1 #include <linux/module.h>
2 #include <linux/string.h>
3 #include <linux/bitops.h>
4 #include <linux/slab.h>
5 #include <linux/init.h>
6 #include <linux/log2.h>
8 #include <linux/wait.h>
9 #include <linux/usb/hcd.h>
11 #define to_urb(d) container_of(d, struct urb, kref)
14 static void urb_destroy(struct kref *kref)
16 struct urb *urb = to_urb(kref);
18 if (urb->transfer_flags & URB_FREE_BUFFER)
19 kfree(urb->transfer_buffer);
25 * usb_init_urb - initializes a urb so that it can be used by a USB driver
26 * @urb: pointer to the urb to initialize
28 * Initializes a urb so that the USB subsystem can use it properly.
30 * If a urb is created with a call to usb_alloc_urb() it is not
31 * necessary to call this function. Only use this if you allocate the
32 * space for a struct urb on your own. If you call this function, be
33 * careful when freeing the memory for your urb that it is no longer in
34 * use by the USB core.
36 * Only use this function if you _really_ understand what you are doing.
38 void usb_init_urb(struct urb *urb)
41 memset(urb, 0, sizeof(*urb));
42 kref_init(&urb->kref);
43 INIT_LIST_HEAD(&urb->anchor_list);
46 EXPORT_SYMBOL_GPL(usb_init_urb);
49 * usb_alloc_urb - creates a new urb for a USB driver to use
50 * @iso_packets: number of iso packets for this urb
51 * @mem_flags: the type of memory to allocate, see kmalloc() for a list of
52 * valid options for this.
54 * Creates an urb for the USB driver to use, initializes a few internal
55 * structures, incrementes the usage counter, and returns a pointer to it.
57 * If no memory is available, NULL is returned.
59 * If the driver want to use this urb for interrupt, control, or bulk
60 * endpoints, pass '0' as the number of iso packets.
62 * The driver must call usb_free_urb() when it is finished with the urb.
64 struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags)
68 urb = kmalloc(sizeof(struct urb) +
69 iso_packets * sizeof(struct usb_iso_packet_descriptor),
72 printk(KERN_ERR "alloc_urb: kmalloc failed\n");
78 EXPORT_SYMBOL_GPL(usb_alloc_urb);
81 * usb_free_urb - frees the memory used by a urb when all users of it are finished
82 * @urb: pointer to the urb to free, may be NULL
84 * Must be called when a user of a urb is finished with it. When the last user
85 * of the urb calls this function, the memory of the urb is freed.
87 * Note: The transfer buffer associated with the urb is not freed unless the
88 * URB_FREE_BUFFER transfer flag is set.
90 void usb_free_urb(struct urb *urb)
93 kref_put(&urb->kref, urb_destroy);
95 EXPORT_SYMBOL_GPL(usb_free_urb);
98 * usb_get_urb - increments the reference count of the urb
99 * @urb: pointer to the urb to modify, may be NULL
101 * This must be called whenever a urb is transferred from a device driver to a
102 * host controller driver. This allows proper reference counting to happen
105 * A pointer to the urb with the incremented reference counter is returned.
107 struct urb *usb_get_urb(struct urb *urb)
110 kref_get(&urb->kref);
113 EXPORT_SYMBOL_GPL(usb_get_urb);
116 * usb_anchor_urb - anchors an URB while it is processed
117 * @urb: pointer to the urb to anchor
118 * @anchor: pointer to the anchor
120 * This can be called to have access to URBs which are to be executed
121 * without bothering to track them
123 void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor)
127 spin_lock_irqsave(&anchor->lock, flags);
129 list_add_tail(&urb->anchor_list, &anchor->urb_list);
130 urb->anchor = anchor;
132 if (unlikely(anchor->poisoned)) {
133 atomic_inc(&urb->reject);
136 spin_unlock_irqrestore(&anchor->lock, flags);
138 EXPORT_SYMBOL_GPL(usb_anchor_urb);
141 * usb_unanchor_urb - unanchors an URB
142 * @urb: pointer to the urb to anchor
144 * Call this to stop the system keeping track of this URB
146 void usb_unanchor_urb(struct urb *urb)
149 struct usb_anchor *anchor;
154 anchor = urb->anchor;
158 spin_lock_irqsave(&anchor->lock, flags);
159 if (unlikely(anchor != urb->anchor)) {
160 /* we've lost the race to another thread */
161 spin_unlock_irqrestore(&anchor->lock, flags);
165 list_del(&urb->anchor_list);
166 spin_unlock_irqrestore(&anchor->lock, flags);
168 if (list_empty(&anchor->urb_list))
169 wake_up(&anchor->wait);
171 EXPORT_SYMBOL_GPL(usb_unanchor_urb);
173 /*-------------------------------------------------------------------*/
176 * usb_submit_urb - issue an asynchronous transfer request for an endpoint
177 * @urb: pointer to the urb describing the request
178 * @mem_flags: the type of memory to allocate, see kmalloc() for a list
179 * of valid options for this.
181 * This submits a transfer request, and transfers control of the URB
182 * describing that request to the USB subsystem. Request completion will
183 * be indicated later, asynchronously, by calling the completion handler.
184 * The three types of completion are success, error, and unlink
185 * (a software-induced fault, also called "request cancellation").
187 * URBs may be submitted in interrupt context.
189 * The caller must have correctly initialized the URB before submitting
190 * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are
191 * available to ensure that most fields are correctly initialized, for
192 * the particular kind of transfer, although they will not initialize
193 * any transfer flags.
195 * Successful submissions return 0; otherwise this routine returns a
196 * negative error number. If the submission is successful, the complete()
197 * callback from the URB will be called exactly once, when the USB core and
198 * Host Controller Driver (HCD) are finished with the URB. When the completion
199 * function is called, control of the URB is returned to the device
200 * driver which issued the request. The completion handler may then
201 * immediately free or reuse that URB.
203 * With few exceptions, USB device drivers should never access URB fields
204 * provided by usbcore or the HCD until its complete() is called.
205 * The exceptions relate to periodic transfer scheduling. For both
206 * interrupt and isochronous urbs, as part of successful URB submission
207 * urb->interval is modified to reflect the actual transfer period used
208 * (normally some power of two units). And for isochronous urbs,
209 * urb->start_frame is modified to reflect when the URB's transfers were
210 * scheduled to start. Not all isochronous transfer scheduling policies
211 * will work, but most host controller drivers should easily handle ISO
212 * queues going from now until 10-200 msec into the future.
214 * For control endpoints, the synchronous usb_control_msg() call is
215 * often used (in non-interrupt context) instead of this call.
216 * That is often used through convenience wrappers, for the requests
217 * that are standardized in the USB 2.0 specification. For bulk
218 * endpoints, a synchronous usb_bulk_msg() call is available.
222 * URBs may be submitted to endpoints before previous ones complete, to
223 * minimize the impact of interrupt latencies and system overhead on data
224 * throughput. With that queuing policy, an endpoint's queue would never
225 * be empty. This is required for continuous isochronous data streams,
226 * and may also be required for some kinds of interrupt transfers. Such
227 * queuing also maximizes bandwidth utilization by letting USB controllers
228 * start work on later requests before driver software has finished the
229 * completion processing for earlier (successful) requests.
231 * As of Linux 2.6, all USB endpoint transfer queues support depths greater
232 * than one. This was previously a HCD-specific behavior, except for ISO
233 * transfers. Non-isochronous endpoint queues are inactive during cleanup
234 * after faults (transfer errors or cancellation).
236 * Reserved Bandwidth Transfers:
238 * Periodic transfers (interrupt or isochronous) are performed repeatedly,
239 * using the interval specified in the urb. Submitting the first urb to
240 * the endpoint reserves the bandwidth necessary to make those transfers.
241 * If the USB subsystem can't allocate sufficient bandwidth to perform
242 * the periodic request, submitting such a periodic request should fail.
244 * For devices under xHCI, the bandwidth is reserved at configuration time, or
245 * when the alt setting is selected. If there is not enough bus bandwidth, the
246 * configuration/alt setting request will fail. Therefore, submissions to
247 * periodic endpoints on devices under xHCI should never fail due to bandwidth
250 * Device drivers must explicitly request that repetition, by ensuring that
251 * some URB is always on the endpoint's queue (except possibly for short
252 * periods during completion callacks). When there is no longer an urb
253 * queued, the endpoint's bandwidth reservation is canceled. This means
254 * drivers can use their completion handlers to ensure they keep bandwidth
255 * they need, by reinitializing and resubmitting the just-completed urb
256 * until the driver longer needs that periodic bandwidth.
260 * The general rules for how to decide which mem_flags to use
261 * are the same as for kmalloc. There are four
262 * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and
265 * GFP_NOFS is not ever used, as it has not been implemented yet.
267 * GFP_ATOMIC is used when
268 * (a) you are inside a completion handler, an interrupt, bottom half,
269 * tasklet or timer, or
270 * (b) you are holding a spinlock or rwlock (does not apply to
272 * (c) current->state != TASK_RUNNING, this is the case only after
275 * GFP_NOIO is used in the block io path and error handling of storage
278 * All other situations use GFP_KERNEL.
280 * Some more specific rules for mem_flags can be inferred, such as
281 * (1) start_xmit, timeout, and receive methods of network drivers must
282 * use GFP_ATOMIC (they are called with a spinlock held);
283 * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also
284 * called with a spinlock held);
285 * (3) If you use a kernel thread with a network driver you must use
286 * GFP_NOIO, unless (b) or (c) apply;
287 * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c)
288 * apply or your are in a storage driver's block io path;
289 * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and
290 * (6) changing firmware on a running storage or net device uses
291 * GFP_NOIO, unless b) or c) apply
294 int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
297 struct usb_device *dev;
298 struct usb_host_endpoint *ep;
301 if (!urb || urb->hcpriv || !urb->complete)
304 if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
307 /* For now, get the endpoint from the pipe. Eventually drivers
308 * will be required to set urb->ep directly and we will eliminate
311 ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
312 [usb_pipeendpoint(urb->pipe)];
317 urb->status = -EINPROGRESS;
318 urb->actual_length = 0;
320 /* Lots of sanity checks, so HCDs can rely on clean data
321 * and don't need to duplicate tests
323 xfertype = usb_endpoint_type(&ep->desc);
324 if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
325 struct usb_ctrlrequest *setup =
326 (struct usb_ctrlrequest *) urb->setup_packet;
330 is_out = !(setup->bRequestType & USB_DIR_IN) ||
333 is_out = usb_endpoint_dir_out(&ep->desc);
336 /* Clear the internal flags and cache the direction for later use */
337 urb->transfer_flags &= ~(URB_DIR_MASK | URB_DMA_MAP_SINGLE |
338 URB_DMA_MAP_PAGE | URB_DMA_MAP_SG | URB_MAP_LOCAL |
339 URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL |
340 URB_DMA_SG_COMBINED);
341 urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN);
343 if (xfertype != USB_ENDPOINT_XFER_CONTROL &&
344 dev->state < USB_STATE_CONFIGURED)
347 max = le16_to_cpu(ep->desc.wMaxPacketSize);
350 "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n",
351 usb_endpoint_num(&ep->desc), is_out ? "out" : "in",
356 /* periodic transfers limit size per frame/uframe,
357 * but drivers only control those sizes for ISO.
358 * while we're checking, initialize return status.
360 if (xfertype == USB_ENDPOINT_XFER_ISOC) {
363 /* FIXME SuperSpeed isoc endpoints have up to 16 bursts */
364 /* "high bandwidth" mode, 1-3 packets/uframe? */
365 if (dev->speed == USB_SPEED_HIGH) {
366 int mult = 1 + ((max >> 11) & 0x03);
371 if (urb->number_of_packets <= 0)
373 for (n = 0; n < urb->number_of_packets; n++) {
374 len = urb->iso_frame_desc[n].length;
375 if (len < 0 || len > max)
377 urb->iso_frame_desc[n].status = -EXDEV;
378 urb->iso_frame_desc[n].actual_length = 0;
382 /* the I/O buffer must be mapped/unmapped, except when length=0 */
383 if (urb->transfer_buffer_length > INT_MAX)
387 /* stuff that drivers shouldn't do, but which shouldn't
388 * cause problems in HCDs if they get it wrong.
391 unsigned int orig_flags = urb->transfer_flags;
392 unsigned int allowed;
393 static int pipetypes[4] = {
394 PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
397 /* Check that the pipe's type matches the endpoint's type */
398 if (usb_pipetype(urb->pipe) != pipetypes[xfertype])
399 return -EPIPE; /* The most suitable error code :-) */
401 /* enforce simple/standard policy */
402 allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK |
405 case USB_ENDPOINT_XFER_BULK:
407 allowed |= URB_ZERO_PACKET;
409 case USB_ENDPOINT_XFER_CONTROL:
410 allowed |= URB_NO_FSBR; /* only affects UHCI */
412 default: /* all non-iso endpoints */
414 allowed |= URB_SHORT_NOT_OK;
416 case USB_ENDPOINT_XFER_ISOC:
417 allowed |= URB_ISO_ASAP;
420 urb->transfer_flags &= allowed;
422 /* fail if submitter gave bogus flags */
423 if (urb->transfer_flags != orig_flags) {
424 dev_err(&dev->dev, "BOGUS urb flags, %x --> %x\n",
425 orig_flags, urb->transfer_flags);
431 * Force periodic transfer intervals to be legal values that are
432 * a power of two (so HCDs don't need to).
434 * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC
435 * supports different values... this uses EHCI/UHCI defaults (and
436 * EHCI can use smaller non-default values).
439 case USB_ENDPOINT_XFER_ISOC:
440 case USB_ENDPOINT_XFER_INT:
442 switch (dev->speed) {
443 case USB_SPEED_WIRELESS:
444 if (urb->interval < 6)
448 if (urb->interval <= 0)
453 switch (dev->speed) {
454 case USB_SPEED_SUPER: /* units are 125us */
455 /* Handle up to 2^(16-1) microframes */
456 if (urb->interval > (1 << 15))
460 case USB_SPEED_WIRELESS:
461 if (urb->interval > 16)
464 case USB_SPEED_HIGH: /* units are microframes */
465 /* NOTE usb handles 2^15 */
466 if (urb->interval > (1024 * 8))
467 urb->interval = 1024 * 8;
470 case USB_SPEED_FULL: /* units are frames/msec */
472 if (xfertype == USB_ENDPOINT_XFER_INT) {
473 if (urb->interval > 255)
475 /* NOTE ohci only handles up to 32 */
478 if (urb->interval > 1024)
479 urb->interval = 1024;
480 /* NOTE usb and ohci handle up to 2^15 */
487 if (dev->speed != USB_SPEED_WIRELESS) {
488 /* Round down to a power of 2, no more than max */
489 urb->interval = min(max, 1 << ilog2(urb->interval));
493 return usb_hcd_submit_urb(urb, mem_flags);
495 EXPORT_SYMBOL_GPL(usb_submit_urb);
497 /*-------------------------------------------------------------------*/
500 * usb_unlink_urb - abort/cancel a transfer request for an endpoint
501 * @urb: pointer to urb describing a previously submitted request,
504 * This routine cancels an in-progress request. URBs complete only once
505 * per submission, and may be canceled only once per submission.
506 * Successful cancellation means termination of @urb will be expedited
507 * and the completion handler will be called with a status code
508 * indicating that the request has been canceled (rather than any other
511 * Drivers should not call this routine or related routines, such as
512 * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect
513 * method has returned. The disconnect function should synchronize with
514 * a driver's I/O routines to insure that all URB-related activity has
515 * completed before it returns.
517 * This request is always asynchronous. Success is indicated by
518 * returning -EINPROGRESS, at which time the URB will probably not yet
519 * have been given back to the device driver. When it is eventually
520 * called, the completion function will see @urb->status == -ECONNRESET.
521 * Failure is indicated by usb_unlink_urb() returning any other value.
522 * Unlinking will fail when @urb is not currently "linked" (i.e., it was
523 * never submitted, or it was unlinked before, or the hardware is already
524 * finished with it), even if the completion handler has not yet run.
526 * Unlinking and Endpoint Queues:
528 * [The behaviors and guarantees described below do not apply to virtual
529 * root hubs but only to endpoint queues for physical USB devices.]
531 * Host Controller Drivers (HCDs) place all the URBs for a particular
532 * endpoint in a queue. Normally the queue advances as the controller
533 * hardware processes each request. But when an URB terminates with an
534 * error its queue generally stops (see below), at least until that URB's
535 * completion routine returns. It is guaranteed that a stopped queue
536 * will not restart until all its unlinked URBs have been fully retired,
537 * with their completion routines run, even if that's not until some time
538 * after the original completion handler returns. The same behavior and
539 * guarantee apply when an URB terminates because it was unlinked.
541 * Bulk and interrupt endpoint queues are guaranteed to stop whenever an
542 * URB terminates with any sort of error, including -ECONNRESET, -ENOENT,
543 * and -EREMOTEIO. Control endpoint queues behave the same way except
544 * that they are not guaranteed to stop for -EREMOTEIO errors. Queues
545 * for isochronous endpoints are treated differently, because they must
546 * advance at fixed rates. Such queues do not stop when an URB
547 * encounters an error or is unlinked. An unlinked isochronous URB may
548 * leave a gap in the stream of packets; it is undefined whether such
549 * gaps can be filled in.
551 * Note that early termination of an URB because a short packet was
552 * received will generate a -EREMOTEIO error if and only if the
553 * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device
554 * drivers can build deep queues for large or complex bulk transfers
555 * and clean them up reliably after any sort of aborted transfer by
556 * unlinking all pending URBs at the first fault.
558 * When a control URB terminates with an error other than -EREMOTEIO, it
559 * is quite likely that the status stage of the transfer will not take
562 int usb_unlink_urb(struct urb *urb)
570 return usb_hcd_unlink_urb(urb, -ECONNRESET);
572 EXPORT_SYMBOL_GPL(usb_unlink_urb);
575 * usb_kill_urb - cancel a transfer request and wait for it to finish
576 * @urb: pointer to URB describing a previously submitted request,
579 * This routine cancels an in-progress request. It is guaranteed that
580 * upon return all completion handlers will have finished and the URB
581 * will be totally idle and available for reuse. These features make
582 * this an ideal way to stop I/O in a disconnect() callback or close()
583 * function. If the request has not already finished or been unlinked
584 * the completion handler will see urb->status == -ENOENT.
586 * While the routine is running, attempts to resubmit the URB will fail
587 * with error -EPERM. Thus even if the URB's completion handler always
588 * tries to resubmit, it will not succeed and the URB will become idle.
590 * This routine may not be used in an interrupt context (such as a bottom
591 * half or a completion handler), or when holding a spinlock, or in other
592 * situations where the caller can't schedule().
594 * This routine should not be called by a driver after its disconnect
595 * method has returned.
597 void usb_kill_urb(struct urb *urb)
600 if (!(urb && urb->dev && urb->ep))
602 atomic_inc(&urb->reject);
604 usb_hcd_unlink_urb(urb, -ENOENT);
605 wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
607 atomic_dec(&urb->reject);
609 EXPORT_SYMBOL_GPL(usb_kill_urb);
612 * usb_poison_urb - reliably kill a transfer and prevent further use of an URB
613 * @urb: pointer to URB describing a previously submitted request,
616 * This routine cancels an in-progress request. It is guaranteed that
617 * upon return all completion handlers will have finished and the URB
618 * will be totally idle and cannot be reused. These features make
619 * this an ideal way to stop I/O in a disconnect() callback.
620 * If the request has not already finished or been unlinked
621 * the completion handler will see urb->status == -ENOENT.
623 * After and while the routine runs, attempts to resubmit the URB will fail
624 * with error -EPERM. Thus even if the URB's completion handler always
625 * tries to resubmit, it will not succeed and the URB will become idle.
627 * This routine may not be used in an interrupt context (such as a bottom
628 * half or a completion handler), or when holding a spinlock, or in other
629 * situations where the caller can't schedule().
631 * This routine should not be called by a driver after its disconnect
632 * method has returned.
634 void usb_poison_urb(struct urb *urb)
637 if (!(urb && urb->dev && urb->ep))
639 atomic_inc(&urb->reject);
641 usb_hcd_unlink_urb(urb, -ENOENT);
642 wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
644 EXPORT_SYMBOL_GPL(usb_poison_urb);
646 void usb_unpoison_urb(struct urb *urb)
651 atomic_dec(&urb->reject);
653 EXPORT_SYMBOL_GPL(usb_unpoison_urb);
656 * usb_kill_anchored_urbs - cancel transfer requests en masse
657 * @anchor: anchor the requests are bound to
659 * this allows all outstanding URBs to be killed starting
660 * from the back of the queue
662 * This routine should not be called by a driver after its disconnect
663 * method has returned.
665 void usb_kill_anchored_urbs(struct usb_anchor *anchor)
669 spin_lock_irq(&anchor->lock);
670 while (!list_empty(&anchor->urb_list)) {
671 victim = list_entry(anchor->urb_list.prev, struct urb,
673 /* we must make sure the URB isn't freed before we kill it*/
675 spin_unlock_irq(&anchor->lock);
676 /* this will unanchor the URB */
677 usb_kill_urb(victim);
679 spin_lock_irq(&anchor->lock);
681 spin_unlock_irq(&anchor->lock);
683 EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs);
687 * usb_poison_anchored_urbs - cease all traffic from an anchor
688 * @anchor: anchor the requests are bound to
690 * this allows all outstanding URBs to be poisoned starting
691 * from the back of the queue. Newly added URBs will also be
694 * This routine should not be called by a driver after its disconnect
695 * method has returned.
697 void usb_poison_anchored_urbs(struct usb_anchor *anchor)
701 spin_lock_irq(&anchor->lock);
702 anchor->poisoned = 1;
703 while (!list_empty(&anchor->urb_list)) {
704 victim = list_entry(anchor->urb_list.prev, struct urb,
706 /* we must make sure the URB isn't freed before we kill it*/
708 spin_unlock_irq(&anchor->lock);
709 /* this will unanchor the URB */
710 usb_poison_urb(victim);
712 spin_lock_irq(&anchor->lock);
714 spin_unlock_irq(&anchor->lock);
716 EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs);
719 * usb_unpoison_anchored_urbs - let an anchor be used successfully again
720 * @anchor: anchor the requests are bound to
722 * Reverses the effect of usb_poison_anchored_urbs
723 * the anchor can be used normally after it returns
725 void usb_unpoison_anchored_urbs(struct usb_anchor *anchor)
730 spin_lock_irqsave(&anchor->lock, flags);
731 list_for_each_entry(lazarus, &anchor->urb_list, anchor_list) {
732 usb_unpoison_urb(lazarus);
734 anchor->poisoned = 0;
735 spin_unlock_irqrestore(&anchor->lock, flags);
737 EXPORT_SYMBOL_GPL(usb_unpoison_anchored_urbs);
739 * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse
740 * @anchor: anchor the requests are bound to
742 * this allows all outstanding URBs to be unlinked starting
743 * from the back of the queue. This function is asynchronous.
744 * The unlinking is just tiggered. It may happen after this
745 * function has returned.
747 * This routine should not be called by a driver after its disconnect
748 * method has returned.
750 void usb_unlink_anchored_urbs(struct usb_anchor *anchor)
755 spin_lock_irqsave(&anchor->lock, flags);
756 while (!list_empty(&anchor->urb_list)) {
757 victim = list_entry(anchor->urb_list.prev, struct urb,
760 spin_unlock_irqrestore(&anchor->lock, flags);
761 /* this will unanchor the URB */
762 usb_unlink_urb(victim);
764 spin_lock_irqsave(&anchor->lock, flags);
766 spin_unlock_irqrestore(&anchor->lock, flags);
768 EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs);
771 * usb_wait_anchor_empty_timeout - wait for an anchor to be unused
772 * @anchor: the anchor you want to become unused
773 * @timeout: how long you are willing to wait in milliseconds
775 * Call this is you want to be sure all an anchor's
778 int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor,
779 unsigned int timeout)
781 return wait_event_timeout(anchor->wait, list_empty(&anchor->urb_list),
782 msecs_to_jiffies(timeout));
784 EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout);
787 * usb_get_from_anchor - get an anchor's oldest urb
788 * @anchor: the anchor whose urb you want
790 * this will take the oldest urb from an anchor,
791 * unanchor and return it
793 struct urb *usb_get_from_anchor(struct usb_anchor *anchor)
798 spin_lock_irqsave(&anchor->lock, flags);
799 if (!list_empty(&anchor->urb_list)) {
800 victim = list_entry(anchor->urb_list.next, struct urb,
803 spin_unlock_irqrestore(&anchor->lock, flags);
804 usb_unanchor_urb(victim);
806 spin_unlock_irqrestore(&anchor->lock, flags);
813 EXPORT_SYMBOL_GPL(usb_get_from_anchor);
816 * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs
817 * @anchor: the anchor whose urbs you want to unanchor
819 * use this to get rid of all an anchor's urbs
821 void usb_scuttle_anchored_urbs(struct usb_anchor *anchor)
826 spin_lock_irqsave(&anchor->lock, flags);
827 while (!list_empty(&anchor->urb_list)) {
828 victim = list_entry(anchor->urb_list.prev, struct urb,
831 spin_unlock_irqrestore(&anchor->lock, flags);
832 /* this may free the URB */
833 usb_unanchor_urb(victim);
835 spin_lock_irqsave(&anchor->lock, flags);
837 spin_unlock_irqrestore(&anchor->lock, flags);
840 EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs);
843 * usb_anchor_empty - is an anchor empty
844 * @anchor: the anchor you want to query
846 * returns 1 if the anchor has no urbs associated with it
848 int usb_anchor_empty(struct usb_anchor *anchor)
850 return list_empty(&anchor->urb_list);
853 EXPORT_SYMBOL_GPL(usb_anchor_empty);