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[libata] restore sg on DMA mapping failure
[linux-2.6/kvm.git] / drivers / usb / core / hub.c
blob256d9f6987156d32dbed6a2706bfcc7021dcbf86
1 /*
2 * USB hub driver.
3 *
4 * (C) Copyright 1999 Linus Torvalds
5 * (C) Copyright 1999 Johannes Erdfelt
6 * (C) Copyright 1999 Gregory P. Smith
7 * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
8 *
9 */
10
11 #include <linux/config.h>
12 #ifdef CONFIG_USB_DEBUG
13 #define DEBUG
14 #else
15 #undef DEBUG
16 #endif
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/completion.h>
22 #include <linux/sched.h>
23 #include <linux/list.h>
24 #include <linux/slab.h>
25 #include <linux/smp_lock.h>
26 #include <linux/ioctl.h>
27 #include <linux/usb.h>
28 #include <linux/usbdevice_fs.h>
29 #include <linux/kthread.h>
30
31 #include <asm/semaphore.h>
32 #include <asm/uaccess.h>
33 #include <asm/byteorder.h>
34
35 #include "usb.h"
36 #include "hcd.h"
37 #include "hub.h"
38
39 /* Protect struct usb_device->state and ->children members
40 * Note: Both are also protected by ->serialize, except that ->state can
41 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
42 static DEFINE_SPINLOCK(device_state_lock);
43
44 /* khubd's worklist and its lock */
45 static DEFINE_SPINLOCK(hub_event_lock);
46 static LIST_HEAD(hub_event_list); /* List of hubs needing servicing */
47
48 /* Wakes up khubd */
49 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
50
51 static struct task_struct *khubd_task;
52
53 /* cycle leds on hubs that aren't blinking for attention */
54 static int blinkenlights = 0;
55 module_param (blinkenlights, bool, S_IRUGO);
56 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
57
58 /*
59 * As of 2.6.10 we introduce a new USB device initialization scheme which
60 * closely resembles the way Windows works. Hopefully it will be compatible
61 * with a wider range of devices than the old scheme. However some previously
62 * working devices may start giving rise to "device not accepting address"
63 * errors; if that happens the user can try the old scheme by adjusting the
64 * following module parameters.
65 *
66 * For maximum flexibility there are two boolean parameters to control the
67 * hub driver's behavior. On the first initialization attempt, if the
68 * "old_scheme_first" parameter is set then the old scheme will be used,
69 * otherwise the new scheme is used. If that fails and "use_both_schemes"
70 * is set, then the driver will make another attempt, using the other scheme.
71 */
72 static int old_scheme_first = 0;
73 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
74 MODULE_PARM_DESC(old_scheme_first,
75 "start with the old device initialization scheme");
76
77 static int use_both_schemes = 1;
78 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
79 MODULE_PARM_DESC(use_both_schemes,
80 "try the other device initialization scheme if the "
81 "first one fails");
82
83
84 #ifdef DEBUG
85 static inline char *portspeed (int portstatus)
86 {
87 if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
88 return "480 Mb/s";
89 else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
90 return "1.5 Mb/s";
91 else
92 return "12 Mb/s";
93 }
94 #endif
95
96 /* Note that hdev or one of its children must be locked! */
97 static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
98 {
99 return usb_get_intfdata(hdev->actconfig->interface[0]);
100 }
101
102 /* USB 2.0 spec Section 11.24.4.5 */
103 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
104 {
105 int i, ret;
106
107 for (i = 0; i < 3; i++) {
108 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
109 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
110 USB_DT_HUB << 8, 0, data, size,
111 USB_CTRL_GET_TIMEOUT);
112 if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
113 return ret;
114 }
115 return -EINVAL;
116 }
117
118 /*
119 * USB 2.0 spec Section 11.24.2.1
120 */
121 static int clear_hub_feature(struct usb_device *hdev, int feature)
122 {
123 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
124 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
125 }
126
127 /*
128 * USB 2.0 spec Section 11.24.2.2
129 */
130 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
131 {
132 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
133 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
134 NULL, 0, 1000);
135 }
136
137 /*
138 * USB 2.0 spec Section 11.24.2.13
139 */
140 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
141 {
142 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
143 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
144 NULL, 0, 1000);
145 }
146
147 /*
148 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
149 * for info about using port indicators
150 */
151 static void set_port_led(
152 struct usb_hub *hub,
153 int port1,
154 int selector
155 )
156 {
157 int status = set_port_feature(hub->hdev, (selector << 8) | port1,
158 USB_PORT_FEAT_INDICATOR);
159 if (status < 0)
160 dev_dbg (hub->intfdev,
161 "port %d indicator %s status %d\n",
162 port1,
163 ({ char *s; switch (selector) {
164 case HUB_LED_AMBER: s = "amber"; break;
165 case HUB_LED_GREEN: s = "green"; break;
166 case HUB_LED_OFF: s = "off"; break;
167 case HUB_LED_AUTO: s = "auto"; break;
168 default: s = "??"; break;
169 }; s; }),
170 status);
171 }
172
173 #define LED_CYCLE_PERIOD ((2*HZ)/3)
174
175 static void led_work (void *__hub)
176 {
177 struct usb_hub *hub = __hub;
178 struct usb_device *hdev = hub->hdev;
179 unsigned i;
180 unsigned changed = 0;
181 int cursor = -1;
182
183 if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
184 return;
185
186 for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
187 unsigned selector, mode;
188
189 /* 30%-50% duty cycle */
190
191 switch (hub->indicator[i]) {
192 /* cycle marker */
193 case INDICATOR_CYCLE:
194 cursor = i;
195 selector = HUB_LED_AUTO;
196 mode = INDICATOR_AUTO;
197 break;
198 /* blinking green = sw attention */
199 case INDICATOR_GREEN_BLINK:
200 selector = HUB_LED_GREEN;
201 mode = INDICATOR_GREEN_BLINK_OFF;
202 break;
203 case INDICATOR_GREEN_BLINK_OFF:
204 selector = HUB_LED_OFF;
205 mode = INDICATOR_GREEN_BLINK;
206 break;
207 /* blinking amber = hw attention */
208 case INDICATOR_AMBER_BLINK:
209 selector = HUB_LED_AMBER;
210 mode = INDICATOR_AMBER_BLINK_OFF;
211 break;
212 case INDICATOR_AMBER_BLINK_OFF:
213 selector = HUB_LED_OFF;
214 mode = INDICATOR_AMBER_BLINK;
215 break;
216 /* blink green/amber = reserved */
217 case INDICATOR_ALT_BLINK:
218 selector = HUB_LED_GREEN;
219 mode = INDICATOR_ALT_BLINK_OFF;
220 break;
221 case INDICATOR_ALT_BLINK_OFF:
222 selector = HUB_LED_AMBER;
223 mode = INDICATOR_ALT_BLINK;
224 break;
225 default:
226 continue;
227 }
228 if (selector != HUB_LED_AUTO)
229 changed = 1;
230 set_port_led(hub, i + 1, selector);
231 hub->indicator[i] = mode;
232 }
233 if (!changed && blinkenlights) {
234 cursor++;
235 cursor %= hub->descriptor->bNbrPorts;
236 set_port_led(hub, cursor + 1, HUB_LED_GREEN);
237 hub->indicator[cursor] = INDICATOR_CYCLE;
238 changed++;
239 }
240 if (changed)
241 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
242 }
243
244 /* use a short timeout for hub/port status fetches */
245 #define USB_STS_TIMEOUT 1000
246 #define USB_STS_RETRIES 5
247
248 /*
249 * USB 2.0 spec Section 11.24.2.6
250 */
251 static int get_hub_status(struct usb_device *hdev,
252 struct usb_hub_status *data)
253 {
254 int i, status = -ETIMEDOUT;
255
256 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
257 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
258 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
259 data, sizeof(*data), USB_STS_TIMEOUT);
260 }
261 return status;
262 }
263
264 /*
265 * USB 2.0 spec Section 11.24.2.7
266 */
267 static int get_port_status(struct usb_device *hdev, int port1,
268 struct usb_port_status *data)
269 {
270 int i, status = -ETIMEDOUT;
271
272 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
273 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
274 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
275 data, sizeof(*data), USB_STS_TIMEOUT);
276 }
277 return status;
278 }
279
280 static void kick_khubd(struct usb_hub *hub)
281 {
282 unsigned long flags;
283
284 spin_lock_irqsave(&hub_event_lock, flags);
285 if (list_empty(&hub->event_list)) {
286 list_add_tail(&hub->event_list, &hub_event_list);
287 wake_up(&khubd_wait);
288 }
289 spin_unlock_irqrestore(&hub_event_lock, flags);
290 }
291
292 void usb_kick_khubd(struct usb_device *hdev)
293 {
294 kick_khubd(hdev_to_hub(hdev));
295 }
296
297
298 /* completion function, fires on port status changes and various faults */
299 static void hub_irq(struct urb *urb, struct pt_regs *regs)
300 {
301 struct usb_hub *hub = (struct usb_hub *)urb->context;
302 int status;
303 int i;
304 unsigned long bits;
305
306 switch (urb->status) {
307 case -ENOENT: /* synchronous unlink */
308 case -ECONNRESET: /* async unlink */
309 case -ESHUTDOWN: /* hardware going away */
310 return;
311
312 default: /* presumably an error */
313 /* Cause a hub reset after 10 consecutive errors */
314 dev_dbg (hub->intfdev, "transfer --> %d\n", urb->status);
315 if ((++hub->nerrors < 10) || hub->error)
316 goto resubmit;
317 hub->error = urb->status;
318 /* FALL THROUGH */
319
320 /* let khubd handle things */
321 case 0: /* we got data: port status changed */
322 bits = 0;
323 for (i = 0; i < urb->actual_length; ++i)
324 bits |= ((unsigned long) ((*hub->buffer)[i]))
325 << (i*8);
326 hub->event_bits[0] = bits;
327 break;
328 }
329
330 hub->nerrors = 0;
331
332 /* Something happened, let khubd figure it out */
333 kick_khubd(hub);
334
335 resubmit:
336 if (hub->quiescing)
337 return;
338
339 if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
340 && status != -ENODEV && status != -EPERM)
341 dev_err (hub->intfdev, "resubmit --> %d\n", status);
342 }
343
344 /* USB 2.0 spec Section 11.24.2.3 */
345 static inline int
346 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
347 {
348 return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
349 HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
350 tt, NULL, 0, 1000);
351 }
352
353 /*
354 * enumeration blocks khubd for a long time. we use keventd instead, since
355 * long blocking there is the exception, not the rule. accordingly, HCDs
356 * talking to TTs must queue control transfers (not just bulk and iso), so
357 * both can talk to the same hub concurrently.
358 */
359 static void hub_tt_kevent (void *arg)
360 {
361 struct usb_hub *hub = arg;
362 unsigned long flags;
363
364 spin_lock_irqsave (&hub->tt.lock, flags);
365 while (!list_empty (&hub->tt.clear_list)) {
366 struct list_head *temp;
367 struct usb_tt_clear *clear;
368 struct usb_device *hdev = hub->hdev;
369 int status;
370
371 temp = hub->tt.clear_list.next;
372 clear = list_entry (temp, struct usb_tt_clear, clear_list);
373 list_del (&clear->clear_list);
374
375 /* drop lock so HCD can concurrently report other TT errors */
376 spin_unlock_irqrestore (&hub->tt.lock, flags);
377 status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
378 spin_lock_irqsave (&hub->tt.lock, flags);
379
380 if (status)
381 dev_err (&hdev->dev,
382 "clear tt %d (%04x) error %d\n",
383 clear->tt, clear->devinfo, status);
384 kfree(clear);
385 }
386 spin_unlock_irqrestore (&hub->tt.lock, flags);
387 }
388
389 /**
390 * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
391 * @udev: the device whose split transaction failed
392 * @pipe: identifies the endpoint of the failed transaction
393 *
394 * High speed HCDs use this to tell the hub driver that some split control or
395 * bulk transaction failed in a way that requires clearing internal state of
396 * a transaction translator. This is normally detected (and reported) from
397 * interrupt context.
398 *
399 * It may not be possible for that hub to handle additional full (or low)
400 * speed transactions until that state is fully cleared out.
401 */
402 void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
403 {
404 struct usb_tt *tt = udev->tt;
405 unsigned long flags;
406 struct usb_tt_clear *clear;
407
408 /* we've got to cope with an arbitrary number of pending TT clears,
409 * since each TT has "at least two" buffers that can need it (and
410 * there can be many TTs per hub). even if they're uncommon.
411 */
412 if ((clear = kmalloc (sizeof *clear, SLAB_ATOMIC)) == NULL) {
413 dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
414 /* FIXME recover somehow ... RESET_TT? */
415 return;
416 }
417
418 /* info that CLEAR_TT_BUFFER needs */
419 clear->tt = tt->multi ? udev->ttport : 1;
420 clear->devinfo = usb_pipeendpoint (pipe);
421 clear->devinfo |= udev->devnum << 4;
422 clear->devinfo |= usb_pipecontrol (pipe)
423 ? (USB_ENDPOINT_XFER_CONTROL << 11)
424 : (USB_ENDPOINT_XFER_BULK << 11);
425 if (usb_pipein (pipe))
426 clear->devinfo |= 1 << 15;
427
428 /* tell keventd to clear state for this TT */
429 spin_lock_irqsave (&tt->lock, flags);
430 list_add_tail (&clear->clear_list, &tt->clear_list);
431 schedule_work (&tt->kevent);
432 spin_unlock_irqrestore (&tt->lock, flags);
433 }
434
435 static void hub_power_on(struct usb_hub *hub)
436 {
437 int port1;
438 unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
439 u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
440
441 /* if hub supports power switching, enable power on each port */
442 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2) {
443 dev_dbg(hub->intfdev, "enabling power on all ports\n");
444 for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
445 set_port_feature(hub->hdev, port1,
446 USB_PORT_FEAT_POWER);
447 }
448
449 /* Wait at least 100 msec for power to become stable */
450 msleep(max(pgood_delay, (unsigned) 100));
451 }
452
453 static inline void __hub_quiesce(struct usb_hub *hub)
454 {
455 /* (nonblocking) khubd and related activity won't re-trigger */
456 hub->quiescing = 1;
457 hub->activating = 0;
458 hub->resume_root_hub = 0;
459 }
460
461 static void hub_quiesce(struct usb_hub *hub)
462 {
463 /* (blocking) stop khubd and related activity */
464 __hub_quiesce(hub);
465 usb_kill_urb(hub->urb);
466 if (hub->has_indicators)
467 cancel_delayed_work(&hub->leds);
468 if (hub->has_indicators || hub->tt.hub)
469 flush_scheduled_work();
470 }
471
472 static void hub_activate(struct usb_hub *hub)
473 {
474 int status;
475
476 hub->quiescing = 0;
477 hub->activating = 1;
478 hub->resume_root_hub = 0;
479 status = usb_submit_urb(hub->urb, GFP_NOIO);
480 if (status < 0)
481 dev_err(hub->intfdev, "activate --> %d\n", status);
482 if (hub->has_indicators && blinkenlights)
483 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
484
485 /* scan all ports ASAP */
486 kick_khubd(hub);
487 }
488
489 static int hub_hub_status(struct usb_hub *hub,
490 u16 *status, u16 *change)
491 {
492 int ret;
493
494 ret = get_hub_status(hub->hdev, &hub->status->hub);
495 if (ret < 0)
496 dev_err (hub->intfdev,
497 "%s failed (err = %d)\n", __FUNCTION__, ret);
498 else {
499 *status = le16_to_cpu(hub->status->hub.wHubStatus);
500 *change = le16_to_cpu(hub->status->hub.wHubChange);
501 ret = 0;
502 }
503 return ret;
504 }
505
506 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
507 {
508 struct usb_device *hdev = hub->hdev;
509 int ret;
510
511 if (hdev->children[port1-1] && set_state) {
512 usb_set_device_state(hdev->children[port1-1],
513 USB_STATE_NOTATTACHED);
514 }
515 ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
516 if (ret)
517 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
518 port1, ret);
519
520 return ret;
521 }
522
523 static int hub_configure(struct usb_hub *hub,
524 struct usb_endpoint_descriptor *endpoint)
525 {
526 struct usb_device *hdev = hub->hdev;
527 struct device *hub_dev = hub->intfdev;
528 u16 hubstatus, hubchange;
529 u16 wHubCharacteristics;
530 unsigned int pipe;
531 int maxp, ret;
532 char *message;
533
534 hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
535 &hub->buffer_dma);
536 if (!hub->buffer) {
537 message = "can't allocate hub irq buffer";
538 ret = -ENOMEM;
539 goto fail;
540 }
541
542 hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
543 if (!hub->status) {
544 message = "can't kmalloc hub status buffer";
545 ret = -ENOMEM;
546 goto fail;
547 }
548
549 hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
550 if (!hub->descriptor) {
551 message = "can't kmalloc hub descriptor";
552 ret = -ENOMEM;
553 goto fail;
554 }
555
556 /* Request the entire hub descriptor.
557 * hub->descriptor can handle USB_MAXCHILDREN ports,
558 * but the hub can/will return fewer bytes here.
559 */
560 ret = get_hub_descriptor(hdev, hub->descriptor,
561 sizeof(*hub->descriptor));
562 if (ret < 0) {
563 message = "can't read hub descriptor";
564 goto fail;
565 } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
566 message = "hub has too many ports!";
567 ret = -ENODEV;
568 goto fail;
569 }
570
571 hdev->maxchild = hub->descriptor->bNbrPorts;
572 dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
573 (hdev->maxchild == 1) ? "" : "s");
574
575 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
576
577 if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
578 int i;
579 char portstr [USB_MAXCHILDREN + 1];
580
581 for (i = 0; i < hdev->maxchild; i++)
582 portstr[i] = hub->descriptor->DeviceRemovable
583 [((i + 1) / 8)] & (1 << ((i + 1) % 8))
584 ? 'F' : 'R';
585 portstr[hdev->maxchild] = 0;
586 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
587 } else
588 dev_dbg(hub_dev, "standalone hub\n");
589
590 switch (wHubCharacteristics & HUB_CHAR_LPSM) {
591 case 0x00:
592 dev_dbg(hub_dev, "ganged power switching\n");
593 break;
594 case 0x01:
595 dev_dbg(hub_dev, "individual port power switching\n");
596 break;
597 case 0x02:
598 case 0x03:
599 dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
600 break;
601 }
602
603 switch (wHubCharacteristics & HUB_CHAR_OCPM) {
604 case 0x00:
605 dev_dbg(hub_dev, "global over-current protection\n");
606 break;
607 case 0x08:
608 dev_dbg(hub_dev, "individual port over-current protection\n");
609 break;
610 case 0x10:
611 case 0x18:
612 dev_dbg(hub_dev, "no over-current protection\n");
613 break;
614 }
615
616 spin_lock_init (&hub->tt.lock);
617 INIT_LIST_HEAD (&hub->tt.clear_list);
618 INIT_WORK (&hub->tt.kevent, hub_tt_kevent, hub);
619 switch (hdev->descriptor.bDeviceProtocol) {
620 case 0:
621 break;
622 case 1:
623 dev_dbg(hub_dev, "Single TT\n");
624 hub->tt.hub = hdev;
625 break;
626 case 2:
627 ret = usb_set_interface(hdev, 0, 1);
628 if (ret == 0) {
629 dev_dbg(hub_dev, "TT per port\n");
630 hub->tt.multi = 1;
631 } else
632 dev_err(hub_dev, "Using single TT (err %d)\n",
633 ret);
634 hub->tt.hub = hdev;
635 break;
636 default:
637 dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
638 hdev->descriptor.bDeviceProtocol);
639 break;
640 }
641
642 /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
643 switch (wHubCharacteristics & HUB_CHAR_TTTT) {
644 case HUB_TTTT_8_BITS:
645 if (hdev->descriptor.bDeviceProtocol != 0) {
646 hub->tt.think_time = 666;
647 dev_dbg(hub_dev, "TT requires at most %d "
648 "FS bit times (%d ns)\n",
649 8, hub->tt.think_time);
650 }
651 break;
652 case HUB_TTTT_16_BITS:
653 hub->tt.think_time = 666 * 2;
654 dev_dbg(hub_dev, "TT requires at most %d "
655 "FS bit times (%d ns)\n",
656 16, hub->tt.think_time);
657 break;
658 case HUB_TTTT_24_BITS:
659 hub->tt.think_time = 666 * 3;
660 dev_dbg(hub_dev, "TT requires at most %d "
661 "FS bit times (%d ns)\n",
662 24, hub->tt.think_time);
663 break;
664 case HUB_TTTT_32_BITS:
665 hub->tt.think_time = 666 * 4;
666 dev_dbg(hub_dev, "TT requires at most %d "
667 "FS bit times (%d ns)\n",
668 32, hub->tt.think_time);
669 break;
670 }
671
672 /* probe() zeroes hub->indicator[] */
673 if (wHubCharacteristics & HUB_CHAR_PORTIND) {
674 hub->has_indicators = 1;
675 dev_dbg(hub_dev, "Port indicators are supported\n");
676 }
677
678 dev_dbg(hub_dev, "power on to power good time: %dms\n",
679 hub->descriptor->bPwrOn2PwrGood * 2);
680
681 /* power budgeting mostly matters with bus-powered hubs,
682 * and battery-powered root hubs (may provide just 8 mA).
683 */
684 ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
685 if (ret < 0) {
686 message = "can't get hub status";
687 goto fail;
688 }
689 le16_to_cpus(&hubstatus);
690 if (hdev == hdev->bus->root_hub) {
691 struct usb_hcd *hcd =
692 container_of(hdev->bus, struct usb_hcd, self);
693
694 hub->power_budget = min(500u, hcd->power_budget) / 2;
695 } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
696 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
697 hub->descriptor->bHubContrCurrent);
698 hub->power_budget = (501 - hub->descriptor->bHubContrCurrent)
699 / 2;
700 }
701 if (hub->power_budget)
702 dev_dbg(hub_dev, "%dmA bus power budget for children\n",
703 hub->power_budget * 2);
704
705
706 ret = hub_hub_status(hub, &hubstatus, &hubchange);
707 if (ret < 0) {
708 message = "can't get hub status";
709 goto fail;
710 }
711
712 /* local power status reports aren't always correct */
713 if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
714 dev_dbg(hub_dev, "local power source is %s\n",
715 (hubstatus & HUB_STATUS_LOCAL_POWER)
716 ? "lost (inactive)" : "good");
717
718 if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
719 dev_dbg(hub_dev, "%sover-current condition exists\n",
720 (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
721
722 /* set up the interrupt endpoint */
723 pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
724 maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
725
726 if (maxp > sizeof(*hub->buffer))
727 maxp = sizeof(*hub->buffer);
728
729 hub->urb = usb_alloc_urb(0, GFP_KERNEL);
730 if (!hub->urb) {
731 message = "couldn't allocate interrupt urb";
732 ret = -ENOMEM;
733 goto fail;
734 }
735
736 usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
737 hub, endpoint->bInterval);
738 hub->urb->transfer_dma = hub->buffer_dma;
739 hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
740
741 /* maybe cycle the hub leds */
742 if (hub->has_indicators && blinkenlights)
743 hub->indicator [0] = INDICATOR_CYCLE;
744
745 hub_power_on(hub);
746 hub_activate(hub);
747 return 0;
748
749 fail:
750 dev_err (hub_dev, "config failed, %s (err %d)\n",
751 message, ret);
752 /* hub_disconnect() frees urb and descriptor */
753 return ret;
754 }
755
756 static unsigned highspeed_hubs;
757
758 /* Called after the hub driver is unbound from a hub with children */
759 static void hub_remove_children_work(void *__hub)
760 {
761 struct usb_hub *hub = __hub;
762 struct usb_device *hdev = hub->hdev;
763 int i;
764
765 kfree(hub);
766
767 usb_lock_device(hdev);
768 for (i = 0; i < hdev->maxchild; ++i) {
769 if (hdev->children[i])
770 usb_disconnect(&hdev->children[i]);
771 }
772 usb_unlock_device(hdev);
773 usb_put_dev(hdev);
774 }
775
776 static void hub_disconnect(struct usb_interface *intf)
777 {
778 struct usb_hub *hub = usb_get_intfdata (intf);
779 struct usb_device *hdev;
780 int n, port1;
781
782 usb_set_intfdata (intf, NULL);
783 hdev = hub->hdev;
784
785 if (hdev->speed == USB_SPEED_HIGH)
786 highspeed_hubs--;
787
788 hub_quiesce(hub);
789 usb_free_urb(hub->urb);
790 hub->urb = NULL;
791
792 spin_lock_irq(&hub_event_lock);
793 list_del_init(&hub->event_list);
794 spin_unlock_irq(&hub_event_lock);
795
796 kfree(hub->descriptor);
797 hub->descriptor = NULL;
798
799 kfree(hub->status);
800 hub->status = NULL;
801
802 if (hub->buffer) {
803 usb_buffer_free(hdev, sizeof(*hub->buffer), hub->buffer,
804 hub->buffer_dma);
805 hub->buffer = NULL;
806 }
807
808 /* If there are any children then this is an unbind only, not a
809 * physical disconnection. The active ports must be disabled
810 * and later on we must call usb_disconnect(). We can't call
811 * it now because we may not hold the hub's device lock.
812 */
813 n = 0;
814 for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
815 if (hdev->children[port1 - 1]) {
816 ++n;
817 hub_port_disable(hub, port1, 1);
818 }
819 }
820
821 if (n == 0)
822 kfree(hub);
823 else {
824 /* Reuse the hub->leds work_struct for our own purposes */
825 INIT_WORK(&hub->leds, hub_remove_children_work, hub);
826 schedule_work(&hub->leds);
827 usb_get_dev(hdev);
828 }
829 }
830
831 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
832 {
833 struct usb_host_interface *desc;
834 struct usb_endpoint_descriptor *endpoint;
835 struct usb_device *hdev;
836 struct usb_hub *hub;
837
838 desc = intf->cur_altsetting;
839 hdev = interface_to_usbdev(intf);
840
841 /* Some hubs have a subclass of 1, which AFAICT according to the */
842 /* specs is not defined, but it works */
843 if ((desc->desc.bInterfaceSubClass != 0) &&
844 (desc->desc.bInterfaceSubClass != 1)) {
845 descriptor_error:
846 dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
847 return -EIO;
848 }
849
850 /* Multiple endpoints? What kind of mutant ninja-hub is this? */
851 if (desc->desc.bNumEndpoints != 1)
852 goto descriptor_error;
853
854 endpoint = &desc->endpoint[0].desc;
855
856 /* Output endpoint? Curiouser and curiouser.. */
857 if (!(endpoint->bEndpointAddress & USB_DIR_IN))
858 goto descriptor_error;
859
860 /* If it's not an interrupt endpoint, we'd better punt! */
861 if ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
862 != USB_ENDPOINT_XFER_INT)
863 goto descriptor_error;
864
865 /* We found a hub */
866 dev_info (&intf->dev, "USB hub found\n");
867
868 hub = kzalloc(sizeof(*hub), GFP_KERNEL);
869 if (!hub) {
870 dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
871 return -ENOMEM;
872 }
873
874 INIT_LIST_HEAD(&hub->event_list);
875 hub->intfdev = &intf->dev;
876 hub->hdev = hdev;
877 INIT_WORK(&hub->leds, led_work, hub);
878
879 usb_set_intfdata (intf, hub);
880
881 if (hdev->speed == USB_SPEED_HIGH)
882 highspeed_hubs++;
883
884 if (hub_configure(hub, endpoint) >= 0)
885 return 0;
886
887 hub_disconnect (intf);
888 return -ENODEV;
889 }
890
891 static int
892 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
893 {
894 struct usb_device *hdev = interface_to_usbdev (intf);
895
896 /* assert ifno == 0 (part of hub spec) */
897 switch (code) {
898 case USBDEVFS_HUB_PORTINFO: {
899 struct usbdevfs_hub_portinfo *info = user_data;
900 int i;
901
902 spin_lock_irq(&device_state_lock);
903 if (hdev->devnum <= 0)
904 info->nports = 0;
905 else {
906 info->nports = hdev->maxchild;
907 for (i = 0; i < info->nports; i++) {
908 if (hdev->children[i] == NULL)
909 info->port[i] = 0;
910 else
911 info->port[i] =
912 hdev->children[i]->devnum;
913 }
914 }
915 spin_unlock_irq(&device_state_lock);
916
917 return info->nports + 1;
918 }
919
920 default:
921 return -ENOSYS;
922 }
923 }
924
925 /* caller has locked the hub device */
926 static void hub_pre_reset(struct usb_hub *hub)
927 {
928 struct usb_device *hdev = hub->hdev;
929 int i;
930
931 for (i = 0; i < hdev->maxchild; ++i) {
932 if (hdev->children[i])
933 usb_disconnect(&hdev->children[i]);
934 }
935 hub_quiesce(hub);
936 }
937
938 /* caller has locked the hub device */
939 static void hub_post_reset(struct usb_hub *hub)
940 {
941 hub_activate(hub);
942 hub_power_on(hub);
943 }
944
945
946 /* grab device/port lock, returning index of that port (zero based).
947 * protects the upstream link used by this device from concurrent
948 * tree operations like suspend, resume, reset, and disconnect, which
949 * apply to everything downstream of a given port.
950 */
951 static int locktree(struct usb_device *udev)
952 {
953 int t;
954 struct usb_device *hdev;
955
956 if (!udev)
957 return -ENODEV;
958
959 /* root hub is always the first lock in the series */
960 hdev = udev->parent;
961 if (!hdev) {
962 usb_lock_device(udev);
963 return 0;
964 }
965
966 /* on the path from root to us, lock everything from
967 * top down, dropping parent locks when not needed
968 */
969 t = locktree(hdev);
970 if (t < 0)
971 return t;
972 for (t = 0; t < hdev->maxchild; t++) {
973 if (hdev->children[t] == udev) {
974 /* everything is fail-fast once disconnect
975 * processing starts
976 */
977 if (udev->state == USB_STATE_NOTATTACHED)
978 break;
979
980 /* when everyone grabs locks top->bottom,
981 * non-overlapping work may be concurrent
982 */
983 down(&udev->serialize);
984 up(&hdev->serialize);
985 return t + 1;
986 }
987 }
988 usb_unlock_device(hdev);
989 return -ENODEV;
990 }
991
992 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
993 {
994 int i;
995
996 for (i = 0; i < udev->maxchild; ++i) {
997 if (udev->children[i])
998 recursively_mark_NOTATTACHED(udev->children[i]);
999 }
1000 udev->state = USB_STATE_NOTATTACHED;
1001 }
1002
1003 /**
1004 * usb_set_device_state - change a device's current state (usbcore, hcds)
1005 * @udev: pointer to device whose state should be changed
1006 * @new_state: new state value to be stored
1007 *
1008 * udev->state is _not_ fully protected by the device lock. Although
1009 * most transitions are made only while holding the lock, the state can
1010 * can change to USB_STATE_NOTATTACHED at almost any time. This
1011 * is so that devices can be marked as disconnected as soon as possible,
1012 * without having to wait for any semaphores to be released. As a result,
1013 * all changes to any device's state must be protected by the
1014 * device_state_lock spinlock.
1015 *
1016 * Once a device has been added to the device tree, all changes to its state
1017 * should be made using this routine. The state should _not_ be set directly.
1018 *
1019 * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1020 * Otherwise udev->state is set to new_state, and if new_state is
1021 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1022 * to USB_STATE_NOTATTACHED.
1023 */
1024 void usb_set_device_state(struct usb_device *udev,
1025 enum usb_device_state new_state)
1026 {
1027 unsigned long flags;
1028
1029 spin_lock_irqsave(&device_state_lock, flags);
1030 if (udev->state == USB_STATE_NOTATTACHED)
1031 ; /* do nothing */
1032 else if (new_state != USB_STATE_NOTATTACHED) {
1033 udev->state = new_state;
1034 if (new_state == USB_STATE_CONFIGURED)
1035 device_init_wakeup(&udev->dev,
1036 (udev->actconfig->desc.bmAttributes
1037 & USB_CONFIG_ATT_WAKEUP));
1038 else if (new_state != USB_STATE_SUSPENDED)
1039 device_init_wakeup(&udev->dev, 0);
1040 } else
1041 recursively_mark_NOTATTACHED(udev);
1042 spin_unlock_irqrestore(&device_state_lock, flags);
1043 }
1044 EXPORT_SYMBOL(usb_set_device_state);
1045
1046
1047 static void choose_address(struct usb_device *udev)
1048 {
1049 int devnum;
1050 struct usb_bus *bus = udev->bus;
1051
1052 /* If khubd ever becomes multithreaded, this will need a lock */
1053
1054 /* Try to allocate the next devnum beginning at bus->devnum_next. */
1055 devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1056 bus->devnum_next);
1057 if (devnum >= 128)
1058 devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
1059
1060 bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1061
1062 if (devnum < 128) {
1063 set_bit(devnum, bus->devmap.devicemap);
1064 udev->devnum = devnum;
1065 }
1066 }
1067
1068 static void release_address(struct usb_device *udev)
1069 {
1070 if (udev->devnum > 0) {
1071 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1072 udev->devnum = -1;
1073 }
1074 }
1075
1076 /**
1077 * usb_disconnect - disconnect a device (usbcore-internal)
1078 * @pdev: pointer to device being disconnected
1079 * Context: !in_interrupt ()
1080 *
1081 * Something got disconnected. Get rid of it and all of its children.
1082 *
1083 * If *pdev is a normal device then the parent hub must already be locked.
1084 * If *pdev is a root hub then this routine will acquire the
1085 * usb_bus_list_lock on behalf of the caller.
1086 *
1087 * Only hub drivers (including virtual root hub drivers for host
1088 * controllers) should ever call this.
1089 *
1090 * This call is synchronous, and may not be used in an interrupt context.
1091 */
1092 void usb_disconnect(struct usb_device **pdev)
1093 {
1094 struct usb_device *udev = *pdev;
1095 int i;
1096
1097 if (!udev) {
1098 pr_debug ("%s nodev\n", __FUNCTION__);
1099 return;
1100 }
1101
1102 /* mark the device as inactive, so any further urb submissions for
1103 * this device (and any of its children) will fail immediately.
1104 * this quiesces everyting except pending urbs.
1105 */
1106 usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1107
1108 /* lock the bus list on behalf of HCDs unregistering their root hubs */
1109 if (!udev->parent) {
1110 down(&usb_bus_list_lock);
1111 usb_lock_device(udev);
1112 } else
1113 down(&udev->serialize);
1114
1115 dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1116
1117 /* Free up all the children before we remove this device */
1118 for (i = 0; i < USB_MAXCHILDREN; i++) {
1119 if (udev->children[i])
1120 usb_disconnect(&udev->children[i]);
1121 }
1122
1123 /* deallocate hcd/hardware state ... nuking all pending urbs and
1124 * cleaning up all state associated with the current configuration
1125 * so that the hardware is now fully quiesced.
1126 */
1127 usb_disable_device(udev, 0);
1128
1129 usb_notify_remove_device(udev);
1130
1131 /* Free the device number, remove the /proc/bus/usb entry and
1132 * the sysfs attributes, and delete the parent's children[]
1133 * (or root_hub) pointer.
1134 */
1135 dev_dbg (&udev->dev, "unregistering device\n");
1136 release_address(udev);
1137 usb_remove_sysfs_dev_files(udev);
1138
1139 /* Avoid races with recursively_mark_NOTATTACHED() */
1140 spin_lock_irq(&device_state_lock);
1141 *pdev = NULL;
1142 spin_unlock_irq(&device_state_lock);
1143
1144 if (!udev->parent) {
1145 usb_unlock_device(udev);
1146 up(&usb_bus_list_lock);
1147 } else
1148 up(&udev->serialize);
1149
1150 device_unregister(&udev->dev);
1151 }
1152
1153 static int choose_configuration(struct usb_device *udev)
1154 {
1155 int c, i;
1156
1157 /* NOTE: this should interact with hub power budgeting */
1158
1159 c = udev->config[0].desc.bConfigurationValue;
1160 if (udev->descriptor.bNumConfigurations != 1) {
1161 for (i = 0; i < udev->descriptor.bNumConfigurations; i++) {
1162 struct usb_interface_descriptor *desc;
1163
1164 /* heuristic: Linux is more likely to have class
1165 * drivers, so avoid vendor-specific interfaces.
1166 */
1167 desc = &udev->config[i].intf_cache[0]
1168 ->altsetting->desc;
1169 if (desc->bInterfaceClass == USB_CLASS_VENDOR_SPEC)
1170 continue;
1171 /* COMM/2/all is CDC ACM, except 0xff is MSFT RNDIS.
1172 * MSFT needs this to be the first config; never use
1173 * it as the default unless Linux has host-side RNDIS.
1174 * A second config would ideally be CDC-Ethernet, but
1175 * may instead be the "vendor specific" CDC subset
1176 * long used by ARM Linux for sa1100 or pxa255.
1177 */
1178 if (desc->bInterfaceClass == USB_CLASS_COMM
1179 && desc->bInterfaceSubClass == 2
1180 && desc->bInterfaceProtocol == 0xff) {
1181 c = udev->config[1].desc.bConfigurationValue;
1182 continue;
1183 }
1184 c = udev->config[i].desc.bConfigurationValue;
1185 break;
1186 }
1187 dev_info(&udev->dev,
1188 "configuration #%d chosen from %d choices\n",
1189 c, udev->descriptor.bNumConfigurations);
1190 }
1191 return c;
1192 }
1193
1194 #ifdef DEBUG
1195 static void show_string(struct usb_device *udev, char *id, char *string)
1196 {
1197 if (!string)
1198 return;
1199 dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1200 }
1201
1202 #else
1203 static inline void show_string(struct usb_device *udev, char *id, char *string)
1204 {}
1205 #endif
1206
1207
1208 #ifdef CONFIG_USB_OTG
1209 #include "otg_whitelist.h"
1210 #endif
1211
1212 /**
1213 * usb_new_device - perform initial device setup (usbcore-internal)
1214 * @udev: newly addressed device (in ADDRESS state)
1215 *
1216 * This is called with devices which have been enumerated, but not yet
1217 * configured. The device descriptor is available, but not descriptors
1218 * for any device configuration. The caller must have locked udev and
1219 * either the parent hub (if udev is a normal device) or else the
1220 * usb_bus_list_lock (if udev is a root hub). The parent's pointer to
1221 * udev has already been installed, but udev is not yet visible through
1222 * sysfs or other filesystem code.
1223 *
1224 * Returns 0 for success (device is configured and listed, with its
1225 * interfaces, in sysfs); else a negative errno value.
1226 *
1227 * This call is synchronous, and may not be used in an interrupt context.
1228 *
1229 * Only the hub driver should ever call this; root hub registration
1230 * uses it indirectly.
1231 */
1232 int usb_new_device(struct usb_device *udev)
1233 {
1234 int err;
1235 int c;
1236
1237 err = usb_get_configuration(udev);
1238 if (err < 0) {
1239 dev_err(&udev->dev, "can't read configurations, error %d\n",
1240 err);
1241 goto fail;
1242 }
1243
1244 /* read the standard strings and cache them if present */
1245 udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
1246 udev->manufacturer = usb_cache_string(udev,
1247 udev->descriptor.iManufacturer);
1248 udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
1249
1250 /* Tell the world! */
1251 dev_dbg(&udev->dev, "new device strings: Mfr=%d, Product=%d, "
1252 "SerialNumber=%d\n",
1253 udev->descriptor.iManufacturer,
1254 udev->descriptor.iProduct,
1255 udev->descriptor.iSerialNumber);
1256 show_string(udev, "Product", udev->product);
1257 show_string(udev, "Manufacturer", udev->manufacturer);
1258 show_string(udev, "SerialNumber", udev->serial);
1259
1260 #ifdef CONFIG_USB_OTG
1261 /*
1262 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1263 * to wake us after we've powered off VBUS; and HNP, switching roles
1264 * "host" to "peripheral". The OTG descriptor helps figure this out.
1265 */
1266 if (!udev->bus->is_b_host
1267 && udev->config
1268 && udev->parent == udev->bus->root_hub) {
1269 struct usb_otg_descriptor *desc = 0;
1270 struct usb_bus *bus = udev->bus;
1271
1272 /* descriptor may appear anywhere in config */
1273 if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1274 le16_to_cpu(udev->config[0].desc.wTotalLength),
1275 USB_DT_OTG, (void **) &desc) == 0) {
1276 if (desc->bmAttributes & USB_OTG_HNP) {
1277 unsigned port1;
1278 struct usb_device *root = udev->parent;
1279
1280 for (port1 = 1; port1 <= root->maxchild;
1281 port1++) {
1282 if (root->children[port1-1] == udev)
1283 break;
1284 }
1285
1286 dev_info(&udev->dev,
1287 "Dual-Role OTG device on %sHNP port\n",
1288 (port1 == bus->otg_port)
1289 ? "" : "non-");
1290
1291 /* enable HNP before suspend, it's simpler */
1292 if (port1 == bus->otg_port)
1293 bus->b_hnp_enable = 1;
1294 err = usb_control_msg(udev,
1295 usb_sndctrlpipe(udev, 0),
1296 USB_REQ_SET_FEATURE, 0,
1297 bus->b_hnp_enable
1298 ? USB_DEVICE_B_HNP_ENABLE
1299 : USB_DEVICE_A_ALT_HNP_SUPPORT,
1300 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1301 if (err < 0) {
1302 /* OTG MESSAGE: report errors here,
1303 * customize to match your product.
1304 */
1305 dev_info(&udev->dev,
1306 "can't set HNP mode; %d\n",
1307 err);
1308 bus->b_hnp_enable = 0;
1309 }
1310 }
1311 }
1312 }
1313
1314 if (!is_targeted(udev)) {
1315
1316 /* Maybe it can talk to us, though we can't talk to it.
1317 * (Includes HNP test device.)
1318 */
1319 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1320 static int __usb_suspend_device(struct usb_device *,
1321 int port1);
1322 err = __usb_suspend_device(udev, udev->bus->otg_port);
1323 if (err < 0)
1324 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1325 }
1326 err = -ENODEV;
1327 goto fail;
1328 }
1329 #endif
1330
1331 /* put device-specific files into sysfs */
1332 err = device_add (&udev->dev);
1333 if (err) {
1334 dev_err(&udev->dev, "can't device_add, error %d\n", err);
1335 goto fail;
1336 }
1337 usb_create_sysfs_dev_files (udev);
1338
1339 /* choose and set the configuration. that registers the interfaces
1340 * with the driver core, and lets usb device drivers bind to them.
1341 */
1342 c = choose_configuration(udev);
1343 if (c < 0)
1344 dev_warn(&udev->dev,
1345 "can't choose an initial configuration\n");
1346 else {
1347 err = usb_set_configuration(udev, c);
1348 if (err) {
1349 dev_err(&udev->dev, "can't set config #%d, error %d\n",
1350 c, err);
1351 usb_remove_sysfs_dev_files(udev);
1352 device_del(&udev->dev);
1353 goto fail;
1354 }
1355 }
1356
1357 /* USB device state == configured ... usable */
1358 usb_notify_add_device(udev);
1359
1360 return 0;
1361
1362 fail:
1363 usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1364 return err;
1365 }
1366
1367
1368 static int hub_port_status(struct usb_hub *hub, int port1,
1369 u16 *status, u16 *change)
1370 {
1371 int ret;
1372
1373 ret = get_port_status(hub->hdev, port1, &hub->status->port);
1374 if (ret < 0)
1375 dev_err (hub->intfdev,
1376 "%s failed (err = %d)\n", __FUNCTION__, ret);
1377 else {
1378 *status = le16_to_cpu(hub->status->port.wPortStatus);
1379 *change = le16_to_cpu(hub->status->port.wPortChange);
1380 ret = 0;
1381 }
1382 return ret;
1383 }
1384
1385 #define PORT_RESET_TRIES 5
1386 #define SET_ADDRESS_TRIES 2
1387 #define GET_DESCRIPTOR_TRIES 2
1388 #define SET_CONFIG_TRIES (2 * (use_both_schemes + 1))
1389 #define USE_NEW_SCHEME(i) ((i) / 2 == old_scheme_first)
1390
1391 #define HUB_ROOT_RESET_TIME 50 /* times are in msec */
1392 #define HUB_SHORT_RESET_TIME 10
1393 #define HUB_LONG_RESET_TIME 200
1394 #define HUB_RESET_TIMEOUT 500
1395
1396 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1397 struct usb_device *udev, unsigned int delay)
1398 {
1399 int delay_time, ret;
1400 u16 portstatus;
1401 u16 portchange;
1402
1403 for (delay_time = 0;
1404 delay_time < HUB_RESET_TIMEOUT;
1405 delay_time += delay) {
1406 /* wait to give the device a chance to reset */
1407 msleep(delay);
1408
1409 /* read and decode port status */
1410 ret = hub_port_status(hub, port1, &portstatus, &portchange);
1411 if (ret < 0)
1412 return ret;
1413
1414 /* Device went away? */
1415 if (!(portstatus & USB_PORT_STAT_CONNECTION))
1416 return -ENOTCONN;
1417
1418 /* bomb out completely if something weird happened */
1419 if ((portchange & USB_PORT_STAT_C_CONNECTION))
1420 return -EINVAL;
1421
1422 /* if we`ve finished resetting, then break out of the loop */
1423 if (!(portstatus & USB_PORT_STAT_RESET) &&
1424 (portstatus & USB_PORT_STAT_ENABLE)) {
1425 if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1426 udev->speed = USB_SPEED_HIGH;
1427 else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1428 udev->speed = USB_SPEED_LOW;
1429 else
1430 udev->speed = USB_SPEED_FULL;
1431 return 0;
1432 }
1433
1434 /* switch to the long delay after two short delay failures */
1435 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1436 delay = HUB_LONG_RESET_TIME;
1437
1438 dev_dbg (hub->intfdev,
1439 "port %d not reset yet, waiting %dms\n",
1440 port1, delay);
1441 }
1442
1443 return -EBUSY;
1444 }
1445
1446 static int hub_port_reset(struct usb_hub *hub, int port1,
1447 struct usb_device *udev, unsigned int delay)
1448 {
1449 int i, status;
1450
1451 /* Reset the port */
1452 for (i = 0; i < PORT_RESET_TRIES; i++) {
1453 status = set_port_feature(hub->hdev,
1454 port1, USB_PORT_FEAT_RESET);
1455 if (status)
1456 dev_err(hub->intfdev,
1457 "cannot reset port %d (err = %d)\n",
1458 port1, status);
1459 else {
1460 status = hub_port_wait_reset(hub, port1, udev, delay);
1461 if (status && status != -ENOTCONN)
1462 dev_dbg(hub->intfdev,
1463 "port_wait_reset: err = %d\n",
1464 status);
1465 }
1466
1467 /* return on disconnect or reset */
1468 switch (status) {
1469 case 0:
1470 /* TRSTRCY = 10 ms; plus some extra */
1471 msleep(10 + 40);
1472 /* FALL THROUGH */
1473 case -ENOTCONN:
1474 case -ENODEV:
1475 clear_port_feature(hub->hdev,
1476 port1, USB_PORT_FEAT_C_RESET);
1477 /* FIXME need disconnect() for NOTATTACHED device */
1478 usb_set_device_state(udev, status
1479 ? USB_STATE_NOTATTACHED
1480 : USB_STATE_DEFAULT);
1481 return status;
1482 }
1483
1484 dev_dbg (hub->intfdev,
1485 "port %d not enabled, trying reset again...\n",
1486 port1);
1487 delay = HUB_LONG_RESET_TIME;
1488 }
1489
1490 dev_err (hub->intfdev,
1491 "Cannot enable port %i. Maybe the USB cable is bad?\n",
1492 port1);
1493
1494 return status;
1495 }
1496
1497 /*
1498 * Disable a port and mark a logical connnect-change event, so that some
1499 * time later khubd will disconnect() any existing usb_device on the port
1500 * and will re-enumerate if there actually is a device attached.
1501 */
1502 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
1503 {
1504 dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
1505 hub_port_disable(hub, port1, 1);
1506
1507 /* FIXME let caller ask to power down the port:
1508 * - some devices won't enumerate without a VBUS power cycle
1509 * - SRP saves power that way
1510 * - ... new call, TBD ...
1511 * That's easy if this hub can switch power per-port, and
1512 * khubd reactivates the port later (timer, SRP, etc).
1513 * Powerdown must be optional, because of reset/DFU.
1514 */
1515
1516 set_bit(port1, hub->change_bits);
1517 kick_khubd(hub);
1518 }
1519
1520
1521 #ifdef CONFIG_USB_SUSPEND
1522
1523 /*
1524 * Selective port suspend reduces power; most suspended devices draw
1525 * less than 500 uA. It's also used in OTG, along with remote wakeup.
1526 * All devices below the suspended port are also suspended.
1527 *
1528 * Devices leave suspend state when the host wakes them up. Some devices
1529 * also support "remote wakeup", where the device can activate the USB
1530 * tree above them to deliver data, such as a keypress or packet. In
1531 * some cases, this wakes the USB host.
1532 */
1533 static int hub_port_suspend(struct usb_hub *hub, int port1,
1534 struct usb_device *udev)
1535 {
1536 int status;
1537
1538 // dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1539
1540 /* enable remote wakeup when appropriate; this lets the device
1541 * wake up the upstream hub (including maybe the root hub).
1542 *
1543 * NOTE: OTG devices may issue remote wakeup (or SRP) even when
1544 * we don't explicitly enable it here.
1545 */
1546 if (device_may_wakeup(&udev->dev)) {
1547 status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1548 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1549 USB_DEVICE_REMOTE_WAKEUP, 0,
1550 NULL, 0,
1551 USB_CTRL_SET_TIMEOUT);
1552 if (status)
1553 dev_dbg(&udev->dev,
1554 "won't remote wakeup, status %d\n",
1555 status);
1556 }
1557
1558 /* see 7.1.7.6 */
1559 status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1560 if (status) {
1561 dev_dbg(hub->intfdev,
1562 "can't suspend port %d, status %d\n",
1563 port1, status);
1564 /* paranoia: "should not happen" */
1565 (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1566 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1567 USB_DEVICE_REMOTE_WAKEUP, 0,
1568 NULL, 0,
1569 USB_CTRL_SET_TIMEOUT);
1570 } else {
1571 /* device has up to 10 msec to fully suspend */
1572 dev_dbg(&udev->dev, "usb suspend\n");
1573 usb_set_device_state(udev, USB_STATE_SUSPENDED);
1574 msleep(10);
1575 }
1576 return status;
1577 }
1578
1579 /*
1580 * Devices on USB hub ports have only one "suspend" state, corresponding
1581 * to ACPI D2, "may cause the device to lose some context".
1582 * State transitions include:
1583 *
1584 * - suspend, resume ... when the VBUS power link stays live
1585 * - suspend, disconnect ... VBUS lost
1586 *
1587 * Once VBUS drop breaks the circuit, the port it's using has to go through
1588 * normal re-enumeration procedures, starting with enabling VBUS power.
1589 * Other than re-initializing the hub (plug/unplug, except for root hubs),
1590 * Linux (2.6) currently has NO mechanisms to initiate that: no khubd
1591 * timer, no SRP, no requests through sysfs.
1592 *
1593 * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
1594 * the root hub for their bus goes into global suspend ... so we don't
1595 * (falsely) update the device power state to say it suspended.
1596 */
1597 static int __usb_suspend_device (struct usb_device *udev, int port1)
1598 {
1599 int status = 0;
1600
1601 /* caller owns the udev device lock */
1602 if (port1 < 0)
1603 return port1;
1604
1605 if (udev->state == USB_STATE_SUSPENDED
1606 || udev->state == USB_STATE_NOTATTACHED) {
1607 return 0;
1608 }
1609
1610 /* all interfaces must already be suspended */
1611 if (udev->actconfig) {
1612 int i;
1613
1614 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1615 struct usb_interface *intf;
1616
1617 intf = udev->actconfig->interface[i];
1618 if (is_active(intf)) {
1619 dev_dbg(&intf->dev, "nyet suspended\n");
1620 return -EBUSY;
1621 }
1622 }
1623 }
1624
1625 /* we only change a device's upstream USB link.
1626 * root hubs have no upstream USB link.
1627 */
1628 if (udev->parent)
1629 status = hub_port_suspend(hdev_to_hub(udev->parent), port1,
1630 udev);
1631
1632 if (status == 0)
1633 udev->dev.power.power_state = PMSG_SUSPEND;
1634 return status;
1635 }
1636
1637 #endif
1638
1639 /*
1640 * usb_suspend_device - suspend a usb device
1641 * @udev: device that's no longer in active use
1642 * Context: must be able to sleep; device not locked; pm locks held
1643 *
1644 * Suspends a USB device that isn't in active use, conserving power.
1645 * Devices may wake out of a suspend, if anything important happens,
1646 * using the remote wakeup mechanism. They may also be taken out of
1647 * suspend by the host, using usb_resume_device(). It's also routine
1648 * to disconnect devices while they are suspended.
1649 *
1650 * This only affects the USB hardware for a device; its interfaces
1651 * (and, for hubs, child devices) must already have been suspended.
1652 *
1653 * Suspending OTG devices may trigger HNP, if that's been enabled
1654 * between a pair of dual-role devices. That will change roles, such
1655 * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1656 *
1657 * Returns 0 on success, else negative errno.
1658 */
1659 int usb_suspend_device(struct usb_device *udev)
1660 {
1661 #ifdef CONFIG_USB_SUSPEND
1662 int port1, status;
1663
1664 port1 = locktree(udev);
1665 if (port1 < 0)
1666 return port1;
1667
1668 status = __usb_suspend_device(udev, port1);
1669 usb_unlock_device(udev);
1670 return status;
1671 #else
1672 /* NOTE: udev->state unchanged, it's not lying ... */
1673 udev->dev.power.power_state = PMSG_SUSPEND;
1674 return 0;
1675 #endif
1676 }
1677 EXPORT_SYMBOL_GPL(usb_suspend_device);
1678
1679 /*
1680 * If the USB "suspend" state is in use (rather than "global suspend"),
1681 * many devices will be individually taken out of suspend state using
1682 * special" resume" signaling. These routines kick in shortly after
1683 * hardware resume signaling is finished, either because of selective
1684 * resume (by host) or remote wakeup (by device) ... now see what changed
1685 * in the tree that's rooted at this device.
1686 */
1687 static int finish_device_resume(struct usb_device *udev)
1688 {
1689 int status;
1690 u16 devstatus;
1691
1692 /* caller owns the udev device lock */
1693 dev_dbg(&udev->dev, "finish resume\n");
1694
1695 /* usb ch9 identifies four variants of SUSPENDED, based on what
1696 * state the device resumes to. Linux currently won't see the
1697 * first two on the host side; they'd be inside hub_port_init()
1698 * during many timeouts, but khubd can't suspend until later.
1699 */
1700 usb_set_device_state(udev, udev->actconfig
1701 ? USB_STATE_CONFIGURED
1702 : USB_STATE_ADDRESS);
1703
1704 /* 10.5.4.5 says be sure devices in the tree are still there.
1705 * For now let's assume the device didn't go crazy on resume,
1706 * and device drivers will know about any resume quirks.
1707 */
1708 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1709 if (status < 0)
1710 dev_dbg(&udev->dev,
1711 "gone after usb resume? status %d\n",
1712 status);
1713 else if (udev->actconfig) {
1714 unsigned i;
1715 int (*resume)(struct device *);
1716
1717 le16_to_cpus(&devstatus);
1718 if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)
1719 && udev->parent) {
1720 status = usb_control_msg(udev,
1721 usb_sndctrlpipe(udev, 0),
1722 USB_REQ_CLEAR_FEATURE,
1723 USB_RECIP_DEVICE,
1724 USB_DEVICE_REMOTE_WAKEUP, 0,
1725 NULL, 0,
1726 USB_CTRL_SET_TIMEOUT);
1727 if (status) {
1728 dev_dbg(&udev->dev, "disable remote "
1729 "wakeup, status %d\n", status);
1730 status = 0;
1731 }
1732 }
1733
1734 /* resume interface drivers; if this is a hub, it
1735 * may have a child resume event to deal with soon
1736 */
1737 resume = udev->dev.bus->resume;
1738 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++)
1739 (void) resume(&udev->actconfig->interface[i]->dev);
1740 status = 0;
1741
1742 } else if (udev->devnum <= 0) {
1743 dev_dbg(&udev->dev, "bogus resume!\n");
1744 status = -EINVAL;
1745 }
1746 return status;
1747 }
1748
1749 #ifdef CONFIG_USB_SUSPEND
1750
1751 static int
1752 hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
1753 {
1754 int status;
1755
1756 // dev_dbg(hub->intfdev, "resume port %d\n", port1);
1757
1758 /* see 7.1.7.7; affects power usage, but not budgeting */
1759 status = clear_port_feature(hub->hdev,
1760 port1, USB_PORT_FEAT_SUSPEND);
1761 if (status) {
1762 dev_dbg(hub->intfdev,
1763 "can't resume port %d, status %d\n",
1764 port1, status);
1765 } else {
1766 u16 devstatus;
1767 u16 portchange;
1768
1769 /* drive resume for at least 20 msec */
1770 if (udev)
1771 dev_dbg(&udev->dev, "RESUME\n");
1772 msleep(25);
1773
1774 #define LIVE_FLAGS ( USB_PORT_STAT_POWER \
1775 | USB_PORT_STAT_ENABLE \
1776 | USB_PORT_STAT_CONNECTION)
1777
1778 /* Virtual root hubs can trigger on GET_PORT_STATUS to
1779 * stop resume signaling. Then finish the resume
1780 * sequence.
1781 */
1782 devstatus = portchange = 0;
1783 status = hub_port_status(hub, port1,
1784 &devstatus, &portchange);
1785 if (status < 0
1786 || (devstatus & LIVE_FLAGS) != LIVE_FLAGS
1787 || (devstatus & USB_PORT_STAT_SUSPEND) != 0
1788 ) {
1789 dev_dbg(hub->intfdev,
1790 "port %d status %04x.%04x after resume, %d\n",
1791 port1, portchange, devstatus, status);
1792 } else {
1793 /* TRSMRCY = 10 msec */
1794 msleep(10);
1795 if (udev)
1796 status = finish_device_resume(udev);
1797 }
1798 }
1799 if (status < 0)
1800 hub_port_logical_disconnect(hub, port1);
1801
1802 return status;
1803 }
1804
1805 #endif
1806
1807 /*
1808 * usb_resume_device - re-activate a suspended usb device
1809 * @udev: device to re-activate
1810 * Context: must be able to sleep; device not locked; pm locks held
1811 *
1812 * This will re-activate the suspended device, increasing power usage
1813 * while letting drivers communicate again with its endpoints.
1814 * USB resume explicitly guarantees that the power session between
1815 * the host and the device is the same as it was when the device
1816 * suspended.
1817 *
1818 * Returns 0 on success, else negative errno.
1819 */
1820 int usb_resume_device(struct usb_device *udev)
1821 {
1822 int port1, status;
1823
1824 port1 = locktree(udev);
1825 if (port1 < 0)
1826 return port1;
1827
1828 #ifdef CONFIG_USB_SUSPEND
1829 /* selective resume of one downstream hub-to-device port */
1830 if (udev->parent) {
1831 if (udev->state == USB_STATE_SUSPENDED) {
1832 // NOTE swsusp may bork us, device state being wrong...
1833 // NOTE this fails if parent is also suspended...
1834 status = hub_port_resume(hdev_to_hub(udev->parent),
1835 port1, udev);
1836 } else
1837 status = 0;
1838 } else
1839 #endif
1840 status = finish_device_resume(udev);
1841 if (status < 0)
1842 dev_dbg(&udev->dev, "can't resume, status %d\n",
1843 status);
1844
1845 usb_unlock_device(udev);
1846
1847 /* rebind drivers that had no suspend() */
1848 if (status == 0) {
1849 usb_lock_all_devices();
1850 bus_rescan_devices(&usb_bus_type);
1851 usb_unlock_all_devices();
1852 }
1853 return status;
1854 }
1855
1856 static int remote_wakeup(struct usb_device *udev)
1857 {
1858 int status = 0;
1859
1860 #ifdef CONFIG_USB_SUSPEND
1861
1862 /* don't repeat RESUME sequence if this device
1863 * was already woken up by some other task
1864 */
1865 down(&udev->serialize);
1866 if (udev->state == USB_STATE_SUSPENDED) {
1867 dev_dbg(&udev->dev, "RESUME (wakeup)\n");
1868 /* TRSMRCY = 10 msec */
1869 msleep(10);
1870 status = finish_device_resume(udev);
1871 }
1872 up(&udev->serialize);
1873 #endif
1874 return status;
1875 }
1876
1877 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
1878 {
1879 struct usb_hub *hub = usb_get_intfdata (intf);
1880 struct usb_device *hdev = hub->hdev;
1881 unsigned port1;
1882
1883 /* fail if children aren't already suspended */
1884 for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1885 struct usb_device *udev;
1886
1887 udev = hdev->children [port1-1];
1888 if (udev && (udev->dev.power.power_state.event
1889 == PM_EVENT_ON
1890 #ifdef CONFIG_USB_SUSPEND
1891 || udev->state != USB_STATE_SUSPENDED
1892 #endif
1893 )) {
1894 dev_dbg(&intf->dev, "port %d nyet suspended\n", port1);
1895 return -EBUSY;
1896 }
1897 }
1898
1899 /* "global suspend" of the downstream HC-to-USB interface */
1900 if (!hdev->parent) {
1901 struct usb_bus *bus = hdev->bus;
1902 if (bus) {
1903 int status = hcd_bus_suspend (bus);
1904
1905 if (status != 0) {
1906 dev_dbg(&hdev->dev, "'global' suspend %d\n",
1907 status);
1908 return status;
1909 }
1910 } else
1911 return -EOPNOTSUPP;
1912 }
1913
1914 /* stop khubd and related activity */
1915 hub_quiesce(hub);
1916 return 0;
1917 }
1918
1919 static int hub_resume(struct usb_interface *intf)
1920 {
1921 struct usb_device *hdev = interface_to_usbdev(intf);
1922 struct usb_hub *hub = usb_get_intfdata (intf);
1923 int status;
1924
1925 /* "global resume" of the downstream HC-to-USB interface */
1926 if (!hdev->parent) {
1927 struct usb_bus *bus = hdev->bus;
1928 if (bus) {
1929 status = hcd_bus_resume (bus);
1930 if (status) {
1931 dev_dbg(&intf->dev, "'global' resume %d\n",
1932 status);
1933 return status;
1934 }
1935 } else
1936 return -EOPNOTSUPP;
1937 if (status == 0) {
1938 /* TRSMRCY = 10 msec */
1939 msleep(10);
1940 }
1941 }
1942
1943 hub_activate(hub);
1944
1945 /* REVISIT: this recursion probably shouldn't exist. Remove
1946 * this code sometime, after retesting with different root and
1947 * external hubs.
1948 */
1949 #ifdef CONFIG_USB_SUSPEND
1950 {
1951 unsigned port1;
1952
1953 for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1954 struct usb_device *udev;
1955 u16 portstat, portchange;
1956
1957 udev = hdev->children [port1-1];
1958 status = hub_port_status(hub, port1, &portstat, &portchange);
1959 if (status == 0) {
1960 if (portchange & USB_PORT_STAT_C_SUSPEND) {
1961 clear_port_feature(hdev, port1,
1962 USB_PORT_FEAT_C_SUSPEND);
1963 portchange &= ~USB_PORT_STAT_C_SUSPEND;
1964 }
1965
1966 /* let khubd handle disconnects etc */
1967 if (portchange)
1968 continue;
1969 }
1970
1971 if (!udev || status < 0)
1972 continue;
1973 down (&udev->serialize);
1974 if (portstat & USB_PORT_STAT_SUSPEND)
1975 status = hub_port_resume(hub, port1, udev);
1976 else {
1977 status = finish_device_resume(udev);
1978 if (status < 0) {
1979 dev_dbg(&intf->dev, "resume port %d --> %d\n",
1980 port1, status);
1981 hub_port_logical_disconnect(hub, port1);
1982 }
1983 }
1984 up(&udev->serialize);
1985 }
1986 }
1987 #endif
1988 return 0;
1989 }
1990
1991 void usb_suspend_root_hub(struct usb_device *hdev)
1992 {
1993 struct usb_hub *hub = hdev_to_hub(hdev);
1994
1995 /* This also makes any led blinker stop retriggering. We're called
1996 * from irq, so the blinker might still be scheduled. Caller promises
1997 * that the root hub status URB will be canceled.
1998 */
1999 __hub_quiesce(hub);
2000 mark_quiesced(to_usb_interface(hub->intfdev));
2001 }
2002
2003 void usb_resume_root_hub(struct usb_device *hdev)
2004 {
2005 struct usb_hub *hub = hdev_to_hub(hdev);
2006
2007 hub->resume_root_hub = 1;
2008 kick_khubd(hub);
2009 }
2010
2011
2012 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2013 *
2014 * Between connect detection and reset signaling there must be a delay
2015 * of 100ms at least for debounce and power-settling. The corresponding
2016 * timer shall restart whenever the downstream port detects a disconnect.
2017 *
2018 * Apparently there are some bluetooth and irda-dongles and a number of
2019 * low-speed devices for which this debounce period may last over a second.
2020 * Not covered by the spec - but easy to deal with.
2021 *
2022 * This implementation uses a 1500ms total debounce timeout; if the
2023 * connection isn't stable by then it returns -ETIMEDOUT. It checks
2024 * every 25ms for transient disconnects. When the port status has been
2025 * unchanged for 100ms it returns the port status.
2026 */
2027
2028 #define HUB_DEBOUNCE_TIMEOUT 1500
2029 #define HUB_DEBOUNCE_STEP 25
2030 #define HUB_DEBOUNCE_STABLE 100
2031
2032 static int hub_port_debounce(struct usb_hub *hub, int port1)
2033 {
2034 int ret;
2035 int total_time, stable_time = 0;
2036 u16 portchange, portstatus;
2037 unsigned connection = 0xffff;
2038
2039 for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2040 ret = hub_port_status(hub, port1, &portstatus, &portchange);
2041 if (ret < 0)
2042 return ret;
2043
2044 if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2045 (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2046 stable_time += HUB_DEBOUNCE_STEP;
2047 if (stable_time >= HUB_DEBOUNCE_STABLE)
2048 break;
2049 } else {
2050 stable_time = 0;
2051 connection = portstatus & USB_PORT_STAT_CONNECTION;
2052 }
2053
2054 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2055 clear_port_feature(hub->hdev, port1,
2056 USB_PORT_FEAT_C_CONNECTION);
2057 }
2058
2059 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2060 break;
2061 msleep(HUB_DEBOUNCE_STEP);
2062 }
2063
2064 dev_dbg (hub->intfdev,
2065 "debounce: port %d: total %dms stable %dms status 0x%x\n",
2066 port1, total_time, stable_time, portstatus);
2067
2068 if (stable_time < HUB_DEBOUNCE_STABLE)
2069 return -ETIMEDOUT;
2070 return portstatus;
2071 }
2072
2073 static void ep0_reinit(struct usb_device *udev)
2074 {
2075 usb_disable_endpoint(udev, 0 + USB_DIR_IN);
2076 usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
2077 udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
2078 }
2079
2080 #define usb_sndaddr0pipe() (PIPE_CONTROL << 30)
2081 #define usb_rcvaddr0pipe() ((PIPE_CONTROL << 30) | USB_DIR_IN)
2082
2083 static int hub_set_address(struct usb_device *udev)
2084 {
2085 int retval;
2086
2087 if (udev->devnum == 0)
2088 return -EINVAL;
2089 if (udev->state == USB_STATE_ADDRESS)
2090 return 0;
2091 if (udev->state != USB_STATE_DEFAULT)
2092 return -EINVAL;
2093 retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2094 USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
2095 NULL, 0, USB_CTRL_SET_TIMEOUT);
2096 if (retval == 0) {
2097 usb_set_device_state(udev, USB_STATE_ADDRESS);
2098 ep0_reinit(udev);
2099 }
2100 return retval;
2101 }
2102
2103 /* Reset device, (re)assign address, get device descriptor.
2104 * Device connection must be stable, no more debouncing needed.
2105 * Returns device in USB_STATE_ADDRESS, except on error.
2106 *
2107 * If this is called for an already-existing device (as part of
2108 * usb_reset_device), the caller must own the device lock. For a
2109 * newly detected device that is not accessible through any global
2110 * pointers, it's not necessary to lock the device.
2111 */
2112 static int
2113 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2114 int retry_counter)
2115 {
2116 static DECLARE_MUTEX(usb_address0_sem);
2117
2118 struct usb_device *hdev = hub->hdev;
2119 int i, j, retval;
2120 unsigned delay = HUB_SHORT_RESET_TIME;
2121 enum usb_device_speed oldspeed = udev->speed;
2122
2123 /* root hub ports have a slightly longer reset period
2124 * (from USB 2.0 spec, section 7.1.7.5)
2125 */
2126 if (!hdev->parent) {
2127 delay = HUB_ROOT_RESET_TIME;
2128 if (port1 == hdev->bus->otg_port)
2129 hdev->bus->b_hnp_enable = 0;
2130 }
2131
2132 /* Some low speed devices have problems with the quick delay, so */
2133 /* be a bit pessimistic with those devices. RHbug #23670 */
2134 if (oldspeed == USB_SPEED_LOW)
2135 delay = HUB_LONG_RESET_TIME;
2136
2137 down(&usb_address0_sem);
2138
2139 /* Reset the device; full speed may morph to high speed */
2140 retval = hub_port_reset(hub, port1, udev, delay);
2141 if (retval < 0) /* error or disconnect */
2142 goto fail;
2143 /* success, speed is known */
2144 retval = -ENODEV;
2145
2146 if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2147 dev_dbg(&udev->dev, "device reset changed speed!\n");
2148 goto fail;
2149 }
2150 oldspeed = udev->speed;
2151
2152 /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2153 * it's fixed size except for full speed devices.
2154 */
2155 switch (udev->speed) {
2156 case USB_SPEED_HIGH: /* fixed at 64 */
2157 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2158 break;
2159 case USB_SPEED_FULL: /* 8, 16, 32, or 64 */
2160 /* to determine the ep0 maxpacket size, try to read
2161 * the device descriptor to get bMaxPacketSize0 and
2162 * then correct our initial guess.
2163 */
2164 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2165 break;
2166 case USB_SPEED_LOW: /* fixed at 8 */
2167 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2168 break;
2169 default:
2170 goto fail;
2171 }
2172
2173 dev_info (&udev->dev,
2174 "%s %s speed USB device using %s and address %d\n",
2175 (udev->config) ? "reset" : "new",
2176 ({ char *speed; switch (udev->speed) {
2177 case USB_SPEED_LOW: speed = "low"; break;
2178 case USB_SPEED_FULL: speed = "full"; break;
2179 case USB_SPEED_HIGH: speed = "high"; break;
2180 default: speed = "?"; break;
2181 }; speed;}),
2182 udev->bus->controller->driver->name,
2183 udev->devnum);
2184
2185 /* Set up TT records, if needed */
2186 if (hdev->tt) {
2187 udev->tt = hdev->tt;
2188 udev->ttport = hdev->ttport;
2189 } else if (udev->speed != USB_SPEED_HIGH
2190 && hdev->speed == USB_SPEED_HIGH) {
2191 udev->tt = &hub->tt;
2192 udev->ttport = port1;
2193 }
2194
2195 /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2196 * Because device hardware and firmware is sometimes buggy in
2197 * this area, and this is how Linux has done it for ages.
2198 * Change it cautiously.
2199 *
2200 * NOTE: If USE_NEW_SCHEME() is true we will start by issuing
2201 * a 64-byte GET_DESCRIPTOR request. This is what Windows does,
2202 * so it may help with some non-standards-compliant devices.
2203 * Otherwise we start with SET_ADDRESS and then try to read the
2204 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2205 * value.
2206 */
2207 for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2208 if (USE_NEW_SCHEME(retry_counter)) {
2209 struct usb_device_descriptor *buf;
2210 int r = 0;
2211
2212 #define GET_DESCRIPTOR_BUFSIZE 64
2213 buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2214 if (!buf) {
2215 retval = -ENOMEM;
2216 continue;
2217 }
2218
2219 /* Use a short timeout the first time through,
2220 * so that recalcitrant full-speed devices with
2221 * 8- or 16-byte ep0-maxpackets won't slow things
2222 * down tremendously by NAKing the unexpectedly
2223 * early status stage. Also, retry on all errors;
2224 * some devices are flakey.
2225 */
2226 for (j = 0; j < 3; ++j) {
2227 buf->bMaxPacketSize0 = 0;
2228 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2229 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2230 USB_DT_DEVICE << 8, 0,
2231 buf, GET_DESCRIPTOR_BUFSIZE,
2232 (i ? USB_CTRL_GET_TIMEOUT : 1000));
2233 switch (buf->bMaxPacketSize0) {
2234 case 8: case 16: case 32: case 64:
2235 if (buf->bDescriptorType ==
2236 USB_DT_DEVICE) {
2237 r = 0;
2238 break;
2239 }
2240 /* FALL THROUGH */
2241 default:
2242 if (r == 0)
2243 r = -EPROTO;
2244 break;
2245 }
2246 if (r == 0)
2247 break;
2248 }
2249 udev->descriptor.bMaxPacketSize0 =
2250 buf->bMaxPacketSize0;
2251 kfree(buf);
2252
2253 retval = hub_port_reset(hub, port1, udev, delay);
2254 if (retval < 0) /* error or disconnect */
2255 goto fail;
2256 if (oldspeed != udev->speed) {
2257 dev_dbg(&udev->dev,
2258 "device reset changed speed!\n");
2259 retval = -ENODEV;
2260 goto fail;
2261 }
2262 if (r) {
2263 dev_err(&udev->dev, "device descriptor "
2264 "read/%s, error %d\n",
2265 "64", r);
2266 retval = -EMSGSIZE;
2267 continue;
2268 }
2269 #undef GET_DESCRIPTOR_BUFSIZE
2270 }
2271
2272 for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2273 retval = hub_set_address(udev);
2274 if (retval >= 0)
2275 break;
2276 msleep(200);
2277 }
2278 if (retval < 0) {
2279 dev_err(&udev->dev,
2280 "device not accepting address %d, error %d\n",
2281 udev->devnum, retval);
2282 goto fail;
2283 }
2284
2285 /* cope with hardware quirkiness:
2286 * - let SET_ADDRESS settle, some device hardware wants it
2287 * - read ep0 maxpacket even for high and low speed,
2288 */
2289 msleep(10);
2290 if (USE_NEW_SCHEME(retry_counter))
2291 break;
2292
2293 retval = usb_get_device_descriptor(udev, 8);
2294 if (retval < 8) {
2295 dev_err(&udev->dev, "device descriptor "
2296 "read/%s, error %d\n",
2297 "8", retval);
2298 if (retval >= 0)
2299 retval = -EMSGSIZE;
2300 } else {
2301 retval = 0;
2302 break;
2303 }
2304 }
2305 if (retval)
2306 goto fail;
2307
2308 i = udev->descriptor.bMaxPacketSize0;
2309 if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2310 if (udev->speed != USB_SPEED_FULL ||
2311 !(i == 8 || i == 16 || i == 32 || i == 64)) {
2312 dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2313 retval = -EMSGSIZE;
2314 goto fail;
2315 }
2316 dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2317 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2318 ep0_reinit(udev);
2319 }
2320
2321 retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2322 if (retval < (signed)sizeof(udev->descriptor)) {
2323 dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2324 "all", retval);
2325 if (retval >= 0)
2326 retval = -ENOMSG;
2327 goto fail;
2328 }
2329
2330 retval = 0;
2331
2332 fail:
2333 if (retval)
2334 hub_port_disable(hub, port1, 0);
2335 up(&usb_address0_sem);
2336 return retval;
2337 }
2338
2339 static void
2340 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2341 {
2342 struct usb_qualifier_descriptor *qual;
2343 int status;
2344
2345 qual = kmalloc (sizeof *qual, SLAB_KERNEL);
2346 if (qual == NULL)
2347 return;
2348
2349 status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2350 qual, sizeof *qual);
2351 if (status == sizeof *qual) {
2352 dev_info(&udev->dev, "not running at top speed; "
2353 "connect to a high speed hub\n");
2354 /* hub LEDs are probably harder to miss than syslog */
2355 if (hub->has_indicators) {
2356 hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2357 schedule_work (&hub->leds);
2358 }
2359 }
2360 kfree(qual);
2361 }
2362
2363 static unsigned
2364 hub_power_remaining (struct usb_hub *hub)
2365 {
2366 struct usb_device *hdev = hub->hdev;
2367 int remaining;
2368 unsigned i;
2369
2370 remaining = hub->power_budget;
2371 if (!remaining) /* self-powered */
2372 return 0;
2373
2374 for (i = 0; i < hdev->maxchild; i++) {
2375 struct usb_device *udev = hdev->children[i];
2376 int delta, ceiling;
2377
2378 if (!udev)
2379 continue;
2380
2381 /* 100mA per-port ceiling, or 8mA for OTG ports */
2382 if (i != (udev->bus->otg_port - 1) || hdev->parent)
2383 ceiling = 50;
2384 else
2385 ceiling = 4;
2386
2387 if (udev->actconfig)
2388 delta = udev->actconfig->desc.bMaxPower;
2389 else
2390 delta = ceiling;
2391 // dev_dbg(&udev->dev, "budgeted %dmA\n", 2 * delta);
2392 if (delta > ceiling)
2393 dev_warn(&udev->dev, "%dmA over %dmA budget!\n",
2394 2 * (delta - ceiling), 2 * ceiling);
2395 remaining -= delta;
2396 }
2397 if (remaining < 0) {
2398 dev_warn(hub->intfdev,
2399 "%dmA over power budget!\n",
2400 -2 * remaining);
2401 remaining = 0;
2402 }
2403 return remaining;
2404 }
2405
2406 /* Handle physical or logical connection change events.
2407 * This routine is called when:
2408 * a port connection-change occurs;
2409 * a port enable-change occurs (often caused by EMI);
2410 * usb_reset_device() encounters changed descriptors (as from
2411 * a firmware download)
2412 * caller already locked the hub
2413 */
2414 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2415 u16 portstatus, u16 portchange)
2416 {
2417 struct usb_device *hdev = hub->hdev;
2418 struct device *hub_dev = hub->intfdev;
2419 u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2420 int status, i;
2421
2422 dev_dbg (hub_dev,
2423 "port %d, status %04x, change %04x, %s\n",
2424 port1, portstatus, portchange, portspeed (portstatus));
2425
2426 if (hub->has_indicators) {
2427 set_port_led(hub, port1, HUB_LED_AUTO);
2428 hub->indicator[port1-1] = INDICATOR_AUTO;
2429 }
2430
2431 /* Disconnect any existing devices under this port */
2432 if (hdev->children[port1-1])
2433 usb_disconnect(&hdev->children[port1-1]);
2434 clear_bit(port1, hub->change_bits);
2435
2436 #ifdef CONFIG_USB_OTG
2437 /* during HNP, don't repeat the debounce */
2438 if (hdev->bus->is_b_host)
2439 portchange &= ~USB_PORT_STAT_C_CONNECTION;
2440 #endif
2441
2442 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2443 status = hub_port_debounce(hub, port1);
2444 if (status < 0) {
2445 dev_err (hub_dev,
2446 "connect-debounce failed, port %d disabled\n",
2447 port1);
2448 goto done;
2449 }
2450 portstatus = status;
2451 }
2452
2453 /* Return now if nothing is connected */
2454 if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2455
2456 /* maybe switch power back on (e.g. root hub was reset) */
2457 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
2458 && !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2459 set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2460
2461 if (portstatus & USB_PORT_STAT_ENABLE)
2462 goto done;
2463 return;
2464 }
2465
2466 #ifdef CONFIG_USB_SUSPEND
2467 /* If something is connected, but the port is suspended, wake it up. */
2468 if (portstatus & USB_PORT_STAT_SUSPEND) {
2469 status = hub_port_resume(hub, port1, NULL);
2470 if (status < 0) {
2471 dev_dbg(hub_dev,
2472 "can't clear suspend on port %d; %d\n",
2473 port1, status);
2474 goto done;
2475 }
2476 }
2477 #endif
2478
2479 for (i = 0; i < SET_CONFIG_TRIES; i++) {
2480 struct usb_device *udev;
2481
2482 /* reallocate for each attempt, since references
2483 * to the previous one can escape in various ways
2484 */
2485 udev = usb_alloc_dev(hdev, hdev->bus, port1);
2486 if (!udev) {
2487 dev_err (hub_dev,
2488 "couldn't allocate port %d usb_device\n",
2489 port1);
2490 goto done;
2491 }
2492
2493 usb_set_device_state(udev, USB_STATE_POWERED);
2494 udev->speed = USB_SPEED_UNKNOWN;
2495
2496 /* set the address */
2497 choose_address(udev);
2498 if (udev->devnum <= 0) {
2499 status = -ENOTCONN; /* Don't retry */
2500 goto loop;
2501 }
2502
2503 /* reset and get descriptor */
2504 status = hub_port_init(hub, udev, port1, i);
2505 if (status < 0)
2506 goto loop;
2507
2508 /* consecutive bus-powered hubs aren't reliable; they can
2509 * violate the voltage drop budget. if the new child has
2510 * a "powered" LED, users should notice we didn't enable it
2511 * (without reading syslog), even without per-port LEDs
2512 * on the parent.
2513 */
2514 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2515 && hub->power_budget) {
2516 u16 devstat;
2517
2518 status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2519 &devstat);
2520 if (status < 0) {
2521 dev_dbg(&udev->dev, "get status %d ?\n", status);
2522 goto loop_disable;
2523 }
2524 cpu_to_le16s(&devstat);
2525 if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2526 dev_err(&udev->dev,
2527 "can't connect bus-powered hub "
2528 "to this port\n");
2529 if (hub->has_indicators) {
2530 hub->indicator[port1-1] =
2531 INDICATOR_AMBER_BLINK;
2532 schedule_work (&hub->leds);
2533 }
2534 status = -ENOTCONN; /* Don't retry */
2535 goto loop_disable;
2536 }
2537 }
2538
2539 /* check for devices running slower than they could */
2540 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2541 && udev->speed == USB_SPEED_FULL
2542 && highspeed_hubs != 0)
2543 check_highspeed (hub, udev, port1);
2544
2545 /* Store the parent's children[] pointer. At this point
2546 * udev becomes globally accessible, although presumably
2547 * no one will look at it until hdev is unlocked.
2548 */
2549 down (&udev->serialize);
2550 status = 0;
2551
2552 /* We mustn't add new devices if the parent hub has
2553 * been disconnected; we would race with the
2554 * recursively_mark_NOTATTACHED() routine.
2555 */
2556 spin_lock_irq(&device_state_lock);
2557 if (hdev->state == USB_STATE_NOTATTACHED)
2558 status = -ENOTCONN;
2559 else
2560 hdev->children[port1-1] = udev;
2561 spin_unlock_irq(&device_state_lock);
2562
2563 /* Run it through the hoops (find a driver, etc) */
2564 if (!status) {
2565 status = usb_new_device(udev);
2566 if (status) {
2567 spin_lock_irq(&device_state_lock);
2568 hdev->children[port1-1] = NULL;
2569 spin_unlock_irq(&device_state_lock);
2570 }
2571 }
2572
2573 up (&udev->serialize);
2574 if (status)
2575 goto loop_disable;
2576
2577 status = hub_power_remaining(hub);
2578 if (status)
2579 dev_dbg(hub_dev,
2580 "%dmA power budget left\n",
2581 2 * status);
2582
2583 return;
2584
2585 loop_disable:
2586 hub_port_disable(hub, port1, 1);
2587 loop:
2588 ep0_reinit(udev);
2589 release_address(udev);
2590 usb_put_dev(udev);
2591 if (status == -ENOTCONN)
2592 break;
2593 }
2594
2595 done:
2596 hub_port_disable(hub, port1, 1);
2597 }
2598
2599 static void hub_events(void)
2600 {
2601 struct list_head *tmp;
2602 struct usb_device *hdev;
2603 struct usb_interface *intf;
2604 struct usb_hub *hub;
2605 struct device *hub_dev;
2606 u16 hubstatus;
2607 u16 hubchange;
2608 u16 portstatus;
2609 u16 portchange;
2610 int i, ret;
2611 int connect_change;
2612
2613 /*
2614 * We restart the list every time to avoid a deadlock with
2615 * deleting hubs downstream from this one. This should be
2616 * safe since we delete the hub from the event list.
2617 * Not the most efficient, but avoids deadlocks.
2618 */
2619 while (1) {
2620
2621 /* Grab the first entry at the beginning of the list */
2622 spin_lock_irq(&hub_event_lock);
2623 if (list_empty(&hub_event_list)) {
2624 spin_unlock_irq(&hub_event_lock);
2625 break;
2626 }
2627
2628 tmp = hub_event_list.next;
2629 list_del_init(tmp);
2630
2631 hub = list_entry(tmp, struct usb_hub, event_list);
2632 hdev = hub->hdev;
2633 intf = to_usb_interface(hub->intfdev);
2634 hub_dev = &intf->dev;
2635
2636 i = hub->resume_root_hub;
2637
2638 dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x%s\n",
2639 hdev->state, hub->descriptor
2640 ? hub->descriptor->bNbrPorts
2641 : 0,
2642 /* NOTE: expects max 15 ports... */
2643 (u16) hub->change_bits[0],
2644 (u16) hub->event_bits[0],
2645 i ? ", resume root" : "");
2646
2647 usb_get_intf(intf);
2648 spin_unlock_irq(&hub_event_lock);
2649
2650 /* Is this is a root hub wanting to reactivate the downstream
2651 * ports? If so, be sure the interface resumes even if its
2652 * stub "device" node was never suspended.
2653 */
2654 if (i) {
2655 dpm_runtime_resume(&hdev->dev);
2656 dpm_runtime_resume(&intf->dev);
2657 }
2658
2659 /* Lock the device, then check to see if we were
2660 * disconnected while waiting for the lock to succeed. */
2661 if (locktree(hdev) < 0) {
2662 usb_put_intf(intf);
2663 continue;
2664 }
2665 if (hub != usb_get_intfdata(intf))
2666 goto loop;
2667
2668 /* If the hub has died, clean up after it */
2669 if (hdev->state == USB_STATE_NOTATTACHED) {
2670 hub_pre_reset(hub);
2671 goto loop;
2672 }
2673
2674 /* If this is an inactive or suspended hub, do nothing */
2675 if (hub->quiescing)
2676 goto loop;
2677
2678 if (hub->error) {
2679 dev_dbg (hub_dev, "resetting for error %d\n",
2680 hub->error);
2681
2682 ret = usb_reset_device(hdev);
2683 if (ret) {
2684 dev_dbg (hub_dev,
2685 "error resetting hub: %d\n", ret);
2686 goto loop;
2687 }
2688
2689 hub->nerrors = 0;
2690 hub->error = 0;
2691 }
2692
2693 /* deal with port status changes */
2694 for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2695 if (test_bit(i, hub->busy_bits))
2696 continue;
2697 connect_change = test_bit(i, hub->change_bits);
2698 if (!test_and_clear_bit(i, hub->event_bits) &&
2699 !connect_change && !hub->activating)
2700 continue;
2701
2702 ret = hub_port_status(hub, i,
2703 &portstatus, &portchange);
2704 if (ret < 0)
2705 continue;
2706
2707 if (hub->activating && !hdev->children[i-1] &&
2708 (portstatus &
2709 USB_PORT_STAT_CONNECTION))
2710 connect_change = 1;
2711
2712 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2713 clear_port_feature(hdev, i,
2714 USB_PORT_FEAT_C_CONNECTION);
2715 connect_change = 1;
2716 }
2717
2718 if (portchange & USB_PORT_STAT_C_ENABLE) {
2719 if (!connect_change)
2720 dev_dbg (hub_dev,
2721 "port %d enable change, "
2722 "status %08x\n",
2723 i, portstatus);
2724 clear_port_feature(hdev, i,
2725 USB_PORT_FEAT_C_ENABLE);
2726
2727 /*
2728 * EM interference sometimes causes badly
2729 * shielded USB devices to be shutdown by
2730 * the hub, this hack enables them again.
2731 * Works at least with mouse driver.
2732 */
2733 if (!(portstatus & USB_PORT_STAT_ENABLE)
2734 && !connect_change
2735 && hdev->children[i-1]) {
2736 dev_err (hub_dev,
2737 "port %i "
2738 "disabled by hub (EMI?), "
2739 "re-enabling...\n",
2740 i);
2741 connect_change = 1;
2742 }
2743 }
2744
2745 if (portchange & USB_PORT_STAT_C_SUSPEND) {
2746 clear_port_feature(hdev, i,
2747 USB_PORT_FEAT_C_SUSPEND);
2748 if (hdev->children[i-1]) {
2749 ret = remote_wakeup(hdev->
2750 children[i-1]);
2751 if (ret < 0)
2752 connect_change = 1;
2753 } else {
2754 ret = -ENODEV;
2755 hub_port_disable(hub, i, 1);
2756 }
2757 dev_dbg (hub_dev,
2758 "resume on port %d, status %d\n",
2759 i, ret);
2760 }
2761
2762 if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2763 dev_err (hub_dev,
2764 "over-current change on port %d\n",
2765 i);
2766 clear_port_feature(hdev, i,
2767 USB_PORT_FEAT_C_OVER_CURRENT);
2768 hub_power_on(hub);
2769 }
2770
2771 if (portchange & USB_PORT_STAT_C_RESET) {
2772 dev_dbg (hub_dev,
2773 "reset change on port %d\n",
2774 i);
2775 clear_port_feature(hdev, i,
2776 USB_PORT_FEAT_C_RESET);
2777 }
2778
2779 if (connect_change)
2780 hub_port_connect_change(hub, i,
2781 portstatus, portchange);
2782 } /* end for i */
2783
2784 /* deal with hub status changes */
2785 if (test_and_clear_bit(0, hub->event_bits) == 0)
2786 ; /* do nothing */
2787 else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2788 dev_err (hub_dev, "get_hub_status failed\n");
2789 else {
2790 if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2791 dev_dbg (hub_dev, "power change\n");
2792 clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2793 }
2794 if (hubchange & HUB_CHANGE_OVERCURRENT) {
2795 dev_dbg (hub_dev, "overcurrent change\n");
2796 msleep(500); /* Cool down */
2797 clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2798 hub_power_on(hub);
2799 }
2800 }
2801
2802 hub->activating = 0;
2803
2804 /* If this is a root hub, tell the HCD it's okay to
2805 * re-enable port-change interrupts now. */
2806 if (!hdev->parent)
2807 usb_enable_root_hub_irq(hdev->bus);
2808
2809 loop:
2810 usb_unlock_device(hdev);
2811 usb_put_intf(intf);
2812
2813 } /* end while (1) */
2814 }
2815
2816 static int hub_thread(void *__unused)
2817 {
2818 do {
2819 hub_events();
2820 wait_event_interruptible(khubd_wait,
2821 !list_empty(&hub_event_list) ||
2822 kthread_should_stop());
2823 try_to_freeze();
2824 } while (!kthread_should_stop() || !list_empty(&hub_event_list));
2825
2826 pr_debug("%s: khubd exiting\n", usbcore_name);
2827 return 0;
2828 }
2829
2830 static struct usb_device_id hub_id_table [] = {
2831 { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2832 .bDeviceClass = USB_CLASS_HUB},
2833 { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2834 .bInterfaceClass = USB_CLASS_HUB},
2835 { } /* Terminating entry */
2836 };
2837
2838 MODULE_DEVICE_TABLE (usb, hub_id_table);
2839
2840 static struct usb_driver hub_driver = {
2841 .owner = THIS_MODULE,
2842 .name = "hub",
2843 .probe = hub_probe,
2844 .disconnect = hub_disconnect,
2845 .suspend = hub_suspend,
2846 .resume = hub_resume,
2847 .ioctl = hub_ioctl,
2848 .id_table = hub_id_table,
2849 };
2850
2851 int usb_hub_init(void)
2852 {
2853 if (usb_register(&hub_driver) < 0) {
2854 printk(KERN_ERR "%s: can't register hub driver\n",
2855 usbcore_name);
2856 return -1;
2857 }
2858
2859 khubd_task = kthread_run(hub_thread, NULL, "khubd");
2860 if (!IS_ERR(khubd_task))
2861 return 0;
2862
2863 /* Fall through if kernel_thread failed */
2864 usb_deregister(&hub_driver);
2865 printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2866
2867 return -1;
2868 }
2869
2870 void usb_hub_cleanup(void)
2871 {
2872 kthread_stop(khubd_task);
2873
2874 /*
2875 * Hub resources are freed for us by usb_deregister. It calls
2876 * usb_driver_purge on every device which in turn calls that
2877 * devices disconnect function if it is using this driver.
2878 * The hub_disconnect function takes care of releasing the
2879 * individual hub resources. -greg
2880 */
2881 usb_deregister(&hub_driver);
2882 } /* usb_hub_cleanup() */
2883
2884 static int config_descriptors_changed(struct usb_device *udev)
2885 {
2886 unsigned index;
2887 unsigned len = 0;
2888 struct usb_config_descriptor *buf;
2889
2890 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2891 if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2892 len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2893 }
2894 buf = kmalloc (len, SLAB_KERNEL);
2895 if (buf == NULL) {
2896 dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2897 /* assume the worst */
2898 return 1;
2899 }
2900 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2901 int length;
2902 int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2903
2904 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2905 old_length);
2906 if (length < old_length) {
2907 dev_dbg(&udev->dev, "config index %d, error %d\n",
2908 index, length);
2909 break;
2910 }
2911 if (memcmp (buf, udev->rawdescriptors[index], old_length)
2912 != 0) {
2913 dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2914 index, buf->bConfigurationValue);
2915 break;
2916 }
2917 }
2918 kfree(buf);
2919 return index != udev->descriptor.bNumConfigurations;
2920 }
2921
2922 /**
2923 * usb_reset_device - perform a USB port reset to reinitialize a device
2924 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2925 *
2926 * WARNING - don't reset any device unless drivers for all of its
2927 * interfaces are expecting that reset! Maybe some driver->reset()
2928 * method should eventually help ensure sufficient cooperation.
2929 *
2930 * Do a port reset, reassign the device's address, and establish its
2931 * former operating configuration. If the reset fails, or the device's
2932 * descriptors change from their values before the reset, or the original
2933 * configuration and altsettings cannot be restored, a flag will be set
2934 * telling khubd to pretend the device has been disconnected and then
2935 * re-connected. All drivers will be unbound, and the device will be
2936 * re-enumerated and probed all over again.
2937 *
2938 * Returns 0 if the reset succeeded, -ENODEV if the device has been
2939 * flagged for logical disconnection, or some other negative error code
2940 * if the reset wasn't even attempted.
2941 *
2942 * The caller must own the device lock. For example, it's safe to use
2943 * this from a driver probe() routine after downloading new firmware.
2944 * For calls that might not occur during probe(), drivers should lock
2945 * the device using usb_lock_device_for_reset().
2946 */
2947 int usb_reset_device(struct usb_device *udev)
2948 {
2949 struct usb_device *parent_hdev = udev->parent;
2950 struct usb_hub *parent_hub;
2951 struct usb_device_descriptor descriptor = udev->descriptor;
2952 struct usb_hub *hub = NULL;
2953 int i, ret = 0, port1 = -1;
2954
2955 if (udev->state == USB_STATE_NOTATTACHED ||
2956 udev->state == USB_STATE_SUSPENDED) {
2957 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2958 udev->state);
2959 return -EINVAL;
2960 }
2961
2962 if (!parent_hdev) {
2963 /* this requires hcd-specific logic; see OHCI hc_restart() */
2964 dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
2965 return -EISDIR;
2966 }
2967
2968 for (i = 0; i < parent_hdev->maxchild; i++)
2969 if (parent_hdev->children[i] == udev) {
2970 port1 = i + 1;
2971 break;
2972 }
2973
2974 if (port1 < 0) {
2975 /* If this ever happens, it's very bad */
2976 dev_err(&udev->dev, "Can't locate device's port!\n");
2977 return -ENOENT;
2978 }
2979 parent_hub = hdev_to_hub(parent_hdev);
2980
2981 /* If we're resetting an active hub, take some special actions */
2982 if (udev->actconfig &&
2983 udev->actconfig->interface[0]->dev.driver ==
2984 &hub_driver.driver &&
2985 (hub = hdev_to_hub(udev)) != NULL) {
2986 hub_pre_reset(hub);
2987 }
2988
2989 set_bit(port1, parent_hub->busy_bits);
2990 for (i = 0; i < SET_CONFIG_TRIES; ++i) {
2991
2992 /* ep0 maxpacket size may change; let the HCD know about it.
2993 * Other endpoints will be handled by re-enumeration. */
2994 ep0_reinit(udev);
2995 ret = hub_port_init(parent_hub, udev, port1, i);
2996 if (ret >= 0)
2997 break;
2998 }
2999 clear_bit(port1, parent_hub->busy_bits);
3000 if (ret < 0)
3001 goto re_enumerate;
3002
3003 /* Device might have changed firmware (DFU or similar) */
3004 if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
3005 || config_descriptors_changed (udev)) {
3006 dev_info(&udev->dev, "device firmware changed\n");
3007 udev->descriptor = descriptor; /* for disconnect() calls */
3008 goto re_enumerate;
3009 }
3010
3011 if (!udev->actconfig)
3012 goto done;
3013
3014 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3015 USB_REQ_SET_CONFIGURATION, 0,
3016 udev->actconfig->desc.bConfigurationValue, 0,
3017 NULL, 0, USB_CTRL_SET_TIMEOUT);
3018 if (ret < 0) {
3019 dev_err(&udev->dev,
3020 "can't restore configuration #%d (error=%d)\n",
3021 udev->actconfig->desc.bConfigurationValue, ret);
3022 goto re_enumerate;
3023 }
3024 usb_set_device_state(udev, USB_STATE_CONFIGURED);
3025
3026 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3027 struct usb_interface *intf = udev->actconfig->interface[i];
3028 struct usb_interface_descriptor *desc;
3029
3030 /* set_interface resets host side toggle even
3031 * for altsetting zero. the interface may have no driver.
3032 */
3033 desc = &intf->cur_altsetting->desc;
3034 ret = usb_set_interface(udev, desc->bInterfaceNumber,
3035 desc->bAlternateSetting);
3036 if (ret < 0) {
3037 dev_err(&udev->dev, "failed to restore interface %d "
3038 "altsetting %d (error=%d)\n",
3039 desc->bInterfaceNumber,
3040 desc->bAlternateSetting,
3041 ret);
3042 goto re_enumerate;
3043 }
3044 }
3045
3046 done:
3047 if (hub)
3048 hub_post_reset(hub);
3049 return 0;
3050
3051 re_enumerate:
3052 hub_port_logical_disconnect(parent_hub, port1);
3053 return -ENODEV;
3054 }
kernel-based virtual machine