MOXA linux-2.6.x / linux-2.6.19-uc1 from UC-7110-LX-BOOTLOADER-1.9_VERSION-4.2.tgz
[linux-2.6.19-moxart.git] / drivers / usb / core / hub.c
blobba165aff9ea44eb15f8f3e99d329d27ac326b50a
1 /*
2 * USB hub driver.
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)
9 */
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/smp_lock.h>
20 #include <linux/ioctl.h>
21 #include <linux/usb.h>
22 #include <linux/usbdevice_fs.h>
23 #include <linux/kthread.h>
24 #include <linux/mutex.h>
26 #include <asm/semaphore.h>
27 #include <asm/uaccess.h>
28 #include <asm/byteorder.h>
30 #include "usb.h"
31 #include "hcd.h"
32 #include "hub.h"
34 /* Protect struct usb_device->state and ->children members
35 * Note: Both are also protected by ->dev.sem, except that ->state can
36 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
37 static DEFINE_SPINLOCK(device_state_lock);
39 /* khubd's worklist and its lock */
40 static DEFINE_SPINLOCK(hub_event_lock);
41 static LIST_HEAD(hub_event_list); /* List of hubs needing servicing */
43 /* Wakes up khubd */
44 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
46 static struct task_struct *khubd_task;
48 /* cycle leds on hubs that aren't blinking for attention */
49 static int blinkenlights = 0;
50 module_param (blinkenlights, bool, S_IRUGO);
51 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
54 * As of 2.6.10 we introduce a new USB device initialization scheme which
55 * closely resembles the way Windows works. Hopefully it will be compatible
56 * with a wider range of devices than the old scheme. However some previously
57 * working devices may start giving rise to "device not accepting address"
58 * errors; if that happens the user can try the old scheme by adjusting the
59 * following module parameters.
61 * For maximum flexibility there are two boolean parameters to control the
62 * hub driver's behavior. On the first initialization attempt, if the
63 * "old_scheme_first" parameter is set then the old scheme will be used,
64 * otherwise the new scheme is used. If that fails and "use_both_schemes"
65 * is set, then the driver will make another attempt, using the other scheme.
67 static int old_scheme_first = 0;
68 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
69 MODULE_PARM_DESC(old_scheme_first,
70 "start with the old device initialization scheme");
72 static int use_both_schemes = 1;
73 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
74 MODULE_PARM_DESC(use_both_schemes,
75 "try the other device initialization scheme if the "
76 "first one fails");
79 #ifdef DEBUG
80 static inline char *portspeed (int portstatus)
82 if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
83 return "480 Mb/s";
84 else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
85 return "1.5 Mb/s";
86 else
87 return "12 Mb/s";
89 #endif
91 /* Note that hdev or one of its children must be locked! */
92 static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
94 return usb_get_intfdata(hdev->actconfig->interface[0]);
97 /* USB 2.0 spec Section 11.24.4.5 */
98 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
100 int i, ret;
102 for (i = 0; i < 3; i++) {
103 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
104 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
105 USB_DT_HUB << 8, 0, data, size,
106 USB_CTRL_GET_TIMEOUT);
107 if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
108 return ret;
110 return -EINVAL;
114 * USB 2.0 spec Section 11.24.2.1
116 static int clear_hub_feature(struct usb_device *hdev, int feature)
118 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
119 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
123 * USB 2.0 spec Section 11.24.2.2
125 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
127 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
128 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
129 NULL, 0, 1000);
133 * USB 2.0 spec Section 11.24.2.13
135 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
137 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
138 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
139 NULL, 0, 1000);
143 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
144 * for info about using port indicators
146 static void set_port_led(
147 struct usb_hub *hub,
148 int port1,
149 int selector
152 int status = set_port_feature(hub->hdev, (selector << 8) | port1,
153 USB_PORT_FEAT_INDICATOR);
154 if (status < 0)
155 dev_dbg (hub->intfdev,
156 "port %d indicator %s status %d\n",
157 port1,
158 ({ char *s; switch (selector) {
159 case HUB_LED_AMBER: s = "amber"; break;
160 case HUB_LED_GREEN: s = "green"; break;
161 case HUB_LED_OFF: s = "off"; break;
162 case HUB_LED_AUTO: s = "auto"; break;
163 default: s = "??"; break;
164 }; s; }),
165 status);
168 #define LED_CYCLE_PERIOD ((2*HZ)/3)
170 static void led_work (void *__hub)
172 struct usb_hub *hub = __hub;
173 struct usb_device *hdev = hub->hdev;
174 unsigned i;
175 unsigned changed = 0;
176 int cursor = -1;
178 if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
179 return;
181 for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
182 unsigned selector, mode;
184 /* 30%-50% duty cycle */
186 switch (hub->indicator[i]) {
187 /* cycle marker */
188 case INDICATOR_CYCLE:
189 cursor = i;
190 selector = HUB_LED_AUTO;
191 mode = INDICATOR_AUTO;
192 break;
193 /* blinking green = sw attention */
194 case INDICATOR_GREEN_BLINK:
195 selector = HUB_LED_GREEN;
196 mode = INDICATOR_GREEN_BLINK_OFF;
197 break;
198 case INDICATOR_GREEN_BLINK_OFF:
199 selector = HUB_LED_OFF;
200 mode = INDICATOR_GREEN_BLINK;
201 break;
202 /* blinking amber = hw attention */
203 case INDICATOR_AMBER_BLINK:
204 selector = HUB_LED_AMBER;
205 mode = INDICATOR_AMBER_BLINK_OFF;
206 break;
207 case INDICATOR_AMBER_BLINK_OFF:
208 selector = HUB_LED_OFF;
209 mode = INDICATOR_AMBER_BLINK;
210 break;
211 /* blink green/amber = reserved */
212 case INDICATOR_ALT_BLINK:
213 selector = HUB_LED_GREEN;
214 mode = INDICATOR_ALT_BLINK_OFF;
215 break;
216 case INDICATOR_ALT_BLINK_OFF:
217 selector = HUB_LED_AMBER;
218 mode = INDICATOR_ALT_BLINK;
219 break;
220 default:
221 continue;
223 if (selector != HUB_LED_AUTO)
224 changed = 1;
225 set_port_led(hub, i + 1, selector);
226 hub->indicator[i] = mode;
228 if (!changed && blinkenlights) {
229 cursor++;
230 cursor %= hub->descriptor->bNbrPorts;
231 set_port_led(hub, cursor + 1, HUB_LED_GREEN);
232 hub->indicator[cursor] = INDICATOR_CYCLE;
233 changed++;
235 if (changed)
236 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
239 /* use a short timeout for hub/port status fetches */
240 #define USB_STS_TIMEOUT 1000
241 #define USB_STS_RETRIES 5
244 * USB 2.0 spec Section 11.24.2.6
246 static int get_hub_status(struct usb_device *hdev,
247 struct usb_hub_status *data)
249 int i, status = -ETIMEDOUT;
251 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
252 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
253 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
254 data, sizeof(*data), USB_STS_TIMEOUT);
256 return status;
260 * USB 2.0 spec Section 11.24.2.7
262 static int get_port_status(struct usb_device *hdev, int port1,
263 struct usb_port_status *data)
265 int i, status = -ETIMEDOUT;
267 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
268 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
269 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
270 data, sizeof(*data), USB_STS_TIMEOUT);
272 return status;
275 static void kick_khubd(struct usb_hub *hub)
277 unsigned long flags;
279 spin_lock_irqsave(&hub_event_lock, flags);
280 if (list_empty(&hub->event_list)) {
281 list_add_tail(&hub->event_list, &hub_event_list);
282 wake_up(&khubd_wait);
284 spin_unlock_irqrestore(&hub_event_lock, flags);
287 void usb_kick_khubd(struct usb_device *hdev)
289 kick_khubd(hdev_to_hub(hdev));
293 /* completion function, fires on port status changes and various faults */
294 static void hub_irq(struct urb *urb)
296 struct usb_hub *hub = urb->context;
297 int status;
298 int i;
299 unsigned long bits;
301 switch (urb->status) {
302 case -ENOENT: /* synchronous unlink */
303 case -ECONNRESET: /* async unlink */
304 case -ESHUTDOWN: /* hardware going away */
305 return;
307 default: /* presumably an error */
308 /* Cause a hub reset after 10 consecutive errors */
309 dev_dbg (hub->intfdev, "transfer --> %d\n", urb->status);
310 if ((++hub->nerrors < 10) || hub->error)
311 goto resubmit;
312 hub->error = urb->status;
313 /* FALL THROUGH */
315 /* let khubd handle things */
316 case 0: /* we got data: port status changed */
317 bits = 0;
318 for (i = 0; i < urb->actual_length; ++i)
319 bits |= ((unsigned long) ((*hub->buffer)[i]))
320 << (i*8);
321 hub->event_bits[0] = bits;
322 break;
325 hub->nerrors = 0;
327 /* Something happened, let khubd figure it out */
328 kick_khubd(hub);
330 resubmit:
331 if (hub->quiescing)
332 return;
334 if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
335 && status != -ENODEV && status != -EPERM)
336 dev_err (hub->intfdev, "resubmit --> %d\n", status);
339 /* USB 2.0 spec Section 11.24.2.3 */
340 static inline int
341 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
343 return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
344 HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
345 tt, NULL, 0, 1000);
349 * enumeration blocks khubd for a long time. we use keventd instead, since
350 * long blocking there is the exception, not the rule. accordingly, HCDs
351 * talking to TTs must queue control transfers (not just bulk and iso), so
352 * both can talk to the same hub concurrently.
354 static void hub_tt_kevent (void *arg)
356 struct usb_hub *hub = arg;
357 unsigned long flags;
359 spin_lock_irqsave (&hub->tt.lock, flags);
360 while (!list_empty (&hub->tt.clear_list)) {
361 struct list_head *temp;
362 struct usb_tt_clear *clear;
363 struct usb_device *hdev = hub->hdev;
364 int status;
366 temp = hub->tt.clear_list.next;
367 clear = list_entry (temp, struct usb_tt_clear, clear_list);
368 list_del (&clear->clear_list);
370 /* drop lock so HCD can concurrently report other TT errors */
371 spin_unlock_irqrestore (&hub->tt.lock, flags);
372 status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
373 spin_lock_irqsave (&hub->tt.lock, flags);
375 if (status)
376 dev_err (&hdev->dev,
377 "clear tt %d (%04x) error %d\n",
378 clear->tt, clear->devinfo, status);
379 kfree(clear);
381 spin_unlock_irqrestore (&hub->tt.lock, flags);
385 * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
386 * @udev: the device whose split transaction failed
387 * @pipe: identifies the endpoint of the failed transaction
389 * High speed HCDs use this to tell the hub driver that some split control or
390 * bulk transaction failed in a way that requires clearing internal state of
391 * a transaction translator. This is normally detected (and reported) from
392 * interrupt context.
394 * It may not be possible for that hub to handle additional full (or low)
395 * speed transactions until that state is fully cleared out.
397 void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
399 struct usb_tt *tt = udev->tt;
400 unsigned long flags;
401 struct usb_tt_clear *clear;
403 /* we've got to cope with an arbitrary number of pending TT clears,
404 * since each TT has "at least two" buffers that can need it (and
405 * there can be many TTs per hub). even if they're uncommon.
407 if ((clear = kmalloc (sizeof *clear, SLAB_ATOMIC)) == NULL) {
408 dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
409 /* FIXME recover somehow ... RESET_TT? */
410 return;
413 /* info that CLEAR_TT_BUFFER needs */
414 clear->tt = tt->multi ? udev->ttport : 1;
415 clear->devinfo = usb_pipeendpoint (pipe);
416 clear->devinfo |= udev->devnum << 4;
417 clear->devinfo |= usb_pipecontrol (pipe)
418 ? (USB_ENDPOINT_XFER_CONTROL << 11)
419 : (USB_ENDPOINT_XFER_BULK << 11);
420 if (usb_pipein (pipe))
421 clear->devinfo |= 1 << 15;
423 /* tell keventd to clear state for this TT */
424 spin_lock_irqsave (&tt->lock, flags);
425 list_add_tail (&clear->clear_list, &tt->clear_list);
426 schedule_work (&tt->kevent);
427 spin_unlock_irqrestore (&tt->lock, flags);
430 static void hub_power_on(struct usb_hub *hub)
432 int port1;
433 unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
434 u16 wHubCharacteristics =
435 le16_to_cpu(hub->descriptor->wHubCharacteristics);
437 /* Enable power on each port. Some hubs have reserved values
438 * of LPSM (> 2) in their descriptors, even though they are
439 * USB 2.0 hubs. Some hubs do not implement port-power switching
440 * but only emulate it. In all cases, the ports won't work
441 * unless we send these messages to the hub.
443 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
444 dev_dbg(hub->intfdev, "enabling power on all ports\n");
445 else
446 dev_dbg(hub->intfdev, "trying to enable port power on "
447 "non-switchable hub\n");
448 for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
449 set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
451 /* Wait at least 100 msec for power to become stable */
452 msleep(max(pgood_delay, (unsigned) 100));
455 static void hub_quiesce(struct usb_hub *hub)
457 /* (nonblocking) khubd and related activity won't re-trigger */
458 hub->quiescing = 1;
459 hub->activating = 0;
460 hub->resume_root_hub = 0;
462 /* (blocking) stop khubd and related activity */
463 usb_kill_urb(hub->urb);
464 if (hub->has_indicators)
465 cancel_delayed_work(&hub->leds);
466 if (hub->has_indicators || hub->tt.hub)
467 flush_scheduled_work();
470 static void hub_activate(struct usb_hub *hub)
472 int status;
474 hub->quiescing = 0;
475 hub->activating = 1;
476 hub->resume_root_hub = 0;
477 status = usb_submit_urb(hub->urb, GFP_NOIO);
478 if (status < 0)
479 dev_err(hub->intfdev, "activate --> %d\n", status);
480 if (hub->has_indicators && blinkenlights)
481 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
483 /* scan all ports ASAP */
484 kick_khubd(hub);
487 static int hub_hub_status(struct usb_hub *hub,
488 u16 *status, u16 *change)
490 int ret;
492 ret = get_hub_status(hub->hdev, &hub->status->hub);
493 if (ret < 0)
494 dev_err (hub->intfdev,
495 "%s failed (err = %d)\n", __FUNCTION__, ret);
496 else {
497 *status = le16_to_cpu(hub->status->hub.wHubStatus);
498 *change = le16_to_cpu(hub->status->hub.wHubChange);
499 ret = 0;
501 return ret;
504 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
506 struct usb_device *hdev = hub->hdev;
507 int ret;
509 if (hdev->children[port1-1] && set_state) {
510 usb_set_device_state(hdev->children[port1-1],
511 USB_STATE_NOTATTACHED);
513 ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
514 if (ret)
515 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
516 port1, ret);
518 return ret;
522 /* caller has locked the hub device */
523 static void hub_pre_reset(struct usb_interface *intf)
525 struct usb_hub *hub = usb_get_intfdata(intf);
526 struct usb_device *hdev = hub->hdev;
527 int port1;
529 for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
530 if (hdev->children[port1 - 1]) {
531 usb_disconnect(&hdev->children[port1 - 1]);
532 if (hub->error == 0)
533 hub_port_disable(hub, port1, 0);
536 hub_quiesce(hub);
539 /* caller has locked the hub device */
540 static void hub_post_reset(struct usb_interface *intf)
542 struct usb_hub *hub = usb_get_intfdata(intf);
544 hub_activate(hub);
545 hub_power_on(hub);
549 static int hub_configure(struct usb_hub *hub,
550 struct usb_endpoint_descriptor *endpoint)
552 struct usb_device *hdev = hub->hdev;
553 struct device *hub_dev = hub->intfdev;
554 u16 hubstatus, hubchange;
555 u16 wHubCharacteristics;
556 unsigned int pipe;
557 int maxp, ret;
558 char *message;
560 hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
561 &hub->buffer_dma);
562 if (!hub->buffer) {
563 message = "can't allocate hub irq buffer";
564 ret = -ENOMEM;
565 goto fail;
568 hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
569 if (!hub->status) {
570 message = "can't kmalloc hub status buffer";
571 ret = -ENOMEM;
572 goto fail;
575 hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
576 if (!hub->descriptor) {
577 message = "can't kmalloc hub descriptor";
578 ret = -ENOMEM;
579 goto fail;
582 /* Request the entire hub descriptor.
583 * hub->descriptor can handle USB_MAXCHILDREN ports,
584 * but the hub can/will return fewer bytes here.
586 ret = get_hub_descriptor(hdev, hub->descriptor,
587 sizeof(*hub->descriptor));
588 if (ret < 0) {
589 message = "can't read hub descriptor";
590 goto fail;
591 } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
592 message = "hub has too many ports!";
593 ret = -ENODEV;
594 goto fail;
597 hdev->maxchild = hub->descriptor->bNbrPorts;
598 dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
599 (hdev->maxchild == 1) ? "" : "s");
601 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
603 if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
604 int i;
605 char portstr [USB_MAXCHILDREN + 1];
607 for (i = 0; i < hdev->maxchild; i++)
608 portstr[i] = hub->descriptor->DeviceRemovable
609 [((i + 1) / 8)] & (1 << ((i + 1) % 8))
610 ? 'F' : 'R';
611 portstr[hdev->maxchild] = 0;
612 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
613 } else
614 dev_dbg(hub_dev, "standalone hub\n");
616 switch (wHubCharacteristics & HUB_CHAR_LPSM) {
617 case 0x00:
618 dev_dbg(hub_dev, "ganged power switching\n");
619 break;
620 case 0x01:
621 dev_dbg(hub_dev, "individual port power switching\n");
622 break;
623 case 0x02:
624 case 0x03:
625 dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
626 break;
629 switch (wHubCharacteristics & HUB_CHAR_OCPM) {
630 case 0x00:
631 dev_dbg(hub_dev, "global over-current protection\n");
632 break;
633 case 0x08:
634 dev_dbg(hub_dev, "individual port over-current protection\n");
635 break;
636 case 0x10:
637 case 0x18:
638 dev_dbg(hub_dev, "no over-current protection\n");
639 break;
642 spin_lock_init (&hub->tt.lock);
643 INIT_LIST_HEAD (&hub->tt.clear_list);
644 INIT_WORK (&hub->tt.kevent, hub_tt_kevent, hub);
645 switch (hdev->descriptor.bDeviceProtocol) {
646 case 0:
647 break;
648 case 1:
649 dev_dbg(hub_dev, "Single TT\n");
650 hub->tt.hub = hdev;
651 break;
652 case 2:
653 ret = usb_set_interface(hdev, 0, 1);
654 if (ret == 0) {
655 dev_dbg(hub_dev, "TT per port\n");
656 hub->tt.multi = 1;
657 } else
658 dev_err(hub_dev, "Using single TT (err %d)\n",
659 ret);
660 hub->tt.hub = hdev;
661 break;
662 default:
663 dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
664 hdev->descriptor.bDeviceProtocol);
665 break;
668 /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
669 switch (wHubCharacteristics & HUB_CHAR_TTTT) {
670 case HUB_TTTT_8_BITS:
671 if (hdev->descriptor.bDeviceProtocol != 0) {
672 hub->tt.think_time = 666;
673 dev_dbg(hub_dev, "TT requires at most %d "
674 "FS bit times (%d ns)\n",
675 8, hub->tt.think_time);
677 break;
678 case HUB_TTTT_16_BITS:
679 hub->tt.think_time = 666 * 2;
680 dev_dbg(hub_dev, "TT requires at most %d "
681 "FS bit times (%d ns)\n",
682 16, hub->tt.think_time);
683 break;
684 case HUB_TTTT_24_BITS:
685 hub->tt.think_time = 666 * 3;
686 dev_dbg(hub_dev, "TT requires at most %d "
687 "FS bit times (%d ns)\n",
688 24, hub->tt.think_time);
689 break;
690 case HUB_TTTT_32_BITS:
691 hub->tt.think_time = 666 * 4;
692 dev_dbg(hub_dev, "TT requires at most %d "
693 "FS bit times (%d ns)\n",
694 32, hub->tt.think_time);
695 break;
698 /* probe() zeroes hub->indicator[] */
699 if (wHubCharacteristics & HUB_CHAR_PORTIND) {
700 hub->has_indicators = 1;
701 dev_dbg(hub_dev, "Port indicators are supported\n");
704 dev_dbg(hub_dev, "power on to power good time: %dms\n",
705 hub->descriptor->bPwrOn2PwrGood * 2);
707 /* power budgeting mostly matters with bus-powered hubs,
708 * and battery-powered root hubs (may provide just 8 mA).
710 ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
711 if (ret < 2) {
712 message = "can't get hub status";
713 goto fail;
715 le16_to_cpus(&hubstatus);
716 if (hdev == hdev->bus->root_hub) {
717 if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
718 hub->mA_per_port = 500;
719 else {
720 hub->mA_per_port = hdev->bus_mA;
721 hub->limited_power = 1;
723 } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
724 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
725 hub->descriptor->bHubContrCurrent);
726 hub->limited_power = 1;
727 if (hdev->maxchild > 0) {
728 int remaining = hdev->bus_mA -
729 hub->descriptor->bHubContrCurrent;
731 if (remaining < hdev->maxchild * 100)
732 dev_warn(hub_dev,
733 "insufficient power available "
734 "to use all downstream ports\n");
735 hub->mA_per_port = 100; /* 7.2.1.1 */
737 } else { /* Self-powered external hub */
738 /* FIXME: What about battery-powered external hubs that
739 * provide less current per port? */
740 hub->mA_per_port = 500;
742 if (hub->mA_per_port < 500)
743 dev_dbg(hub_dev, "%umA bus power budget for each child\n",
744 hub->mA_per_port);
746 ret = hub_hub_status(hub, &hubstatus, &hubchange);
747 if (ret < 0) {
748 message = "can't get hub status";
749 goto fail;
752 /* local power status reports aren't always correct */
753 if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
754 dev_dbg(hub_dev, "local power source is %s\n",
755 (hubstatus & HUB_STATUS_LOCAL_POWER)
756 ? "lost (inactive)" : "good");
758 if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
759 dev_dbg(hub_dev, "%sover-current condition exists\n",
760 (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
762 /* set up the interrupt endpoint */
763 pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
764 maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
766 if (maxp > sizeof(*hub->buffer))
767 maxp = sizeof(*hub->buffer);
769 hub->urb = usb_alloc_urb(0, GFP_KERNEL);
770 if (!hub->urb) {
771 message = "couldn't allocate interrupt urb";
772 ret = -ENOMEM;
773 goto fail;
776 usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
777 hub, endpoint->bInterval);
778 hub->urb->transfer_dma = hub->buffer_dma;
779 hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
781 /* maybe cycle the hub leds */
782 if (hub->has_indicators && blinkenlights)
783 hub->indicator [0] = INDICATOR_CYCLE;
785 hub_power_on(hub);
786 hub_activate(hub);
787 return 0;
789 fail:
790 dev_err (hub_dev, "config failed, %s (err %d)\n",
791 message, ret);
792 /* hub_disconnect() frees urb and descriptor */
793 return ret;
796 static unsigned highspeed_hubs;
798 static void hub_disconnect(struct usb_interface *intf)
800 struct usb_hub *hub = usb_get_intfdata (intf);
801 struct usb_device *hdev;
803 /* Disconnect all children and quiesce the hub */
804 hub->error = 0;
805 hub_pre_reset(intf);
807 usb_set_intfdata (intf, NULL);
808 hdev = hub->hdev;
810 if (hdev->speed == USB_SPEED_HIGH)
811 highspeed_hubs--;
813 usb_free_urb(hub->urb);
814 hub->urb = NULL;
816 spin_lock_irq(&hub_event_lock);
817 list_del_init(&hub->event_list);
818 spin_unlock_irq(&hub_event_lock);
820 kfree(hub->descriptor);
821 hub->descriptor = NULL;
823 kfree(hub->status);
824 hub->status = NULL;
826 if (hub->buffer) {
827 usb_buffer_free(hdev, sizeof(*hub->buffer), hub->buffer,
828 hub->buffer_dma);
829 hub->buffer = NULL;
832 kfree(hub);
835 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
837 struct usb_host_interface *desc;
838 struct usb_endpoint_descriptor *endpoint;
839 struct usb_device *hdev;
840 struct usb_hub *hub;
842 desc = intf->cur_altsetting;
843 hdev = interface_to_usbdev(intf);
845 #ifdef CONFIG_USB_OTG_BLACKLIST_HUB
846 if (hdev->parent) {
847 dev_warn(&intf->dev, "ignoring external hub\n");
848 return -ENODEV;
850 #endif
852 /* Some hubs have a subclass of 1, which AFAICT according to the */
853 /* specs is not defined, but it works */
854 if ((desc->desc.bInterfaceSubClass != 0) &&
855 (desc->desc.bInterfaceSubClass != 1)) {
856 descriptor_error:
857 dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
858 return -EIO;
861 /* Multiple endpoints? What kind of mutant ninja-hub is this? */
862 if (desc->desc.bNumEndpoints != 1)
863 goto descriptor_error;
865 endpoint = &desc->endpoint[0].desc;
867 /* If it's not an interrupt in endpoint, we'd better punt! */
868 if (!usb_endpoint_is_int_in(endpoint))
869 goto descriptor_error;
871 /* We found a hub */
872 dev_info (&intf->dev, "USB hub found\n");
874 hub = kzalloc(sizeof(*hub), GFP_KERNEL);
875 if (!hub) {
876 dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
877 return -ENOMEM;
880 INIT_LIST_HEAD(&hub->event_list);
881 hub->intfdev = &intf->dev;
882 hub->hdev = hdev;
883 INIT_WORK(&hub->leds, led_work, hub);
885 usb_set_intfdata (intf, hub);
887 if (hdev->speed == USB_SPEED_HIGH)
888 highspeed_hubs++;
890 if (hub_configure(hub, endpoint) >= 0)
891 return 0;
893 hub_disconnect (intf);
894 return -ENODEV;
897 static int
898 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
900 struct usb_device *hdev = interface_to_usbdev (intf);
902 /* assert ifno == 0 (part of hub spec) */
903 switch (code) {
904 case USBDEVFS_HUB_PORTINFO: {
905 struct usbdevfs_hub_portinfo *info = user_data;
906 int i;
908 spin_lock_irq(&device_state_lock);
909 if (hdev->devnum <= 0)
910 info->nports = 0;
911 else {
912 info->nports = hdev->maxchild;
913 for (i = 0; i < info->nports; i++) {
914 if (hdev->children[i] == NULL)
915 info->port[i] = 0;
916 else
917 info->port[i] =
918 hdev->children[i]->devnum;
921 spin_unlock_irq(&device_state_lock);
923 return info->nports + 1;
926 default:
927 return -ENOSYS;
932 /* grab device/port lock, returning index of that port (zero based).
933 * protects the upstream link used by this device from concurrent
934 * tree operations like suspend, resume, reset, and disconnect, which
935 * apply to everything downstream of a given port.
937 static int locktree(struct usb_device *udev)
939 int t;
940 struct usb_device *hdev;
942 if (!udev)
943 return -ENODEV;
945 /* root hub is always the first lock in the series */
946 hdev = udev->parent;
947 if (!hdev) {
948 usb_lock_device(udev);
949 return 0;
952 /* on the path from root to us, lock everything from
953 * top down, dropping parent locks when not needed
955 t = locktree(hdev);
956 if (t < 0)
957 return t;
959 /* everything is fail-fast once disconnect
960 * processing starts
962 if (udev->state == USB_STATE_NOTATTACHED) {
963 usb_unlock_device(hdev);
964 return -ENODEV;
967 /* when everyone grabs locks top->bottom,
968 * non-overlapping work may be concurrent
970 usb_lock_device(udev);
971 usb_unlock_device(hdev);
972 return udev->portnum;
975 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
977 int i;
979 for (i = 0; i < udev->maxchild; ++i) {
980 if (udev->children[i])
981 recursively_mark_NOTATTACHED(udev->children[i]);
983 udev->state = USB_STATE_NOTATTACHED;
987 * usb_set_device_state - change a device's current state (usbcore, hcds)
988 * @udev: pointer to device whose state should be changed
989 * @new_state: new state value to be stored
991 * udev->state is _not_ fully protected by the device lock. Although
992 * most transitions are made only while holding the lock, the state can
993 * can change to USB_STATE_NOTATTACHED at almost any time. This
994 * is so that devices can be marked as disconnected as soon as possible,
995 * without having to wait for any semaphores to be released. As a result,
996 * all changes to any device's state must be protected by the
997 * device_state_lock spinlock.
999 * Once a device has been added to the device tree, all changes to its state
1000 * should be made using this routine. The state should _not_ be set directly.
1002 * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1003 * Otherwise udev->state is set to new_state, and if new_state is
1004 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1005 * to USB_STATE_NOTATTACHED.
1007 void usb_set_device_state(struct usb_device *udev,
1008 enum usb_device_state new_state)
1010 unsigned long flags;
1012 spin_lock_irqsave(&device_state_lock, flags);
1013 if (udev->state == USB_STATE_NOTATTACHED)
1014 ; /* do nothing */
1015 else if (new_state != USB_STATE_NOTATTACHED) {
1017 /* root hub wakeup capabilities are managed out-of-band
1018 * and may involve silicon errata ... ignore them here.
1020 if (udev->parent) {
1021 if (udev->state == USB_STATE_SUSPENDED
1022 || new_state == USB_STATE_SUSPENDED)
1023 ; /* No change to wakeup settings */
1024 else if (new_state == USB_STATE_CONFIGURED)
1025 device_init_wakeup(&udev->dev,
1026 (udev->actconfig->desc.bmAttributes
1027 & USB_CONFIG_ATT_WAKEUP));
1028 else
1029 device_init_wakeup(&udev->dev, 0);
1031 udev->state = new_state;
1032 } else
1033 recursively_mark_NOTATTACHED(udev);
1034 spin_unlock_irqrestore(&device_state_lock, flags);
1038 #ifdef CONFIG_PM
1041 * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
1042 * @rhdev: struct usb_device for the root hub
1044 * The USB host controller driver calls this function when its root hub
1045 * is resumed and Vbus power has been interrupted or the controller
1046 * has been reset. The routine marks all the children of the root hub
1047 * as NOTATTACHED and marks logical connect-change events on their ports.
1049 void usb_root_hub_lost_power(struct usb_device *rhdev)
1051 struct usb_hub *hub;
1052 int port1;
1053 unsigned long flags;
1055 dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
1057 /* Make sure no potential wakeup events get lost,
1058 * by forcing the root hub to be resumed.
1060 rhdev->dev.power.prev_state.event = PM_EVENT_ON;
1062 spin_lock_irqsave(&device_state_lock, flags);
1063 hub = hdev_to_hub(rhdev);
1064 for (port1 = 1; port1 <= rhdev->maxchild; ++port1) {
1065 if (rhdev->children[port1 - 1]) {
1066 recursively_mark_NOTATTACHED(
1067 rhdev->children[port1 - 1]);
1068 set_bit(port1, hub->change_bits);
1071 spin_unlock_irqrestore(&device_state_lock, flags);
1073 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
1075 #endif /* CONFIG_PM */
1077 static void choose_address(struct usb_device *udev)
1079 int devnum;
1080 struct usb_bus *bus = udev->bus;
1082 /* If khubd ever becomes multithreaded, this will need a lock */
1084 /* Try to allocate the next devnum beginning at bus->devnum_next. */
1085 devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1086 bus->devnum_next);
1087 if (devnum >= 128)
1088 devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
1090 bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1092 if (devnum < 128) {
1093 set_bit(devnum, bus->devmap.devicemap);
1094 udev->devnum = devnum;
1098 static void release_address(struct usb_device *udev)
1100 if (udev->devnum > 0) {
1101 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1102 udev->devnum = -1;
1107 * usb_disconnect - disconnect a device (usbcore-internal)
1108 * @pdev: pointer to device being disconnected
1109 * Context: !in_interrupt ()
1111 * Something got disconnected. Get rid of it and all of its children.
1113 * If *pdev is a normal device then the parent hub must already be locked.
1114 * If *pdev is a root hub then this routine will acquire the
1115 * usb_bus_list_lock on behalf of the caller.
1117 * Only hub drivers (including virtual root hub drivers for host
1118 * controllers) should ever call this.
1120 * This call is synchronous, and may not be used in an interrupt context.
1122 void usb_disconnect(struct usb_device **pdev)
1124 struct usb_device *udev = *pdev;
1125 int i;
1127 if (!udev) {
1128 pr_debug ("%s nodev\n", __FUNCTION__);
1129 return;
1132 /* mark the device as inactive, so any further urb submissions for
1133 * this device (and any of its children) will fail immediately.
1134 * this quiesces everyting except pending urbs.
1136 usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1137 dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1139 usb_lock_device(udev);
1141 /* Free up all the children before we remove this device */
1142 for (i = 0; i < USB_MAXCHILDREN; i++) {
1143 if (udev->children[i])
1144 usb_disconnect(&udev->children[i]);
1147 /* deallocate hcd/hardware state ... nuking all pending urbs and
1148 * cleaning up all state associated with the current configuration
1149 * so that the hardware is now fully quiesced.
1151 dev_dbg (&udev->dev, "unregistering device\n");
1152 usb_disable_device(udev, 0);
1154 usb_unlock_device(udev);
1156 /* Unregister the device. The device driver is responsible
1157 * for removing the device files from usbfs and sysfs and for
1158 * de-configuring the device.
1160 device_del(&udev->dev);
1162 /* Free the device number and delete the parent's children[]
1163 * (or root_hub) pointer.
1165 release_address(udev);
1167 /* Avoid races with recursively_mark_NOTATTACHED() */
1168 spin_lock_irq(&device_state_lock);
1169 *pdev = NULL;
1170 spin_unlock_irq(&device_state_lock);
1172 put_device(&udev->dev);
1175 #ifdef DEBUG
1176 static void show_string(struct usb_device *udev, char *id, char *string)
1178 if (!string)
1179 return;
1180 dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1183 #else
1184 static inline void show_string(struct usb_device *udev, char *id, char *string)
1186 #endif
1189 #ifdef CONFIG_USB_OTG
1190 #include "otg_whitelist.h"
1191 static int __usb_port_suspend(struct usb_device *, int port1);
1192 #endif
1195 * usb_new_device - perform initial device setup (usbcore-internal)
1196 * @udev: newly addressed device (in ADDRESS state)
1198 * This is called with devices which have been enumerated, but not yet
1199 * configured. The device descriptor is available, but not descriptors
1200 * for any device configuration. The caller must have locked either
1201 * the parent hub (if udev is a normal device) or else the
1202 * usb_bus_list_lock (if udev is a root hub). The parent's pointer to
1203 * udev has already been installed, but udev is not yet visible through
1204 * sysfs or other filesystem code.
1206 * Returns 0 for success (device is configured and listed, with its
1207 * interfaces, in sysfs); else a negative errno value.
1209 * This call is synchronous, and may not be used in an interrupt context.
1211 * Only the hub driver or root-hub registrar should ever call this.
1213 int usb_new_device(struct usb_device *udev)
1215 int err;
1217 err = usb_get_configuration(udev);
1218 if (err < 0) {
1219 dev_err(&udev->dev, "can't read configurations, error %d\n",
1220 err);
1221 goto fail;
1224 /* read the standard strings and cache them if present */
1225 udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
1226 udev->manufacturer = usb_cache_string(udev,
1227 udev->descriptor.iManufacturer);
1228 udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
1230 /* Tell the world! */
1231 dev_dbg(&udev->dev, "new device strings: Mfr=%d, Product=%d, "
1232 "SerialNumber=%d\n",
1233 udev->descriptor.iManufacturer,
1234 udev->descriptor.iProduct,
1235 udev->descriptor.iSerialNumber);
1236 show_string(udev, "Product", udev->product);
1237 show_string(udev, "Manufacturer", udev->manufacturer);
1238 show_string(udev, "SerialNumber", udev->serial);
1240 #ifdef CONFIG_USB_OTG
1242 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1243 * to wake us after we've powered off VBUS; and HNP, switching roles
1244 * "host" to "peripheral". The OTG descriptor helps figure this out.
1246 if (!udev->bus->is_b_host
1247 && udev->config
1248 && udev->parent == udev->bus->root_hub) {
1249 struct usb_otg_descriptor *desc = 0;
1250 struct usb_bus *bus = udev->bus;
1252 /* descriptor may appear anywhere in config */
1253 if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1254 le16_to_cpu(udev->config[0].desc.wTotalLength),
1255 USB_DT_OTG, (void **) &desc) == 0) {
1256 if (desc->bmAttributes & USB_OTG_HNP) {
1257 unsigned port1 = udev->portnum;
1259 dev_info(&udev->dev,
1260 "Dual-Role OTG device on %sHNP port\n",
1261 (port1 == bus->otg_port)
1262 ? "" : "non-");
1264 /* enable HNP before suspend, it's simpler */
1265 if (port1 == bus->otg_port)
1266 bus->b_hnp_enable = 1;
1267 err = usb_control_msg(udev,
1268 usb_sndctrlpipe(udev, 0),
1269 USB_REQ_SET_FEATURE, 0,
1270 bus->b_hnp_enable
1271 ? USB_DEVICE_B_HNP_ENABLE
1272 : USB_DEVICE_A_ALT_HNP_SUPPORT,
1273 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1274 if (err < 0) {
1275 /* OTG MESSAGE: report errors here,
1276 * customize to match your product.
1278 dev_info(&udev->dev,
1279 "can't set HNP mode; %d\n",
1280 err);
1281 bus->b_hnp_enable = 0;
1287 if (!is_targeted(udev)) {
1289 /* Maybe it can talk to us, though we can't talk to it.
1290 * (Includes HNP test device.)
1292 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1293 err = __usb_port_suspend(udev, udev->bus->otg_port);
1294 if (err < 0)
1295 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1297 err = -ENODEV;
1298 goto fail;
1300 #endif
1302 /* Register the device. The device driver is responsible
1303 * for adding the device files to usbfs and sysfs and for
1304 * configuring the device.
1306 err = device_add (&udev->dev);
1307 if (err) {
1308 dev_err(&udev->dev, "can't device_add, error %d\n", err);
1309 goto fail;
1312 return 0;
1314 fail:
1315 usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1316 return err;
1320 static int hub_port_status(struct usb_hub *hub, int port1,
1321 u16 *status, u16 *change)
1323 int ret;
1325 ret = get_port_status(hub->hdev, port1, &hub->status->port);
1326 if (ret < 0)
1327 dev_err (hub->intfdev,
1328 "%s failed (err = %d)\n", __FUNCTION__, ret);
1329 else {
1330 *status = le16_to_cpu(hub->status->port.wPortStatus);
1331 *change = le16_to_cpu(hub->status->port.wPortChange);
1332 ret = 0;
1334 return ret;
1338 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
1339 static unsigned hub_is_wusb(struct usb_hub *hub)
1341 struct usb_hcd *hcd;
1342 if (hub->hdev->parent != NULL) /* not a root hub? */
1343 return 0;
1344 hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
1345 return hcd->wireless;
1349 #define PORT_RESET_TRIES 5
1350 #define SET_ADDRESS_TRIES 2
1351 #define GET_DESCRIPTOR_TRIES 2
1352 #define SET_CONFIG_TRIES (2 * (use_both_schemes + 1))
1353 #define USE_NEW_SCHEME(i) ((i) / 2 == old_scheme_first)
1355 #define HUB_ROOT_RESET_TIME 50 /* times are in msec */
1356 #define HUB_SHORT_RESET_TIME 10
1357 #define HUB_LONG_RESET_TIME 200
1358 #define HUB_RESET_TIMEOUT 500
1360 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1361 struct usb_device *udev, unsigned int delay)
1363 int delay_time, ret;
1364 u16 portstatus;
1365 u16 portchange;
1367 for (delay_time = 0;
1368 delay_time < HUB_RESET_TIMEOUT;
1369 delay_time += delay) {
1370 /* wait to give the device a chance to reset */
1371 msleep(delay);
1373 /* read and decode port status */
1374 ret = hub_port_status(hub, port1, &portstatus, &portchange);
1375 if (ret < 0)
1376 return ret;
1378 /* Device went away? */
1379 if (!(portstatus & USB_PORT_STAT_CONNECTION))
1380 return -ENOTCONN;
1382 /* bomb out completely if something weird happened */
1383 if ((portchange & USB_PORT_STAT_C_CONNECTION))
1384 return -EINVAL;
1386 /* if we`ve finished resetting, then break out of the loop */
1387 if (!(portstatus & USB_PORT_STAT_RESET) &&
1388 (portstatus & USB_PORT_STAT_ENABLE)) {
1389 if (hub_is_wusb(hub))
1390 udev->speed = USB_SPEED_VARIABLE;
1391 else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1392 udev->speed = USB_SPEED_HIGH;
1393 else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1394 udev->speed = USB_SPEED_LOW;
1395 else
1396 udev->speed = USB_SPEED_FULL;
1397 return 0;
1400 /* switch to the long delay after two short delay failures */
1401 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1402 delay = HUB_LONG_RESET_TIME;
1404 dev_dbg (hub->intfdev,
1405 "port %d not reset yet, waiting %dms\n",
1406 port1, delay);
1409 return -EBUSY;
1412 static int hub_port_reset(struct usb_hub *hub, int port1,
1413 struct usb_device *udev, unsigned int delay)
1415 int i, status;
1417 /* Reset the port */
1418 for (i = 0; i < PORT_RESET_TRIES; i++) {
1419 status = set_port_feature(hub->hdev,
1420 port1, USB_PORT_FEAT_RESET);
1421 if (status)
1422 dev_err(hub->intfdev,
1423 "cannot reset port %d (err = %d)\n",
1424 port1, status);
1425 else {
1426 status = hub_port_wait_reset(hub, port1, udev, delay);
1427 if (status && status != -ENOTCONN)
1428 dev_dbg(hub->intfdev,
1429 "port_wait_reset: err = %d\n",
1430 status);
1433 /* return on disconnect or reset */
1434 switch (status) {
1435 case 0:
1436 /* TRSTRCY = 10 ms; plus some extra */
1437 msleep(10 + 40);
1438 /* FALL THROUGH */
1439 case -ENOTCONN:
1440 case -ENODEV:
1441 clear_port_feature(hub->hdev,
1442 port1, USB_PORT_FEAT_C_RESET);
1443 /* FIXME need disconnect() for NOTATTACHED device */
1444 usb_set_device_state(udev, status
1445 ? USB_STATE_NOTATTACHED
1446 : USB_STATE_DEFAULT);
1447 return status;
1450 dev_dbg (hub->intfdev,
1451 "port %d not enabled, trying reset again...\n",
1452 port1);
1453 delay = HUB_LONG_RESET_TIME;
1456 dev_err (hub->intfdev,
1457 "Cannot enable port %i. Maybe the USB cable is bad?\n",
1458 port1);
1460 return status;
1464 * Disable a port and mark a logical connnect-change event, so that some
1465 * time later khubd will disconnect() any existing usb_device on the port
1466 * and will re-enumerate if there actually is a device attached.
1468 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
1470 dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
1471 hub_port_disable(hub, port1, 1);
1473 /* FIXME let caller ask to power down the port:
1474 * - some devices won't enumerate without a VBUS power cycle
1475 * - SRP saves power that way
1476 * - ... new call, TBD ...
1477 * That's easy if this hub can switch power per-port, and
1478 * khubd reactivates the port later (timer, SRP, etc).
1479 * Powerdown must be optional, because of reset/DFU.
1482 set_bit(port1, hub->change_bits);
1483 kick_khubd(hub);
1486 #ifdef CONFIG_PM
1488 #ifdef CONFIG_USB_SUSPEND
1491 * Selective port suspend reduces power; most suspended devices draw
1492 * less than 500 uA. It's also used in OTG, along with remote wakeup.
1493 * All devices below the suspended port are also suspended.
1495 * Devices leave suspend state when the host wakes them up. Some devices
1496 * also support "remote wakeup", where the device can activate the USB
1497 * tree above them to deliver data, such as a keypress or packet. In
1498 * some cases, this wakes the USB host.
1500 static int hub_port_suspend(struct usb_hub *hub, int port1,
1501 struct usb_device *udev)
1503 int status;
1505 // dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1507 /* enable remote wakeup when appropriate; this lets the device
1508 * wake up the upstream hub (including maybe the root hub).
1510 * NOTE: OTG devices may issue remote wakeup (or SRP) even when
1511 * we don't explicitly enable it here.
1513 if (udev->do_remote_wakeup) {
1514 status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1515 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1516 USB_DEVICE_REMOTE_WAKEUP, 0,
1517 NULL, 0,
1518 USB_CTRL_SET_TIMEOUT);
1519 if (status)
1520 dev_dbg(&udev->dev,
1521 "won't remote wakeup, status %d\n",
1522 status);
1525 /* see 7.1.7.6 */
1526 status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1527 if (status) {
1528 dev_dbg(hub->intfdev,
1529 "can't suspend port %d, status %d\n",
1530 port1, status);
1531 /* paranoia: "should not happen" */
1532 (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1533 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1534 USB_DEVICE_REMOTE_WAKEUP, 0,
1535 NULL, 0,
1536 USB_CTRL_SET_TIMEOUT);
1537 } else {
1538 /* device has up to 10 msec to fully suspend */
1539 dev_dbg(&udev->dev, "usb %ssuspend\n",
1540 udev->auto_pm ? "auto-" : "");
1541 usb_set_device_state(udev, USB_STATE_SUSPENDED);
1542 msleep(10);
1544 return status;
1548 * Devices on USB hub ports have only one "suspend" state, corresponding
1549 * to ACPI D2, "may cause the device to lose some context".
1550 * State transitions include:
1552 * - suspend, resume ... when the VBUS power link stays live
1553 * - suspend, disconnect ... VBUS lost
1555 * Once VBUS drop breaks the circuit, the port it's using has to go through
1556 * normal re-enumeration procedures, starting with enabling VBUS power.
1557 * Other than re-initializing the hub (plug/unplug, except for root hubs),
1558 * Linux (2.6) currently has NO mechanisms to initiate that: no khubd
1559 * timer, no SRP, no requests through sysfs.
1561 * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
1562 * the root hub for their bus goes into global suspend ... so we don't
1563 * (falsely) update the device power state to say it suspended.
1565 static int __usb_port_suspend (struct usb_device *udev, int port1)
1567 int status = 0;
1569 /* caller owns the udev device lock */
1570 if (port1 < 0)
1571 return port1;
1573 /* we change the device's upstream USB link,
1574 * but root hubs have no upstream USB link.
1576 if (udev->parent)
1577 status = hub_port_suspend(hdev_to_hub(udev->parent), port1,
1578 udev);
1579 else {
1580 dev_dbg(&udev->dev, "usb %ssuspend\n",
1581 udev->auto_pm ? "auto-" : "");
1582 usb_set_device_state(udev, USB_STATE_SUSPENDED);
1584 return status;
1588 * usb_port_suspend - suspend a usb device's upstream port
1589 * @udev: device that's no longer in active use
1590 * Context: must be able to sleep; device not locked; pm locks held
1592 * Suspends a USB device that isn't in active use, conserving power.
1593 * Devices may wake out of a suspend, if anything important happens,
1594 * using the remote wakeup mechanism. They may also be taken out of
1595 * suspend by the host, using usb_port_resume(). It's also routine
1596 * to disconnect devices while they are suspended.
1598 * This only affects the USB hardware for a device; its interfaces
1599 * (and, for hubs, child devices) must already have been suspended.
1601 * Suspending OTG devices may trigger HNP, if that's been enabled
1602 * between a pair of dual-role devices. That will change roles, such
1603 * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1605 * Returns 0 on success, else negative errno.
1607 int usb_port_suspend(struct usb_device *udev)
1609 return __usb_port_suspend(udev, udev->portnum);
1613 * If the USB "suspend" state is in use (rather than "global suspend"),
1614 * many devices will be individually taken out of suspend state using
1615 * special" resume" signaling. These routines kick in shortly after
1616 * hardware resume signaling is finished, either because of selective
1617 * resume (by host) or remote wakeup (by device) ... now see what changed
1618 * in the tree that's rooted at this device.
1620 static int finish_port_resume(struct usb_device *udev)
1622 int status;
1623 u16 devstatus;
1625 /* caller owns the udev device lock */
1626 dev_dbg(&udev->dev, "finish resume\n");
1628 /* usb ch9 identifies four variants of SUSPENDED, based on what
1629 * state the device resumes to. Linux currently won't see the
1630 * first two on the host side; they'd be inside hub_port_init()
1631 * during many timeouts, but khubd can't suspend until later.
1633 usb_set_device_state(udev, udev->actconfig
1634 ? USB_STATE_CONFIGURED
1635 : USB_STATE_ADDRESS);
1637 /* 10.5.4.5 says be sure devices in the tree are still there.
1638 * For now let's assume the device didn't go crazy on resume,
1639 * and device drivers will know about any resume quirks.
1641 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1642 if (status >= 0)
1643 status = (status == 2 ? 0 : -ENODEV);
1645 if (status)
1646 dev_dbg(&udev->dev,
1647 "gone after usb resume? status %d\n",
1648 status);
1649 else if (udev->actconfig) {
1650 le16_to_cpus(&devstatus);
1651 if ((devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
1652 && udev->parent) {
1653 status = usb_control_msg(udev,
1654 usb_sndctrlpipe(udev, 0),
1655 USB_REQ_CLEAR_FEATURE,
1656 USB_RECIP_DEVICE,
1657 USB_DEVICE_REMOTE_WAKEUP, 0,
1658 NULL, 0,
1659 USB_CTRL_SET_TIMEOUT);
1660 if (status)
1661 dev_dbg(&udev->dev, "disable remote "
1662 "wakeup, status %d\n", status);
1664 status = 0;
1666 } else if (udev->devnum <= 0) {
1667 dev_dbg(&udev->dev, "bogus resume!\n");
1668 status = -EINVAL;
1670 return status;
1673 static int
1674 hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
1676 int status;
1678 // dev_dbg(hub->intfdev, "resume port %d\n", port1);
1680 set_bit(port1, hub->busy_bits);
1682 /* see 7.1.7.7; affects power usage, but not budgeting */
1683 status = clear_port_feature(hub->hdev,
1684 port1, USB_PORT_FEAT_SUSPEND);
1685 if (status) {
1686 dev_dbg(hub->intfdev,
1687 "can't resume port %d, status %d\n",
1688 port1, status);
1689 } else {
1690 u16 devstatus;
1691 u16 portchange;
1693 /* drive resume for at least 20 msec */
1694 if (udev)
1695 dev_dbg(&udev->dev, "usb %sresume\n",
1696 udev->auto_pm ? "auto-" : "");
1697 msleep(25);
1699 #define LIVE_FLAGS ( USB_PORT_STAT_POWER \
1700 | USB_PORT_STAT_ENABLE \
1701 | USB_PORT_STAT_CONNECTION)
1703 /* Virtual root hubs can trigger on GET_PORT_STATUS to
1704 * stop resume signaling. Then finish the resume
1705 * sequence.
1707 devstatus = portchange = 0;
1708 status = hub_port_status(hub, port1,
1709 &devstatus, &portchange);
1710 if (status < 0
1711 || (devstatus & LIVE_FLAGS) != LIVE_FLAGS
1712 || (devstatus & USB_PORT_STAT_SUSPEND) != 0
1714 dev_dbg(hub->intfdev,
1715 "port %d status %04x.%04x after resume, %d\n",
1716 port1, portchange, devstatus, status);
1717 if (status >= 0)
1718 status = -ENODEV;
1719 } else {
1720 if (portchange & USB_PORT_STAT_C_SUSPEND)
1721 clear_port_feature(hub->hdev, port1,
1722 USB_PORT_FEAT_C_SUSPEND);
1723 /* TRSMRCY = 10 msec */
1724 msleep(10);
1725 if (udev)
1726 status = finish_port_resume(udev);
1729 if (status < 0)
1730 hub_port_logical_disconnect(hub, port1);
1732 clear_bit(port1, hub->busy_bits);
1733 if (!hub->hdev->parent && !hub->busy_bits[0])
1734 usb_enable_root_hub_irq(hub->hdev->bus);
1736 return status;
1740 * usb_port_resume - re-activate a suspended usb device's upstream port
1741 * @udev: device to re-activate
1742 * Context: must be able to sleep; device not locked; pm locks held
1744 * This will re-activate the suspended device, increasing power usage
1745 * while letting drivers communicate again with its endpoints.
1746 * USB resume explicitly guarantees that the power session between
1747 * the host and the device is the same as it was when the device
1748 * suspended.
1750 * Returns 0 on success, else negative errno.
1752 int usb_port_resume(struct usb_device *udev)
1754 int status;
1756 /* we change the device's upstream USB link,
1757 * but root hubs have no upstream USB link.
1759 if (udev->parent) {
1760 // NOTE this fails if parent is also suspended...
1761 status = hub_port_resume(hdev_to_hub(udev->parent),
1762 udev->portnum, udev);
1763 } else {
1764 dev_dbg(&udev->dev, "usb %sresume\n",
1765 udev->auto_pm ? "auto-" : "");
1766 status = finish_port_resume(udev);
1768 if (status < 0)
1769 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
1770 return status;
1773 static int remote_wakeup(struct usb_device *udev)
1775 int status = 0;
1777 /* All this just to avoid sending a port-resume message
1778 * to the parent hub! */
1780 usb_lock_device(udev);
1781 usb_pm_lock(udev);
1782 if (udev->state == USB_STATE_SUSPENDED) {
1783 dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
1784 /* TRSMRCY = 10 msec */
1785 msleep(10);
1786 status = finish_port_resume(udev);
1787 if (status == 0)
1788 udev->dev.power.power_state.event = PM_EVENT_ON;
1790 usb_pm_unlock(udev);
1792 if (status == 0)
1793 usb_autoresume_device(udev, 0);
1794 usb_unlock_device(udev);
1795 return status;
1798 #else /* CONFIG_USB_SUSPEND */
1800 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
1802 int usb_port_suspend(struct usb_device *udev)
1804 return 0;
1807 static inline int
1808 finish_port_resume(struct usb_device *udev)
1810 return 0;
1813 static inline int
1814 hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
1816 return 0;
1819 int usb_port_resume(struct usb_device *udev)
1821 return 0;
1824 static inline int remote_wakeup(struct usb_device *udev)
1826 return 0;
1829 #endif
1831 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
1833 struct usb_hub *hub = usb_get_intfdata (intf);
1834 struct usb_device *hdev = hub->hdev;
1835 unsigned port1;
1837 /* fail if children aren't already suspended */
1838 for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1839 struct usb_device *udev;
1841 udev = hdev->children [port1-1];
1842 if (udev && msg.event == PM_EVENT_SUSPEND &&
1843 #ifdef CONFIG_USB_SUSPEND
1844 udev->state != USB_STATE_SUSPENDED
1845 #else
1846 udev->dev.power.power_state.event
1847 == PM_EVENT_ON
1848 #endif
1850 if (!hdev->auto_pm)
1851 dev_dbg(&intf->dev, "port %d nyet suspended\n",
1852 port1);
1853 return -EBUSY;
1857 /* "global suspend" of the downstream HC-to-USB interface */
1858 if (!hdev->parent) {
1859 struct usb_bus *bus = hdev->bus;
1860 if (bus) {
1861 int status = hcd_bus_suspend (bus);
1863 if (status != 0) {
1864 dev_dbg(&hdev->dev, "'global' suspend %d\n",
1865 status);
1866 return status;
1868 } else
1869 return -EOPNOTSUPP;
1872 /* stop khubd and related activity */
1873 hub_quiesce(hub);
1874 return 0;
1877 static int hub_resume(struct usb_interface *intf)
1879 struct usb_device *hdev = interface_to_usbdev(intf);
1880 struct usb_hub *hub = usb_get_intfdata (intf);
1881 int status;
1883 /* "global resume" of the downstream HC-to-USB interface */
1884 if (!hdev->parent) {
1885 struct usb_bus *bus = hdev->bus;
1886 if (bus) {
1887 status = hcd_bus_resume (bus);
1888 if (status) {
1889 dev_dbg(&intf->dev, "'global' resume %d\n",
1890 status);
1891 return status;
1893 } else
1894 return -EOPNOTSUPP;
1895 if (status == 0) {
1896 /* TRSMRCY = 10 msec */
1897 msleep(10);
1901 /* tell khubd to look for changes on this hub */
1902 hub_activate(hub);
1903 return 0;
1906 #else /* CONFIG_PM */
1908 static inline int remote_wakeup(struct usb_device *udev)
1910 return 0;
1913 #define hub_suspend NULL
1914 #define hub_resume NULL
1915 #endif
1917 void usb_resume_root_hub(struct usb_device *hdev)
1919 struct usb_hub *hub = hdev_to_hub(hdev);
1921 hub->resume_root_hub = 1;
1922 kick_khubd(hub);
1926 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
1928 * Between connect detection and reset signaling there must be a delay
1929 * of 100ms at least for debounce and power-settling. The corresponding
1930 * timer shall restart whenever the downstream port detects a disconnect.
1932 * Apparently there are some bluetooth and irda-dongles and a number of
1933 * low-speed devices for which this debounce period may last over a second.
1934 * Not covered by the spec - but easy to deal with.
1936 * This implementation uses a 1500ms total debounce timeout; if the
1937 * connection isn't stable by then it returns -ETIMEDOUT. It checks
1938 * every 25ms for transient disconnects. When the port status has been
1939 * unchanged for 100ms it returns the port status.
1942 #define HUB_DEBOUNCE_TIMEOUT 1500
1943 #define HUB_DEBOUNCE_STEP 25
1944 #define HUB_DEBOUNCE_STABLE 100
1946 static int hub_port_debounce(struct usb_hub *hub, int port1)
1948 int ret;
1949 int total_time, stable_time = 0;
1950 u16 portchange, portstatus;
1951 unsigned connection = 0xffff;
1953 for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
1954 ret = hub_port_status(hub, port1, &portstatus, &portchange);
1955 if (ret < 0)
1956 return ret;
1958 if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
1959 (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
1960 stable_time += HUB_DEBOUNCE_STEP;
1961 if (stable_time >= HUB_DEBOUNCE_STABLE)
1962 break;
1963 } else {
1964 stable_time = 0;
1965 connection = portstatus & USB_PORT_STAT_CONNECTION;
1968 if (portchange & USB_PORT_STAT_C_CONNECTION) {
1969 clear_port_feature(hub->hdev, port1,
1970 USB_PORT_FEAT_C_CONNECTION);
1973 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
1974 break;
1975 msleep(HUB_DEBOUNCE_STEP);
1978 dev_dbg (hub->intfdev,
1979 "debounce: port %d: total %dms stable %dms status 0x%x\n",
1980 port1, total_time, stable_time, portstatus);
1982 if (stable_time < HUB_DEBOUNCE_STABLE)
1983 return -ETIMEDOUT;
1984 return portstatus;
1987 static void ep0_reinit(struct usb_device *udev)
1989 usb_disable_endpoint(udev, 0 + USB_DIR_IN);
1990 usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
1991 udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
1994 #define usb_sndaddr0pipe() (PIPE_CONTROL << 30)
1995 #define usb_rcvaddr0pipe() ((PIPE_CONTROL << 30) | USB_DIR_IN)
1997 static int hub_set_address(struct usb_device *udev)
1999 int retval;
2001 if (udev->devnum == 0)
2002 return -EINVAL;
2003 if (udev->state == USB_STATE_ADDRESS)
2004 return 0;
2005 if (udev->state != USB_STATE_DEFAULT)
2006 return -EINVAL;
2007 retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2008 USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
2009 NULL, 0, USB_CTRL_SET_TIMEOUT);
2010 if (retval == 0) {
2011 usb_set_device_state(udev, USB_STATE_ADDRESS);
2012 ep0_reinit(udev);
2014 return retval;
2017 /* Reset device, (re)assign address, get device descriptor.
2018 * Device connection must be stable, no more debouncing needed.
2019 * Returns device in USB_STATE_ADDRESS, except on error.
2021 * If this is called for an already-existing device (as part of
2022 * usb_reset_device), the caller must own the device lock. For a
2023 * newly detected device that is not accessible through any global
2024 * pointers, it's not necessary to lock the device.
2026 static int
2027 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2028 int retry_counter)
2030 static DEFINE_MUTEX(usb_address0_mutex);
2032 struct usb_device *hdev = hub->hdev;
2033 int i, j, retval;
2034 unsigned delay = HUB_SHORT_RESET_TIME;
2035 enum usb_device_speed oldspeed = udev->speed;
2036 char *speed, *type;
2038 /* root hub ports have a slightly longer reset period
2039 * (from USB 2.0 spec, section 7.1.7.5)
2041 if (!hdev->parent) {
2042 delay = HUB_ROOT_RESET_TIME;
2043 if (port1 == hdev->bus->otg_port)
2044 hdev->bus->b_hnp_enable = 0;
2047 /* Some low speed devices have problems with the quick delay, so */
2048 /* be a bit pessimistic with those devices. RHbug #23670 */
2049 if (oldspeed == USB_SPEED_LOW)
2050 delay = HUB_LONG_RESET_TIME;
2052 mutex_lock(&usb_address0_mutex);
2054 /* Reset the device; full speed may morph to high speed */
2055 retval = hub_port_reset(hub, port1, udev, delay);
2056 if (retval < 0) /* error or disconnect */
2057 goto fail;
2058 /* success, speed is known */
2059 retval = -ENODEV;
2061 if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2062 dev_dbg(&udev->dev, "device reset changed speed!\n");
2063 goto fail;
2065 oldspeed = udev->speed;
2067 /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2068 * it's fixed size except for full speed devices.
2069 * For Wireless USB devices, ep0 max packet is always 512 (tho
2070 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
2072 switch (udev->speed) {
2073 case USB_SPEED_VARIABLE: /* fixed at 512 */
2074 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(512);
2075 break;
2076 case USB_SPEED_HIGH: /* fixed at 64 */
2077 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2078 break;
2079 case USB_SPEED_FULL: /* 8, 16, 32, or 64 */
2080 /* to determine the ep0 maxpacket size, try to read
2081 * the device descriptor to get bMaxPacketSize0 and
2082 * then correct our initial guess.
2084 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2085 break;
2086 case USB_SPEED_LOW: /* fixed at 8 */
2087 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2088 break;
2089 default:
2090 goto fail;
2093 type = "";
2094 switch (udev->speed) {
2095 case USB_SPEED_LOW: speed = "low"; break;
2096 case USB_SPEED_FULL: speed = "full"; break;
2097 case USB_SPEED_HIGH: speed = "high"; break;
2098 case USB_SPEED_VARIABLE:
2099 speed = "variable";
2100 type = "Wireless ";
2101 break;
2102 default: speed = "?"; break;
2104 dev_info (&udev->dev,
2105 "%s %s speed %sUSB device using %s and address %d\n",
2106 (udev->config) ? "reset" : "new", speed, type,
2107 udev->bus->controller->driver->name, udev->devnum);
2109 /* Set up TT records, if needed */
2110 if (hdev->tt) {
2111 udev->tt = hdev->tt;
2112 udev->ttport = hdev->ttport;
2113 } else if (udev->speed != USB_SPEED_HIGH
2114 && hdev->speed == USB_SPEED_HIGH) {
2115 udev->tt = &hub->tt;
2116 udev->ttport = port1;
2119 /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2120 * Because device hardware and firmware is sometimes buggy in
2121 * this area, and this is how Linux has done it for ages.
2122 * Change it cautiously.
2124 * NOTE: If USE_NEW_SCHEME() is true we will start by issuing
2125 * a 64-byte GET_DESCRIPTOR request. This is what Windows does,
2126 * so it may help with some non-standards-compliant devices.
2127 * Otherwise we start with SET_ADDRESS and then try to read the
2128 * first 8 bytes of the device descriptor to get the ep0 maxpacket
2129 * value.
2131 for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2132 if (USE_NEW_SCHEME(retry_counter)) {
2133 struct usb_device_descriptor *buf;
2134 int r = 0;
2136 #define GET_DESCRIPTOR_BUFSIZE 64
2137 buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2138 if (!buf) {
2139 retval = -ENOMEM;
2140 continue;
2143 /* Use a short timeout the first time through,
2144 * so that recalcitrant full-speed devices with
2145 * 8- or 16-byte ep0-maxpackets won't slow things
2146 * down tremendously by NAKing the unexpectedly
2147 * early status stage. Also, retry on all errors;
2148 * some devices are flakey.
2149 * 255 is for WUSB devices, we actually need to use 512.
2150 * WUSB1.0[4.8.1].
2152 for (j = 0; j < 3; ++j) {
2153 buf->bMaxPacketSize0 = 0;
2154 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2155 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2156 USB_DT_DEVICE << 8, 0,
2157 buf, GET_DESCRIPTOR_BUFSIZE,
2158 (i ? USB_CTRL_GET_TIMEOUT : 1000));
2159 switch (buf->bMaxPacketSize0) {
2160 case 8: case 16: case 32: case 64: case 255:
2161 if (buf->bDescriptorType ==
2162 USB_DT_DEVICE) {
2163 r = 0;
2164 break;
2166 /* FALL THROUGH */
2167 default:
2168 if (r == 0)
2169 r = -EPROTO;
2170 break;
2172 if (r == 0)
2173 break;
2175 udev->descriptor.bMaxPacketSize0 =
2176 buf->bMaxPacketSize0;
2177 kfree(buf);
2179 retval = hub_port_reset(hub, port1, udev, delay);
2180 if (retval < 0) /* error or disconnect */
2181 goto fail;
2182 if (oldspeed != udev->speed) {
2183 dev_dbg(&udev->dev,
2184 "device reset changed speed!\n");
2185 retval = -ENODEV;
2186 goto fail;
2188 if (r) {
2189 dev_err(&udev->dev, "device descriptor "
2190 "read/%s, error %d\n",
2191 "64", r);
2192 retval = -EMSGSIZE;
2193 continue;
2195 #undef GET_DESCRIPTOR_BUFSIZE
2198 for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2199 retval = hub_set_address(udev);
2200 if (retval >= 0)
2201 break;
2202 msleep(200);
2204 if (retval < 0) {
2205 dev_err(&udev->dev,
2206 "device not accepting address %d, error %d\n",
2207 udev->devnum, retval);
2208 goto fail;
2211 /* cope with hardware quirkiness:
2212 * - let SET_ADDRESS settle, some device hardware wants it
2213 * - read ep0 maxpacket even for high and low speed,
2215 msleep(10);
2216 if (USE_NEW_SCHEME(retry_counter))
2217 break;
2219 retval = usb_get_device_descriptor(udev, 8);
2220 if (retval < 8) {
2221 dev_err(&udev->dev, "device descriptor "
2222 "read/%s, error %d\n",
2223 "8", retval);
2224 if (retval >= 0)
2225 retval = -EMSGSIZE;
2226 } else {
2227 retval = 0;
2228 break;
2231 if (retval)
2232 goto fail;
2234 i = udev->descriptor.bMaxPacketSize0 == 0xff?
2235 512 : udev->descriptor.bMaxPacketSize0;
2236 if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2237 if (udev->speed != USB_SPEED_FULL ||
2238 !(i == 8 || i == 16 || i == 32 || i == 64)) {
2239 dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2240 retval = -EMSGSIZE;
2241 goto fail;
2243 dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2244 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2245 ep0_reinit(udev);
2248 retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2249 if (retval < (signed)sizeof(udev->descriptor)) {
2250 dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2251 "all", retval);
2252 if (retval >= 0)
2253 retval = -ENOMSG;
2254 goto fail;
2257 retval = 0;
2259 fail:
2260 if (retval)
2261 hub_port_disable(hub, port1, 0);
2262 mutex_unlock(&usb_address0_mutex);
2263 return retval;
2266 static void
2267 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2269 struct usb_qualifier_descriptor *qual;
2270 int status;
2272 qual = kmalloc (sizeof *qual, SLAB_KERNEL);
2273 if (qual == NULL)
2274 return;
2276 status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2277 qual, sizeof *qual);
2278 if (status == sizeof *qual) {
2279 dev_info(&udev->dev, "not running at top speed; "
2280 "connect to a high speed hub\n");
2281 /* hub LEDs are probably harder to miss than syslog */
2282 if (hub->has_indicators) {
2283 hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2284 schedule_work (&hub->leds);
2287 kfree(qual);
2290 static unsigned
2291 hub_power_remaining (struct usb_hub *hub)
2293 struct usb_device *hdev = hub->hdev;
2294 int remaining;
2295 int port1;
2297 if (!hub->limited_power)
2298 return 0;
2300 remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
2301 for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2302 struct usb_device *udev = hdev->children[port1 - 1];
2303 int delta;
2305 if (!udev)
2306 continue;
2308 /* Unconfigured devices may not use more than 100mA,
2309 * or 8mA for OTG ports */
2310 if (udev->actconfig)
2311 delta = udev->actconfig->desc.bMaxPower * 2;
2312 else if (port1 != udev->bus->otg_port || hdev->parent)
2313 delta = 100;
2314 else
2315 delta = 8;
2316 if (delta > hub->mA_per_port)
2317 dev_warn(&udev->dev, "%dmA is over %umA budget "
2318 "for port %d!\n",
2319 delta, hub->mA_per_port, port1);
2320 remaining -= delta;
2322 if (remaining < 0) {
2323 dev_warn(hub->intfdev, "%dmA over power budget!\n",
2324 - remaining);
2325 remaining = 0;
2327 return remaining;
2330 /* Handle physical or logical connection change events.
2331 * This routine is called when:
2332 * a port connection-change occurs;
2333 * a port enable-change occurs (often caused by EMI);
2334 * usb_reset_device() encounters changed descriptors (as from
2335 * a firmware download)
2336 * caller already locked the hub
2338 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2339 u16 portstatus, u16 portchange)
2341 struct usb_device *hdev = hub->hdev;
2342 struct device *hub_dev = hub->intfdev;
2343 u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2344 int status, i;
2346 dev_dbg (hub_dev,
2347 "port %d, status %04x, change %04x, %s\n",
2348 port1, portstatus, portchange, portspeed (portstatus));
2350 if (hub->has_indicators) {
2351 set_port_led(hub, port1, HUB_LED_AUTO);
2352 hub->indicator[port1-1] = INDICATOR_AUTO;
2355 /* Disconnect any existing devices under this port */
2356 if (hdev->children[port1-1])
2357 usb_disconnect(&hdev->children[port1-1]);
2358 clear_bit(port1, hub->change_bits);
2360 #ifdef CONFIG_USB_OTG
2361 /* during HNP, don't repeat the debounce */
2362 if (hdev->bus->is_b_host)
2363 portchange &= ~USB_PORT_STAT_C_CONNECTION;
2364 #endif
2366 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2367 status = hub_port_debounce(hub, port1);
2368 if (status < 0) {
2369 dev_err (hub_dev,
2370 "connect-debounce failed, port %d disabled\n",
2371 port1);
2372 goto done;
2374 portstatus = status;
2377 /* Return now if nothing is connected */
2378 if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2380 /* maybe switch power back on (e.g. root hub was reset) */
2381 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
2382 && !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2383 set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2385 if (portstatus & USB_PORT_STAT_ENABLE)
2386 goto done;
2387 return;
2390 #ifdef CONFIG_USB_SUSPEND
2391 /* If something is connected, but the port is suspended, wake it up. */
2392 if (portstatus & USB_PORT_STAT_SUSPEND) {
2393 status = hub_port_resume(hub, port1, NULL);
2394 if (status < 0) {
2395 dev_dbg(hub_dev,
2396 "can't clear suspend on port %d; %d\n",
2397 port1, status);
2398 goto done;
2401 #endif
2403 for (i = 0; i < SET_CONFIG_TRIES; i++) {
2404 struct usb_device *udev;
2406 /* reallocate for each attempt, since references
2407 * to the previous one can escape in various ways
2409 udev = usb_alloc_dev(hdev, hdev->bus, port1);
2410 if (!udev) {
2411 dev_err (hub_dev,
2412 "couldn't allocate port %d usb_device\n",
2413 port1);
2414 goto done;
2417 usb_set_device_state(udev, USB_STATE_POWERED);
2418 udev->speed = USB_SPEED_UNKNOWN;
2419 udev->bus_mA = hub->mA_per_port;
2420 udev->level = hdev->level + 1;
2422 /* set the address */
2423 choose_address(udev);
2424 if (udev->devnum <= 0) {
2425 status = -ENOTCONN; /* Don't retry */
2426 goto loop;
2429 /* reset and get descriptor */
2430 status = hub_port_init(hub, udev, port1, i);
2431 if (status < 0)
2432 goto loop;
2434 /* consecutive bus-powered hubs aren't reliable; they can
2435 * violate the voltage drop budget. if the new child has
2436 * a "powered" LED, users should notice we didn't enable it
2437 * (without reading syslog), even without per-port LEDs
2438 * on the parent.
2440 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2441 && udev->bus_mA <= 100) {
2442 u16 devstat;
2444 status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2445 &devstat);
2446 if (status < 2) {
2447 dev_dbg(&udev->dev, "get status %d ?\n", status);
2448 goto loop_disable;
2450 le16_to_cpus(&devstat);
2451 if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2452 dev_err(&udev->dev,
2453 "can't connect bus-powered hub "
2454 "to this port\n");
2455 if (hub->has_indicators) {
2456 hub->indicator[port1-1] =
2457 INDICATOR_AMBER_BLINK;
2458 schedule_work (&hub->leds);
2460 status = -ENOTCONN; /* Don't retry */
2461 goto loop_disable;
2465 /* check for devices running slower than they could */
2466 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2467 && udev->speed == USB_SPEED_FULL
2468 && highspeed_hubs != 0)
2469 check_highspeed (hub, udev, port1);
2471 /* Store the parent's children[] pointer. At this point
2472 * udev becomes globally accessible, although presumably
2473 * no one will look at it until hdev is unlocked.
2475 status = 0;
2477 /* We mustn't add new devices if the parent hub has
2478 * been disconnected; we would race with the
2479 * recursively_mark_NOTATTACHED() routine.
2481 spin_lock_irq(&device_state_lock);
2482 if (hdev->state == USB_STATE_NOTATTACHED)
2483 status = -ENOTCONN;
2484 else
2485 hdev->children[port1-1] = udev;
2486 spin_unlock_irq(&device_state_lock);
2488 /* Run it through the hoops (find a driver, etc) */
2489 if (!status) {
2490 status = usb_new_device(udev);
2491 if (status) {
2492 spin_lock_irq(&device_state_lock);
2493 hdev->children[port1-1] = NULL;
2494 spin_unlock_irq(&device_state_lock);
2498 if (status)
2499 goto loop_disable;
2501 status = hub_power_remaining(hub);
2502 if (status)
2503 dev_dbg(hub_dev, "%dmA power budget left\n", status);
2505 return;
2507 loop_disable:
2508 hub_port_disable(hub, port1, 1);
2509 loop:
2510 ep0_reinit(udev);
2511 release_address(udev);
2512 usb_put_dev(udev);
2513 if (status == -ENOTCONN)
2514 break;
2517 done:
2518 hub_port_disable(hub, port1, 1);
2521 static void hub_events(void)
2523 struct list_head *tmp;
2524 struct usb_device *hdev;
2525 struct usb_interface *intf;
2526 struct usb_hub *hub;
2527 struct device *hub_dev;
2528 u16 hubstatus;
2529 u16 hubchange;
2530 u16 portstatus;
2531 u16 portchange;
2532 int i, ret;
2533 int connect_change;
2536 * We restart the list every time to avoid a deadlock with
2537 * deleting hubs downstream from this one. This should be
2538 * safe since we delete the hub from the event list.
2539 * Not the most efficient, but avoids deadlocks.
2541 while (1) {
2543 /* Grab the first entry at the beginning of the list */
2544 spin_lock_irq(&hub_event_lock);
2545 if (list_empty(&hub_event_list)) {
2546 spin_unlock_irq(&hub_event_lock);
2547 break;
2550 tmp = hub_event_list.next;
2551 list_del_init(tmp);
2553 hub = list_entry(tmp, struct usb_hub, event_list);
2554 hdev = hub->hdev;
2555 intf = to_usb_interface(hub->intfdev);
2556 hub_dev = &intf->dev;
2558 i = hub->resume_root_hub;
2560 dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x%s\n",
2561 hdev->state, hub->descriptor
2562 ? hub->descriptor->bNbrPorts
2563 : 0,
2564 /* NOTE: expects max 15 ports... */
2565 (u16) hub->change_bits[0],
2566 (u16) hub->event_bits[0],
2567 i ? ", resume root" : "");
2569 usb_get_intf(intf);
2570 spin_unlock_irq(&hub_event_lock);
2572 /* Lock the device, then check to see if we were
2573 * disconnected while waiting for the lock to succeed. */
2574 if (locktree(hdev) < 0) {
2575 usb_put_intf(intf);
2576 continue;
2578 if (hub != usb_get_intfdata(intf))
2579 goto loop;
2581 /* If the hub has died, clean up after it */
2582 if (hdev->state == USB_STATE_NOTATTACHED) {
2583 hub->error = -ENODEV;
2584 hub_pre_reset(intf);
2585 goto loop;
2588 /* Is this is a root hub wanting to reactivate the downstream
2589 * ports? If so, be sure the interface resumes even if its
2590 * stub "device" node was never suspended.
2592 if (i)
2593 usb_autoresume_device(hdev, 0);
2595 /* If this is an inactive or suspended hub, do nothing */
2596 if (hub->quiescing)
2597 goto loop;
2599 if (hub->error) {
2600 dev_dbg (hub_dev, "resetting for error %d\n",
2601 hub->error);
2603 ret = usb_reset_composite_device(hdev, intf);
2604 if (ret) {
2605 dev_dbg (hub_dev,
2606 "error resetting hub: %d\n", ret);
2607 goto loop;
2610 hub->nerrors = 0;
2611 hub->error = 0;
2614 /* deal with port status changes */
2615 for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2616 if (test_bit(i, hub->busy_bits))
2617 continue;
2618 connect_change = test_bit(i, hub->change_bits);
2619 if (!test_and_clear_bit(i, hub->event_bits) &&
2620 !connect_change && !hub->activating)
2621 continue;
2623 ret = hub_port_status(hub, i,
2624 &portstatus, &portchange);
2625 if (ret < 0)
2626 continue;
2628 if (hub->activating && !hdev->children[i-1] &&
2629 (portstatus &
2630 USB_PORT_STAT_CONNECTION))
2631 connect_change = 1;
2633 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2634 clear_port_feature(hdev, i,
2635 USB_PORT_FEAT_C_CONNECTION);
2636 connect_change = 1;
2639 if (portchange & USB_PORT_STAT_C_ENABLE) {
2640 if (!connect_change)
2641 dev_dbg (hub_dev,
2642 "port %d enable change, "
2643 "status %08x\n",
2644 i, portstatus);
2645 clear_port_feature(hdev, i,
2646 USB_PORT_FEAT_C_ENABLE);
2649 * EM interference sometimes causes badly
2650 * shielded USB devices to be shutdown by
2651 * the hub, this hack enables them again.
2652 * Works at least with mouse driver.
2654 if (!(portstatus & USB_PORT_STAT_ENABLE)
2655 && !connect_change
2656 && hdev->children[i-1]) {
2657 dev_err (hub_dev,
2658 "port %i "
2659 "disabled by hub (EMI?), "
2660 "re-enabling...\n",
2662 connect_change = 1;
2666 if (portchange & USB_PORT_STAT_C_SUSPEND) {
2667 clear_port_feature(hdev, i,
2668 USB_PORT_FEAT_C_SUSPEND);
2669 if (hdev->children[i-1]) {
2670 ret = remote_wakeup(hdev->
2671 children[i-1]);
2672 if (ret < 0)
2673 connect_change = 1;
2674 } else {
2675 ret = -ENODEV;
2676 hub_port_disable(hub, i, 1);
2678 dev_dbg (hub_dev,
2679 "resume on port %d, status %d\n",
2680 i, ret);
2683 if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2684 dev_err (hub_dev,
2685 "over-current change on port %d\n",
2687 clear_port_feature(hdev, i,
2688 USB_PORT_FEAT_C_OVER_CURRENT);
2689 hub_power_on(hub);
2692 if (portchange & USB_PORT_STAT_C_RESET) {
2693 dev_dbg (hub_dev,
2694 "reset change on port %d\n",
2696 clear_port_feature(hdev, i,
2697 USB_PORT_FEAT_C_RESET);
2700 if (connect_change)
2701 hub_port_connect_change(hub, i,
2702 portstatus, portchange);
2703 } /* end for i */
2705 /* deal with hub status changes */
2706 if (test_and_clear_bit(0, hub->event_bits) == 0)
2707 ; /* do nothing */
2708 else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2709 dev_err (hub_dev, "get_hub_status failed\n");
2710 else {
2711 if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2712 dev_dbg (hub_dev, "power change\n");
2713 clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2714 if (hubstatus & HUB_STATUS_LOCAL_POWER)
2715 /* FIXME: Is this always true? */
2716 hub->limited_power = 0;
2717 else
2718 hub->limited_power = 1;
2720 if (hubchange & HUB_CHANGE_OVERCURRENT) {
2721 dev_dbg (hub_dev, "overcurrent change\n");
2722 msleep(500); /* Cool down */
2723 clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2724 hub_power_on(hub);
2728 hub->activating = 0;
2730 /* If this is a root hub, tell the HCD it's okay to
2731 * re-enable port-change interrupts now. */
2732 if (!hdev->parent && !hub->busy_bits[0])
2733 usb_enable_root_hub_irq(hdev->bus);
2735 loop:
2736 usb_unlock_device(hdev);
2737 usb_put_intf(intf);
2739 } /* end while (1) */
2742 static int hub_thread(void *__unused)
2744 do {
2745 hub_events();
2746 wait_event_interruptible(khubd_wait,
2747 !list_empty(&hub_event_list) ||
2748 kthread_should_stop());
2749 try_to_freeze();
2750 } while (!kthread_should_stop() || !list_empty(&hub_event_list));
2752 pr_debug("%s: khubd exiting\n", usbcore_name);
2753 return 0;
2756 static struct usb_device_id hub_id_table [] = {
2757 { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2758 .bDeviceClass = USB_CLASS_HUB},
2759 { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2760 .bInterfaceClass = USB_CLASS_HUB},
2761 { } /* Terminating entry */
2764 MODULE_DEVICE_TABLE (usb, hub_id_table);
2766 static struct usb_driver hub_driver = {
2767 .name = "hub",
2768 .probe = hub_probe,
2769 .disconnect = hub_disconnect,
2770 .suspend = hub_suspend,
2771 .resume = hub_resume,
2772 .pre_reset = hub_pre_reset,
2773 .post_reset = hub_post_reset,
2774 .ioctl = hub_ioctl,
2775 .id_table = hub_id_table,
2778 int usb_hub_init(void)
2780 if (usb_register(&hub_driver) < 0) {
2781 printk(KERN_ERR "%s: can't register hub driver\n",
2782 usbcore_name);
2783 return -1;
2786 khubd_task = kthread_run(hub_thread, NULL, "khubd");
2787 if (!IS_ERR(khubd_task))
2788 return 0;
2790 /* Fall through if kernel_thread failed */
2791 usb_deregister(&hub_driver);
2792 printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2794 return -1;
2797 void usb_hub_cleanup(void)
2799 kthread_stop(khubd_task);
2802 * Hub resources are freed for us by usb_deregister. It calls
2803 * usb_driver_purge on every device which in turn calls that
2804 * devices disconnect function if it is using this driver.
2805 * The hub_disconnect function takes care of releasing the
2806 * individual hub resources. -greg
2808 usb_deregister(&hub_driver);
2809 } /* usb_hub_cleanup() */
2811 static int config_descriptors_changed(struct usb_device *udev)
2813 unsigned index;
2814 unsigned len = 0;
2815 struct usb_config_descriptor *buf;
2817 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2818 if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2819 len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2821 buf = kmalloc (len, SLAB_KERNEL);
2822 if (buf == NULL) {
2823 dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2824 /* assume the worst */
2825 return 1;
2827 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2828 int length;
2829 int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2831 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2832 old_length);
2833 if (length < old_length) {
2834 dev_dbg(&udev->dev, "config index %d, error %d\n",
2835 index, length);
2836 break;
2838 if (memcmp (buf, udev->rawdescriptors[index], old_length)
2839 != 0) {
2840 dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2841 index, buf->bConfigurationValue);
2842 break;
2845 kfree(buf);
2846 return index != udev->descriptor.bNumConfigurations;
2850 * usb_reset_device - perform a USB port reset to reinitialize a device
2851 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2853 * WARNING - don't use this routine to reset a composite device
2854 * (one with multiple interfaces owned by separate drivers)!
2855 * Use usb_reset_composite_device() instead.
2857 * Do a port reset, reassign the device's address, and establish its
2858 * former operating configuration. If the reset fails, or the device's
2859 * descriptors change from their values before the reset, or the original
2860 * configuration and altsettings cannot be restored, a flag will be set
2861 * telling khubd to pretend the device has been disconnected and then
2862 * re-connected. All drivers will be unbound, and the device will be
2863 * re-enumerated and probed all over again.
2865 * Returns 0 if the reset succeeded, -ENODEV if the device has been
2866 * flagged for logical disconnection, or some other negative error code
2867 * if the reset wasn't even attempted.
2869 * The caller must own the device lock. For example, it's safe to use
2870 * this from a driver probe() routine after downloading new firmware.
2871 * For calls that might not occur during probe(), drivers should lock
2872 * the device using usb_lock_device_for_reset().
2874 int usb_reset_device(struct usb_device *udev)
2876 struct usb_device *parent_hdev = udev->parent;
2877 struct usb_hub *parent_hub;
2878 struct usb_device_descriptor descriptor = udev->descriptor;
2879 int i, ret = 0;
2880 int port1 = udev->portnum;
2882 if (udev->state == USB_STATE_NOTATTACHED ||
2883 udev->state == USB_STATE_SUSPENDED) {
2884 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2885 udev->state);
2886 return -EINVAL;
2889 if (!parent_hdev) {
2890 /* this requires hcd-specific logic; see OHCI hc_restart() */
2891 dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
2892 return -EISDIR;
2894 parent_hub = hdev_to_hub(parent_hdev);
2896 set_bit(port1, parent_hub->busy_bits);
2897 for (i = 0; i < SET_CONFIG_TRIES; ++i) {
2899 /* ep0 maxpacket size may change; let the HCD know about it.
2900 * Other endpoints will be handled by re-enumeration. */
2901 ep0_reinit(udev);
2902 ret = hub_port_init(parent_hub, udev, port1, i);
2903 if (ret >= 0)
2904 break;
2906 clear_bit(port1, parent_hub->busy_bits);
2907 if (!parent_hdev->parent && !parent_hub->busy_bits[0])
2908 usb_enable_root_hub_irq(parent_hdev->bus);
2910 if (ret < 0)
2911 goto re_enumerate;
2913 /* Device might have changed firmware (DFU or similar) */
2914 if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
2915 || config_descriptors_changed (udev)) {
2916 dev_info(&udev->dev, "device firmware changed\n");
2917 udev->descriptor = descriptor; /* for disconnect() calls */
2918 goto re_enumerate;
2921 if (!udev->actconfig)
2922 goto done;
2924 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2925 USB_REQ_SET_CONFIGURATION, 0,
2926 udev->actconfig->desc.bConfigurationValue, 0,
2927 NULL, 0, USB_CTRL_SET_TIMEOUT);
2928 if (ret < 0) {
2929 dev_err(&udev->dev,
2930 "can't restore configuration #%d (error=%d)\n",
2931 udev->actconfig->desc.bConfigurationValue, ret);
2932 goto re_enumerate;
2934 usb_set_device_state(udev, USB_STATE_CONFIGURED);
2936 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
2937 struct usb_interface *intf = udev->actconfig->interface[i];
2938 struct usb_interface_descriptor *desc;
2940 /* set_interface resets host side toggle even
2941 * for altsetting zero. the interface may have no driver.
2943 desc = &intf->cur_altsetting->desc;
2944 ret = usb_set_interface(udev, desc->bInterfaceNumber,
2945 desc->bAlternateSetting);
2946 if (ret < 0) {
2947 dev_err(&udev->dev, "failed to restore interface %d "
2948 "altsetting %d (error=%d)\n",
2949 desc->bInterfaceNumber,
2950 desc->bAlternateSetting,
2951 ret);
2952 goto re_enumerate;
2956 done:
2957 return 0;
2959 re_enumerate:
2960 hub_port_logical_disconnect(parent_hub, port1);
2961 return -ENODEV;
2963 EXPORT_SYMBOL(usb_reset_device);
2966 * usb_reset_composite_device - warn interface drivers and perform a USB port reset
2967 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2968 * @iface: interface bound to the driver making the request (optional)
2970 * Warns all drivers bound to registered interfaces (using their pre_reset
2971 * method), performs the port reset, and then lets the drivers know that
2972 * the reset is over (using their post_reset method).
2974 * Return value is the same as for usb_reset_device().
2976 * The caller must own the device lock. For example, it's safe to use
2977 * this from a driver probe() routine after downloading new firmware.
2978 * For calls that might not occur during probe(), drivers should lock
2979 * the device using usb_lock_device_for_reset().
2981 * The interface locks are acquired during the pre_reset stage and released
2982 * during the post_reset stage. However if iface is not NULL and is
2983 * currently being probed, we assume that the caller already owns its
2984 * lock.
2986 int usb_reset_composite_device(struct usb_device *udev,
2987 struct usb_interface *iface)
2989 int ret;
2990 struct usb_host_config *config = udev->actconfig;
2992 if (udev->state == USB_STATE_NOTATTACHED ||
2993 udev->state == USB_STATE_SUSPENDED) {
2994 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2995 udev->state);
2996 return -EINVAL;
2999 /* Prevent autosuspend during the reset */
3000 usb_autoresume_device(udev, 1);
3002 if (iface && iface->condition != USB_INTERFACE_BINDING)
3003 iface = NULL;
3005 if (config) {
3006 int i;
3007 struct usb_interface *cintf;
3008 struct usb_driver *drv;
3010 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
3011 cintf = config->interface[i];
3012 if (cintf != iface)
3013 down(&cintf->dev.sem);
3014 if (device_is_registered(&cintf->dev) &&
3015 cintf->dev.driver) {
3016 drv = to_usb_driver(cintf->dev.driver);
3017 if (drv->pre_reset)
3018 (drv->pre_reset)(cintf);
3023 ret = usb_reset_device(udev);
3025 if (config) {
3026 int i;
3027 struct usb_interface *cintf;
3028 struct usb_driver *drv;
3030 for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
3031 cintf = config->interface[i];
3032 if (device_is_registered(&cintf->dev) &&
3033 cintf->dev.driver) {
3034 drv = to_usb_driver(cintf->dev.driver);
3035 if (drv->post_reset)
3036 (drv->post_reset)(cintf);
3038 if (cintf != iface)
3039 up(&cintf->dev.sem);
3043 usb_autosuspend_device(udev, 1);
3044 return ret;
3046 EXPORT_SYMBOL(usb_reset_composite_device);