Commit | Line | Data |
---|---|---|
1da177e4 LT |
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> | |
1da177e4 | 6 | #include <linux/usb.h> |
51a2f077 | 7 | #include <linux/wait.h> |
1da177e4 LT |
8 | #include "hcd.h" |
9 | ||
10 | #define to_urb(d) container_of(d, struct urb, kref) | |
11 | ||
12 | static void urb_destroy(struct kref *kref) | |
13 | { | |
14 | struct urb *urb = to_urb(kref); | |
51a2f077 | 15 | |
8b3b01c8 MH |
16 | if (urb->transfer_flags & URB_FREE_BUFFER) |
17 | kfree(urb->transfer_buffer); | |
18 | ||
1da177e4 LT |
19 | kfree(urb); |
20 | } | |
21 | ||
22 | /** | |
23 | * usb_init_urb - initializes a urb so that it can be used by a USB driver | |
24 | * @urb: pointer to the urb to initialize | |
25 | * | |
26 | * Initializes a urb so that the USB subsystem can use it properly. | |
27 | * | |
28 | * If a urb is created with a call to usb_alloc_urb() it is not | |
29 | * necessary to call this function. Only use this if you allocate the | |
30 | * space for a struct urb on your own. If you call this function, be | |
31 | * careful when freeing the memory for your urb that it is no longer in | |
32 | * use by the USB core. | |
33 | * | |
34 | * Only use this function if you _really_ understand what you are doing. | |
35 | */ | |
36 | void usb_init_urb(struct urb *urb) | |
37 | { | |
38 | if (urb) { | |
39 | memset(urb, 0, sizeof(*urb)); | |
40 | kref_init(&urb->kref); | |
41 | spin_lock_init(&urb->lock); | |
51a2f077 | 42 | INIT_LIST_HEAD(&urb->anchor_list); |
1da177e4 LT |
43 | } |
44 | } | |
45 | ||
46 | /** | |
47 | * usb_alloc_urb - creates a new urb for a USB driver to use | |
48 | * @iso_packets: number of iso packets for this urb | |
49 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list of | |
50 | * valid options for this. | |
51 | * | |
52 | * Creates an urb for the USB driver to use, initializes a few internal | |
53 | * structures, incrementes the usage counter, and returns a pointer to it. | |
54 | * | |
55 | * If no memory is available, NULL is returned. | |
56 | * | |
57 | * If the driver want to use this urb for interrupt, control, or bulk | |
58 | * endpoints, pass '0' as the number of iso packets. | |
59 | * | |
60 | * The driver must call usb_free_urb() when it is finished with the urb. | |
61 | */ | |
55016f10 | 62 | struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) |
1da177e4 LT |
63 | { |
64 | struct urb *urb; | |
65 | ||
ec17cf1c | 66 | urb = kmalloc(sizeof(struct urb) + |
1da177e4 LT |
67 | iso_packets * sizeof(struct usb_iso_packet_descriptor), |
68 | mem_flags); | |
69 | if (!urb) { | |
70 | err("alloc_urb: kmalloc failed"); | |
71 | return NULL; | |
72 | } | |
73 | usb_init_urb(urb); | |
74 | return urb; | |
75 | } | |
76 | ||
77 | /** | |
78 | * usb_free_urb - frees the memory used by a urb when all users of it are finished | |
79 | * @urb: pointer to the urb to free, may be NULL | |
80 | * | |
81 | * Must be called when a user of a urb is finished with it. When the last user | |
82 | * of the urb calls this function, the memory of the urb is freed. | |
83 | * | |
84 | * Note: The transfer buffer associated with the urb is not freed, that must be | |
85 | * done elsewhere. | |
86 | */ | |
87 | void usb_free_urb(struct urb *urb) | |
88 | { | |
89 | if (urb) | |
90 | kref_put(&urb->kref, urb_destroy); | |
91 | } | |
92 | ||
93 | /** | |
94 | * usb_get_urb - increments the reference count of the urb | |
95 | * @urb: pointer to the urb to modify, may be NULL | |
96 | * | |
97 | * This must be called whenever a urb is transferred from a device driver to a | |
98 | * host controller driver. This allows proper reference counting to happen | |
99 | * for urbs. | |
100 | * | |
101 | * A pointer to the urb with the incremented reference counter is returned. | |
102 | */ | |
103 | struct urb * usb_get_urb(struct urb *urb) | |
104 | { | |
105 | if (urb) | |
106 | kref_get(&urb->kref); | |
107 | return urb; | |
108 | } | |
51a2f077 ON |
109 | |
110 | /** | |
111 | * usb_anchor_urb - anchors an URB while it is processed | |
112 | * @urb: pointer to the urb to anchor | |
113 | * @anchor: pointer to the anchor | |
114 | * | |
115 | * This can be called to have access to URBs which are to be executed | |
116 | * without bothering to track them | |
117 | */ | |
118 | void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) | |
119 | { | |
120 | unsigned long flags; | |
121 | ||
122 | spin_lock_irqsave(&anchor->lock, flags); | |
123 | usb_get_urb(urb); | |
124 | list_add_tail(&urb->anchor_list, &anchor->urb_list); | |
125 | urb->anchor = anchor; | |
126 | spin_unlock_irqrestore(&anchor->lock, flags); | |
127 | } | |
128 | EXPORT_SYMBOL_GPL(usb_anchor_urb); | |
129 | ||
130 | /** | |
131 | * usb_unanchor_urb - unanchors an URB | |
132 | * @urb: pointer to the urb to anchor | |
133 | * | |
134 | * Call this to stop the system keeping track of this URB | |
135 | */ | |
136 | void usb_unanchor_urb(struct urb *urb) | |
137 | { | |
138 | unsigned long flags; | |
139 | struct usb_anchor *anchor; | |
140 | ||
141 | if (!urb) | |
142 | return; | |
143 | ||
144 | anchor = urb->anchor; | |
145 | if (!anchor) | |
146 | return; | |
147 | ||
148 | spin_lock_irqsave(&anchor->lock, flags); | |
149 | if (unlikely(anchor != urb->anchor)) { | |
150 | /* we've lost the race to another thread */ | |
151 | spin_unlock_irqrestore(&anchor->lock, flags); | |
152 | return; | |
153 | } | |
154 | urb->anchor = NULL; | |
155 | list_del(&urb->anchor_list); | |
156 | spin_unlock_irqrestore(&anchor->lock, flags); | |
157 | usb_put_urb(urb); | |
158 | if (list_empty(&anchor->urb_list)) | |
159 | wake_up(&anchor->wait); | |
160 | } | |
161 | EXPORT_SYMBOL_GPL(usb_unanchor_urb); | |
162 | ||
1da177e4 LT |
163 | /*-------------------------------------------------------------------*/ |
164 | ||
165 | /** | |
166 | * usb_submit_urb - issue an asynchronous transfer request for an endpoint | |
167 | * @urb: pointer to the urb describing the request | |
168 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list | |
169 | * of valid options for this. | |
170 | * | |
171 | * This submits a transfer request, and transfers control of the URB | |
172 | * describing that request to the USB subsystem. Request completion will | |
173 | * be indicated later, asynchronously, by calling the completion handler. | |
174 | * The three types of completion are success, error, and unlink | |
093cf723 | 175 | * (a software-induced fault, also called "request cancellation"). |
1da177e4 LT |
176 | * |
177 | * URBs may be submitted in interrupt context. | |
178 | * | |
179 | * The caller must have correctly initialized the URB before submitting | |
180 | * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are | |
181 | * available to ensure that most fields are correctly initialized, for | |
182 | * the particular kind of transfer, although they will not initialize | |
183 | * any transfer flags. | |
184 | * | |
185 | * Successful submissions return 0; otherwise this routine returns a | |
186 | * negative error number. If the submission is successful, the complete() | |
187 | * callback from the URB will be called exactly once, when the USB core and | |
188 | * Host Controller Driver (HCD) are finished with the URB. When the completion | |
189 | * function is called, control of the URB is returned to the device | |
190 | * driver which issued the request. The completion handler may then | |
191 | * immediately free or reuse that URB. | |
192 | * | |
193 | * With few exceptions, USB device drivers should never access URB fields | |
194 | * provided by usbcore or the HCD until its complete() is called. | |
195 | * The exceptions relate to periodic transfer scheduling. For both | |
196 | * interrupt and isochronous urbs, as part of successful URB submission | |
197 | * urb->interval is modified to reflect the actual transfer period used | |
198 | * (normally some power of two units). And for isochronous urbs, | |
199 | * urb->start_frame is modified to reflect when the URB's transfers were | |
200 | * scheduled to start. Not all isochronous transfer scheduling policies | |
201 | * will work, but most host controller drivers should easily handle ISO | |
202 | * queues going from now until 10-200 msec into the future. | |
203 | * | |
204 | * For control endpoints, the synchronous usb_control_msg() call is | |
205 | * often used (in non-interrupt context) instead of this call. | |
206 | * That is often used through convenience wrappers, for the requests | |
207 | * that are standardized in the USB 2.0 specification. For bulk | |
208 | * endpoints, a synchronous usb_bulk_msg() call is available. | |
209 | * | |
210 | * Request Queuing: | |
211 | * | |
212 | * URBs may be submitted to endpoints before previous ones complete, to | |
213 | * minimize the impact of interrupt latencies and system overhead on data | |
214 | * throughput. With that queuing policy, an endpoint's queue would never | |
215 | * be empty. This is required for continuous isochronous data streams, | |
216 | * and may also be required for some kinds of interrupt transfers. Such | |
217 | * queuing also maximizes bandwidth utilization by letting USB controllers | |
218 | * start work on later requests before driver software has finished the | |
219 | * completion processing for earlier (successful) requests. | |
220 | * | |
221 | * As of Linux 2.6, all USB endpoint transfer queues support depths greater | |
222 | * than one. This was previously a HCD-specific behavior, except for ISO | |
223 | * transfers. Non-isochronous endpoint queues are inactive during cleanup | |
093cf723 | 224 | * after faults (transfer errors or cancellation). |
1da177e4 LT |
225 | * |
226 | * Reserved Bandwidth Transfers: | |
227 | * | |
228 | * Periodic transfers (interrupt or isochronous) are performed repeatedly, | |
229 | * using the interval specified in the urb. Submitting the first urb to | |
230 | * the endpoint reserves the bandwidth necessary to make those transfers. | |
231 | * If the USB subsystem can't allocate sufficient bandwidth to perform | |
232 | * the periodic request, submitting such a periodic request should fail. | |
233 | * | |
234 | * Device drivers must explicitly request that repetition, by ensuring that | |
235 | * some URB is always on the endpoint's queue (except possibly for short | |
236 | * periods during completion callacks). When there is no longer an urb | |
237 | * queued, the endpoint's bandwidth reservation is canceled. This means | |
238 | * drivers can use their completion handlers to ensure they keep bandwidth | |
239 | * they need, by reinitializing and resubmitting the just-completed urb | |
240 | * until the driver longer needs that periodic bandwidth. | |
241 | * | |
242 | * Memory Flags: | |
243 | * | |
244 | * The general rules for how to decide which mem_flags to use | |
245 | * are the same as for kmalloc. There are four | |
246 | * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and | |
247 | * GFP_ATOMIC. | |
248 | * | |
249 | * GFP_NOFS is not ever used, as it has not been implemented yet. | |
250 | * | |
251 | * GFP_ATOMIC is used when | |
252 | * (a) you are inside a completion handler, an interrupt, bottom half, | |
253 | * tasklet or timer, or | |
254 | * (b) you are holding a spinlock or rwlock (does not apply to | |
255 | * semaphores), or | |
256 | * (c) current->state != TASK_RUNNING, this is the case only after | |
257 | * you've changed it. | |
258 | * | |
259 | * GFP_NOIO is used in the block io path and error handling of storage | |
260 | * devices. | |
261 | * | |
262 | * All other situations use GFP_KERNEL. | |
263 | * | |
264 | * Some more specific rules for mem_flags can be inferred, such as | |
265 | * (1) start_xmit, timeout, and receive methods of network drivers must | |
266 | * use GFP_ATOMIC (they are called with a spinlock held); | |
267 | * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also | |
268 | * called with a spinlock held); | |
269 | * (3) If you use a kernel thread with a network driver you must use | |
270 | * GFP_NOIO, unless (b) or (c) apply; | |
271 | * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c) | |
272 | * apply or your are in a storage driver's block io path; | |
273 | * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and | |
274 | * (6) changing firmware on a running storage or net device uses | |
275 | * GFP_NOIO, unless b) or c) apply | |
276 | * | |
277 | */ | |
55016f10 | 278 | int usb_submit_urb(struct urb *urb, gfp_t mem_flags) |
1da177e4 LT |
279 | { |
280 | int pipe, temp, max; | |
281 | struct usb_device *dev; | |
1da177e4 LT |
282 | int is_out; |
283 | ||
284 | if (!urb || urb->hcpriv || !urb->complete) | |
285 | return -EINVAL; | |
286 | if (!(dev = urb->dev) || | |
287 | (dev->state < USB_STATE_DEFAULT) || | |
288 | (!dev->bus) || (dev->devnum <= 0)) | |
289 | return -ENODEV; | |
b13296c6 DB |
290 | if (dev->bus->controller->power.power_state.event != PM_EVENT_ON |
291 | || dev->state == USB_STATE_SUSPENDED) | |
1da177e4 | 292 | return -EHOSTUNREACH; |
1da177e4 LT |
293 | |
294 | urb->status = -EINPROGRESS; | |
295 | urb->actual_length = 0; | |
1da177e4 LT |
296 | |
297 | /* Lots of sanity checks, so HCDs can rely on clean data | |
298 | * and don't need to duplicate tests | |
299 | */ | |
300 | pipe = urb->pipe; | |
9251644a ON |
301 | temp = usb_pipetype(pipe); |
302 | is_out = usb_pipeout(pipe); | |
1da177e4 | 303 | |
9251644a | 304 | if (!usb_pipecontrol(pipe) && dev->state < USB_STATE_CONFIGURED) |
1da177e4 LT |
305 | return -ENODEV; |
306 | ||
307 | /* FIXME there should be a sharable lock protecting us against | |
308 | * config/altsetting changes and disconnects, kicking in here. | |
309 | * (here == before maxpacket, and eventually endpoint type, | |
310 | * checks get made.) | |
311 | */ | |
312 | ||
9251644a | 313 | max = usb_maxpacket(dev, pipe, is_out); |
1da177e4 LT |
314 | if (max <= 0) { |
315 | dev_dbg(&dev->dev, | |
316 | "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n", | |
9251644a | 317 | usb_pipeendpoint(pipe), is_out ? "out" : "in", |
1da177e4 LT |
318 | __FUNCTION__, max); |
319 | return -EMSGSIZE; | |
320 | } | |
321 | ||
322 | /* periodic transfers limit size per frame/uframe, | |
323 | * but drivers only control those sizes for ISO. | |
324 | * while we're checking, initialize return status. | |
325 | */ | |
326 | if (temp == PIPE_ISOCHRONOUS) { | |
327 | int n, len; | |
328 | ||
329 | /* "high bandwidth" mode, 1-3 packets/uframe? */ | |
330 | if (dev->speed == USB_SPEED_HIGH) { | |
331 | int mult = 1 + ((max >> 11) & 0x03); | |
332 | max &= 0x07ff; | |
333 | max *= mult; | |
334 | } | |
335 | ||
336 | if (urb->number_of_packets <= 0) | |
337 | return -EINVAL; | |
338 | for (n = 0; n < urb->number_of_packets; n++) { | |
9251644a | 339 | len = urb->iso_frame_desc[n].length; |
1da177e4 LT |
340 | if (len < 0 || len > max) |
341 | return -EMSGSIZE; | |
9251644a ON |
342 | urb->iso_frame_desc[n].status = -EXDEV; |
343 | urb->iso_frame_desc[n].actual_length = 0; | |
1da177e4 LT |
344 | } |
345 | } | |
346 | ||
347 | /* the I/O buffer must be mapped/unmapped, except when length=0 */ | |
348 | if (urb->transfer_buffer_length < 0) | |
349 | return -EMSGSIZE; | |
350 | ||
351 | #ifdef DEBUG | |
352 | /* stuff that drivers shouldn't do, but which shouldn't | |
353 | * cause problems in HCDs if they get it wrong. | |
354 | */ | |
355 | { | |
356 | unsigned int orig_flags = urb->transfer_flags; | |
357 | unsigned int allowed; | |
358 | ||
359 | /* enforce simple/standard policy */ | |
b375a049 AS |
360 | allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP | |
361 | URB_NO_INTERRUPT); | |
1da177e4 LT |
362 | switch (temp) { |
363 | case PIPE_BULK: | |
364 | if (is_out) | |
365 | allowed |= URB_ZERO_PACKET; | |
366 | /* FALLTHROUGH */ | |
367 | case PIPE_CONTROL: | |
368 | allowed |= URB_NO_FSBR; /* only affects UHCI */ | |
369 | /* FALLTHROUGH */ | |
370 | default: /* all non-iso endpoints */ | |
371 | if (!is_out) | |
372 | allowed |= URB_SHORT_NOT_OK; | |
373 | break; | |
374 | case PIPE_ISOCHRONOUS: | |
375 | allowed |= URB_ISO_ASAP; | |
376 | break; | |
377 | } | |
378 | urb->transfer_flags &= allowed; | |
379 | ||
380 | /* fail if submitter gave bogus flags */ | |
381 | if (urb->transfer_flags != orig_flags) { | |
9251644a | 382 | err("BOGUS urb flags, %x --> %x", |
1da177e4 LT |
383 | orig_flags, urb->transfer_flags); |
384 | return -EINVAL; | |
385 | } | |
386 | } | |
387 | #endif | |
388 | /* | |
389 | * Force periodic transfer intervals to be legal values that are | |
390 | * a power of two (so HCDs don't need to). | |
391 | * | |
392 | * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC | |
393 | * supports different values... this uses EHCI/UHCI defaults (and | |
394 | * EHCI can use smaller non-default values). | |
395 | */ | |
396 | switch (temp) { | |
397 | case PIPE_ISOCHRONOUS: | |
398 | case PIPE_INTERRUPT: | |
399 | /* too small? */ | |
400 | if (urb->interval <= 0) | |
401 | return -EINVAL; | |
402 | /* too big? */ | |
403 | switch (dev->speed) { | |
404 | case USB_SPEED_HIGH: /* units are microframes */ | |
405 | // NOTE usb handles 2^15 | |
406 | if (urb->interval > (1024 * 8)) | |
407 | urb->interval = 1024 * 8; | |
408 | temp = 1024 * 8; | |
409 | break; | |
410 | case USB_SPEED_FULL: /* units are frames/msec */ | |
411 | case USB_SPEED_LOW: | |
412 | if (temp == PIPE_INTERRUPT) { | |
413 | if (urb->interval > 255) | |
414 | return -EINVAL; | |
415 | // NOTE ohci only handles up to 32 | |
416 | temp = 128; | |
417 | } else { | |
418 | if (urb->interval > 1024) | |
419 | urb->interval = 1024; | |
420 | // NOTE usb and ohci handle up to 2^15 | |
421 | temp = 1024; | |
422 | } | |
423 | break; | |
424 | default: | |
425 | return -EINVAL; | |
426 | } | |
427 | /* power of two? */ | |
428 | while (temp > urb->interval) | |
429 | temp >>= 1; | |
430 | urb->interval = temp; | |
431 | } | |
432 | ||
9251644a | 433 | return usb_hcd_submit_urb(urb, mem_flags); |
1da177e4 LT |
434 | } |
435 | ||
436 | /*-------------------------------------------------------------------*/ | |
437 | ||
438 | /** | |
439 | * usb_unlink_urb - abort/cancel a transfer request for an endpoint | |
440 | * @urb: pointer to urb describing a previously submitted request, | |
441 | * may be NULL | |
442 | * | |
beafef07 AS |
443 | * This routine cancels an in-progress request. URBs complete only once |
444 | * per submission, and may be canceled only once per submission. | |
445 | * Successful cancellation means termination of @urb will be expedited | |
446 | * and the completion handler will be called with a status code | |
447 | * indicating that the request has been canceled (rather than any other | |
448 | * code). | |
449 | * | |
450 | * This request is always asynchronous. Success is indicated by | |
451 | * returning -EINPROGRESS, at which time the URB will probably not yet | |
452 | * have been given back to the device driver. When it is eventually | |
453 | * called, the completion function will see @urb->status == -ECONNRESET. | |
454 | * Failure is indicated by usb_unlink_urb() returning any other value. | |
455 | * Unlinking will fail when @urb is not currently "linked" (i.e., it was | |
456 | * never submitted, or it was unlinked before, or the hardware is already | |
457 | * finished with it), even if the completion handler has not yet run. | |
1da177e4 LT |
458 | * |
459 | * Unlinking and Endpoint Queues: | |
460 | * | |
beafef07 AS |
461 | * [The behaviors and guarantees described below do not apply to virtual |
462 | * root hubs but only to endpoint queues for physical USB devices.] | |
463 | * | |
1da177e4 LT |
464 | * Host Controller Drivers (HCDs) place all the URBs for a particular |
465 | * endpoint in a queue. Normally the queue advances as the controller | |
8835f665 | 466 | * hardware processes each request. But when an URB terminates with an |
beafef07 AS |
467 | * error its queue generally stops (see below), at least until that URB's |
468 | * completion routine returns. It is guaranteed that a stopped queue | |
469 | * will not restart until all its unlinked URBs have been fully retired, | |
470 | * with their completion routines run, even if that's not until some time | |
471 | * after the original completion handler returns. The same behavior and | |
472 | * guarantee apply when an URB terminates because it was unlinked. | |
473 | * | |
474 | * Bulk and interrupt endpoint queues are guaranteed to stop whenever an | |
475 | * URB terminates with any sort of error, including -ECONNRESET, -ENOENT, | |
476 | * and -EREMOTEIO. Control endpoint queues behave the same way except | |
477 | * that they are not guaranteed to stop for -EREMOTEIO errors. Queues | |
478 | * for isochronous endpoints are treated differently, because they must | |
479 | * advance at fixed rates. Such queues do not stop when an URB | |
480 | * encounters an error or is unlinked. An unlinked isochronous URB may | |
481 | * leave a gap in the stream of packets; it is undefined whether such | |
482 | * gaps can be filled in. | |
483 | * | |
484 | * Note that early termination of an URB because a short packet was | |
485 | * received will generate a -EREMOTEIO error if and only if the | |
486 | * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device | |
487 | * drivers can build deep queues for large or complex bulk transfers | |
488 | * and clean them up reliably after any sort of aborted transfer by | |
489 | * unlinking all pending URBs at the first fault. | |
490 | * | |
491 | * When a control URB terminates with an error other than -EREMOTEIO, it | |
492 | * is quite likely that the status stage of the transfer will not take | |
493 | * place. | |
1da177e4 LT |
494 | */ |
495 | int usb_unlink_urb(struct urb *urb) | |
496 | { | |
497 | if (!urb) | |
498 | return -EINVAL; | |
a6d2bb9f | 499 | if (!(urb->dev && urb->dev->bus)) |
1da177e4 | 500 | return -ENODEV; |
a6d2bb9f | 501 | return usb_hcd_unlink_urb(urb, -ECONNRESET); |
1da177e4 LT |
502 | } |
503 | ||
504 | /** | |
505 | * usb_kill_urb - cancel a transfer request and wait for it to finish | |
506 | * @urb: pointer to URB describing a previously submitted request, | |
507 | * may be NULL | |
508 | * | |
509 | * This routine cancels an in-progress request. It is guaranteed that | |
510 | * upon return all completion handlers will have finished and the URB | |
511 | * will be totally idle and available for reuse. These features make | |
512 | * this an ideal way to stop I/O in a disconnect() callback or close() | |
513 | * function. If the request has not already finished or been unlinked | |
514 | * the completion handler will see urb->status == -ENOENT. | |
515 | * | |
516 | * While the routine is running, attempts to resubmit the URB will fail | |
517 | * with error -EPERM. Thus even if the URB's completion handler always | |
518 | * tries to resubmit, it will not succeed and the URB will become idle. | |
519 | * | |
520 | * This routine may not be used in an interrupt context (such as a bottom | |
521 | * half or a completion handler), or when holding a spinlock, or in other | |
522 | * situations where the caller can't schedule(). | |
523 | */ | |
524 | void usb_kill_urb(struct urb *urb) | |
525 | { | |
e9aa795a | 526 | might_sleep(); |
a6d2bb9f | 527 | if (!(urb && urb->dev && urb->dev->bus)) |
1da177e4 LT |
528 | return; |
529 | spin_lock_irq(&urb->lock); | |
530 | ++urb->reject; | |
531 | spin_unlock_irq(&urb->lock); | |
532 | ||
a6d2bb9f | 533 | usb_hcd_unlink_urb(urb, -ENOENT); |
1da177e4 LT |
534 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); |
535 | ||
536 | spin_lock_irq(&urb->lock); | |
537 | --urb->reject; | |
538 | spin_unlock_irq(&urb->lock); | |
539 | } | |
540 | ||
51a2f077 ON |
541 | /** |
542 | * usb_kill_anchored_urbs - cancel transfer requests en masse | |
543 | * @anchor: anchor the requests are bound to | |
544 | * | |
545 | * this allows all outstanding URBs to be killed starting | |
546 | * from the back of the queue | |
547 | */ | |
548 | void usb_kill_anchored_urbs(struct usb_anchor *anchor) | |
549 | { | |
550 | struct urb *victim; | |
551 | ||
552 | spin_lock_irq(&anchor->lock); | |
553 | while (!list_empty(&anchor->urb_list)) { | |
554 | victim = list_entry(anchor->urb_list.prev, struct urb, anchor_list); | |
555 | /* we must make sure the URB isn't freed before we kill it*/ | |
556 | usb_get_urb(victim); | |
557 | spin_unlock_irq(&anchor->lock); | |
558 | /* this will unanchor the URB */ | |
559 | usb_kill_urb(victim); | |
560 | usb_put_urb(victim); | |
561 | spin_lock_irq(&anchor->lock); | |
562 | } | |
563 | spin_unlock_irq(&anchor->lock); | |
564 | } | |
565 | EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); | |
566 | ||
567 | /** | |
568 | * usb_wait_anchor_empty_timeout - wait for an anchor to be unused | |
569 | * @anchor: the anchor you want to become unused | |
570 | * @timeout: how long you are willing to wait in milliseconds | |
571 | * | |
572 | * Call this is you want to be sure all an anchor's | |
573 | * URBs have finished | |
574 | */ | |
575 | int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, | |
576 | unsigned int timeout) | |
577 | { | |
578 | return wait_event_timeout(anchor->wait, list_empty(&anchor->urb_list), | |
579 | msecs_to_jiffies(timeout)); | |
580 | } | |
581 | EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); | |
582 | ||
1da177e4 LT |
583 | EXPORT_SYMBOL(usb_init_urb); |
584 | EXPORT_SYMBOL(usb_alloc_urb); | |
585 | EXPORT_SYMBOL(usb_free_urb); | |
586 | EXPORT_SYMBOL(usb_get_urb); | |
587 | EXPORT_SYMBOL(usb_submit_urb); | |
588 | EXPORT_SYMBOL(usb_unlink_urb); | |
589 | EXPORT_SYMBOL(usb_kill_urb); |