout,
113 "initial 64-byte descriptor request timeout in milliseconds "
114 "(default 5000 - 5.0 seconds)");
115
116 /*
117 * As of 2.6.10 we introduce a new USB device initialization scheme which
118 * closely resembles the way Windows works. Hopefully it will be compatible
119 * with a wider range of devices than the old scheme. However some previously
120 * working devices may start giving rise to "device not accepting address"
121 * errors; if that happens the user can try the old scheme by adjusting the
122 * following module parameters.
123 *
124 * For maximum flexibility there are two boolean parameters to control the
125 * hub driver's behavior. On the first initialization attempt, if the
126 * "old_scheme_first" parameter is set then the old scheme will be used,
127 * otherwise the new scheme is used. If that fails and "use_both_schemes"
128 * is set, then the driver will make another attempt, using the other scheme.
129 */
130 static int old_scheme_first = 0;
131 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
132 MODULE_PARM_DESC(old_scheme_first,
133 "start with the old device initialization scheme");
134
135 static int use_both_schemes = 1;
136 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
137 MODULE_PARM_DESC(use_both_schemes,
138 "try the other device initialization scheme if the "
139 "first one fails");
140
141 /* Mutual exclusion for EHCI CF initialization. This interferes with
142 * port reset on some companion controllers.
143 */
144 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
145 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
146
147 #define HUB_DEBOUNCE_TIMEOUT 1500
148 #define HUB_DEBOUNCE_STEP 25
149 #define HUB_DEBOUNCE_STABLE 100
150
151
152 static int usb_reset_and_verify_device(struct usb_device *udev);
153
154 static inline char *portspeed(int portstatus)
155 {
156 if (portstatus & USB_PORT_STAT_HIGH_SPEED)
157 return "480 Mb/s";
158 else if (portstatus & USB_PORT_STAT_LOW_SPEED)
159 return "1.5 Mb/s";
160 else if (portstatus & USB_PORT_STAT_SUPER_SPEED)
161 return "5.0 Gb/s";
162 else
163 return "12 Mb/s";
164 }
165
166 /* Note that hdev or one of its children must be locked! */
167 static struct usb_hub *hdev_to_hub(struct usb_device *hdev)
168 {
169 if (!hdev || !hdev->actconfig)
170 return NULL;
171 return usb_get_intfdata(hdev->actconfig->interface[0]);
172 }
173
174 /* USB 2.0 spec Section 11.24.4.5 */
175 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
176 {
177 int i, ret;
178
179 for (i = 0; i < 3; i++) {
180 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
181 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
182 USB_DT_HUB << 8, 0, data, size,
183 USB_CTRL_GET_TIMEOUT);
184 if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
185 return ret;
186 }
187 return -EINVAL;
188 }
189
190 /*
191 * USB 2.0 spec Section 11.24.2.1
192 */
193 static int clear_hub_feature(struct usb_device *hdev, int feature)
194 {
195 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
196 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
197 }
198
199 /*
200 * USB 2.0 spec Section 11.24.2.2
201 */
202 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
203 {
204 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
205 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
206 NULL, 0, 1000);
207 }
208
209 /*
210 * USB 2.0 spec Section 11.24.2.13
211 */
212 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
213 {
214 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
215 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
216 NULL, 0, 1000);
217 }
218
219 /*
220 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
221 * for info about using port indicators
222 */
223 static void set_port_led(
224 struct usb_hub *hub,
225 int port1,
226 int selector
227 )
228 {
229 int status = set_port_feature(hub->hdev, (selector << 8) | port1,
230 USB_PORT_FEAT_INDICATOR);
231 if (status < 0)
232 dev_dbg (hub->intfdev,
233 "port %d indicator %s status %d\n",
234 port1,
235 ({ char *s; switch (selector) {
236 case HUB_LED_AMBER: s = "amber"; break;
237 case HUB_LED_GREEN: s = "green"; break;
238 case HUB_LED_OFF: s = "off"; break;
239 case HUB_LED_AUTO: s = "auto"; break;
240 default: s = "??"; break;
241 }; s; }),
242 status);
243 }
244
245 #define LED_CYCLE_PERIOD ((2*HZ)/3)
246
247 static void led_work (struct work_struct *work)
248 {
249 struct usb_hub *hub =
250 container_of(work, struct usb_hub, leds.work);
251 struct usb_device *hdev = hub->hdev;
252 unsigned i;
253 unsigned changed = 0;
254 int cursor = -1;
255
256 if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
257 return;
258
259 for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
260 unsigned selector, mode;
261
262 /* 30%-50% duty cycle */
263
264 switch (hub->indicator[i]) {
265 /* cycle marker */
266 case INDICATOR_CYCLE:
267 cursor = i;
268 selector = HUB_LED_AUTO;
269 mode = INDICATOR_AUTO;
270 break;
271 /* blinking green = sw attention */
272 case INDICATOR_GREEN_BLINK:
273 selector = HUB_LED_GREEN;
274 mode = INDICATOR_GREEN_BLINK_OFF;
275 break;
276 case INDICATOR_GREEN_BLINK_OFF:
277 selector = HUB_LED_OFF;
278 mode = INDICATOR_GREEN_BLINK;
279 break;
280 /* blinking amber = hw attention */
281 case INDICATOR_AMBER_BLINK:
282 selector = HUB_LED_AMBER;
283 mode = INDICATOR_AMBER_BLINK_OFF;
284 break;
285 case INDICATOR_AMBER_BLINK_OFF:
286 selector = HUB_LED_OFF;
287 mode = INDICATOR_AMBER_BLINK;
288 break;
289 /* blink green/amber = reserved */
290 case INDICATOR_ALT_BLINK:
291 selector = HUB_LED_GREEN;
292 mode = INDICATOR_ALT_BLINK_OFF;
293 break;
294 case INDICATOR_ALT_BLINK_OFF:
295 selector = HUB_LED_AMBER;
296 mode = INDICATOR_ALT_BLINK;
297 break;
298 default:
299 continue;
300 }
301 if (selector != HUB_LED_AUTO)
302 changed = 1;
303 set_port_led(hub, i + 1, selector);
304 hub->indicator[i] = mode;
305 }
306 if (!changed && blinkenlights) {
307 cursor++;
308 cursor %= hub->descriptor->bNbrPorts;
309 set_port_led(hub, cursor + 1, HUB_LED_GREEN);
310 hub->indicator[cursor] = INDICATOR_CYCLE;
311 changed++;
312 }
313 if (changed)
314 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
315 }
316
317 /* use a short timeout for hub/port status fetches */
318 #define USB_STS_TIMEOUT 1000
319 #define USB_STS_RETRIES 5
320
321 /*
322 * USB 2.0 spec Section 11.24.2.6
323 */
324 static int get_hub_status(struct usb_device *hdev,
325 struct usb_hub_status *data)
326 {
327 int i, status = -ETIMEDOUT;
328
329 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
330 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
331 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
332 data, sizeof(*data), USB_STS_TIMEOUT);
333 }
334 return status;
335 }
336
337 /*
338 * USB 2.0 spec Section 11.24.2.7
339 */
340 static int get_port_status(struct usb_device *hdev, int port1,
341 struct usb_port_status *data)
342 {
343 int i, status = -ETIMEDOUT;
344
345 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
346 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
347 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
348 data, sizeof(*data), USB_STS_TIMEOUT);
349 }
350 return status;
351 }
352
353 static int hub_port_status(struct usb_hub *hub, int port1,
354 u16 *status, u16 *change)
355 {
356 int ret;
357
358 mutex_lock(&hub->status_mutex);
359 ret = get_port_status(hub->hdev, port1, &hub->status->port);
360 if (ret < 4) {
361 dev_err(hub->intfdev,
362 "%s failed (err = %d)\n", __func__, ret);
363 if (ret >= 0)
364 ret = -EIO;
365 } else {
366 *status = le16_to_cpu(hub->status->port.wPortStatus);
367 *change = le16_to_cpu(hub->status->port.wPortChange);
368 ret = 0;
369 }
370 mutex_unlock(&hub->status_mutex);
371 return ret;
372 }
373
374 static void kick_khubd(struct usb_hub *hub)
375 {
376 unsigned long flags;
377
378 spin_lock_irqsave(&hub_event_lock, flags);
379 if (!hub->disconnected && list_empty(&hub->event_list)) {
380 list_add_tail(&hub->event_list, &hub_event_list);
381
382 /* Suppress autosuspend until khubd runs */
383 usb_autopm_get_interface_no_resume(
384 to_usb_interface(hub->intfdev));
385 wake_up(&khubd_wait);
386 }
387 spin_unlock_irqrestore(&hub_event_lock, flags);
388 }
389
390 void usb_kick_khubd(struct usb_device *hdev)
391 {
392 struct usb_hub *hub = hdev_to_hub(hdev);
393
394 if (hub)
395 kick_khubd(hub);
396 }
397
398
399 /* completion function, fires on port status changes and various faults */
400 static void hub_irq(struct urb *urb)
401 {
402 struct usb_hub *hub = urb->context;
403 int status = urb->status;
404 unsigned i;
405 unsigned long bits;
406
407 switch (status) {
408 case -ENOENT: /* synchronous unlink */
409 case -ECONNRESET: /* async unlink */
410 case -ESHUTDOWN: /* hardware going away */
411 return;
412
413 default: /* presumably an error */
414 /* Cause a hub reset after 10 consecutive errors */
415 dev_dbg (hub->intfdev, "transfer --> %d\n", status);
416 if ((++hub->nerrors < 10) || hub->error)
417 goto resubmit;
418 hub->error = status;
419 /* FALL THROUGH */
420
421 /* let khubd handle things */
422 case 0: /* we got data: port status changed */
423 bits = 0;
424 for (i = 0; i < urb->actual_length; ++i)
425 bits |= ((unsigned long) ((*hub->buffer)[i]))
426 << (i*8);
427 hub->event_bits[0] = bits;
428 break;
429 }
430
431 hub->nerrors = 0;
432
433 /* Something happened, let khubd figure it out */
434 kick_khubd(hub);
435
436 resubmit:
437 if (hub->quiescing)
438 return;
439
440 if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
441 && status != -ENODEV && status != -EPERM)
442 dev_err (hub->intfdev, "resubmit --> %d\n", status);
443 }
444
445 /* USB 2.0 spec Section 11.24.2.3 */
446 static inline int
447 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
448 {
449 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
450 HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
451 tt, NULL, 0, 1000);
452 }
453
454 /*
455 * enumeration blocks khubd for a long time. we use keventd instead, since
456 * long blocking there is the exception, not the rule. accordingly, HCDs
457 * talking to TTs must queue control transfers (not just bulk and iso), so
458 * both can talk to the same hub concurrently.
459 */
460 static void hub_tt_work(struct work_struct *work)
461 {
462 struct usb_hub *hub =
463 container_of(work, struct usb_hub, tt.clear_work);
464 unsigned long flags;
465 int limit = 100;
466
467 spin_lock_irqsave (&hub->tt.lock, flags);
468 while (--limit && !list_empty (&hub->tt.clear_list)) {
469 struct list_head *next;
470 struct usb_tt_clear *clear;
471 struct usb_device *hdev = hub->hdev;
472 const struct hc_driver *drv;
473 int status;
474
475 next = hub->tt.clear_list.next;
476 clear = list_entry (next, struct usb_tt_clear, clear_list);
477 list_del (&clear->clear_list);
478
479 /* drop lock so HCD can concurrently report other TT errors */
480 spin_unlock_irqrestore (&hub->tt.lock, flags);
481 status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
482 if (status)
483 dev_err (&hdev->dev,
484 "clear tt %d (%04x) error %d\n",
485 clear->tt, clear->devinfo, status);
486
487 /* Tell the HCD, even if the operation failed */
488 drv = clear->hcd->driver;
489 if (drv->clear_tt_buffer_complete)
490 (drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
491
492 kfree(clear);
493 spin_lock_irqsave(&hub->tt.lock, flags);
494 }
495 spin_unlock_irqrestore (&hub->tt.lock, flags);
496 }
497
498 /**
499 * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
500 * @urb: an URB associated with the failed or incomplete split transaction
501 *
502 * High speed HCDs use this to tell the hub driver that some split control or
503 * bulk transaction failed in a way that requires clearing internal state of
504 * a transaction translator. This is normally detected (and reported) from
505 * interrupt context.
506 *
507 * It may not be possible for that hub to handle additional full (or low)
508 * speed transactions until that state is fully cleared out.
509 */
510 int usb_hub_clear_tt_buffer(struct urb *urb)
511 {
512 struct usb_device *udev = urb->dev;
513 int pipe = urb->pipe;
514 struct usb_tt *tt = udev->tt;
515 unsigned long flags;
516 struct usb_tt_clear *clear;
517
518 /* we've got to cope with an arbitrary number of pending TT clears,
519 * since each TT has "at least two" buffers that can need it (and
520 * there can be many TTs per hub). even if they're uncommon.
521 */
522 if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
523 dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
524 /* FIXME recover somehow ... RESET_TT? */
525 return -ENOMEM;
526 }
527
528 /* info that CLEAR_TT_BUFFER needs */
529 clear->tt = tt->multi ? udev->ttport : 1;
530 clear->devinfo = usb_pipeendpoint (pipe);
531 clear->devinfo |= udev->devnum << 4;
532 clear->devinfo |= usb_pipecontrol (pipe)
533 ? (USB_ENDPOINT_XFER_CONTROL << 11)
534 : (USB_ENDPOINT_XFER_BULK << 11);
535 if (usb_pipein (pipe))
536 clear->devinfo |= 1 << 15;
537
538 /* info for completion callback */
539 clear->hcd = bus_to_hcd(udev->bus);
540 clear->ep = urb->ep;
541
542 /* tell keventd to clear state for this TT */
543 spin_lock_irqsave (&tt->lock, flags);
544 list_add_tail (&clear->clear_list, &tt->clear_list);
545 schedule_work(&tt->clear_work);
546 spin_unlock_irqrestore (&tt->lock, flags);
547 return 0;
548 }
549 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
550
551 /* If do_delay is false, return the number of milliseconds the caller
552 * needs to delay.
553 */
554 static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
555 {
556 int port1;
557 unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
558 unsigned delay;
559 u16 wHubCharacteristics =
560 le16_to_cpu(hub->descriptor->wHubCharacteristics);
561
562 /* Enable power on each port. Some hubs have reserved values
563 * of LPSM (> 2) in their descriptors, even though they are
564 * USB 2.0 hubs. Some hubs do not implement port-power switching
565 * but only emulate it. In all cases, the ports won't work
566 * unless we send these messages to the hub.
567 */
568 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
569 dev_dbg(hub->intfdev, "enabling power on all ports\n");
570 else
571 dev_dbg(hub->intfdev, "trying to enable port power on "
572 "non-switchable hub\n");
573 for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
574 set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
575
576 /* Wait at least 100 msec for power to become stable */
577 delay = max(pgood_delay, (unsigned) 100);
578 if (do_delay)
579 msleep(delay);
580 return delay;
581 }
582
583 static int hub_hub_status(struct usb_hub *hub,
584 u16 *status, u16 *change)
585 {
586 int ret;
587
588 mutex_lock(&hub->status_mutex);
589 ret = get_hub_status(hub->hdev, &hub->status->hub);
590 if (ret < 0)
591 dev_err (hub->intfdev,
592 "%s failed (err = %d)\n", __func__, ret);
593 else {
594 *status = le16_to_cpu(hub->status->hub.wHubStatus);
595 *change = le16_to_cpu(hub->status->hub.wHubChange);
596 ret = 0;
597 }
598 mutex_unlock(&hub->status_mutex);
599 return ret;
600 }
601
602 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
603 {
604 struct usb_device *hdev = hub->hdev;
605 int ret = 0;
606
607 if (hdev->children[port1-1] && set_state)
608 usb_set_device_state(hdev->children[port1-1],
609 USB_STATE_NOTATTACHED);
610 if (!hub->error)
611 ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
612 if (ret)
613 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
614 port1, ret);
615 return ret;
616 }
617
618 /*
619 * Disable a port and mark a logical connnect-change event, so that some
620 * time later khubd will disconnect() any existing usb_device on the port
621 * and will re-enumerate if there actually is a device attached.
622 */
623 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
624 {
625 dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
626 hub_port_disable(hub, port1, 1);
627
628 /* FIXME let caller ask to power down the port:
629 * - some devices won't enumerate without a VBUS power cycle
630 * - SRP saves power that way
631 * - ... new call, TBD ...
632 * That's easy if this hub can switch power per-port, and
633 * khubd reactivates the port later (timer, SRP, etc).
634 * Powerdown must be optional, because of reset/DFU.
635 */
636
637 set_bit(port1, hub->change_bits);
638 kick_khubd(hub);
639 }
640
641 /**
642 * usb_remove_device - disable a device's port on its parent hub
643 * @udev: device to be disabled and removed
644 * Context: @udev locked, must be able to sleep.
645 *
646 * After @udev's port has been disabled, khubd is notified and it will
647 * see that the device has been disconnected. When the device is
648 * physically unplugged and something is plugged in, the events will
649 * be received and processed normally.
650 */
651 int usb_remove_device(struct usb_device *udev)
652 {
653 struct usb_hub *hub;
654 struct usb_interface *intf;
655
656 if (!udev->parent) /* Can't remove a root hub */
657 return -EINVAL;
658 hub = hdev_to_hub(udev->parent);
659 intf = to_usb_interface(hub->intfdev);
660
661 usb_autopm_get_interface(intf);
662 set_bit(udev->portnum, hub->removed_bits);
663 hub_port_logical_disconnect(hub, udev->portnum);
664 usb_autopm_put_interface(intf);
665 return 0;
666 }
667
668 enum hub_activation_type {
669 HUB_INIT, HUB_INIT2, HUB_INIT3, /* INITs must come first */
670 HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
671 };
672
673 static void hub_init_func2(struct work_struct *ws);
674 static void hub_init_func3(struct work_struct *ws);
675
676 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
677 {
678 struct usb_device *hdev = hub->hdev;
679 struct usb_hcd *hcd;
680 int ret;
681 int port1;
682 int status;
683 bool need_debounce_delay = false;
684 unsigned delay;
685
686 /* Continue a partial initialization */
687 if (type == HUB_INIT2)
688 goto init2;
689 if (type == HUB_INIT3)
690 goto init3;
691
692 /* After a resume, port power should still be on.
693 * For any other type of activation, turn it on.
694 */
695 if (type != HUB_RESUME) {
696
697 /* Speed up system boot by using a delayed_work for the
698 * hub's initial power-up delays. This is pretty awkward
699 * and the implementation looks like a home-brewed sort of
700 * setjmp/longjmp, but it saves at least 100 ms for each
701 * root hub (assuming usbcore is compiled into the kernel
702 * rather than as a module). It adds up.
703 *
704 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
705 * because for those activation types the ports have to be
706 * operational when we return. In theory this could be done
707 * for HUB_POST_RESET, but it's easier not to.
708 */
709 if (type == HUB_INIT) {
710 delay = hub_power_on(hub, false);
711 PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
712 schedule_delayed_work(&hub->init_work,
713 msecs_to_jiffies(delay));
714
715 /* Suppress autosuspend until init is done */
716 usb_autopm_get_interface_no_resume(
717 to_usb_interface(hub->intfdev));
718 return; /* Continues at init2: below */
719 } else if (type == HUB_RESET_RESUME) {
720 /* The internal host controller state for the hub device
721 * may be gone after a host power loss on system resume.
722 * Update the device's info so the HW knows it's a hub.
723 */
724 hcd = bus_to_hcd(hdev->bus);
725 if (hcd->driver->update_hub_device) {
726 ret = hcd->driver->update_hub_device(hcd, hdev,
727 &hub->tt, GFP_NOIO);
728 if (ret < 0) {
729 dev_err(hub->intfdev, "Host not "
730 "accepting hub info "
731 "update.\n");
732 dev_err(hub->intfdev, "LS/FS devices "
733 "and hubs may not work "
734 "under this hub\n.");
735 }
736 }
737 hub_power_on(hub, true);
738 } else {
739 hub_power_on(hub, true);
740 }
741 }
742 init2:
743
744 /* Check each port and set hub->change_bits to let khubd know
745 * which ports need attention.
746 */
747 for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
748 struct usb_device *udev = hdev->children[port1-1];
749 u16 portstatus, portchange;
750
751 portstatus = portchange = 0;
752 status = hub_port_status(hub, port1, &portstatus, &portchange);
753 if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
754 dev_dbg(hub->intfdev,
755 "port %d: status %04x change %04x\n",
756 port1, portstatus, portchange);
757
758 /* After anything other than HUB_RESUME (i.e., initialization
759 * or any sort of reset), every port should be disabled.
760 * Unconnected ports should likewise be disabled (paranoia),
761 * and so should ports for which we have no usb_device.
762 */
763 if ((portstatus & USB_PORT_STAT_ENABLE) && (
764 type != HUB_RESUME ||
765 !(portstatus & USB_PORT_STAT_CONNECTION) ||
766 !udev ||
767 udev->state == USB_STATE_NOTATTACHED)) {
768 /*
769 * USB3 protocol ports will automatically transition
770 * to Enabled state when detect an USB3.0 device attach.
771 * Do not disable USB3 protocol ports.
772 * FIXME: USB3 root hub and external hubs are treated
773 * differently here.
774 */
775 if (hdev->descriptor.bDeviceProtocol != 3 ||
776 (!hdev->parent &&
777 !(portstatus & USB_PORT_STAT_SUPER_SPEED))) {
778 clear_port_feature(hdev, port1,
779 USB_PORT_FEAT_ENABLE);
780 portstatus &= ~USB_PORT_STAT_ENABLE;
781 } else {
782 /* Pretend that power was lost for USB3 devs */
783 portstatus &= ~USB_PORT_STAT_ENABLE;
784 }
785 }
786
787 /* Clear status-change flags; we'll debounce later */
788 if (portchange & USB_PORT_STAT_C_CONNECTION) {
789 need_debounce_delay = true;
790 clear_port_feature(hub->hdev, port1,
791 USB_PORT_FEAT_C_CONNECTION);
792 }
793 if (portchange & USB_PORT_STAT_C_ENABLE) {
794 need_debounce_delay = true;
795 clear_port_feature(hub->hdev, port1,
796 USB_PORT_FEAT_C_ENABLE);
797 }
798
799 /* We can forget about a "removed" device when there's a
800 * physical disconnect or the connect status changes.
801 */
802 if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
803 (portchange & USB_PORT_STAT_C_CONNECTION))
804 clear_bit(port1, hub->removed_bits);
805
806 if (!udev || udev->state == USB_STATE_NOTATTACHED) {
807 /* Tell khubd to disconnect the device or
808 * check for a new connection
809 */
810 if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
811 set_bit(port1, hub->change_bits);
812
813 } else if (portstatus & USB_PORT_STAT_ENABLE) {
814 /* The power session apparently survived the resume.
815 * If there was an overcurrent or suspend change
816 * (i.e., remote wakeup request), have khubd
817 * take care of it.
818 */
819 if (portchange)
820 set_bit(port1, hub->change_bits);
821
822 } else if (udev->persist_enabled) {
823 #ifdef CONFIG_PM
824 udev->reset_resume = 1;
825 #endif
826 set_bit(port1, hub->change_bits);
827
828 } else {
829 /* The power session is gone; tell khubd */
830 usb_set_device_state(udev, USB_STATE_NOTATTACHED);
831 set_bit(port1, hub->change_bits);
832 }
833 }
834
835 /* If no port-status-change flags were set, we don't need any
836 * debouncing. If flags were set we can try to debounce the
837 * ports all at once right now, instead of letting khubd do them
838 * one at a time later on.
839 *
840 * If any port-status changes do occur during this delay, khubd
841 * will see them later and handle them normally.
842 */
843 if (need_debounce_delay) {
844 delay = HUB_DEBOUNCE_STABLE;
845
846 /* Don't do a long sleep inside a workqueue routine */
847 if (type == HUB_INIT2) {
848 PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
849 schedule_delayed_work(&hub->init_work,
850 msecs_to_jiffies(delay));
851 return; /* Continues at init3: below */
852 } else {
853 msleep(delay);
854 }
855 }
856 init3:
857 hub->quiescing = 0;
858
859 status = usb_submit_urb(hub->urb, GFP_NOIO);
860 if (status < 0)
861 dev_err(hub->intfdev, "activate --> %d\n", status);
862 if (hub->has_indicators && blinkenlights)
863 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
864
865 /* Scan all ports that need attention */
866 kick_khubd(hub);
867
868 /* Allow autosuspend if it was suppressed */
869 if (type <= HUB_INIT3)
870 usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
871 }
872
873 /* Implement the continuations for the delays above */
874 static void hub_init_func2(struct work_struct *ws)
875 {
876 struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
877
878 hub_activate(hub, HUB_INIT2);
879 }
880
881 static void hub_init_func3(struct work_struct *ws)
882 {
883 struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
884
885 hub_activate(hub, HUB_INIT3);
886 }
887
888 enum hub_quiescing_type {
889 HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
890 };
891
892 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
893 {
894 struct usb_device *hdev = hub->hdev;
895 int i;
896
897 cancel_delayed_work_sync(&hub->init_work);
898
899 /* khubd and related activity won't re-trigger */
900 hub->quiescing = 1;
901
902 if (type != HUB_SUSPEND) {
903 /* Disconnect all the children */
904 for (i = 0; i < hdev->maxchild; ++i) {
905 if (hdev->children[i])
906 usb_disconnect(&hdev->children[i]);
907 }
908 }
909
910 /* Stop khubd and related activity */
911 usb_kill_urb(hub->urb);
912 if (hub->has_indicators)
913 cancel_delayed_work_sync(&hub->leds);
914 if (hub->tt.hub)
915 cancel_work_sync(&hub->tt.clear_work);
916 }
917
918 /* caller has locked the hub device */
919 static int hub_pre_reset(struct usb_interface *intf)
920 {
921 struct usb_hub *hub = usb_get_intfdata(intf);
922
923 hub_quiesce(hub, HUB_PRE_RESET);
924 return 0;
925 }
926
927 /* caller has locked the hub device */
928 static int hub_post_reset(struct usb_interface *intf)
929 {
930 struct usb_hub *hub = usb_get_intfdata(intf);
931
932 hub_activate(hub, HUB_POST_RESET);
933 return 0;
934 }
935
936 static int hub_configure(struct usb_hub *hub,
937 struct usb_endpoint_descriptor *endpoint)
938 {
939 struct usb_hcd *hcd;
940 struct usb_device *hdev = hub->hdev;
941 struct device *hub_dev = hub->intfdev;
942 u16 hubstatus, hubchange;
943 u16 wHubCharacteristics;
944 unsigned int pipe;
945 int maxp, ret;
946 char *message = "out of memory";
947
948 hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
949 if (!hub->buffer) {
950 ret = -ENOMEM;
951 goto fail;
952 }
953
954 hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
955 if (!hub->status) {
956 ret = -ENOMEM;
957 goto fail;
958 }
959 mutex_init(&hub->status_mutex);
960
961 hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
962 if (!hub->descriptor) {
963 ret = -ENOMEM;
964 goto fail;
965 }
966
967 /* Request the entire hub descriptor.
968 * hub->descriptor can handle USB_MAXCHILDREN ports,
969 * but the hub can/will return fewer bytes here.
970 */
971 ret = get_hub_descriptor(hdev, hub->descriptor,
972 sizeof(*hub->descriptor));
973 if (ret < 0) {
974 message = "can't read hub descriptor";
975 goto fail;
976 } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
977 message = "hub has too many ports!";
978 ret = -ENODEV;
979 goto fail;
980 }
981
982 hdev->maxchild = hub->descriptor->bNbrPorts;
983 dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
984 (hdev->maxchild == 1) ? "" : "s");
985
986 hub->port_owners = kzalloc(hdev->maxchild * sizeof(void *), GFP_KERNEL);
987 if (!hub->port_owners) {
988 ret = -ENOMEM;
989 goto fail;
990 }
991
992 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
993
994 if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
995 int i;
996 char portstr [USB_MAXCHILDREN + 1];
997
998 for (i = 0; i < hdev->maxchild; i++)
999 portstr[i] = hub->descriptor->DeviceRemovable
1000 [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1001 ? 'F' : 'R';
1002 portstr[hdev->maxchild] = 0;
1003 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1004 } else
1005 dev_dbg(hub_dev, "standalone hub\n");
1006
1007 switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1008 case 0x00:
1009 dev_dbg(hub_dev, "ganged power switching\n");
1010 break;
1011 case 0x01:
1012 dev_dbg(hub_dev, "individual port power switching\n");
1013 break;
1014 case 0x02:
1015 case 0x03:
1016 dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1017 break;
1018 }
1019
1020 switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1021 case 0x00:
1022 dev_dbg(hub_dev, "global over-current protection\n");
1023 break;
1024 case 0x08:
1025 dev_dbg(hub_dev, "individual port over-current protection\n");
1026 break;
1027 case 0x10:
1028 case 0x18:
1029 dev_dbg(hub_dev, "no over-current protection\n");
1030 break;
1031 }
1032
1033 spin_lock_init (&hub->tt.lock);
1034 INIT_LIST_HEAD (&hub->tt.clear_list);
1035 INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1036 switch (hdev->descriptor.bDeviceProtocol) {
1037 case 0:
1038 break;
1039 case 1:
1040 dev_dbg(hub_dev, "Single TT\n");
1041 hub->tt.hub = hdev;
1042 break;
1043 case 2:
1044 ret = usb_set_interface(hdev, 0, 1);
1045 if (ret == 0) {
1046 dev_dbg(hub_dev, "TT per port\n");
1047 hub->tt.multi = 1;
1048 } else
1049 dev_err(hub_dev, "Using single TT (err %d)\n",
1050 ret);
1051 hub->tt.hub = hdev;
1052 break;
1053 case 3:
1054 /* USB 3.0 hubs don't have a TT */
1055 break;
1056 default:
1057 dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1058 hdev->descriptor.bDeviceProtocol);
1059 break;
1060 }
1061
1062 /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1063 switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1064 case HUB_TTTT_8_BITS:
1065 if (hdev->descriptor.bDeviceProtocol != 0) {
1066 hub->tt.think_time = 666;
1067 dev_dbg(hub_dev, "TT requires at most %d "
1068 "FS bit times (%d ns)\n",
1069 8, hub->tt.think_time);
1070 }
1071 break;
1072 case HUB_TTTT_16_BITS:
1073 hub->tt.think_time = 666 * 2;
1074 dev_dbg(hub_dev, "TT requires at most %d "
1075 "FS bit times (%d ns)\n",
1076 16, hub->tt.think_time);
1077 break;
1078 case HUB_TTTT_24_BITS:
1079 hub->tt.think_time = 666 * 3;
1080 dev_dbg(hub_dev, "TT requires at most %d "
1081 "FS bit times (%d ns)\n",
1082 24, hub->tt.think_time);
1083 break;
1084 case HUB_TTTT_32_BITS:
1085 hub->tt.think_time = 666 * 4;
1086 dev_dbg(hub_dev, "TT requires at most %d "
1087 "FS bit times (%d ns)\n",
1088 32, hub->tt.think_time);
1089 break;
1090 }
1091
1092 /* probe() zeroes hub->indicator[] */
1093 if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1094 hub->has_indicators = 1;
1095 dev_dbg(hub_dev, "Port indicators are supported\n");
1096 }
1097
1098 dev_dbg(hub_dev, "power on to power good time: %dms\n",
1099 hub->descriptor->bPwrOn2PwrGood * 2);
1100
1101 /* power budgeting mostly matters with bus-powered hubs,
1102 * and battery-powered root hubs (may provide just 8 mA).
1103 */
1104 ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1105 if (ret < 2) {
1106 message = "can't get hub status";
1107 goto fail;
1108 }
1109 le16_to_cpus(&hubstatus);
1110 if (hdev == hdev->bus->root_hub) {
1111 if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
1112 hub->mA_per_port = 500;
1113 else {
1114 hub->mA_per_port = hdev->bus_mA;
1115 hub->limited_power = 1;
1116 }
1117 } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1118 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1119 hub->descriptor->bHubContrCurrent);
1120 hub->limited_power = 1;
1121 if (hdev->maxchild > 0) {
1122 int remaining = hdev->bus_mA -
1123 hub->descriptor->bHubContrCurrent;
1124
1125 if (remaining < hdev->maxchild * 100)
1126 dev_warn(hub_dev,
1127 "insufficient power available "
1128 "to use all downstream ports\n");
1129 hub->mA_per_port = 100; /* 7.2.1.1 */
1130 }
1131 } else { /* Self-powered external hub */
1132 /* FIXME: What about battery-powered external hubs that
1133 * provide less current per port? */
1134 hub->mA_per_port = 500;
1135 }
1136 if (hub->mA_per_port < 500)
1137 dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1138 hub->mA_per_port);
1139
1140 /* Update the HCD's internal representation of this hub before khubd
1141 * starts getting port status changes for devices under the hub.
1142 */
1143 hcd = bus_to_hcd(hdev->bus);
1144 if (hcd->driver->update_hub_device) {
1145 ret = hcd->driver->update_hub_device(hcd, hdev,
1146 &hub->tt, GFP_KERNEL);
1147 if (ret < 0) {
1148 message = "can't update HCD hub info";
1149 goto fail;
1150 }
1151 }
1152
1153 ret = hub_hub_status(hub, &hubstatus, &hubchange);
1154 if (ret < 0) {
1155 message = "can't get hub status";
1156 goto fail;
1157 }
1158
1159 /* local power status reports aren't always correct */
1160 if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1161 dev_dbg(hub_dev, "local power source is %s\n",
1162 (hubstatus & HUB_STATUS_LOCAL_POWER)
1163 ? "lost (inactive)" : "good");
1164
1165 if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1166 dev_dbg(hub_dev, "%sover-current condition exists\n",
1167 (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1168
1169 /* set up the interrupt endpoint
1170 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1171 * bytes as USB2.0[11.12.3] says because some hubs are known
1172 * to send more data (and thus cause overflow). For root hubs,
1173 * maxpktsize is defined in hcd.c's fake endpoint descriptors
1174 * to be big enough for at least USB_MAXCHILDREN ports. */
1175 pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1176 maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
1177
1178 if (maxp > sizeof(*hub->buffer))
1179 maxp = sizeof(*hub->buffer);
1180
1181 hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1182 if (!hub->urb) {
1183 ret = -ENOMEM;
1184 goto fail;
1185 }
1186
1187 usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1188 hub, endpoint->bInterval);
1189
1190 /* maybe cycle the hub leds */
1191 if (hub->has_indicators && blinkenlights)
1192 hub->indicator [0] = INDICATOR_CYCLE;
1193
1194 hub_activate(hub, HUB_INIT);
1195 return 0;
1196
1197 fail:
1198 dev_err (hub_dev, "config failed, %s (err %d)\n",
1199 message, ret);
1200 /* hub_disconnect() frees urb and descriptor */
1201 return ret;
1202 }
1203
1204 static void hub_release(struct kref *kref)
1205 {
1206 struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1207
1208 usb_put_intf(to_usb_interface(hub->intfdev));
1209 kfree(hub);
1210 }
1211
1212 static unsigned highspeed_hubs;
1213
1214 static void hub_disconnect(struct usb_interface *intf)
1215 {
1216 struct usb_hub *hub = usb_get_intfdata (intf);
1217
1218 /* Take the hub off the event list and don't let it be added again */
1219 spin_lock_irq(&hub_event_lock);
1220 if (!list_empty(&hub->event_list)) {
1221 list_del_init(&hub->event_list);
1222 usb_autopm_put_interface_no_suspend(intf);
1223 }
1224 hub->disconnected = 1;
1225 spin_unlock_irq(&hub_event_lock);
1226
1227 /* Disconnect all children and quiesce the hub */
1228 hub->error = 0;
1229 hub_quiesce(hub, HUB_DISCONNECT);
1230
1231 usb_set_intfdata (intf, NULL);
1232 hub->hdev->maxchild = 0;
1233
1234 if (hub->hdev->speed == USB_SPEED_HIGH)
1235 highspeed_hubs--;
1236
1237 usb_free_urb(hub->urb);
1238 kfree(hub->port_owners);
1239 kfree(hub->descriptor);
1240 kfree(hub->status);
1241 kfree(hub->buffer);
1242
1243 kref_put(&hub->kref, hub_release);
1244 }
1245
1246 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1247 {
1248 struct usb_host_interface *desc;
1249 struct usb_endpoint_descriptor *endpoint;
1250 struct usb_device *hdev;
1251 struct usb_hub *hub;
1252
1253 desc = intf->cur_altsetting;
1254 hdev = interface_to_usbdev(intf);
1255
1256 /* Hubs have proper suspend/resume support */
1257 usb_enable_autosuspend(hdev);
1258
1259 if (hdev->level == MAX_TOPO_LEVEL) {
1260 dev_err(&intf->dev,
1261 "Unsupported bus topology: hub nested too deep\n");
1262 return -E2BIG;
1263 }
1264
1265 #ifdef CONFIG_USB_OTG_BLACKLIST_HUB
1266 if (hdev->parent) {
1267 dev_warn(&intf->dev, "ignoring external hub\n");
1268 return -ENODEV;
1269 }
1270 #endif
1271
1272 /* Some hubs have a subclass of 1, which AFAICT according to the */
1273 /* specs is not defined, but it works */
1274 if ((desc->desc.bInterfaceSubClass != 0) &&
1275 (desc->desc.bInterfaceSubClass != 1)) {
1276 descriptor_error:
1277 dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
1278 return -EIO;
1279 }
1280
1281 /* Multiple endpoints? What kind of mutant ninja-hub is this? */
1282 if (desc->desc.bNumEndpoints != 1)
1283 goto descriptor_error;
1284
1285 endpoint = &desc->endpoint[0].desc;
1286
1287 /* If it's not an interrupt in endpoint, we'd better punt! */
1288 if (!usb_endpoint_is_int_in(endpoint))
1289 goto descriptor_error;
1290
1291 /* We found a hub */
1292 dev_info (&intf->dev, "USB hub found\n");
1293
1294 hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1295 if (!hub) {
1296 dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
1297 return -ENOMEM;
1298 }
1299
1300 kref_init(&hub->kref);
1301 INIT_LIST_HEAD(&hub->event_list);
1302 hub->intfdev = &intf->dev;
1303 hub->hdev = hdev;
1304 INIT_DELAYED_WORK(&hub->leds, led_work);
1305 INIT_DELAYED_WORK(&hub->init_work, NULL);
1306 usb_get_intf(intf);
1307
1308 usb_set_intfdata (intf, hub);
1309 intf->needs_remote_wakeup = 1;
1310
1311 if (hdev->speed == USB_SPEED_HIGH)
1312 highspeed_hubs++;
1313
1314 if (hub_configure(hub, endpoint) >= 0)
1315 return 0;
1316
1317 hub_disconnect (intf);
1318 return -ENODEV;
1319 }
1320
1321 /* No BKL needed */
1322 static int
1323 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1324 {
1325 struct usb_device *hdev = interface_to_usbdev (intf);
1326
1327 /* assert ifno == 0 (part of hub spec) */
1328 switch (code) {
1329 case USBDEVFS_HUB_PORTINFO: {
1330 struct usbdevfs_hub_portinfo *info = user_data;
1331 int i;
1332
1333 spin_lock_irq(&device_state_lock);
1334 if (hdev->devnum <= 0)
1335 info->nports = 0;
1336 else {
1337 info->nports = hdev->maxchild;
1338 for (i = 0; i < info->nports; i++) {
1339 if (hdev->children[i] == NULL)
1340 info->port[i] = 0;
1341 else
1342 info->port[i] =
1343 hdev->children[i]->devnum;
1344 }
1345 }
1346 spin_unlock_irq(&device_state_lock);
1347
1348 return info->nports + 1;
1349 }
1350
1351 default:
1352 return -ENOSYS;
1353 }
1354 }
1355
1356 /*
1357 * Allow user programs to claim ports on a hub. When a device is attached
1358 * to one of these "claimed" ports, the program will "own" the device.
1359 */
1360 static int find_port_owner(struct usb_device *hdev, unsigned port1,
1361 void ***ppowner)
1362 {
1363 if (hdev->state == USB_STATE_NOTATTACHED)
1364 return -ENODEV;
1365 if (port1 == 0 || port1 > hdev->maxchild)
1366 return -EINVAL;
1367
1368 /* This assumes that devices not managed by the hub driver
1369 * will always have maxchild equal to 0.
1370 */
1371 *ppowner = &(hdev_to_hub(hdev)->port_owners[port1 - 1]);
1372 return 0;
1373 }
1374
1375 /* In the following three functions, the caller must hold hdev's lock */
1376 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1, void *owner)
1377 {
1378 int rc;
1379 void **powner;
1380
1381 rc = find_port_owner(hdev, port1, &powner);
1382 if (rc)
1383 return rc;
1384 if (*powner)
1385 return -EBUSY;
1386 *powner = owner;
1387 return rc;
1388 }
1389
1390 int usb_hub_release_port(struct usb_device *hdev, unsigned port1, void *owner)
1391 {
1392 int rc;
1393 void **powner;
1394
1395 rc = find_port_owner(hdev, port1, &powner);
1396 if (rc)
1397 return rc;
1398 if (*powner != owner)
1399 return -ENOENT;
1400 *powner = NULL;
1401 return rc;
1402 }
1403
1404 void usb_hub_release_all_ports(struct usb_device *hdev, void *owner)
1405 {
1406 int n;
1407 void **powner;
1408
1409 n = find_port_owner(hdev, 1, &powner);
1410 if (n == 0) {
1411 for (; n < hdev->maxchild; (++n, ++powner)) {
1412 if (*powner == owner)
1413 *powner = NULL;
1414 }
1415 }
1416 }
1417
1418 /* The caller must hold udev's lock */
1419 bool usb_device_is_owned(struct usb_device *udev)
1420 {
1421 struct usb_hub *hub;
1422
1423 if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
1424 return false;
1425 hub = hdev_to_hub(udev->parent);
1426 return !!hub->port_owners[udev->portnum - 1];
1427 }
1428
1429
1430 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1431 {
1432 int i;
1433
1434 for (i = 0; i < udev->maxchild; ++i) {
1435 if (udev->children[i])
1436 recursively_mark_NOTATTACHED(udev->children[i]);
1437 }
1438 if (udev->state == USB_STATE_SUSPENDED)
1439 udev->active_duration -= jiffies;
1440 udev->state = USB_STATE_NOTATTACHED;
1441 }
1442
1443 /**
1444 * usb_set_device_state - change a device's current state (usbcore, hcds)
1445 * @udev: pointer to device whose state should be changed
1446 * @new_state: new state value to be stored
1447 *
1448 * udev->state is _not_ fully protected by the device lock. Although
1449 * most transitions are made only while holding the lock, the state can
1450 * can change to USB_STATE_NOTATTACHED at almost any time. This
1451 * is so that devices can be marked as disconnected as soon as possible,
1452 * without having to wait for any semaphores to be released. As a result,
1453 * all changes to any device's state must be protected by the
1454 * device_state_lock spinlock.
1455 *
1456 * Once a device has been added to the device tree, all changes to its state
1457 * should be made using this routine. The state should _not_ be set directly.
1458 *
1459 * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1460 * Otherwise udev->state is set to new_state, and if new_state is
1461 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1462 * to USB_STATE_NOTATTACHED.
1463 */
1464 void usb_set_device_state(struct usb_device *udev,
1465 enum usb_device_state new_state)
1466 {
1467 unsigned long flags;
1468
1469 spin_lock_irqsave(&device_state_lock, flags);
1470 if (udev->state == USB_STATE_NOTATTACHED)
1471 ; /* do nothing */
1472 else if (new_state != USB_STATE_NOTATTACHED) {
1473
1474 /* root hub wakeup capabilities are managed out-of-band
1475 * and may involve silicon errata ... ignore them here.
1476 */
1477 if (udev->parent) {
1478 if (udev->state == USB_STATE_SUSPENDED
1479 || new_state == USB_STATE_SUSPENDED)
1480 ; /* No change to wakeup settings */
1481 else if (new_state == USB_STATE_CONFIGURED)
1482 device_set_wakeup_capable(&udev->dev,
1483 (udev->actconfig->desc.bmAttributes
1484 & USB_CONFIG_ATT_WAKEUP));
1485 else
1486 device_set_wakeup_capable(&udev->dev, 0);
1487 }
1488 if (udev->state == USB_STATE_SUSPENDED &&
1489 new_state != USB_STATE_SUSPENDED)
1490 udev->active_duration -= jiffies;
1491 else if (new_state == USB_STATE_SUSPENDED &&
1492 udev->state != USB_STATE_SUSPENDED)
1493 udev->active_duration += jiffies;
1494 udev->state = new_state;
1495 } else
1496 recursively_mark_NOTATTACHED(udev);
1497 spin_unlock_irqrestore(&device_state_lock, flags);
1498 }
1499 EXPORT_SYMBOL_GPL(usb_set_device_state);
1500
1501 /*
1502 * WUSB devices are simple: they have no hubs behind, so the mapping
1503 * device <-> virtual port number becomes 1:1. Why? to simplify the
1504 * life of the device connection logic in
1505 * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
1506 * handshake we need to assign a temporary address in the unauthorized
1507 * space. For simplicity we use the first virtual port number found to
1508 * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
1509 * and that becomes it's address [X < 128] or its unauthorized address
1510 * [X | 0x80].
1511 *
1512 * We add 1 as an offset to the one-based USB-stack port number
1513 * (zero-based wusb virtual port index) for two reasons: (a) dev addr
1514 * 0 is reserved by USB for default address; (b) Linux's USB stack
1515 * uses always #1 for the root hub of the controller. So USB stack's
1516 * port #1, which is wusb virtual-port #0 has address #2.
1517 *
1518 * Devices connected under xHCI are not as simple. The host controller
1519 * supports virtualization, so the hardware assigns device addresses and
1520 * the HCD must setup data structures before issuing a set address
1521 * command to the hardware.
1522 */
1523 static void choose_address(struct usb_device *udev)
1524 {
1525 int devnum;
1526 struct usb_bus *bus = udev->bus;
1527
1528 /* If khubd ever becomes multithreaded, this will need a lock */
1529 if (udev->wusb) {
1530 devnum = udev->portnum + 1;
1531 BUG_ON(test_bit(devnum, bus->devmap.devicemap));
1532 } else {
1533 /* Try to allocate the next devnum beginning at
1534 * bus->devnum_next. */
1535 devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1536 bus->devnum_next);
1537 if (devnum >= 128)
1538 devnum = find_next_zero_bit(bus->devmap.devicemap,
1539 128, 1);
1540 bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1541 }
1542 if (devnum < 128) {
1543 set_bit(devnum, bus->devmap.devicemap);
1544 udev->devnum = devnum;
1545 }
1546 }
1547
1548 static void release_address(struct usb_device *udev)
1549 {
1550 if (udev->devnum > 0) {
1551 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1552 udev->devnum = -1;
1553 }
1554 }
1555
1556 static void update_address(struct usb_device *udev, int devnum)
1557 {
1558 /* The address for a WUSB device is managed by wusbcore. */
1559 if (!udev->wusb)
1560 udev->devnum = devnum;
1561 }
1562
1563 static void hub_free_dev(struct usb_device *udev)
1564 {
1565 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1566
1567 /* Root hubs aren't real devices, so don't free HCD resources */
1568 if (hcd->driver->free_dev && udev->parent)
1569 hcd->driver->free_dev(hcd, udev);
1570 }
1571
1572 /**
1573 * usb_disconnect - disconnect a device (usbcore-internal)
1574 * @pdev: pointer to device being disconnected
1575 * Context: !in_interrupt ()
1576 *
1577 * Something got disconnected. Get rid of it and all of its children.
1578 *
1579 * If *pdev is a normal device then the parent hub must already be locked.
1580 * If *pdev is a root hub then this routine will acquire the
1581 * usb_bus_list_lock on behalf of the caller.
1582 *
1583 * Only hub drivers (including virtual root hub drivers for host
1584 * controllers) should ever call this.
1585 *
1586 * This call is synchronous, and may not be used in an interrupt context.
1587 */
1588 void usb_disconnect(struct usb_device **pdev)
1589 {
1590 struct usb_device *udev = *pdev;
1591 int i;
1592
1593 if (!udev) {
1594 pr_debug ("%s nodev\n", __func__);
1595 return;
1596 }
1597
1598 /* mark the device as inactive, so any further urb submissions for
1599 * this device (and any of its children) will fail immediately.
1600 * this quiesces everyting except pending urbs.
1601 */
1602 usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1603 dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1604
1605 usb_lock_device(udev);
1606
1607 /* Free up all the children before we remove this device */
1608 for (i = 0; i < USB_MAXCHILDREN; i++) {
1609 if (udev->children[i])
1610 usb_disconnect(&udev->children[i]);
1611 }
1612
1613 /* deallocate hcd/hardware state ... nuking all pending urbs and
1614 * cleaning up all state associated with the current configuration
1615 * so that the hardware is now fully quiesced.
1616 */
1617 dev_dbg (&udev->dev, "unregistering device\n");
1618 usb_disable_device(udev, 0);
1619 usb_hcd_synchronize_unlinks(udev);
1620
1621 usb_remove_ep_devs(&udev->ep0);
1622 usb_unlock_device(udev);
1623
1624 /* Unregister the device. The device driver is responsible
1625 * for de-configuring the device and invoking the remove-device
1626 * notifier chain (used by usbfs and possibly others).
1627 */
1628 device_del(&udev->dev);
1629
1630 /* Free the device number and delete the parent's children[]
1631 * (or root_hub) pointer.
1632 */
1633 release_address(udev);
1634
1635 /* Avoid races with recursively_mark_NOTATTACHED() */
1636 spin_lock_irq(&device_state_lock);
1637 *pdev = NULL;
1638 spin_unlock_irq(&device_state_lock);
1639
1640 hub_free_dev(udev);
1641
1642 put_device(&udev->dev);
1643 }
1644
1645 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
1646 static void show_string(struct usb_device *udev, char *id, char *string)
1647 {
1648 if (!string)
1649 return;
1650 dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1651 }
1652
1653 static void announce_device(struct usb_device *udev)
1654 {
1655 dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
1656 le16_to_cpu(udev->descriptor.idVendor),
1657 le16_to_cpu(udev->descriptor.idProduct));
1658 dev_info(&udev->dev,
1659 "New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
1660 udev->descriptor.iManufacturer,
1661 udev->descriptor.iProduct,
1662 udev->descriptor.iSerialNumber);
1663 show_string(udev, "Product", udev->product);
1664 show_string(udev, "Manufacturer", udev->manufacturer);
1665 show_string(udev, "SerialNumber", udev->serial);
1666 }
1667 #else
1668 static inline void announce_device(struct usb_device *udev) { }
1669 #endif
1670
1671 #ifdef CONFIG_USB_OTG
1672 #include "otg_whitelist.h"
1673 #endif
1674
1675 /**
1676 * usb_enumerate_device_otg - FIXME (usbcore-internal)
1677 * @udev: newly addressed device (in ADDRESS state)
1678 *
1679 * Finish enumeration for On-The-Go devices
1680 */
1681 static int usb_enumerate_device_otg(struct usb_device *udev)
1682 {
1683 int err = 0;
1684
1685 #ifdef CONFIG_USB_OTG
1686 /*
1687 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1688 * to wake us after we've powered off VBUS; and HNP, switching roles
1689 * "host" to "peripheral". The OTG descriptor helps figure this out.
1690 */
1691 if (!udev->bus->is_b_host
1692 && udev->config
1693 && udev->parent == udev->bus->root_hub) {
1694 struct usb_otg_descriptor *desc = NULL;
1695 struct usb_bus *bus = udev->bus;
1696
1697 /* descriptor may appear anywhere in config */
1698 if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1699 le16_to_cpu(udev->config[0].desc.wTotalLength),
1700 USB_DT_OTG, (void **) &desc) == 0) {
1701 if (desc->bmAttributes & USB_OTG_HNP) {
1702 unsigned port1 = udev->portnum;
1703
1704 dev_info(&udev->dev,
1705 "Dual-Role OTG device on %sHNP port\n",
1706 (port1 == bus->otg_port)
1707 ? "" : "non-");
1708
1709 /* enable HNP before suspend, it's simpler */
1710 if (port1 == bus->otg_port)
1711 bus->b_hnp_enable = 1;
1712 err = usb_control_msg(udev,
1713 usb_sndctrlpipe(udev, 0),
1714 USB_REQ_SET_FEATURE, 0,
1715 bus->b_hnp_enable
1716 ? USB_DEVICE_B_HNP_ENABLE
1717 : USB_DEVICE_A_ALT_HNP_SUPPORT,
1718 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1719 if (err < 0) {
1720 /* OTG MESSAGE: report errors here,
1721 * customize to match your product.
1722 */
1723 dev_info(&udev->dev,
1724 "can't set HNP mode: %d\n",
1725 err);
1726 bus->b_hnp_enable = 0;
1727 }
1728 }
1729 }
1730 }
1731
1732 if (!is_targeted(udev)) {
1733
1734 /* Maybe it can talk to us, though we can't talk to it.
1735 * (Includes HNP test device.)
1736 */
1737 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1738 err = usb_port_suspend(udev, PMSG_SUSPEND);
1739 if (err < 0)
1740 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1741 }
1742 err = -ENOTSUPP;
1743 goto fail;
1744 }
1745 fail:
1746 #endif
1747 return err;
1748 }
1749
1750
1751 /**
1752 * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
1753 * @udev: newly addressed device (in ADDRESS state)
1754 *
1755 * This is only called by usb_new_device() and usb_authorize_device()
1756 * and FIXME -- all comments that apply to them apply here wrt to
1757 * environment.
1758 *
1759 * If the device is WUSB and not authorized, we don't attempt to read
1760 * the string descriptors, as they will be errored out by the device
1761 * until it has been authorized.
1762 */
1763 static int usb_enumerate_device(struct usb_device *udev)
1764 {
1765 int err;
1766
1767 if (udev->config == NULL) {
1768 err = usb_get_configuration(udev);
1769 if (err < 0) {
1770 dev_err(&udev->dev, "can't read configurations, error %d\n",
1771 err);
1772 goto fail;
1773 }
1774 }
1775 if (udev->wusb == 1 && udev->authorized == 0) {
1776 udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1777 udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1778 udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1779 }
1780 else {
1781 /* read the standard strings and cache them if present */
1782 udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
1783 udev->manufacturer = usb_cache_string(udev,
1784 udev->descriptor.iManufacturer);
1785 udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
1786 }
1787 err = usb_enumerate_device_otg(udev);
1788 fail:
1789 return err;
1790 }
1791
1792
1793 /**
1794 * usb_new_device - perform initial device setup (usbcore-internal)
1795 * @udev: newly addressed device (in ADDRESS state)
1796 *
1797 * This is called with devices which have been detected but not fully
1798 * enumerated. The device descriptor is available, but not descriptors
1799 * for any device configuration. The caller must have locked either
1800 * the parent hub (if udev is a normal device) or else the
1801 * usb_bus_list_lock (if udev is a root hub). The parent's pointer to
1802 * udev has already been installed, but udev is not yet visible through
1803 * sysfs or other filesystem code.
1804 *
1805 * It will return if the device is configured properly or not. Zero if
1806 * the interface was registered with the driver core; else a negative
1807 * errno value.
1808 *
1809 * This call is synchronous, and may not be used in an interrupt context.
1810 *
1811 * Only the hub driver or root-hub registrar should ever call this.
1812 */
1813 int usb_new_device(struct usb_device *udev)
1814 {
1815 int err;
1816
1817 if (udev->parent) {
1818 /* Initialize non-root-hub device wakeup to disabled;
1819 * device (un)configuration controls wakeup capable
1820 * sysfs power/wakeup controls wakeup enabled/disabled
1821 */
1822 device_init_wakeup(&udev->dev, 0);
1823 }
1824
1825 /* Tell the runtime-PM framework the device is active */
1826 pm_runtime_set_active(&udev->dev);
1827 pm_runtime_get_noresume(&udev->dev);
1828 pm_runtime_use_autosuspend(&udev->dev);
1829 pm_runtime_enable(&udev->dev);
1830
1831 /* By default, forbid autosuspend for all devices. It will be
1832 * allowed for hubs during binding.
1833 */
1834 usb_disable_autosuspend(udev);
1835
1836 err = usb_enumerate_device(udev); /* Read descriptors */
1837 if (err < 0)
1838 goto fail;
1839 dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
1840 udev->devnum, udev->bus->busnum,
1841 (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
1842 /* export the usbdev device-node for libusb */
1843 udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
1844 (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
1845
1846 /* Tell the world! */
1847 announce_device(udev);
1848
1849 device_enable_async_suspend(&udev->dev);
1850 /* Register the device. The device driver is responsible
1851 * for configuring the device and invoking the add-device
1852 * notifier chain (used by usbfs and possibly others).
1853 */
1854 err = device_add(&udev->dev);
1855 if (err) {
1856 dev_err(&udev->dev, "can't device_add, error %d\n", err);
1857 goto fail;
1858 }
1859
1860 (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
1861 usb_mark_last_busy(udev);
1862 pm_runtime_put_sync_autosuspend(&udev->dev);
1863 return err;
1864
1865 fail:
1866 usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1867 pm_runtime_disable(&udev->dev);
1868 pm_runtime_set_suspended(&udev->dev);
1869 return err;
1870 }
1871
1872
1873 /**
1874 * usb_deauthorize_device - deauthorize a device (usbcore-internal)
1875 * @usb_dev: USB device
1876 *
1877 * Move the USB device to a very basic state where interfaces are disabled
1878 * and the device is in fact unconfigured and unusable.
1879 *
1880 * We share a lock (that we have) with device_del(), so we need to
1881 * defer its call.
1882 */
1883 int usb_deauthorize_device(struct usb_device *usb_dev)
1884 {
1885 usb_lock_device(usb_dev);
1886 if (usb_dev->authorized == 0)
1887 goto out_unauthorized;
1888
1889 usb_dev->authorized = 0;
1890 usb_set_configuration(usb_dev, -1);
1891
1892 kfree(usb_dev->product);
1893 usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1894 kfree(usb_dev->manufacturer);
1895 usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1896 kfree(usb_dev->serial);
1897 usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1898
1899 usb_destroy_configuration(usb_dev);
1900 usb_dev->descriptor.bNumConfigurations = 0;
1901
1902 out_unauthorized:
1903 usb_unlock_device(usb_dev);
1904 return 0;
1905 }
1906
1907
1908 int usb_authorize_device(struct usb_device *usb_dev)
1909 {
1910 int result = 0, c;
1911
1912 usb_lock_device(usb_dev);
1913 if (usb_dev->authorized == 1)
1914 goto out_authorized;
1915
1916 result = usb_autoresume_device(usb_dev);
1917 if (result < 0) {
1918 dev_err(&usb_dev->dev,
1919 "can't autoresume for authorization: %d\n", result);
1920 goto error_autoresume;
1921 }
1922 result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
1923 if (result < 0) {
1924 dev_err(&usb_dev->dev, "can't re-read device descriptor for "
1925 "authorization: %d\n", result);
1926 goto error_device_descriptor;
1927 }
1928
1929 kfree(usb_dev->product);
1930 usb_dev->product = NULL;
1931 kfree(usb_dev->manufacturer);
1932 usb_dev->manufacturer = NULL;
1933 kfree(usb_dev->serial);
1934 usb_dev->serial = NULL;
1935
1936 usb_dev->authorized = 1;
1937 result = usb_enumerate_device(usb_dev);
1938 if (result < 0)
1939 goto error_enumerate;
1940 /* Choose and set the configuration. This registers the interfaces
1941 * with the driver core and lets interface drivers bind to them.
1942 */
1943 c = usb_choose_configuration(usb_dev);
1944 if (c >= 0) {
1945 result = usb_set_configuration(usb_dev, c);
1946 if (result) {
1947 dev_err(&usb_dev->dev,
1948 "can't set config #%d, error %d\n", c, result);
1949 /* This need not be fatal. The user can try to
1950 * set other configurations. */
1951 }
1952 }
1953 dev_info(&usb_dev->dev, "authorized to connect\n");
1954
1955 error_enumerate:
1956 error_device_descriptor:
1957 usb_autosuspend_device(usb_dev);
1958 error_autoresume:
1959 out_authorized:
1960 usb_unlock_device(usb_dev); // complements locktree
1961 return result;
1962 }
1963
1964
1965 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
1966 static unsigned hub_is_wusb(struct usb_hub *hub)
1967 {
1968 struct usb_hcd *hcd;
1969 if (hub->hdev->parent != NULL) /* not a root hub? */
1970 return 0;
1971 hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
1972 return hcd->wireless;
1973 }
1974
1975
1976 #define PORT_RESET_TRIES 5
1977 #define SET_ADDRESS_TRIES 2
1978 #define GET_DESCRIPTOR_TRIES 2
1979 #define SET_CONFIG_TRIES (2 * (use_both_schemes + 1))
1980 #define USE_NEW_SCHEME(i) ((i) / 2 == old_scheme_first)
1981
1982 #define HUB_ROOT_RESET_TIME 50 /* times are in msec */
1983 #define HUB_SHORT_RESET_TIME 10
1984 #define HUB_LONG_RESET_TIME 200
1985 #define HUB_RESET_TIMEOUT 500
1986
1987 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1988 struct usb_device *udev, unsigned int delay)
1989 {
1990 int delay_time, ret;
1991 u16 portstatus;
1992 u16 portchange;
1993
1994 for (delay_time = 0;
1995 delay_time < HUB_RESET_TIMEOUT;
1996 delay_time += delay) {
1997 /* wait to give the device a chance to reset */
1998 msleep(delay);
1999
2000 /* read and decode port status */
2001 ret = hub_port_status(hub, port1, &portstatus, &portchange);
2002 if (ret < 0)
2003 return ret;
2004
2005 /* Device went away? */
2006 if (!(portstatus & USB_PORT_STAT_CONNECTION))
2007 return -ENOTCONN;
2008
2009 /* bomb out completely if the connection bounced */
2010 if ((portchange & USB_PORT_STAT_C_CONNECTION))
2011 return -ENOTCONN;
2012
2013 /* if we`ve finished resetting, then break out of the loop */
2014 if (!(portstatus & USB_PORT_STAT_RESET) &&
2015 (portstatus & USB_PORT_STAT_ENABLE)) {
2016 if (hub_is_wusb(hub))
2017 udev->speed = USB_SPEED_WIRELESS;
2018 else if (portstatus & USB_PORT_STAT_SUPER_SPEED)
2019 udev->speed = USB_SPEED_SUPER;
2020 else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2021 udev->speed = USB_SPEED_HIGH;
2022 else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2023 udev->speed = USB_SPEED_LOW;
2024 else
2025 udev->speed = USB_SPEED_FULL;
2026 return 0;
2027 }
2028
2029 /* switch to the long delay after two short delay failures */
2030 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2031 delay = HUB_LONG_RESET_TIME;
2032
2033 dev_dbg (hub->intfdev,
2034 "port %d not reset yet, waiting %dms\n",
2035 port1, delay);
2036 }
2037
2038 return -EBUSY;
2039 }
2040
2041 static int hub_port_reset(struct usb_hub *hub, int port1,
2042 struct usb_device *udev, unsigned int delay)
2043 {
2044 int i, status;
2045 struct usb_hcd *hcd;
2046
2047 hcd = bus_to_hcd(udev->bus);
2048 /* Block EHCI CF initialization during the port reset.
2049 * Some companion controllers don't like it when they mix.
2050 */
2051 down_read(&ehci_cf_port_reset_rwsem);
2052
2053 /* Reset the port */
2054 for (i = 0; i < PORT_RESET_TRIES; i++) {
2055 status = set_port_feature(hub->hdev,
2056 port1, USB_PORT_FEAT_RESET);
2057 if (status)
2058 dev_err(hub->intfdev,
2059 "cannot reset port %d (err = %d)\n",
2060 port1, status);
2061 else {
2062 status = hub_port_wait_reset(hub, port1, udev, delay);
2063 if (status && status != -ENOTCONN)
2064 dev_dbg(hub->intfdev,
2065 "port_wait_reset: err = %d\n",
2066 status);
2067 }
2068
2069 /* return on disconnect or reset */
2070 switch (status) {
2071 case 0:
2072 /* TRSTRCY = 10 ms; plus some extra */
2073 msleep(10 + 40);
2074 update_address(udev, 0);
2075 if (hcd->driver->reset_device) {
2076 status = hcd->driver->reset_device(hcd, udev);
2077 if (status < 0) {
2078 dev_err(&udev->dev, "Cannot reset "
2079 "HCD device state\n");
2080 break;
2081 }
2082 }
2083 /* FALL THROUGH */
2084 case -ENOTCONN:
2085 case -ENODEV:
2086 clear_port_feature(hub->hdev,
2087 port1, USB_PORT_FEAT_C_RESET);
2088 /* FIXME need disconnect() for NOTATTACHED device */
2089 usb_set_device_state(udev, status
2090 ? USB_STATE_NOTATTACHED
2091 : USB_STATE_DEFAULT);
2092 goto done;
2093 }
2094
2095 dev_dbg (hub->intfdev,
2096 "port %d not enabled, trying reset again...\n",
2097 port1);
2098 delay = HUB_LONG_RESET_TIME;
2099 }
2100
2101 dev_err (hub->intfdev,
2102 "Cannot enable port %i. Maybe the USB cable is bad?\n",
2103 port1);
2104
2105 done:
2106 up_read(&ehci_cf_port_reset_rwsem);
2107 return status;
2108 }
2109
2110 #ifdef CONFIG_PM
2111
2112 #define MASK_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \
2113 USB_PORT_STAT_SUSPEND)
2114 #define WANT_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION)
2115
2116 /* Determine whether the device on a port is ready for a normal resume,
2117 * is ready for a reset-resume, or should be disconnected.
2118 */
2119 static int check_port_resume_type(struct usb_device *udev,
2120 struct usb_hub *hub, int port1,
2121 int status, unsigned portchange, unsigned portstatus)
2122 {
2123 /* Is the device still present? */
2124 if (status || (portstatus & MASK_BITS) != WANT_BITS) {
2125 if (status >= 0)
2126 status = -ENODEV;
2127 }
2128
2129 /* Can't do a normal resume if the port isn't enabled,
2130 * so try a reset-resume instead.
2131 */
2132 else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
2133 if (udev->persist_enabled)
2134 udev->reset_resume = 1;
2135 else
2136 status = -ENODEV;
2137 }
2138
2139 if (status) {
2140 dev_dbg(hub->intfdev,
2141 "port %d status %04x.%04x after resume, %d\n",
2142 port1, portchange, portstatus, status);
2143 } else if (udev->reset_resume) {
2144
2145 /* Late port handoff can set status-change bits */
2146 if (portchange & USB_PORT_STAT_C_CONNECTION)
2147 clear_port_feature(hub->hdev, port1,
2148 USB_PORT_FEAT_C_CONNECTION);
2149 if (portchange & USB_PORT_STAT_C_ENABLE)
2150 clear_port_feature(hub->hdev, port1,
2151 USB_PORT_FEAT_C_ENABLE);
2152 }
2153
2154 return status;
2155 }
2156
2157 #ifdef CONFIG_USB_SUSPEND
2158
2159 /*
2160 * usb_port_suspend - suspend a usb device's upstream port
2161 * @udev: device that's no longer in active use, not a root hub
2162 * Context: must be able to sleep; device not locked; pm locks held
2163 *
2164 * Suspends a USB device that isn't in active use, conserving power.
2165 * Devices may wake out of a suspend, if anything important happens,
2166 * using the remote wakeup mechanism. They may also be taken out of
2167 * suspend by the host, using usb_port_resume(). It's also routine
2168 * to disconnect devices while they are suspended.
2169 *
2170 * This only affects the USB hardware for a device; its interfaces
2171 * (and, for hubs, child devices) must already have been suspended.
2172 *
2173 * Selective port suspend reduces power; most suspended devices draw
2174 * less than 500 uA. It's also used in OTG, along with remote wakeup.
2175 * All devices below the suspended port are also suspended.
2176 *
2177 * Devices leave suspend state when the host wakes them up. Some devices
2178 * also support "remote wakeup", where the device can activate the USB
2179 * tree above them to deliver data, such as a keypress or packet. In
2180 * some cases, this wakes the USB host.
2181 *
2182 * Suspending OTG devices may trigger HNP, if that's been enabled
2183 * between a pair of dual-role devices. That will change roles, such
2184 * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
2185 *
2186 * Devices on USB hub ports have only one "suspend" state, corresponding
2187 * to ACPI D2, "may cause the device to lose some context".
2188 * State transitions include:
2189 *
2190 * - suspend, resume ... when the VBUS power link stays live
2191 * - suspend, disconnect ... VBUS lost
2192 *
2193 * Once VBUS drop breaks the circuit, the port it's using has to go through
2194 * normal re-enumeration procedures, starting with enabling VBUS power.
2195 * Other than re-initializing the hub (plug/unplug, except for root hubs),
2196 * Linux (2.6) currently has NO mechanisms to initiate that: no khubd
2197 * timer, no SRP, no requests through sysfs.
2198 *
2199 * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
2200 * the root hub for their bus goes into global suspend ... so we don't
2201 * (falsely) update the device power state to say it suspended.
2202 *
2203 * Returns 0 on success, else negative errno.
2204 */
2205 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
2206 {
2207 struct usb_hub *hub = hdev_to_hub(udev->parent);
2208 int port1 = udev->portnum;
2209 int status;
2210
2211 // dev_dbg(hub->intfdev, "suspend port %d\n", port1);
2212
2213 /* enable remote wakeup when appropriate; this lets the device
2214 * wake up the upstream hub (including maybe the root hub).
2215 *
2216 * NOTE: OTG devices may issue remote wakeup (or SRP) even when
2217 * we don't explicitly enable it here.
2218 */
2219 if (udev->do_remote_wakeup) {
2220 status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2221 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2222 USB_DEVICE_REMOTE_WAKEUP, 0,
2223 NULL, 0,
2224 USB_CTRL_SET_TIMEOUT);
2225 if (status) {
2226 dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
2227 status);
2228 /* bail if autosuspend is requested */
2229 if (msg.event & PM_EVENT_AUTO)
2230 return status;
2231 }
2232 }
2233
2234 /* see 7.1.7.6 */
2235 status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
2236 if (status) {
2237 dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
2238 port1, status);
2239 /* paranoia: "should not happen" */
2240 if (udev->do_remote_wakeup)
2241 (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2242 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2243 USB_DEVICE_REMOTE_WAKEUP, 0,
2244 NULL, 0,
2245 USB_CTRL_SET_TIMEOUT);
2246 } else {
2247 /* device has up to 10 msec to fully suspend */
2248 dev_dbg(&udev->dev, "usb %ssuspend\n",
2249 (msg.event & PM_EVENT_AUTO ? "auto-" : ""));
2250 usb_set_device_state(udev, USB_STATE_SUSPENDED);
2251 msleep(10);
2252 }
2253 usb_mark_last_busy(hub->hdev);
2254 return status;
2255 }
2256
2257 /*
2258 * If the USB "suspend" state is in use (rather than "global suspend"),
2259 * many devices will be individually taken out of suspend state using
2260 * special "resume" signaling. This routine kicks in shortly after
2261 * hardware resume signaling is finished, either because of selective
2262 * resume (by host) or remote wakeup (by device) ... now see what changed
2263 * in the tree that's rooted at this device.
2264 *
2265 * If @udev->reset_resume is set then the device is reset before the
2266 * status check is done.
2267 */
2268 static int finish_port_resume(struct usb_device *udev)
2269 {
2270 int status = 0;
2271 u16 devstatus;
2272
2273 /* caller owns the udev device lock */
2274 dev_dbg(&udev->dev, "%s\n",
2275 udev->reset_resume ? "finish reset-resume" : "finish resume");
2276
2277 /* usb ch9 identifies four variants of SUSPENDED, based on what
2278 * state the device resumes to. Linux currently won't see the
2279 * first two on the host side; they'd be inside hub_port_init()
2280 * during many timeouts, but khubd can't suspend until later.
2281 */
2282 usb_set_device_state(udev, udev->actconfig
2283 ? USB_STATE_CONFIGURED
2284 : USB_STATE_ADDRESS);
2285
2286 /* 10.5.4.5 says not to reset a suspended port if the attached
2287 * device is enabled for remote wakeup. Hence the reset
2288 * operation is carried out here, after the port has been
2289 * resumed.
2290 */
2291 if (udev->reset_resume)
2292 retry_reset_resume:
2293 status = usb_reset_and_verify_device(udev);
2294
2295 /* 10.5.4.5 says be sure devices in the tree are still there.
2296 * For now let's assume the device didn't go crazy on resume,
2297 * and device drivers will know about any resume quirks.
2298 */
2299 if (status == 0) {
2300 devstatus = 0;
2301 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
2302 if (status >= 0)
2303 status = (status > 0 ? 0 : -ENODEV);
2304
2305 /* If a normal resume failed, try doing a reset-resume */
2306 if (status && !udev->reset_resume && udev->persist_enabled) {
2307 dev_dbg(&udev->dev, "retry with reset-resume\n");
2308 udev->reset_resume = 1;
2309 goto retry_reset_resume;
2310 }
2311 }
2312
2313 if (status) {
2314 dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
2315 status);
2316 } else if (udev->actconfig) {
2317 le16_to_cpus(&devstatus);
2318 if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
2319 status = usb_control_msg(udev,
2320 usb_sndctrlpipe(udev, 0),
2321 USB_REQ_CLEAR_FEATURE,
2322 USB_RECIP_DEVICE,
2323 USB_DEVICE_REMOTE_WAKEUP, 0,
2324 NULL, 0,
2325 USB_CTRL_SET_TIMEOUT);
2326 if (status)
2327 dev_dbg(&udev->dev,
2328 "disable remote wakeup, status %d\n",
2329 status);
2330 }
2331 status = 0;
2332 }
2333 return status;
2334 }
2335
2336 /*
2337 * usb_port_resume - re-activate a suspended usb device's upstream port
2338 * @udev: device to re-activate, not a root hub
2339 * Context: must be able to sleep; device not locked; pm locks held
2340 *
2341 * This will re-activate the suspended device, increasing power usage
2342 * while letting drivers communicate again with its endpoints.
2343 * USB resume explicitly guarantees that the power session between
2344 * the host and the device is the same as it was when the device
2345 * suspended.
2346 *
2347 * If @udev->reset_resume is set then this routine won't check that the
2348 * port is still enabled. Furthermore, finish_port_resume() above will
2349 * reset @udev. The end result is that a broken power session can be
2350 * recovered and @udev will appear to persist across a loss of VBUS power.
2351 *
2352 * For example, if a host controller doesn't maintain VBUS suspend current
2353 * during a system sleep or is reset when the system wakes up, all the USB
2354 * power sessions below it will be broken. This is especially troublesome
2355 * for mass-storage devices containing mounted filesystems, since the
2356 * device will appear to have disconnected and all the memory mappings
2357 * to it will be lost. Using the USB_PERSIST facility, the device can be
2358 * made to appear as if it had not disconnected.
2359 *
2360 * This facility can be dangerous. Although usb_reset_and_verify_device() makes
2361 * every effort to insure that the same device is present after the
2362 * reset as before, it cannot provide a 100% guarantee. Furthermore it's
2363 * quite possible for a device to remain unaltered but its media to be
2364 * changed. If the user replaces a flash memory card while the system is
2365 * asleep, he will have only himself to blame when the filesystem on the
2366 * new card is corrupted and the system crashes.
2367 *
2368 * Returns 0 on success, else negative errno.
2369 */
2370 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
2371 {
2372 struct usb_hub *hub = hdev_to_hub(udev->parent);
2373 int port1 = udev->portnum;
2374 int status;
2375 u16 portchange, portstatus;
2376
2377 /* Skip the initial Clear-Suspend step for a remote wakeup */
2378 status = hub_port_status(hub, port1, &portstatus, &portchange);
2379 if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
2380 goto SuspendCleared;
2381
2382 // dev_dbg(hub->intfdev, "resume port %d\n", port1);
2383
2384 set_bit(port1, hub->busy_bits);
2385
2386 /* see 7.1.7.7; affects power usage, but not budgeting */
2387 status = clear_port_feature(hub->hdev,
2388 port1, USB_PORT_FEAT_SUSPEND);
2389 if (status) {
2390 dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
2391 port1, status);
2392 } else {
2393 /* drive resume for at least 20 msec */
2394 dev_dbg(&udev->dev, "usb %sresume\n",
2395 (msg.event & PM_EVENT_AUTO ? "auto-" : ""));
2396 msleep(25);
2397
2398 /* Virtual root hubs can trigger on GET_PORT_STATUS to
2399 * stop resume signaling. Then finish the resume
2400 * sequence.
2401 */
2402 status = hub_port_status(hub, port1, &portstatus, &portchange);
2403
2404 /* TRSMRCY = 10 msec */
2405 msleep(10);
2406 }
2407
2408 SuspendCleared:
2409 if (status == 0) {
2410 if (portchange & USB_PORT_STAT_C_SUSPEND)
2411 clear_port_feature(hub->hdev, port1,
2412 USB_PORT_FEAT_C_SUSPEND);
2413 }
2414
2415 clear_bit(port1, hub->busy_bits);
2416
2417 status = check_port_resume_type(udev,
2418 hub, port1, status, portchange, portstatus);
2419 if (status == 0)
2420 status = finish_port_resume(udev);
2421 if (status < 0) {
2422 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
2423 hub_port_logical_disconnect(hub, port1);
2424 }
2425 return status;
2426 }
2427
2428 /* caller has locked udev */
2429 int usb_remote_wakeup(struct usb_device *udev)
2430 {
2431 int status = 0;
2432
2433 if (udev->state == USB_STATE_SUSPENDED) {
2434 dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
2435 status = usb_autoresume_device(udev);
2436 if (status == 0) {
2437 /* Let the drivers do their thing, then... */
2438 usb_autosuspend_device(udev);
2439 }
2440 }
2441 return status;
2442 }
2443
2444 #else /* CONFIG_USB_SUSPEND */
2445
2446 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
2447
2448 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
2449 {
2450 return 0;
2451 }
2452
2453 /* However we may need to do a reset-resume */
2454
2455 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
2456 {
2457 struct usb_hub *hub = hdev_to_hub(udev->parent);
2458 int port1 = udev->portnum;
2459 int status;
2460 u16 portchange, portstatus;
2461
2462 status = hub_port_status(hub, port1, &portstatus, &portchange);
2463 status = check_port_resume_type(udev,
2464 hub, port1, status, portchange, portstatus);
2465
2466 if (status) {
2467 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
2468 hub_port_logical_disconnect(hub, port1);
2469 } else if (udev->reset_resume) {
2470 dev_dbg(&udev->dev, "reset-resume\n");
2471 status = usb_reset_and_verify_device(udev);
2472 }
2473 return status;
2474 }
2475
2476 #endif
2477
2478 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
2479 {
2480 struct usb_hub *hub = usb_get_intfdata (intf);
2481 struct usb_device *hdev = hub->hdev;
2482 unsigned port1;
2483
2484 /* fail if children aren't already suspended */
2485 for (port1 = 1; port1 <= hdev->maxchild; port1++) {
2486 struct usb_device *udev;
2487
2488 udev = hdev->children [port1-1];
2489 if (udev && udev->can_submit) {
2490 if (!(msg.event & PM_EVENT_AUTO))
2491 dev_dbg(&intf->dev, "port %d nyet suspended\n",
2492 port1);
2493 return -EBUSY;
2494 }
2495 }
2496
2497 dev_dbg(&intf->dev, "%s\n", __func__);
2498
2499 /* stop khubd and related activity */
2500 hub_quiesce(hub, HUB_SUSPEND);
2501 return 0;
2502 }
2503
2504 static int hub_resume(struct usb_interface *intf)
2505 {
2506 struct usb_hub *hub = usb_get_intfdata(intf);
2507
2508 dev_dbg(&intf->dev, "%s\n", __func__);
2509 hub_activate(hub, HUB_RESUME);
2510 return 0;
2511 }
2512
2513 static int hub_reset_resume(struct usb_interface *intf)
2514 {
2515 struct usb_hub *hub = usb_get_intfdata(intf);
2516
2517 dev_dbg(&intf->dev, "%s\n", __func__);
2518 hub_activate(hub, HUB_RESET_RESUME);
2519 return 0;
2520 }
2521
2522 /**
2523 * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
2524 * @rhdev: struct usb_device for the root hub
2525 *
2526 * The USB host controller driver calls this function when its root hub
2527 * is resumed and Vbus power has been interrupted or the controller
2528 * has been reset. The routine marks @rhdev as having lost power.
2529 * When the hub driver is resumed it will take notice and carry out
2530 * power-session recovery for all the "USB-PERSIST"-enabled child devices;
2531 * the others will be disconnected.
2532 */
2533 void usb_root_hub_lost_power(struct usb_device *rhdev)
2534 {
2535 dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
2536 rhdev->reset_resume = 1;
2537 }
2538 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
2539
2540 #else /* CONFIG_PM */
2541
2542 #define hub_suspend NULL
2543 #define hub_resume NULL
2544 #define hub_reset_resume NULL
2545 #endif
2546
2547
2548 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2549 *
2550 * Between connect detection and reset signaling there must be a delay
2551 * of 100ms at least for debounce and power-settling. The corresponding
2552 * timer shall restart whenever the downstream port detects a disconnect.
2553 *
2554 * Apparently there are some bluetooth and irda-dongles and a number of
2555 * low-speed devices for which this debounce period may last over a second.
2556 * Not covered by the spec - but easy to deal with.
2557 *
2558 * This implementation uses a 1500ms total debounce timeout; if the
2559 * connection isn't stable by then it returns -ETIMEDOUT. It checks
2560 * every 25ms for transient disconnects. When the port status has been
2561 * unchanged for 100ms it returns the port status.
2562 */
2563 static int hub_port_debounce(struct usb_hub *hub, int port1)
2564 {
2565 int ret;
2566 int total_time, stable_time = 0;
2567 u16 portchange, portstatus;
2568 unsigned connection = 0xffff;
2569
2570 for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2571 ret = hub_port_status(hub, port1, &portstatus, &portchange);
2572 if (ret < 0)
2573 return ret;
2574
2575 if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2576 (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2577 stable_time += HUB_DEBOUNCE_STEP;
2578 if (stable_time >= HUB_DEBOUNCE_STABLE)
2579 break;
2580 } else {
2581 stable_time = 0;
2582 connection = portstatus & USB_PORT_STAT_CONNECTION;
2583 }
2584
2585 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2586 clear_port_feature(hub->hdev, port1,
2587 USB_PORT_FEAT_C_CONNECTION);
2588 }
2589
2590 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2591 break;
2592 msleep(HUB_DEBOUNCE_STEP);
2593 }
2594
2595 dev_dbg (hub->intfdev,
2596 "debounce: port %d: total %dms stable %dms status 0x%x\n",
2597 port1, total_time, stable_time, portstatus);
2598
2599 if (stable_time < HUB_DEBOUNCE_STABLE)
2600 return -ETIMEDOUT;
2601 return portstatus;
2602 }
2603
2604 void usb_ep0_reinit(struct usb_device *udev)
2605 {
2606 usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
2607 usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
2608 usb_enable_endpoint(udev, &udev->ep0, true);
2609 }
2610 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
2611
2612 #define usb_sndaddr0pipe() (PIPE_CONTROL << 30)
2613 #define usb_rcvaddr0pipe() ((PIPE_CONTROL << 30) | USB_DIR_IN)
2614
2615 static int hub_set_address(struct usb_device *udev, int devnum)
2616 {
2617 int retval;
2618 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2619
2620 /*
2621 * The host controller will choose the device address,
2622 * instead of the core having chosen it earlier
2623 */
2624 if (!hcd->driver->address_device && devnum <= 1)
2625 return -EINVAL;
2626 if (udev->state == USB_STATE_ADDRESS)
2627 return 0;
2628 if (udev->state != USB_STATE_DEFAULT)
2629 return -EINVAL;
2630 if (hcd->driver->address_device)
2631 retval = hcd->driver->address_device(hcd, udev);
2632 else
2633 retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2634 USB_REQ_SET_ADDRESS, 0, devnum, 0,
2635 NULL, 0, USB_CTRL_SET_TIMEOUT);
2636 if (retval == 0) {
2637 update_address(udev, devnum);
2638 /* Device now using proper address. */
2639 usb_set_device_state(udev, USB_STATE_ADDRESS);
2640 usb_ep0_reinit(udev);
2641 }
2642 return retval;
2643 }
2644
2645 /* Reset device, (re)assign address, get device descriptor.
2646 * Device connection must be stable, no more debouncing needed.
2647 * Returns device in USB_STATE_ADDRESS, except on error.
2648 *
2649 * If this is called for an already-existing device (as part of
2650 * usb_reset_and_verify_device), the caller must own the device lock. For a
2651 * newly detected device that is not accessible through any global
2652 * pointers, it's not necessary to lock the device.
2653 */
2654 static int
2655 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2656 int retry_counter)
2657 {
2658 static DEFINE_MUTEX(usb_address0_mutex);
2659
2660 struct usb_device *hdev = hub->hdev;
2661 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
2662 int i, j, retval;
2663 unsigned delay = HUB_SHORT_RESET_TIME;
2664 enum usb_device_speed oldspeed = udev->speed;
2665 char *speed, *type;
2666 int devnum = udev->devnum;
2667
2668 /* root hub ports have a slightly longer reset period
2669 * (from USB 2.0 spec, section 7.1.7.5)
2670 */
2671 if (!hdev->parent) {
2672 delay = HUB_ROOT_RESET_TIME;
2673 if (port1 == hdev->bus->otg_port)
2674 hdev->bus->b_hnp_enable = 0;
2675 }
2676
2677 /* Some low speed devices have problems with the quick delay, so */
2678 /* be a bit pessimistic with those devices. RHbug #23670 */
2679 if (oldspeed == USB_SPEED_LOW)
2680 delay = HUB_LONG_RESET_TIME;
2681
2682 mutex_lock(&usb_address0_mutex);
2683
2684 /* Reset the device; full speed may morph to high speed */
2685 /* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
2686 retval = hub_port_reset(hub, port1, udev, delay);
2687 if (retval < 0) /* error or disconnect */
2688 goto fail;
2689 /* success, speed is known */
2690
2691 retval = -ENODEV;
2692
2693 if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2694 dev_dbg(&udev->dev, "device reset changed speed!\n");
2695 goto fail;
2696 }
2697 oldspeed = udev->speed;
2698
2699 /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2700 * it's fixed size except for full speed devices.
2701 * For Wireless USB devices, ep0 max packet is always 512 (tho
2702 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
2703 */
2704 switch (udev->speed) {
2705 case USB_SPEED_SUPER:
2706 case USB_SPEED_WIRELESS: /* fixed at 512 */
2707 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
2708 break;
2709 case USB_SPEED_HIGH: /* fixed at 64 */
2710 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
2711 break;
2712 case USB_SPEED_FULL: /* 8, 16, 32, or 64 */
2713 /* to determine the ep0 maxpacket size, try to read
2714 * the device descriptor to get bMaxPacketSize0 and
2715 * then correct our initial guess.
2716 */
2717 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
2718 break;
2719 case USB_SPEED_LOW: /* fixed at 8 */
2720 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
2721 break;
2722 default:
2723 goto fail;
2724 }
2725
2726 type = "";
2727 switch (udev->speed) {
2728 case USB_SPEED_LOW: speed = "low"; break;
2729 case USB_SPEED_FULL: speed = "full"; break;
2730 case USB_SPEED_HIGH: speed = "high"; break;
2731 case USB_SPEED_SUPER:
2732 speed = "super";
2733 break;
2734 case USB_SPEED_WIRELESS:
2735 speed = "variable";
2736 type = "Wireless ";
2737 break;
2738 default: speed = "?"; break;
2739 }
2740 if (udev->speed != USB_SPEED_SUPER)
2741 dev_info(&udev->dev,
2742 "%s %s speed %sUSB device using %s and address %d\n",
2743 (udev->config) ? "reset" : "new", speed, type,
2744 udev->bus->controller->driver->name, devnum);
2745
2746 /* Set up TT records, if needed */
2747 if (hdev->tt) {
2748 udev->tt = hdev->tt;
2749 udev->ttport = hdev->ttport;
2750 } else if (udev->speed != USB_SPEED_HIGH
2751 && hdev->speed == USB_SPEED_HIGH) {
2752 if (!hub->tt.hub) {
2753 dev_err(&udev->dev, "parent hub has no TT\n");
2754 retval = -EINVAL;
2755 goto fail;
2756 }
2757 udev->tt = &hub->tt;
2758 udev->ttport = port1;
2759 }
2760
2761 /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2762 * Because device hardware and firmware is sometimes buggy in
2763 * this area, and this is how Linux has done it for ages.
2764 * Change it cautiously.
2765 *
2766 * NOTE: If USE_NEW_SCHEME() is true we will start by issuing
2767 * a 64-byte GET_DESCRIPTOR request. This is what Windows does,
2768 * so it may help with some non-standards-compliant devices.
2769 * Otherwise we start with SET_ADDRESS and then try to read the
2770 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2771 * value.
2772 */
2773 for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2774 /*
2775 * An xHCI controller cannot send any packets to a device until
2776 * a set address command successfully completes.
2777 */
2778 if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3)) {
2779 struct usb_device_descriptor *buf;
2780 int r = 0;
2781
2782 #define GET_DESCRIPTOR_BUFSIZE 64
2783 buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2784 if (!buf) {
2785 retval = -ENOMEM;
2786 continue;
2787 }
2788
2789 /* Retry on all errors; some devices are flakey.
2790 * 255 is for WUSB devices, we actually need to use
2791 * 512 (WUSB1.0[4.8.1]).
2792 */
2793 for (j = 0; j < 3; ++j) {
2794 buf->bMaxPacketSize0 = 0;
2795 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2796 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2797 USB_DT_DEVICE << 8, 0,
2798 buf, GET_DESCRIPTOR_BUFSIZE,
2799 initial_descriptor_timeout);
2800 switch (buf->bMaxPacketSize0) {
2801 case 8: case 16: case 32: case 64: case 255:
2802 if (buf->bDescriptorType ==
2803 USB_DT_DEVICE) {
2804 r = 0;
2805 break;
2806 }
2807 /* FALL THROUGH */
2808 default:
2809 if (r == 0)
2810 r = -EPROTO;
2811 break;
2812 }
2813 if (r == 0)
2814 break;
2815 }
2816 udev->descriptor.bMaxPacketSize0 =
2817 buf->bMaxPacketSize0;
2818 kfree(buf);
2819
2820 retval = hub_port_reset(hub, port1, udev, delay);
2821 if (retval < 0) /* error or disconnect */
2822 goto fail;
2823 if (oldspeed != udev->speed) {
2824 dev_dbg(&udev->dev,
2825 "device reset changed speed!\n");
2826 retval = -ENODEV;
2827 goto fail;
2828 }
2829 if (r) {
2830 dev_err(&udev->dev,
2831 "device descriptor read/64, error %d\n",
2832 r);
2833 retval = -EMSGSIZE;
2834 continue;
2835 }
2836 #undef GET_DESCRIPTOR_BUFSIZE
2837 }
2838
2839 /*
2840 * If device is WUSB, we already assigned an
2841 * unauthorized address in the Connect Ack sequence;
2842 * authorization will assign the final address.
2843 */
2844 if (udev->wusb == 0) {
2845 for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2846 retval = hub_set_address(udev, devnum);
2847 if (retval >= 0)
2848 break;
2849 msleep(200);
2850 }
2851 if (retval < 0) {
2852 dev_err(&udev->dev,
2853 "device not accepting address %d, error %d\n",
2854 devnum, retval);
2855 goto fail;
2856 }
2857 if (udev->speed == USB_SPEED_SUPER) {
2858 devnum = udev->devnum;
2859 dev_info(&udev->dev,
2860 "%s SuperSpeed USB device using %s and address %d\n",
2861 (udev->config) ? "reset" : "new",
2862 udev->bus->controller->driver->name, devnum);
2863 }
2864
2865 /* cope with hardware quirkiness:
2866 * - let SET_ADDRESS settle, some device hardware wants it
2867 * - read ep0 maxpacket even for high and low speed,
2868 */
2869 msleep(10);
2870 if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3))
2871 break;
2872 }
2873
2874 retval = usb_get_device_descriptor(udev, 8);
2875 if (retval < 8) {
2876 dev_err(&udev->dev,
2877 "device descriptor read/8, error %d\n",
2878 retval);
2879 if (retval >= 0)
2880 retval = -EMSGSIZE;
2881 } else {
2882 retval = 0;
2883 break;
2884 }
2885 }
2886 if (retval)
2887 goto fail;
2888
2889 if (udev->descriptor.bMaxPacketSize0 == 0xff ||
2890 udev->speed == USB_SPEED_SUPER)
2891 i = 512;
2892 else
2893 i = udev->descriptor.bMaxPacketSize0;
2894 if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2895 if (udev->speed == USB_SPEED_LOW ||
2896 !(i == 8 || i == 16 || i == 32 || i == 64)) {
2897 dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i);
2898 retval = -EMSGSIZE;
2899 goto fail;
2900 }
2901 if (udev->speed == USB_SPEED_FULL)
2902 dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2903 else
2904 dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
2905 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2906 usb_ep0_reinit(udev);
2907 }
2908
2909 retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2910 if (retval < (signed)sizeof(udev->descriptor)) {
2911 dev_err(&udev->dev, "device descriptor read/all, error %d\n",
2912 retval);
2913 if (retval >= 0)
2914 retval = -ENOMSG;
2915 goto fail;
2916 }
2917
2918 retval = 0;
2919 /* notify HCD that we have a device connected and addressed */
2920 if (hcd->driver->update_device)
2921 hcd->driver->update_device(hcd, udev);
2922 fail:
2923 if (retval) {
2924 hub_port_disable(hub, port1, 0);
2925 update_address(udev, devnum); /* for disconnect processing */
2926 }
2927 mutex_unlock(&usb_address0_mutex);
2928 return retval;
2929 }
2930
2931 static void
2932 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2933 {
2934 struct usb_qualifier_descriptor *qual;
2935 int status;
2936
2937 qual = kmalloc (sizeof *qual, GFP_KERNEL);
2938 if (qual == NULL)
2939 return;
2940
2941 status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2942 qual, sizeof *qual);
2943 if (status == sizeof *qual) {
2944 dev_info(&udev->dev, "not running at top speed; "
2945 "connect to a high speed hub\n");
2946 /* hub LEDs are probably harder to miss than syslog */
2947 if (hub->has_indicators) {
2948 hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2949 schedule_delayed_work (&hub->leds, 0);
2950 }
2951 }
2952 kfree(qual);
2953 }
2954
2955 static unsigned
2956 hub_power_remaining (struct usb_hub *hub)
2957 {
2958 struct usb_device *hdev = hub->hdev;
2959 int remaining;
2960 int port1;
2961
2962 if (!hub->limited_power)
2963 return 0;
2964
2965 remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
2966 for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2967 struct usb_device *udev = hdev->children[port1 - 1];
2968 int delta;
2969
2970 if (!udev)
2971 continue;
2972
2973 /* Unconfigured devices may not use more than 100mA,
2974 * or 8mA for OTG ports */
2975 if (udev->actconfig)
2976 delta = udev->actconfig->desc.bMaxPower * 2;
2977 else if (port1 != udev->bus->otg_port || hdev->parent)
2978 delta = 100;
2979 else
2980 delta = 8;
2981 if (delta > hub->mA_per_port)
2982 dev_warn(&udev->dev,
2983 "%dmA is over %umA budget for port %d!\n",
2984 delta, hub->mA_per_port, port1);
2985 remaining -= delta;
2986 }
2987 if (remaining < 0) {
2988 dev_warn(hub->intfdev, "%dmA over power budget!\n",
2989 - remaining);
2990 remaining = 0;
2991 }
2992 return remaining;
2993 }
2994
2995 /* Handle physical or logical connection change events.
2996 * This routine is called when:
2997 * a port connection-change occurs;
2998 * a port enable-change occurs (often caused by EMI);
2999 * usb_reset_and_verify_device() encounters changed descriptors (as from
3000 * a firmware download)
3001 * caller already locked the hub
3002 */
3003 static void hub_port_connect_change(struct usb_hub *hub, int port1,
3004 u16 portstatus, u16 portchange)
3005 {
3006 struct usb_device *hdev = hub->hdev;
3007 struct device *hub_dev = hub->intfdev;
3008 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
3009 unsigned wHubCharacteristics =
3010 le16_to_cpu(hub->descriptor->wHubCharacteristics);
3011 struct usb_device *udev;
3012 int status, i;
3013
3014 dev_dbg (hub_dev,
3015 "port %d, status %04x, change %04x, %s\n",
3016 port1, portstatus, portchange, portspeed (portstatus));
3017
3018 if (hub->has_indicators) {
3019 set_port_led(hub, port1, HUB_LED_AUTO);
3020 hub->indicator[port1-1] = INDICATOR_AUTO;
3021 }
3022
3023 #ifdef CONFIG_USB_OTG
3024 /* during HNP, don't repeat the debounce */
3025 if (hdev->bus->is_b_host)
3026 portchange &= ~(USB_PORT_STAT_C_CONNECTION |
3027 USB_PORT_STAT_C_ENABLE);
3028 #endif
3029
3030 /* Try to resuscitate an existing device */
3031 udev = hdev->children[port1-1];
3032 if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
3033 udev->state != USB_STATE_NOTATTACHED) {
3034 usb_lock_device(udev);
3035 if (portstatus & USB_PORT_STAT_ENABLE) {
3036 status = 0; /* Nothing to do */
3037
3038 #ifdef CONFIG_USB_SUSPEND
3039 } else if (udev->state == USB_STATE_SUSPENDED &&
3040 udev->persist_enabled) {
3041 /* For a suspended device, treat this as a
3042 * remote wakeup event.
3043 */
3044 status = usb_remote_wakeup(udev);
3045 #endif
3046
3047 } else {
3048 status = -ENODEV; /* Don't resuscitate */
3049 }
3050 usb_unlock_device(udev);
3051
3052 if (status == 0) {
3053 clear_bit(port1, hub->change_bits);
3054 return;
3055 }
3056 }
3057
3058 /* Disconnect any existing devices under this port */
3059 if (udev)
3060 usb_disconnect(&hdev->children[port1-1]);
3061 clear_bit(port1, hub->change_bits);
3062
3063 /* We can forget about a "removed" device when there's a physical
3064 * disconnect or the connect status changes.
3065 */
3066 if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
3067 (portchange & USB_PORT_STAT_C_CONNECTION))
3068 clear_bit(port1, hub->removed_bits);
3069
3070 if (portchange & (USB_PORT_STAT_C_CONNECTION |
3071 USB_PORT_STAT_C_ENABLE)) {
3072 status = hub_port_debounce(hub, port1);
3073 if (status < 0) {
3074 if (printk_ratelimit())
3075 dev_err(hub_dev, "connect-debounce failed, "
3076 "port %d disabled\n", port1);
3077 portstatus &= ~USB_PORT_STAT_CONNECTION;
3078 } else {
3079 portstatus = status;
3080 }
3081 }
3082
3083 /* Return now if debouncing failed or nothing is connected or
3084 * the device was "removed".
3085 */
3086 if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
3087 test_bit(port1, hub->removed_bits)) {
3088
3089 /* maybe switch power back on (e.g. root hub was reset) */
3090 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
3091 && !(portstatus & USB_PORT_STAT_POWER))
3092 set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
3093
3094 if (portstatus & USB_PORT_STAT_ENABLE)
3095 goto done;
3096 return;
3097 }
3098
3099 for (i = 0; i < SET_CONFIG_TRIES; i++) {
3100
3101 /* reallocate for each attempt, since references
3102 * to the previous one can escape in various ways
3103 */
3104 udev = usb_alloc_dev(hdev, hdev->bus, port1);
3105 if (!udev) {
3106 dev_err (hub_dev,
3107 "couldn't allocate port %d usb_device\n",
3108 port1);
3109 goto done;
3110 }
3111
3112 usb_set_device_state(udev, USB_STATE_POWERED);
3113 udev->bus_mA = hub->mA_per_port;
3114 udev->level = hdev->level + 1;
3115 udev->wusb = hub_is_wusb(hub);
3116
3117 /*
3118 * USB 3.0 devices are reset automatically before the connect
3119 * port status change appears, and the root hub port status
3120 * shows the correct speed. We also get port change
3121 * notifications for USB 3.0 devices from the USB 3.0 portion of
3122 * an external USB 3.0 hub, but this isn't handled correctly yet
3123 * FIXME.
3124 */
3125
3126 if (!(hcd->driver->flags & HCD_USB3))
3127 udev->speed = USB_SPEED_UNKNOWN;
3128 else if ((hdev->parent == NULL) &&
3129 (portstatus & USB_PORT_STAT_SUPER_SPEED))
3130 udev->speed = USB_SPEED_SUPER;
3131 else
3132 udev->speed = USB_SPEED_UNKNOWN;
3133
3134 /*
3135 * Set the address.
3136 * Note xHCI needs to issue an address device command later
3137 * in the hub_port_init sequence for SS/HS/FS/LS devices,
3138 * and xHC will assign an address to the device. But use
3139 * kernel assigned address here, to avoid any address conflict
3140 * issue.
3141 */
3142 choose_address(udev);
3143 if (udev->devnum <= 0) {
3144 status = -ENOTCONN; /* Don't retry */
3145 goto loop;
3146 }
3147
3148 /* reset (non-USB 3.0 devices) and get descriptor */
3149 status = hub_port_init(hub, udev, port1, i);
3150 if (status < 0)
3151 goto loop;
3152
3153 usb_detect_quirks(udev);
3154 if (udev->quirks & USB_QUIRK_DELAY_INIT)
3155 msleep(1000);
3156
3157 /* consecutive bus-powered hubs aren't reliable; they can
3158 * violate the voltage drop budget. if the new child has
3159 * a "powered" LED, users should notice we didn't enable it
3160 * (without reading syslog), even without per-port LEDs
3161 * on the parent.
3162 */
3163 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
3164 && udev->bus_mA <= 100) {
3165 u16 devstat;
3166
3167 status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
3168 &devstat);
3169 if (status < 2) {
3170 dev_dbg(&udev->dev, "get status %d ?\n", status);
3171 goto loop_disable;
3172 }
3173 le16_to_cpus(&devstat);
3174 if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
3175 dev_err(&udev->dev,
3176 "can't connect bus-powered hub "
3177 "to this port\n");
3178 if (hub->has_indicators) {
3179 hub->indicator[port1-1] =
3180 INDICATOR_AMBER_BLINK;
3181 schedule_delayed_work (&hub->leds, 0);
3182 }
3183 status = -ENOTCONN; /* Don't retry */
3184 goto loop_disable;
3185 }
3186 }
3187
3188 /* check for devices running slower than they could */
3189 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
3190 && udev->speed == USB_SPEED_FULL
3191 && highspeed_hubs != 0)
3192 check_highspeed (hub, udev, port1);
3193
3194 /* Store the parent's children[] pointer. At this point
3195 * udev becomes globally accessible, although presumably
3196 * no one will look at it until hdev is unlocked.
3197 */
3198 status = 0;
3199
3200 /* We mustn't add new devices if the parent hub has
3201 * been disconnected; we would race with the
3202 * recursively_mark_NOTATTACHED() routine.
3203 */
3204 spin_lock_irq(&device_state_lock);
3205 if (hdev->state == USB_STATE_NOTATTACHED)
3206 status = -ENOTCONN;
3207 else
3208 hdev->children[port1-1] = udev;
3209 spin_unlock_irq(&device_state_lock);
3210
3211 /* Run it through the hoops (find a driver, etc) */
3212 if (!status) {
3213 status = usb_new_device(udev);
3214 if (status) {
3215 spin_lock_irq(&device_state_lock);
3216 hdev->children[port1-1] = NULL;
3217 spin_unlock_irq(&device_state_lock);
3218 }
3219 }
3220
3221 if (status)
3222 goto loop_disable;
3223
3224 status = hub_power_remaining(hub);
3225 if (status)
3226 dev_dbg(hub_dev, "%dmA power budget left\n", status);
3227
3228 return;
3229
3230 loop_disable:
3231 hub_port_disable(hub, port1, 1);
3232 loop:
3233 usb_ep0_reinit(udev);
3234 release_address(udev);
3235 hub_free_dev(udev);
3236 usb_put_dev(udev);
3237 if ((status == -ENOTCONN) || (status == -ENOTSUPP))
3238 break;
3239 }
3240 if (hub->hdev->parent ||
3241 !hcd->driver->port_handed_over ||
3242 !(hcd->driver->port_handed_over)(hcd, port1))
3243 dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
3244 port1);
3245
3246 done:
3247 hub_port_disable(hub, port1, 1);
3248 if (hcd->driver->relinquish_port && !hub->hdev->parent)
3249 hcd->driver->relinquish_port(hcd, port1);
3250 }
3251
3252 static void hub_events(void)
3253 {
3254 struct list_head *tmp;
3255 struct usb_device *hdev;
3256 struct usb_interface *intf;
3257 struct usb_hub *hub;
3258 struct device *hub_dev;
3259 u16 hubstatus;
3260 u16 hubchange;
3261 u16 portstatus;
3262 u16 portchange;
3263 int i, ret;
3264 int connect_change;
3265
3266 /*
3267 * We restart the list every time to avoid a deadlock with
3268 * deleting hubs downstream from this one. This should be
3269 * safe since we delete the hub from the event list.
3270 * Not the most efficient, but avoids deadlocks.
3271 */
3272 while (1) {
3273
3274 /* Grab the first entry at the beginning of the list */
3275 spin_lock_irq(&hub_event_lock);
3276 if (list_empty(&hub_event_list)) {
3277 spin_unlock_irq(&hub_event_lock);
3278 break;
3279 }
3280
3281 tmp = hub_event_list.next;
3282 list_del_init(tmp);
3283
3284 hub = list_entry(tmp, struct usb_hub, event_list);
3285 kref_get(&hub->kref);
3286 spin_unlock_irq(&hub_event_lock);
3287
3288 hdev = hub->hdev;
3289 hub_dev = hub->intfdev;
3290 intf = to_usb_interface(hub_dev);
3291 dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
3292 hdev->state, hub->descriptor
3293 ? hub->descriptor->bNbrPorts
3294 : 0,
3295 /* NOTE: expects max 15 ports... */
3296 (u16) hub->change_bits[0],
3297 (u16) hub->event_bits[0]);
3298
3299 /* Lock the device, then check to see if we were
3300 * disconnected while waiting for the lock to succeed. */
3301 usb_lock_device(hdev);
3302 if (unlikely(hub->disconnected))
3303 goto loop_disconnected;
3304
3305 /* If the hub has died, clean up after it */
3306 if (hdev->state == USB_STATE_NOTATTACHED) {
3307 hub->error = -ENODEV;
3308 hub_quiesce(hub, HUB_DISCONNECT);
3309 goto loop;
3310 }
3311
3312 /* Autoresume */
3313 ret = usb_autopm_get_interface(intf);
3314 if (ret) {
3315 dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
3316 goto loop;
3317 }
3318
3319 /* If this is an inactive hub, do nothing */
3320 if (hub->quiescing)
3321 goto loop_autopm;
3322
3323 if (hub->error) {
3324 dev_dbg (hub_dev, "resetting for error %d\n",
3325 hub->error);
3326
3327 ret = usb_reset_device(hdev);
3328 if (ret) {
3329 dev_dbg (hub_dev,
3330 "error resetting hub: %d\n", ret);
3331 goto loop_autopm;
3332 }
3333
3334 hub->nerrors = 0;
3335 hub->error = 0;
3336 }
3337
3338 /* deal with port status changes */
3339 for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
3340 if (test_bit(i, hub->busy_bits))
3341 continue;
3342 connect_change = test_bit(i, hub->change_bits);
3343 if (!test_and_clear_bit(i, hub->event_bits) &&
3344 !connect_change)
3345 continue;
3346
3347 ret = hub_port_status(hub, i,
3348 &portstatus, &portchange);
3349 if (ret < 0)
3350 continue;
3351
3352 if (portchange & USB_PORT_STAT_C_CONNECTION) {
3353 clear_port_feature(hdev, i,
3354 USB_PORT_FEAT_C_CONNECTION);
3355 connect_change = 1;
3356 }
3357
3358 if (portchange & USB_PORT_STAT_C_ENABLE) {
3359 if (!connect_change)
3360 dev_dbg (hub_dev,
3361 "port %d enable change, "
3362 "status %08x\n",
3363 i, portstatus);
3364 clear_port_feature(hdev, i,
3365 USB_PORT_FEAT_C_ENABLE);
3366
3367 /*
3368 * EM interference sometimes causes badly
3369 * shielded USB devices to be shutdown by
3370 * the hub, this hack enables them again.
3371 * Works at least with mouse driver.
3372 */
3373 if (!(portstatus & USB_PORT_STAT_ENABLE)
3374 && !connect_change
3375 && hdev->children[i-1]) {
3376 dev_err (hub_dev,
3377 "port %i "
3378 "disabled by hub (EMI?), "
3379 "re-enabling...\n",
3380 i);
3381 connect_change = 1;
3382 }
3383 }
3384
3385 if (portchange & USB_PORT_STAT_C_SUSPEND) {
3386 struct usb_device *udev;
3387
3388 clear_port_feature(hdev, i,
3389 USB_PORT_FEAT_C_SUSPEND);
3390 udev = hdev->children[i-1];
3391 if (udev) {
3392 /* TRSMRCY = 10 msec */
3393 msleep(10);
3394
3395 usb_lock_device(udev);
3396 ret = usb_remote_wakeup(hdev->
3397 children[i-1]);
3398 usb_unlock_device(udev);
3399 if (ret < 0)
3400 connect_change = 1;
3401 } else {
3402 ret = -ENODEV;
3403 hub_port_disable(hub, i, 1);
3404 }
3405 dev_dbg (hub_dev,
3406 "resume on port %d, status %d\n",
3407 i, ret);
3408 }
3409
3410 if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
3411 dev_err (hub_dev,
3412 "over-current change on port %d\n",
3413 i);
3414 clear_port_feature(hdev, i,
3415 USB_PORT_FEAT_C_OVER_CURRENT);
3416 hub_power_on(hub, true);
3417 }
3418
3419 if (portchange & USB_PORT_STAT_C_RESET) {
3420 dev_dbg (hub_dev,
3421 "reset change on port %d\n",
3422 i);
3423 clear_port_feature(hdev, i,
3424 USB_PORT_FEAT_C_RESET);
3425 }
3426
3427 if (connect_change)
3428 hub_port_connect_change(hub, i,
3429 portstatus, portchange);
3430 } /* end for i */
3431
3432 /* deal with hub status changes */
3433 if (test_and_clear_bit(0, hub->event_bits) == 0)
3434 ; /* do nothing */
3435 else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
3436 dev_err (hub_dev, "get_hub_status failed\n");
3437 else {
3438 if (hubchange & HUB_CHANGE_LOCAL_POWER) {
3439 dev_dbg (hub_dev, "power change\n");
3440 clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
3441 if (hubstatus & HUB_STATUS_LOCAL_POWER)
3442 /* FIXME: Is this always true? */
3443 hub->limited_power = 1;
3444 else
3445 hub->limited_power = 0;
3446 }
3447 if (hubchange & HUB_CHANGE_OVERCURRENT) {
3448 dev_dbg (hub_dev, "overcurrent change\n");
3449 msleep(500); /* Cool down */
3450 clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
3451 hub_power_on(hub, true);
3452 }
3453 }
3454
3455 loop_autopm:
3456 /* Balance the usb_autopm_get_interface() above */
3457 usb_autopm_put_interface_no_suspend(intf);
3458 loop:
3459 /* Balance the usb_autopm_get_interface_no_resume() in
3460 * kick_khubd() and allow autosuspend.
3461 */
3462 usb_autopm_put_interface(intf);
3463 loop_disconnected:
3464 usb_unlock_device(hdev);
3465 kref_put(&hub->kref, hub_release);
3466
3467 } /* end while (1) */
3468 }
3469
3470 static int hub_thread(void *__unused)
3471 {
3472 /* khubd needs to be freezable to avoid intefering with USB-PERSIST
3473 * port handover. Otherwise it might see that a full-speed device
3474 * was gone before the EHCI controller had handed its port over to
3475 * the companion full-speed controller.
3476 */
3477 set_freezable();
3478
3479 do {
3480 hub_events();
3481 wait_event_freezable(khubd_wait,
3482 !list_empty(&hub_event_list) ||
3483 kthread_should_stop());
3484 } while (!kthread_should_stop() || !list_empty(&hub_event_list));
3485
3486 pr_debug("%s: khubd exiting\n", usbcore_name);
3487 return 0;
3488 }
3489
3490 static const struct usb_device_id hub_id_table[] = {
3491 { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
3492 .bDeviceClass = USB_CLASS_HUB},
3493 { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
3494 .bInterfaceClass = USB_CLASS_HUB},
3495 { } /* Terminating entry */
3496 };
3497
3498 MODULE_DEVICE_TABLE (usb, hub_id_table);
3499
3500 static struct usb_driver hub_driver = {
3501 .name = "hub",
3502 .probe = hub_probe,
3503 .disconnect = hub_disconnect,
3504 .suspend = hub_suspend,
3505 .resume = hub_resume,
3506 .reset_resume = hub_reset_resume,
3507 .pre_reset = hub_pre_reset,
3508 .post_reset = hub_post_reset,
3509 .unlocked_ioctl = hub_ioctl,
3510 .id_table = hub_id_table,
3511 .supports_autosuspend = 1,
3512 };
3513
3514 int usb_hub_init(void)
3515 {
3516 if (usb_register(&hub_driver) < 0) {
3517 printk(KERN_ERR "%s: can't register hub driver\n",
3518 usbcore_name);
3519 return -1;
3520 }
3521
3522 khubd_task = kthread_run(hub_thread, NULL, "khubd");
3523 if (!IS_ERR(khubd_task))
3524 return 0;
3525
3526 /* Fall through if kernel_thread failed */
3527 usb_deregister(&hub_driver);
3528 printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
3529
3530 return -1;
3531 }
3532
3533 void usb_hub_cleanup(void)
3534 {
3535 kthread_stop(khubd_task);
3536
3537 /*
3538 * Hub resources are freed for us by usb_deregister. It calls
3539 * usb_driver_purge on every device which in turn calls that
3540 * devices disconnect function if it is using this driver.
3541 * The hub_disconnect function takes care of releasing the
3542 * individual hub resources. -greg
3543 */
3544 usb_deregister(&hub_driver);
3545 } /* usb_hub_cleanup() */
3546
3547 static int descriptors_changed(struct usb_device *udev,
3548 struct usb_device_descriptor *old_device_descriptor)
3549 {
3550 int changed = 0;
3551 unsigned index;
3552 unsigned serial_len = 0;
3553 unsigned len;
3554 unsigned old_length;
3555 int length;
3556 char *buf;
3557
3558 if (memcmp(&udev->descriptor, old_device_descriptor,
3559 sizeof(*old_device_descriptor)) != 0)
3560 return 1;
3561
3562 /* Since the idVendor, idProduct, and bcdDevice values in the
3563 * device descriptor haven't changed, we will assume the
3564 * Manufacturer and Product strings haven't changed either.
3565 * But the SerialNumber string could be different (e.g., a
3566 * different flash card of the same brand).
3567 */
3568 if (udev->serial)
3569 serial_len = strlen(udev->serial) + 1;
3570
3571 len = serial_len;
3572 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
3573 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
3574 len = max(len, old_length);
3575 }
3576
3577 buf = kmalloc(len, GFP_NOIO);
3578 if (buf == NULL) {
3579 dev_err(&udev->dev, "no mem to re-read configs after reset\n");
3580 /* assume the worst */
3581 return 1;
3582 }
3583 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
3584 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
3585 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
3586 old_length);
3587 if (length != old_length) {
3588 dev_dbg(&udev->dev, "config index %d, error %d\n",
3589 index, length);
3590 changed = 1;
3591 break;
3592 }
3593 if (memcmp (buf, udev->rawdescriptors[index], old_length)
3594 != 0) {
3595 dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
3596 index,
3597 ((struct usb_config_descriptor *) buf)->
3598 bConfigurationValue);
3599 changed = 1;
3600 break;
3601 }
3602 }
3603
3604 if (!changed && serial_len) {
3605 length = usb_string(udev, udev->descriptor.iSerialNumber,
3606 buf, serial_len);
3607 if (length + 1 != serial_len) {
3608 dev_dbg(&udev->dev, "serial string error %d\n",
3609 length);
3610 changed = 1;
3611 } else if (memcmp(buf, udev->serial, length) != 0) {
3612 dev_dbg(&udev->dev, "serial string changed\n");
3613 changed = 1;
3614 }
3615 }
3616
3617 kfree(buf);
3618 return changed;
3619 }
3620
3621 /**
3622 * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
3623 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3624 *
3625 * WARNING - don't use this routine to reset a composite device
3626 * (one with multiple interfaces owned by separate drivers)!
3627 * Use usb_reset_device() instead.
3628 *
3629 * Do a port reset, reassign the device's address, and establish its
3630 * former operating configuration. If the reset fails, or the device's
3631 * descriptors change from their values before the reset, or the original
3632 * configuration and altsettings cannot be restored, a flag will be set
3633 * telling khubd to pretend the device has been disconnected and then
3634 * re-connected. All drivers will be unbound, and the device will be
3635 * re-enumerated and probed all over again.
3636 *
3637 * Returns 0 if the reset succeeded, -ENODEV if the device has been
3638 * flagged for logical disconnection, or some other negative error code
3639 * if the reset wasn't even attempted.
3640 *
3641 * The caller must own the device lock. For example, it's safe to use
3642 * this from a driver probe() routine after downloading new firmware.
3643 * For calls that might not occur during probe(), drivers should lock
3644 * the device using usb_lock_device_for_reset().
3645 *
3646 * Locking exception: This routine may also be called from within an
3647 * autoresume handler. Such usage won't conflict with other tasks
3648 * holding the device lock because these tasks should always call
3649 * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
3650 */
3651 static int usb_reset_and_verify_device(struct usb_device *udev)
3652 {
3653 struct usb_device *parent_hdev = udev->parent;
3654 struct usb_hub *parent_hub;
3655 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3656 struct usb_device_descriptor descriptor = udev->descriptor;
3657 int i, ret = 0;
3658 int port1 = udev->portnum;
3659
3660 if (udev->state == USB_STATE_NOTATTACHED ||
3661 udev->state == USB_STATE_SUSPENDED) {
3662 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3663 udev->state);
3664 return -EINVAL;
3665 }
3666
3667 if (!parent_hdev) {
3668 /* this requires hcd-specific logic; see ohci_restart() */
3669 dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
3670 return -EISDIR;
3671 }
3672 parent_hub = hdev_to_hub(parent_hdev);
3673
3674 set_bit(port1, parent_hub->busy_bits);
3675 for (i = 0; i < SET_CONFIG_TRIES; ++i) {
3676
3677 /* ep0 maxpacket size may change; let the HCD know about it.
3678 * Other endpoints will be handled by re-enumeration. */
3679 usb_ep0_reinit(udev);
3680 ret = hub_port_init(parent_hub, udev, port1, i);
3681 if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
3682 break;
3683 }
3684 clear_bit(port1, parent_hub->busy_bits);
3685
3686 if (ret < 0)
3687 goto re_enumerate;
3688
3689 /* Device might have changed firmware (DFU or similar) */
3690 if (descriptors_changed(udev, &descriptor)) {
3691 dev_info(&udev->dev, "device firmware changed\n");
3692 udev->descriptor = descriptor; /* for disconnect() calls */
3693 goto re_enumerate;
3694 }
3695
3696 /* Restore the device's previous configuration */
3697 if (!udev->actconfig)
3698 goto done;
3699
3700 mutex_lock(&hcd->bandwidth_mutex);
3701 ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
3702 if (ret < 0) {
3703 dev_warn(&udev->dev,
3704 "Busted HC? Not enough HCD resources for "
3705 "old configuration.\n");
3706 mutex_unlock(&hcd->bandwidth_mutex);
3707 goto re_enumerate;
3708 }
3709 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3710 USB_REQ_SET_CONFIGURATION, 0,
3711 udev->actconfig->desc.bConfigurationValue, 0,
3712 NULL, 0, USB_CTRL_SET_TIMEOUT);
3713 if (ret < 0) {
3714 dev_err(&udev->dev,
3715 "can't restore configuration #%d (error=%d)\n",
3716 udev->actconfig->desc.bConfigurationValue, ret);
3717 mutex_unlock(&hcd->bandwidth_mutex);
3718 goto re_enumerate;
3719 }
3720 mutex_unlock(&hcd->bandwidth_mutex);
3721 usb_set_device_state(udev, USB_STATE_CONFIGURED);
3722
3723 /* Put interfaces back into the same altsettings as before.
3724 * Don't bother to send the Set-Interface request for interfaces
3725 * that were already in altsetting 0; besides being unnecessary,
3726 * many devices can't handle it. Instead just reset the host-side
3727 * endpoint state.
3728 */
3729 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3730 struct usb_host_config *config = udev->actconfig;
3731 struct usb_interface *intf = config->interface[i];
3732 struct usb_interface_descriptor *desc;
3733
3734 desc = &intf->cur_altsetting->desc;
3735 if (desc->bAlternateSetting == 0) {
3736 usb_disable_interface(udev, intf, true);
3737 usb_enable_interface(udev, intf, true);
3738 ret = 0;
3739 } else {
3740 /* Let the bandwidth allocation function know that this
3741 * device has been reset, and it will have to use
3742 * alternate setting 0 as the current alternate setting.
3743 */
3744 intf->resetting_device = 1;
3745 ret = usb_set_interface(udev, desc->bInterfaceNumber,
3746 desc->bAlternateSetting);
3747 intf->resetting_device = 0;
3748 }
3749 if (ret < 0) {
3750 dev_err(&udev->dev, "failed to restore interface %d "
3751 "altsetting %d (error=%d)\n",
3752 desc->bInterfaceNumber,
3753 desc->bAlternateSetting,
3754 ret);
3755 goto re_enumerate;
3756 }
3757 }
3758
3759 done:
3760 return 0;
3761
3762 re_enumerate:
3763 hub_port_logical_disconnect(parent_hub, port1);
3764 return -ENODEV;
3765 }
3766
3767 /**
3768 * usb_reset_device - warn interface drivers and perform a USB port reset
3769 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3770 *
3771 * Warns all drivers bound to registered interfaces (using their pre_reset
3772 * method), performs the port reset, and then lets the drivers know that
3773 * the reset is over (using their post_reset method).
3774 *
3775 * Return value is the same as for usb_reset_and_verify_device().
3776 *
3777 * The caller must own the device lock. For example, it's safe to use
3778 * this from a driver probe() routine after downloading new firmware.
3779 * For calls that might not occur during probe(), drivers should lock
3780 * the device using usb_lock_device_for_reset().
3781 *
3782 * If an interface is currently being probed or disconnected, we assume
3783 * its driver knows how to handle resets. For all other interfaces,
3784 * if the driver doesn't have pre_reset and post_reset methods then
3785 * we attempt to unbind it and rebind afterward.
3786 */
3787 int usb_reset_device(struct usb_device *udev)
3788 {
3789 int ret;
3790 int i;
3791 struct usb_host_config *config = udev->actconfig;
3792
3793 if (udev->state == USB_STATE_NOTATTACHED ||
3794 udev->state == USB_STATE_SUSPENDED) {
3795 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3796 udev->state);
3797 return -EINVAL;
3798 }
3799
3800 /* Prevent autosuspend during the reset */
3801 usb_autoresume_device(udev);
3802
3803 if (config) {
3804 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
3805 struct usb_interface *cintf = config->interface[i];
3806 struct usb_driver *drv;
3807 int unbind = 0;
3808
3809 if (cintf->dev.driver) {
3810 drv = to_usb_driver(cintf->dev.driver);
3811 if (drv->pre_reset && drv->post_reset)
3812 unbind = (drv->pre_reset)(cintf);
3813 else if (cintf->condition ==
3814 USB_INTERFACE_BOUND)
3815 unbind = 1;
3816 if (unbind)
3817 usb_forced_unbind_intf(cintf);
3818 }
3819 }
3820 }
3821
3822 ret = usb_reset_and_verify_device(udev);
3823
3824 if (config) {
3825 for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
3826 struct usb_interface *cintf = config->interface[i];
3827 struct usb_driver *drv;
3828 int rebind = cintf->needs_binding;
3829
3830 if (!rebind && cintf->dev.driver) {
3831 drv = to_usb_driver(cintf->dev.driver);
3832 if (drv->post_reset)
3833 rebind = (drv->post_reset)(cintf);
3834 else if (cintf->condition ==
3835 USB_INTERFACE_BOUND)
3836 rebind = 1;
3837 }
3838 if (ret == 0 && rebind)
3839 usb_rebind_intf(cintf);
3840 }
3841 }
3842
3843 usb_autosuspend_device(udev);
3844 return ret;
3845 }
3846 EXPORT_SYMBOL_GPL(usb_reset_device);
3847
3848
3849 /**
3850 * usb_queue_reset_device - Reset a USB device from an atomic context
3851 * @iface: USB interface belonging to the device to reset
3852 *
3853 * This function can be used to reset a USB device from an atomic
3854 * context, where usb_reset_device() won't work (as it blocks).
3855 *
3856 * Doing a reset via this method is functionally equivalent to calling
3857 * usb_reset_device(), except for the fact that it is delayed to a
3858 * workqueue. This means that any drivers bound to other interfaces
3859 * might be unbound, as well as users from usbfs in user space.
3860 *
3861 * Corner cases:
3862 *
3863 * - Scheduling two resets at the same time from two different drivers
3864 * attached to two different interfaces of the same device is
3865 * possible; depending on how the driver attached to each interface
3866 * handles ->pre_reset(), the second reset might happen or not.
3867 *
3868 * - If a driver is unbound and it had a pending reset, the reset will
3869 * be cancelled.
3870 *
3871 * - This function can be called during .probe() or .disconnect()
3872 * times. On return from .disconnect(), any pending resets will be
3873 * cancelled.
3874 *
3875 * There is no no need to lock/unlock the @reset_ws as schedule_work()
3876 * does its own.
3877 *
3878 * NOTE: We don't do any reference count tracking because it is not
3879 * needed. The lifecycle of the work_struct is tied to the
3880 * usb_interface. Before destroying the interface we cancel the
3881 * work_struct, so the fact that work_struct is queued and or
3882 * running means the interface (and thus, the device) exist and
3883 * are referenced.
3884 */
3885 void usb_queue_reset_device(struct usb_interface *iface)
3886 {
3887 schedule_work(&iface->reset_ws);
3888 }
3889 EXPORT_SYMBOL_GPL(usb_queue_reset_device);