Commit | Line | Data |
---|---|---|
b65fba3d GKH |
1 | /* |
2 | * Released under the GPLv2 only. | |
3 | * SPDX-License-Identifier: GPL-2.0 | |
4 | */ | |
5 | ||
1da177e4 LT |
6 | #include <linux/module.h> |
7 | #include <linux/string.h> | |
8 | #include <linux/bitops.h> | |
9 | #include <linux/slab.h> | |
d617bc83 | 10 | #include <linux/log2.h> |
1da177e4 | 11 | #include <linux/usb.h> |
51a2f077 | 12 | #include <linux/wait.h> |
27729aad | 13 | #include <linux/usb/hcd.h> |
10e232c5 | 14 | #include <linux/scatterlist.h> |
1da177e4 LT |
15 | |
16 | #define to_urb(d) container_of(d, struct urb, kref) | |
17 | ||
6a2839be | 18 | |
1da177e4 LT |
19 | static void urb_destroy(struct kref *kref) |
20 | { | |
21 | struct urb *urb = to_urb(kref); | |
51a2f077 | 22 | |
8b3b01c8 MH |
23 | if (urb->transfer_flags & URB_FREE_BUFFER) |
24 | kfree(urb->transfer_buffer); | |
25 | ||
1da177e4 LT |
26 | kfree(urb); |
27 | } | |
28 | ||
29 | /** | |
30 | * usb_init_urb - initializes a urb so that it can be used by a USB driver | |
31 | * @urb: pointer to the urb to initialize | |
32 | * | |
33 | * Initializes a urb so that the USB subsystem can use it properly. | |
34 | * | |
35 | * If a urb is created with a call to usb_alloc_urb() it is not | |
36 | * necessary to call this function. Only use this if you allocate the | |
37 | * space for a struct urb on your own. If you call this function, be | |
38 | * careful when freeing the memory for your urb that it is no longer in | |
39 | * use by the USB core. | |
40 | * | |
41 | * Only use this function if you _really_ understand what you are doing. | |
42 | */ | |
43 | void usb_init_urb(struct urb *urb) | |
44 | { | |
45 | if (urb) { | |
46 | memset(urb, 0, sizeof(*urb)); | |
47 | kref_init(&urb->kref); | |
51a2f077 | 48 | INIT_LIST_HEAD(&urb->anchor_list); |
1da177e4 LT |
49 | } |
50 | } | |
782e70c6 | 51 | EXPORT_SYMBOL_GPL(usb_init_urb); |
1da177e4 LT |
52 | |
53 | /** | |
54 | * usb_alloc_urb - creates a new urb for a USB driver to use | |
55 | * @iso_packets: number of iso packets for this urb | |
56 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list of | |
57 | * valid options for this. | |
58 | * | |
59 | * Creates an urb for the USB driver to use, initializes a few internal | |
025d4430 | 60 | * structures, increments the usage counter, and returns a pointer to it. |
1da177e4 | 61 | * |
1da177e4 LT |
62 | * If the driver want to use this urb for interrupt, control, or bulk |
63 | * endpoints, pass '0' as the number of iso packets. | |
64 | * | |
65 | * The driver must call usb_free_urb() when it is finished with the urb. | |
626f090c YB |
66 | * |
67 | * Return: A pointer to the new urb, or %NULL if no memory is available. | |
1da177e4 | 68 | */ |
55016f10 | 69 | struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) |
1da177e4 LT |
70 | { |
71 | struct urb *urb; | |
72 | ||
ec17cf1c | 73 | urb = kmalloc(sizeof(struct urb) + |
1da177e4 LT |
74 | iso_packets * sizeof(struct usb_iso_packet_descriptor), |
75 | mem_flags); | |
b62a7a99 | 76 | if (!urb) |
1da177e4 | 77 | return NULL; |
1da177e4 LT |
78 | usb_init_urb(urb); |
79 | return urb; | |
80 | } | |
782e70c6 | 81 | EXPORT_SYMBOL_GPL(usb_alloc_urb); |
1da177e4 LT |
82 | |
83 | /** | |
84 | * usb_free_urb - frees the memory used by a urb when all users of it are finished | |
85 | * @urb: pointer to the urb to free, may be NULL | |
86 | * | |
87 | * Must be called when a user of a urb is finished with it. When the last user | |
88 | * of the urb calls this function, the memory of the urb is freed. | |
89 | * | |
2870fde7 RV |
90 | * Note: The transfer buffer associated with the urb is not freed unless the |
91 | * URB_FREE_BUFFER transfer flag is set. | |
1da177e4 LT |
92 | */ |
93 | void usb_free_urb(struct urb *urb) | |
94 | { | |
95 | if (urb) | |
96 | kref_put(&urb->kref, urb_destroy); | |
97 | } | |
782e70c6 | 98 | EXPORT_SYMBOL_GPL(usb_free_urb); |
1da177e4 LT |
99 | |
100 | /** | |
101 | * usb_get_urb - increments the reference count of the urb | |
102 | * @urb: pointer to the urb to modify, may be NULL | |
103 | * | |
104 | * This must be called whenever a urb is transferred from a device driver to a | |
105 | * host controller driver. This allows proper reference counting to happen | |
106 | * for urbs. | |
107 | * | |
626f090c | 108 | * Return: A pointer to the urb with the incremented reference counter. |
1da177e4 | 109 | */ |
2c044a48 | 110 | struct urb *usb_get_urb(struct urb *urb) |
1da177e4 LT |
111 | { |
112 | if (urb) | |
113 | kref_get(&urb->kref); | |
114 | return urb; | |
115 | } | |
782e70c6 | 116 | EXPORT_SYMBOL_GPL(usb_get_urb); |
51a2f077 ON |
117 | |
118 | /** | |
119 | * usb_anchor_urb - anchors an URB while it is processed | |
120 | * @urb: pointer to the urb to anchor | |
121 | * @anchor: pointer to the anchor | |
122 | * | |
123 | * This can be called to have access to URBs which are to be executed | |
124 | * without bothering to track them | |
125 | */ | |
126 | void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) | |
127 | { | |
128 | unsigned long flags; | |
129 | ||
130 | spin_lock_irqsave(&anchor->lock, flags); | |
131 | usb_get_urb(urb); | |
132 | list_add_tail(&urb->anchor_list, &anchor->urb_list); | |
133 | urb->anchor = anchor; | |
6a2839be | 134 | |
ae416ba4 | 135 | if (unlikely(anchor->poisoned)) |
49367d8f | 136 | atomic_inc(&urb->reject); |
6a2839be | 137 | |
51a2f077 ON |
138 | spin_unlock_irqrestore(&anchor->lock, flags); |
139 | } | |
140 | EXPORT_SYMBOL_GPL(usb_anchor_urb); | |
141 | ||
6ec4147e HG |
142 | static int usb_anchor_check_wakeup(struct usb_anchor *anchor) |
143 | { | |
144 | return atomic_read(&anchor->suspend_wakeups) == 0 && | |
145 | list_empty(&anchor->urb_list); | |
146 | } | |
147 | ||
b3e67044 CL |
148 | /* Callers must hold anchor->lock */ |
149 | static void __usb_unanchor_urb(struct urb *urb, struct usb_anchor *anchor) | |
150 | { | |
151 | urb->anchor = NULL; | |
152 | list_del(&urb->anchor_list); | |
153 | usb_put_urb(urb); | |
6ec4147e | 154 | if (usb_anchor_check_wakeup(anchor)) |
b3e67044 CL |
155 | wake_up(&anchor->wait); |
156 | } | |
157 | ||
51a2f077 ON |
158 | /** |
159 | * usb_unanchor_urb - unanchors an URB | |
160 | * @urb: pointer to the urb to anchor | |
161 | * | |
162 | * Call this to stop the system keeping track of this URB | |
163 | */ | |
164 | void usb_unanchor_urb(struct urb *urb) | |
165 | { | |
166 | unsigned long flags; | |
167 | struct usb_anchor *anchor; | |
168 | ||
169 | if (!urb) | |
170 | return; | |
171 | ||
172 | anchor = urb->anchor; | |
173 | if (!anchor) | |
174 | return; | |
175 | ||
176 | spin_lock_irqsave(&anchor->lock, flags); | |
b3e67044 CL |
177 | /* |
178 | * At this point, we could be competing with another thread which | |
179 | * has the same intention. To protect the urb from being unanchored | |
180 | * twice, only the winner of the race gets the job. | |
181 | */ | |
182 | if (likely(anchor == urb->anchor)) | |
183 | __usb_unanchor_urb(urb, anchor); | |
51a2f077 | 184 | spin_unlock_irqrestore(&anchor->lock, flags); |
51a2f077 ON |
185 | } |
186 | EXPORT_SYMBOL_GPL(usb_unanchor_urb); | |
187 | ||
1da177e4 LT |
188 | /*-------------------------------------------------------------------*/ |
189 | ||
e901b987 TI |
190 | static const int pipetypes[4] = { |
191 | PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT | |
192 | }; | |
193 | ||
194 | /** | |
195 | * usb_urb_ep_type_check - sanity check of endpoint in the given urb | |
196 | * @urb: urb to be checked | |
197 | * | |
198 | * This performs a light-weight sanity check for the endpoint in the | |
199 | * given urb. It returns 0 if the urb contains a valid endpoint, otherwise | |
200 | * a negative error code. | |
201 | */ | |
202 | int usb_urb_ep_type_check(const struct urb *urb) | |
203 | { | |
204 | const struct usb_host_endpoint *ep; | |
205 | ||
206 | ep = usb_pipe_endpoint(urb->dev, urb->pipe); | |
207 | if (!ep) | |
208 | return -EINVAL; | |
209 | if (usb_pipetype(urb->pipe) != pipetypes[usb_endpoint_type(&ep->desc)]) | |
210 | return -EINVAL; | |
211 | return 0; | |
212 | } | |
213 | EXPORT_SYMBOL_GPL(usb_urb_ep_type_check); | |
214 | ||
1da177e4 LT |
215 | /** |
216 | * usb_submit_urb - issue an asynchronous transfer request for an endpoint | |
217 | * @urb: pointer to the urb describing the request | |
218 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list | |
219 | * of valid options for this. | |
220 | * | |
221 | * This submits a transfer request, and transfers control of the URB | |
222 | * describing that request to the USB subsystem. Request completion will | |
223 | * be indicated later, asynchronously, by calling the completion handler. | |
224 | * The three types of completion are success, error, and unlink | |
2c044a48 | 225 | * (a software-induced fault, also called "request cancellation"). |
1da177e4 LT |
226 | * |
227 | * URBs may be submitted in interrupt context. | |
228 | * | |
229 | * The caller must have correctly initialized the URB before submitting | |
230 | * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are | |
231 | * available to ensure that most fields are correctly initialized, for | |
232 | * the particular kind of transfer, although they will not initialize | |
233 | * any transfer flags. | |
234 | * | |
626f090c YB |
235 | * If the submission is successful, the complete() callback from the URB |
236 | * will be called exactly once, when the USB core and Host Controller Driver | |
237 | * (HCD) are finished with the URB. When the completion function is called, | |
238 | * control of the URB is returned to the device driver which issued the | |
239 | * request. The completion handler may then immediately free or reuse that | |
240 | * URB. | |
1da177e4 LT |
241 | * |
242 | * With few exceptions, USB device drivers should never access URB fields | |
243 | * provided by usbcore or the HCD until its complete() is called. | |
244 | * The exceptions relate to periodic transfer scheduling. For both | |
245 | * interrupt and isochronous urbs, as part of successful URB submission | |
246 | * urb->interval is modified to reflect the actual transfer period used | |
247 | * (normally some power of two units). And for isochronous urbs, | |
248 | * urb->start_frame is modified to reflect when the URB's transfers were | |
a03bede5 AS |
249 | * scheduled to start. |
250 | * | |
251 | * Not all isochronous transfer scheduling policies will work, but most | |
252 | * host controller drivers should easily handle ISO queues going from now | |
253 | * until 10-200 msec into the future. Drivers should try to keep at | |
254 | * least one or two msec of data in the queue; many controllers require | |
255 | * that new transfers start at least 1 msec in the future when they are | |
256 | * added. If the driver is unable to keep up and the queue empties out, | |
257 | * the behavior for new submissions is governed by the URB_ISO_ASAP flag. | |
258 | * If the flag is set, or if the queue is idle, then the URB is always | |
259 | * assigned to the first available (and not yet expired) slot in the | |
260 | * endpoint's schedule. If the flag is not set and the queue is active | |
261 | * then the URB is always assigned to the next slot in the schedule | |
262 | * following the end of the endpoint's previous URB, even if that slot is | |
263 | * in the past. When a packet is assigned in this way to a slot that has | |
264 | * already expired, the packet is not transmitted and the corresponding | |
265 | * usb_iso_packet_descriptor's status field will return -EXDEV. If this | |
266 | * would happen to all the packets in the URB, submission fails with a | |
267 | * -EXDEV error code. | |
1da177e4 LT |
268 | * |
269 | * For control endpoints, the synchronous usb_control_msg() call is | |
270 | * often used (in non-interrupt context) instead of this call. | |
271 | * That is often used through convenience wrappers, for the requests | |
272 | * that are standardized in the USB 2.0 specification. For bulk | |
273 | * endpoints, a synchronous usb_bulk_msg() call is available. | |
274 | * | |
626f090c YB |
275 | * Return: |
276 | * 0 on successful submissions. A negative error number otherwise. | |
277 | * | |
1da177e4 LT |
278 | * Request Queuing: |
279 | * | |
280 | * URBs may be submitted to endpoints before previous ones complete, to | |
281 | * minimize the impact of interrupt latencies and system overhead on data | |
282 | * throughput. With that queuing policy, an endpoint's queue would never | |
283 | * be empty. This is required for continuous isochronous data streams, | |
284 | * and may also be required for some kinds of interrupt transfers. Such | |
285 | * queuing also maximizes bandwidth utilization by letting USB controllers | |
286 | * start work on later requests before driver software has finished the | |
287 | * completion processing for earlier (successful) requests. | |
288 | * | |
289 | * As of Linux 2.6, all USB endpoint transfer queues support depths greater | |
290 | * than one. This was previously a HCD-specific behavior, except for ISO | |
291 | * transfers. Non-isochronous endpoint queues are inactive during cleanup | |
093cf723 | 292 | * after faults (transfer errors or cancellation). |
1da177e4 LT |
293 | * |
294 | * Reserved Bandwidth Transfers: | |
295 | * | |
296 | * Periodic transfers (interrupt or isochronous) are performed repeatedly, | |
297 | * using the interval specified in the urb. Submitting the first urb to | |
298 | * the endpoint reserves the bandwidth necessary to make those transfers. | |
299 | * If the USB subsystem can't allocate sufficient bandwidth to perform | |
300 | * the periodic request, submitting such a periodic request should fail. | |
301 | * | |
79abb1ab SS |
302 | * For devices under xHCI, the bandwidth is reserved at configuration time, or |
303 | * when the alt setting is selected. If there is not enough bus bandwidth, the | |
304 | * configuration/alt setting request will fail. Therefore, submissions to | |
305 | * periodic endpoints on devices under xHCI should never fail due to bandwidth | |
306 | * constraints. | |
307 | * | |
1da177e4 LT |
308 | * Device drivers must explicitly request that repetition, by ensuring that |
309 | * some URB is always on the endpoint's queue (except possibly for short | |
025d4430 | 310 | * periods during completion callbacks). When there is no longer an urb |
1da177e4 LT |
311 | * queued, the endpoint's bandwidth reservation is canceled. This means |
312 | * drivers can use their completion handlers to ensure they keep bandwidth | |
313 | * they need, by reinitializing and resubmitting the just-completed urb | |
314 | * until the driver longer needs that periodic bandwidth. | |
315 | * | |
316 | * Memory Flags: | |
317 | * | |
318 | * The general rules for how to decide which mem_flags to use | |
319 | * are the same as for kmalloc. There are four | |
320 | * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and | |
321 | * GFP_ATOMIC. | |
322 | * | |
323 | * GFP_NOFS is not ever used, as it has not been implemented yet. | |
324 | * | |
325 | * GFP_ATOMIC is used when | |
326 | * (a) you are inside a completion handler, an interrupt, bottom half, | |
327 | * tasklet or timer, or | |
328 | * (b) you are holding a spinlock or rwlock (does not apply to | |
329 | * semaphores), or | |
330 | * (c) current->state != TASK_RUNNING, this is the case only after | |
331 | * you've changed it. | |
2c044a48 | 332 | * |
1da177e4 LT |
333 | * GFP_NOIO is used in the block io path and error handling of storage |
334 | * devices. | |
335 | * | |
336 | * All other situations use GFP_KERNEL. | |
337 | * | |
338 | * Some more specific rules for mem_flags can be inferred, such as | |
339 | * (1) start_xmit, timeout, and receive methods of network drivers must | |
340 | * use GFP_ATOMIC (they are called with a spinlock held); | |
341 | * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also | |
342 | * called with a spinlock held); | |
343 | * (3) If you use a kernel thread with a network driver you must use | |
344 | * GFP_NOIO, unless (b) or (c) apply; | |
345 | * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c) | |
346 | * apply or your are in a storage driver's block io path; | |
347 | * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and | |
348 | * (6) changing firmware on a running storage or net device uses | |
349 | * GFP_NOIO, unless b) or c) apply | |
350 | * | |
351 | */ | |
55016f10 | 352 | int usb_submit_urb(struct urb *urb, gfp_t mem_flags) |
1da177e4 | 353 | { |
5b653c79 AS |
354 | int xfertype, max; |
355 | struct usb_device *dev; | |
356 | struct usb_host_endpoint *ep; | |
357 | int is_out; | |
3482528e | 358 | unsigned int allowed; |
1da177e4 | 359 | |
2f02bc8a | 360 | if (!urb || !urb->complete) |
1da177e4 | 361 | return -EINVAL; |
2f02bc8a | 362 | if (urb->hcpriv) { |
2f964780 | 363 | WARN_ONCE(1, "URB %pK submitted while active\n", urb); |
2f02bc8a AS |
364 | return -EBUSY; |
365 | } | |
366 | ||
2c044a48 | 367 | dev = urb->dev; |
6da9c990 | 368 | if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED)) |
1da177e4 | 369 | return -ENODEV; |
1da177e4 | 370 | |
5b653c79 AS |
371 | /* For now, get the endpoint from the pipe. Eventually drivers |
372 | * will be required to set urb->ep directly and we will eliminate | |
373 | * urb->pipe. | |
374 | */ | |
fe54b058 | 375 | ep = usb_pipe_endpoint(dev, urb->pipe); |
5b653c79 AS |
376 | if (!ep) |
377 | return -ENOENT; | |
378 | ||
379 | urb->ep = ep; | |
1da177e4 LT |
380 | urb->status = -EINPROGRESS; |
381 | urb->actual_length = 0; | |
1da177e4 LT |
382 | |
383 | /* Lots of sanity checks, so HCDs can rely on clean data | |
384 | * and don't need to duplicate tests | |
385 | */ | |
5b653c79 | 386 | xfertype = usb_endpoint_type(&ep->desc); |
fea34091 AS |
387 | if (xfertype == USB_ENDPOINT_XFER_CONTROL) { |
388 | struct usb_ctrlrequest *setup = | |
389 | (struct usb_ctrlrequest *) urb->setup_packet; | |
390 | ||
391 | if (!setup) | |
392 | return -ENOEXEC; | |
393 | is_out = !(setup->bRequestType & USB_DIR_IN) || | |
394 | !setup->wLength; | |
395 | } else { | |
396 | is_out = usb_endpoint_dir_out(&ep->desc); | |
397 | } | |
398 | ||
ff9c895f AS |
399 | /* Clear the internal flags and cache the direction for later use */ |
400 | urb->transfer_flags &= ~(URB_DIR_MASK | URB_DMA_MAP_SINGLE | | |
401 | URB_DMA_MAP_PAGE | URB_DMA_MAP_SG | URB_MAP_LOCAL | | |
402 | URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL | | |
403 | URB_DMA_SG_COMBINED); | |
404 | urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN); | |
1da177e4 | 405 | |
5b653c79 AS |
406 | if (xfertype != USB_ENDPOINT_XFER_CONTROL && |
407 | dev->state < USB_STATE_CONFIGURED) | |
1da177e4 LT |
408 | return -ENODEV; |
409 | ||
29cc8897 | 410 | max = usb_endpoint_maxp(&ep->desc); |
1da177e4 LT |
411 | if (max <= 0) { |
412 | dev_dbg(&dev->dev, | |
413 | "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n", | |
5b653c79 | 414 | usb_endpoint_num(&ep->desc), is_out ? "out" : "in", |
441b62c1 | 415 | __func__, max); |
1da177e4 LT |
416 | return -EMSGSIZE; |
417 | } | |
418 | ||
419 | /* periodic transfers limit size per frame/uframe, | |
420 | * but drivers only control those sizes for ISO. | |
421 | * while we're checking, initialize return status. | |
422 | */ | |
5b653c79 | 423 | if (xfertype == USB_ENDPOINT_XFER_ISOC) { |
1da177e4 LT |
424 | int n, len; |
425 | ||
500132a0 PZ |
426 | /* SuperSpeed isoc endpoints have up to 16 bursts of up to |
427 | * 3 packets each | |
428 | */ | |
8a1b2725 | 429 | if (dev->speed >= USB_SPEED_SUPER) { |
500132a0 PZ |
430 | int burst = 1 + ep->ss_ep_comp.bMaxBurst; |
431 | int mult = USB_SS_MULT(ep->ss_ep_comp.bmAttributes); | |
432 | max *= burst; | |
433 | max *= mult; | |
434 | } | |
435 | ||
1da177e4 | 436 | /* "high bandwidth" mode, 1-3 packets/uframe? */ |
5909cbc8 MK |
437 | if (dev->speed == USB_SPEED_HIGH) |
438 | max *= usb_endpoint_maxp_mult(&ep->desc); | |
1da177e4 | 439 | |
2c044a48 | 440 | if (urb->number_of_packets <= 0) |
1da177e4 LT |
441 | return -EINVAL; |
442 | for (n = 0; n < urb->number_of_packets; n++) { | |
9251644a | 443 | len = urb->iso_frame_desc[n].length; |
2c044a48 | 444 | if (len < 0 || len > max) |
1da177e4 | 445 | return -EMSGSIZE; |
9251644a ON |
446 | urb->iso_frame_desc[n].status = -EXDEV; |
447 | urb->iso_frame_desc[n].actual_length = 0; | |
1da177e4 | 448 | } |
bcc48f1a ML |
449 | } else if (urb->num_sgs && !urb->dev->bus->no_sg_constraint && |
450 | dev->speed != USB_SPEED_WIRELESS) { | |
10e232c5 ML |
451 | struct scatterlist *sg; |
452 | int i; | |
453 | ||
454 | for_each_sg(urb->sg, sg, urb->num_sgs - 1, i) | |
455 | if (sg->length % max) | |
456 | return -EINVAL; | |
1da177e4 LT |
457 | } |
458 | ||
459 | /* the I/O buffer must be mapped/unmapped, except when length=0 */ | |
71d2718f | 460 | if (urb->transfer_buffer_length > INT_MAX) |
1da177e4 LT |
461 | return -EMSGSIZE; |
462 | ||
3482528e GKH |
463 | /* |
464 | * stuff that drivers shouldn't do, but which shouldn't | |
1da177e4 LT |
465 | * cause problems in HCDs if they get it wrong. |
466 | */ | |
f661c6f8 AS |
467 | |
468 | /* Check that the pipe's type matches the endpoint's type */ | |
e901b987 | 469 | if (usb_urb_ep_type_check(urb)) |
0cb54a3e | 470 | dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n", |
f7dd6491 | 471 | usb_pipetype(urb->pipe), pipetypes[xfertype]); |
1da177e4 | 472 | |
0cb54a3e | 473 | /* Check against a simple/standard policy */ |
0ede76fc AS |
474 | allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK | |
475 | URB_FREE_BUFFER); | |
5b653c79 AS |
476 | switch (xfertype) { |
477 | case USB_ENDPOINT_XFER_BULK: | |
9672f0fe | 478 | case USB_ENDPOINT_XFER_INT: |
1da177e4 LT |
479 | if (is_out) |
480 | allowed |= URB_ZERO_PACKET; | |
481 | /* FALLTHROUGH */ | |
5b653c79 | 482 | case USB_ENDPOINT_XFER_CONTROL: |
1da177e4 LT |
483 | allowed |= URB_NO_FSBR; /* only affects UHCI */ |
484 | /* FALLTHROUGH */ | |
485 | default: /* all non-iso endpoints */ | |
486 | if (!is_out) | |
487 | allowed |= URB_SHORT_NOT_OK; | |
488 | break; | |
5b653c79 | 489 | case USB_ENDPOINT_XFER_ISOC: |
1da177e4 LT |
490 | allowed |= URB_ISO_ASAP; |
491 | break; | |
492 | } | |
0cb54a3e | 493 | allowed &= urb->transfer_flags; |
1da177e4 | 494 | |
0cb54a3e AS |
495 | /* warn if submitter gave bogus flags */ |
496 | if (allowed != urb->transfer_flags) | |
497 | dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n", | |
498 | urb->transfer_flags, allowed); | |
3482528e | 499 | |
1da177e4 LT |
500 | /* |
501 | * Force periodic transfer intervals to be legal values that are | |
502 | * a power of two (so HCDs don't need to). | |
503 | * | |
504 | * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC | |
505 | * supports different values... this uses EHCI/UHCI defaults (and | |
506 | * EHCI can use smaller non-default values). | |
507 | */ | |
5b653c79 AS |
508 | switch (xfertype) { |
509 | case USB_ENDPOINT_XFER_ISOC: | |
510 | case USB_ENDPOINT_XFER_INT: | |
1da177e4 | 511 | /* too small? */ |
8e08b976 | 512 | switch (dev->speed) { |
551cdbbe | 513 | case USB_SPEED_WIRELESS: |
a2cd612d TP |
514 | if ((urb->interval < 6) |
515 | && (xfertype == USB_ENDPOINT_XFER_INT)) | |
8e08b976 | 516 | return -EINVAL; |
8e08b976 DV |
517 | default: |
518 | if (urb->interval <= 0) | |
519 | return -EINVAL; | |
520 | break; | |
521 | } | |
1da177e4 LT |
522 | /* too big? */ |
523 | switch (dev->speed) { | |
8a1b2725 | 524 | case USB_SPEED_SUPER_PLUS: |
6b403b02 SS |
525 | case USB_SPEED_SUPER: /* units are 125us */ |
526 | /* Handle up to 2^(16-1) microframes */ | |
527 | if (urb->interval > (1 << 15)) | |
528 | return -EINVAL; | |
529 | max = 1 << 15; | |
f09a15e6 | 530 | break; |
551cdbbe | 531 | case USB_SPEED_WIRELESS: |
8e08b976 DV |
532 | if (urb->interval > 16) |
533 | return -EINVAL; | |
534 | break; | |
1da177e4 | 535 | case USB_SPEED_HIGH: /* units are microframes */ |
2c044a48 | 536 | /* NOTE usb handles 2^15 */ |
1da177e4 LT |
537 | if (urb->interval > (1024 * 8)) |
538 | urb->interval = 1024 * 8; | |
5b653c79 | 539 | max = 1024 * 8; |
1da177e4 LT |
540 | break; |
541 | case USB_SPEED_FULL: /* units are frames/msec */ | |
542 | case USB_SPEED_LOW: | |
5b653c79 | 543 | if (xfertype == USB_ENDPOINT_XFER_INT) { |
1da177e4 LT |
544 | if (urb->interval > 255) |
545 | return -EINVAL; | |
2c044a48 | 546 | /* NOTE ohci only handles up to 32 */ |
5b653c79 | 547 | max = 128; |
1da177e4 LT |
548 | } else { |
549 | if (urb->interval > 1024) | |
550 | urb->interval = 1024; | |
2c044a48 | 551 | /* NOTE usb and ohci handle up to 2^15 */ |
5b653c79 | 552 | max = 1024; |
1da177e4 LT |
553 | } |
554 | break; | |
555 | default: | |
556 | return -EINVAL; | |
557 | } | |
551cdbbe | 558 | if (dev->speed != USB_SPEED_WIRELESS) { |
8e08b976 DV |
559 | /* Round down to a power of 2, no more than max */ |
560 | urb->interval = min(max, 1 << ilog2(urb->interval)); | |
561 | } | |
1da177e4 LT |
562 | } |
563 | ||
9251644a | 564 | return usb_hcd_submit_urb(urb, mem_flags); |
1da177e4 | 565 | } |
782e70c6 | 566 | EXPORT_SYMBOL_GPL(usb_submit_urb); |
1da177e4 LT |
567 | |
568 | /*-------------------------------------------------------------------*/ | |
569 | ||
570 | /** | |
571 | * usb_unlink_urb - abort/cancel a transfer request for an endpoint | |
572 | * @urb: pointer to urb describing a previously submitted request, | |
573 | * may be NULL | |
574 | * | |
beafef07 AS |
575 | * This routine cancels an in-progress request. URBs complete only once |
576 | * per submission, and may be canceled only once per submission. | |
577 | * Successful cancellation means termination of @urb will be expedited | |
578 | * and the completion handler will be called with a status code | |
579 | * indicating that the request has been canceled (rather than any other | |
580 | * code). | |
581 | * | |
cde217a5 AS |
582 | * Drivers should not call this routine or related routines, such as |
583 | * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect | |
584 | * method has returned. The disconnect function should synchronize with | |
585 | * a driver's I/O routines to insure that all URB-related activity has | |
586 | * completed before it returns. | |
587 | * | |
371f3b49 SAS |
588 | * This request is asynchronous, however the HCD might call the ->complete() |
589 | * callback during unlink. Therefore when drivers call usb_unlink_urb(), they | |
590 | * must not hold any locks that may be taken by the completion function. | |
591 | * Success is indicated by returning -EINPROGRESS, at which time the URB will | |
592 | * probably not yet have been given back to the device driver. When it is | |
593 | * eventually called, the completion function will see @urb->status == | |
594 | * -ECONNRESET. | |
beafef07 AS |
595 | * Failure is indicated by usb_unlink_urb() returning any other value. |
596 | * Unlinking will fail when @urb is not currently "linked" (i.e., it was | |
597 | * never submitted, or it was unlinked before, or the hardware is already | |
598 | * finished with it), even if the completion handler has not yet run. | |
1da177e4 | 599 | * |
da8bfb09 AS |
600 | * The URB must not be deallocated while this routine is running. In |
601 | * particular, when a driver calls this routine, it must insure that the | |
602 | * completion handler cannot deallocate the URB. | |
603 | * | |
626f090c YB |
604 | * Return: -EINPROGRESS on success. See description for other values on |
605 | * failure. | |
606 | * | |
1da177e4 LT |
607 | * Unlinking and Endpoint Queues: |
608 | * | |
beafef07 AS |
609 | * [The behaviors and guarantees described below do not apply to virtual |
610 | * root hubs but only to endpoint queues for physical USB devices.] | |
611 | * | |
1da177e4 LT |
612 | * Host Controller Drivers (HCDs) place all the URBs for a particular |
613 | * endpoint in a queue. Normally the queue advances as the controller | |
8835f665 | 614 | * hardware processes each request. But when an URB terminates with an |
beafef07 AS |
615 | * error its queue generally stops (see below), at least until that URB's |
616 | * completion routine returns. It is guaranteed that a stopped queue | |
617 | * will not restart until all its unlinked URBs have been fully retired, | |
618 | * with their completion routines run, even if that's not until some time | |
619 | * after the original completion handler returns. The same behavior and | |
620 | * guarantee apply when an URB terminates because it was unlinked. | |
621 | * | |
622 | * Bulk and interrupt endpoint queues are guaranteed to stop whenever an | |
623 | * URB terminates with any sort of error, including -ECONNRESET, -ENOENT, | |
624 | * and -EREMOTEIO. Control endpoint queues behave the same way except | |
625 | * that they are not guaranteed to stop for -EREMOTEIO errors. Queues | |
626 | * for isochronous endpoints are treated differently, because they must | |
627 | * advance at fixed rates. Such queues do not stop when an URB | |
628 | * encounters an error or is unlinked. An unlinked isochronous URB may | |
629 | * leave a gap in the stream of packets; it is undefined whether such | |
630 | * gaps can be filled in. | |
631 | * | |
632 | * Note that early termination of an URB because a short packet was | |
633 | * received will generate a -EREMOTEIO error if and only if the | |
634 | * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device | |
635 | * drivers can build deep queues for large or complex bulk transfers | |
636 | * and clean them up reliably after any sort of aborted transfer by | |
637 | * unlinking all pending URBs at the first fault. | |
638 | * | |
639 | * When a control URB terminates with an error other than -EREMOTEIO, it | |
640 | * is quite likely that the status stage of the transfer will not take | |
641 | * place. | |
1da177e4 LT |
642 | */ |
643 | int usb_unlink_urb(struct urb *urb) | |
644 | { | |
645 | if (!urb) | |
646 | return -EINVAL; | |
d617bc83 | 647 | if (!urb->dev) |
1da177e4 | 648 | return -ENODEV; |
d617bc83 AS |
649 | if (!urb->ep) |
650 | return -EIDRM; | |
a6d2bb9f | 651 | return usb_hcd_unlink_urb(urb, -ECONNRESET); |
1da177e4 | 652 | } |
782e70c6 | 653 | EXPORT_SYMBOL_GPL(usb_unlink_urb); |
1da177e4 LT |
654 | |
655 | /** | |
656 | * usb_kill_urb - cancel a transfer request and wait for it to finish | |
657 | * @urb: pointer to URB describing a previously submitted request, | |
658 | * may be NULL | |
659 | * | |
660 | * This routine cancels an in-progress request. It is guaranteed that | |
661 | * upon return all completion handlers will have finished and the URB | |
662 | * will be totally idle and available for reuse. These features make | |
663 | * this an ideal way to stop I/O in a disconnect() callback or close() | |
664 | * function. If the request has not already finished or been unlinked | |
665 | * the completion handler will see urb->status == -ENOENT. | |
666 | * | |
667 | * While the routine is running, attempts to resubmit the URB will fail | |
668 | * with error -EPERM. Thus even if the URB's completion handler always | |
669 | * tries to resubmit, it will not succeed and the URB will become idle. | |
670 | * | |
da8bfb09 AS |
671 | * The URB must not be deallocated while this routine is running. In |
672 | * particular, when a driver calls this routine, it must insure that the | |
673 | * completion handler cannot deallocate the URB. | |
674 | * | |
1da177e4 LT |
675 | * This routine may not be used in an interrupt context (such as a bottom |
676 | * half or a completion handler), or when holding a spinlock, or in other | |
677 | * situations where the caller can't schedule(). | |
cde217a5 AS |
678 | * |
679 | * This routine should not be called by a driver after its disconnect | |
680 | * method has returned. | |
1da177e4 LT |
681 | */ |
682 | void usb_kill_urb(struct urb *urb) | |
683 | { | |
e9aa795a | 684 | might_sleep(); |
d617bc83 | 685 | if (!(urb && urb->dev && urb->ep)) |
1da177e4 | 686 | return; |
49367d8f | 687 | atomic_inc(&urb->reject); |
1da177e4 | 688 | |
a6d2bb9f | 689 | usb_hcd_unlink_urb(urb, -ENOENT); |
1da177e4 LT |
690 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); |
691 | ||
49367d8f | 692 | atomic_dec(&urb->reject); |
1da177e4 | 693 | } |
782e70c6 | 694 | EXPORT_SYMBOL_GPL(usb_kill_urb); |
1da177e4 | 695 | |
55b447bf ON |
696 | /** |
697 | * usb_poison_urb - reliably kill a transfer and prevent further use of an URB | |
698 | * @urb: pointer to URB describing a previously submitted request, | |
699 | * may be NULL | |
700 | * | |
701 | * This routine cancels an in-progress request. It is guaranteed that | |
702 | * upon return all completion handlers will have finished and the URB | |
703 | * will be totally idle and cannot be reused. These features make | |
704 | * this an ideal way to stop I/O in a disconnect() callback. | |
705 | * If the request has not already finished or been unlinked | |
706 | * the completion handler will see urb->status == -ENOENT. | |
707 | * | |
708 | * After and while the routine runs, attempts to resubmit the URB will fail | |
709 | * with error -EPERM. Thus even if the URB's completion handler always | |
710 | * tries to resubmit, it will not succeed and the URB will become idle. | |
711 | * | |
da8bfb09 AS |
712 | * The URB must not be deallocated while this routine is running. In |
713 | * particular, when a driver calls this routine, it must insure that the | |
714 | * completion handler cannot deallocate the URB. | |
715 | * | |
55b447bf ON |
716 | * This routine may not be used in an interrupt context (such as a bottom |
717 | * half or a completion handler), or when holding a spinlock, or in other | |
718 | * situations where the caller can't schedule(). | |
cde217a5 AS |
719 | * |
720 | * This routine should not be called by a driver after its disconnect | |
721 | * method has returned. | |
55b447bf ON |
722 | */ |
723 | void usb_poison_urb(struct urb *urb) | |
724 | { | |
725 | might_sleep(); | |
68a2bed1 | 726 | if (!urb) |
55b447bf | 727 | return; |
49367d8f | 728 | atomic_inc(&urb->reject); |
55b447bf | 729 | |
68a2bed1 JH |
730 | if (!urb->dev || !urb->ep) |
731 | return; | |
732 | ||
55b447bf ON |
733 | usb_hcd_unlink_urb(urb, -ENOENT); |
734 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); | |
735 | } | |
736 | EXPORT_SYMBOL_GPL(usb_poison_urb); | |
737 | ||
738 | void usb_unpoison_urb(struct urb *urb) | |
739 | { | |
740 | if (!urb) | |
741 | return; | |
742 | ||
49367d8f | 743 | atomic_dec(&urb->reject); |
55b447bf ON |
744 | } |
745 | EXPORT_SYMBOL_GPL(usb_unpoison_urb); | |
746 | ||
8815bb09 ON |
747 | /** |
748 | * usb_block_urb - reliably prevent further use of an URB | |
749 | * @urb: pointer to URB to be blocked, may be NULL | |
750 | * | |
751 | * After the routine has run, attempts to resubmit the URB will fail | |
752 | * with error -EPERM. Thus even if the URB's completion handler always | |
753 | * tries to resubmit, it will not succeed and the URB will become idle. | |
754 | * | |
755 | * The URB must not be deallocated while this routine is running. In | |
756 | * particular, when a driver calls this routine, it must insure that the | |
757 | * completion handler cannot deallocate the URB. | |
758 | */ | |
759 | void usb_block_urb(struct urb *urb) | |
760 | { | |
761 | if (!urb) | |
762 | return; | |
763 | ||
764 | atomic_inc(&urb->reject); | |
765 | } | |
766 | EXPORT_SYMBOL_GPL(usb_block_urb); | |
767 | ||
51a2f077 ON |
768 | /** |
769 | * usb_kill_anchored_urbs - cancel transfer requests en masse | |
770 | * @anchor: anchor the requests are bound to | |
771 | * | |
772 | * this allows all outstanding URBs to be killed starting | |
773 | * from the back of the queue | |
cde217a5 AS |
774 | * |
775 | * This routine should not be called by a driver after its disconnect | |
776 | * method has returned. | |
51a2f077 ON |
777 | */ |
778 | void usb_kill_anchored_urbs(struct usb_anchor *anchor) | |
779 | { | |
780 | struct urb *victim; | |
781 | ||
782 | spin_lock_irq(&anchor->lock); | |
783 | while (!list_empty(&anchor->urb_list)) { | |
2c044a48 GKH |
784 | victim = list_entry(anchor->urb_list.prev, struct urb, |
785 | anchor_list); | |
51a2f077 ON |
786 | /* we must make sure the URB isn't freed before we kill it*/ |
787 | usb_get_urb(victim); | |
788 | spin_unlock_irq(&anchor->lock); | |
789 | /* this will unanchor the URB */ | |
790 | usb_kill_urb(victim); | |
791 | usb_put_urb(victim); | |
792 | spin_lock_irq(&anchor->lock); | |
793 | } | |
794 | spin_unlock_irq(&anchor->lock); | |
795 | } | |
796 | EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); | |
797 | ||
6a2839be ON |
798 | |
799 | /** | |
800 | * usb_poison_anchored_urbs - cease all traffic from an anchor | |
801 | * @anchor: anchor the requests are bound to | |
802 | * | |
803 | * this allows all outstanding URBs to be poisoned starting | |
804 | * from the back of the queue. Newly added URBs will also be | |
805 | * poisoned | |
cde217a5 AS |
806 | * |
807 | * This routine should not be called by a driver after its disconnect | |
808 | * method has returned. | |
6a2839be ON |
809 | */ |
810 | void usb_poison_anchored_urbs(struct usb_anchor *anchor) | |
811 | { | |
812 | struct urb *victim; | |
813 | ||
814 | spin_lock_irq(&anchor->lock); | |
815 | anchor->poisoned = 1; | |
816 | while (!list_empty(&anchor->urb_list)) { | |
817 | victim = list_entry(anchor->urb_list.prev, struct urb, | |
818 | anchor_list); | |
819 | /* we must make sure the URB isn't freed before we kill it*/ | |
820 | usb_get_urb(victim); | |
821 | spin_unlock_irq(&anchor->lock); | |
822 | /* this will unanchor the URB */ | |
823 | usb_poison_urb(victim); | |
824 | usb_put_urb(victim); | |
825 | spin_lock_irq(&anchor->lock); | |
826 | } | |
827 | spin_unlock_irq(&anchor->lock); | |
828 | } | |
829 | EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs); | |
cde217a5 | 830 | |
856395d6 ON |
831 | /** |
832 | * usb_unpoison_anchored_urbs - let an anchor be used successfully again | |
833 | * @anchor: anchor the requests are bound to | |
834 | * | |
835 | * Reverses the effect of usb_poison_anchored_urbs | |
836 | * the anchor can be used normally after it returns | |
837 | */ | |
838 | void usb_unpoison_anchored_urbs(struct usb_anchor *anchor) | |
839 | { | |
840 | unsigned long flags; | |
841 | struct urb *lazarus; | |
842 | ||
843 | spin_lock_irqsave(&anchor->lock, flags); | |
844 | list_for_each_entry(lazarus, &anchor->urb_list, anchor_list) { | |
845 | usb_unpoison_urb(lazarus); | |
846 | } | |
847 | anchor->poisoned = 0; | |
848 | spin_unlock_irqrestore(&anchor->lock, flags); | |
849 | } | |
850 | EXPORT_SYMBOL_GPL(usb_unpoison_anchored_urbs); | |
eda76959 ON |
851 | /** |
852 | * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse | |
853 | * @anchor: anchor the requests are bound to | |
854 | * | |
855 | * this allows all outstanding URBs to be unlinked starting | |
856 | * from the back of the queue. This function is asynchronous. | |
e227867f | 857 | * The unlinking is just triggered. It may happen after this |
eda76959 | 858 | * function has returned. |
cde217a5 AS |
859 | * |
860 | * This routine should not be called by a driver after its disconnect | |
861 | * method has returned. | |
eda76959 ON |
862 | */ |
863 | void usb_unlink_anchored_urbs(struct usb_anchor *anchor) | |
864 | { | |
865 | struct urb *victim; | |
866 | ||
b3e67044 | 867 | while ((victim = usb_get_from_anchor(anchor)) != NULL) { |
eda76959 | 868 | usb_unlink_urb(victim); |
77571f05 | 869 | usb_put_urb(victim); |
eda76959 | 870 | } |
eda76959 ON |
871 | } |
872 | EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); | |
873 | ||
6ec4147e HG |
874 | /** |
875 | * usb_anchor_suspend_wakeups | |
876 | * @anchor: the anchor you want to suspend wakeups on | |
877 | * | |
878 | * Call this to stop the last urb being unanchored from waking up any | |
879 | * usb_wait_anchor_empty_timeout waiters. This is used in the hcd urb give- | |
880 | * back path to delay waking up until after the completion handler has run. | |
881 | */ | |
882 | void usb_anchor_suspend_wakeups(struct usb_anchor *anchor) | |
883 | { | |
884 | if (anchor) | |
885 | atomic_inc(&anchor->suspend_wakeups); | |
886 | } | |
887 | EXPORT_SYMBOL_GPL(usb_anchor_suspend_wakeups); | |
888 | ||
889 | /** | |
890 | * usb_anchor_resume_wakeups | |
891 | * @anchor: the anchor you want to resume wakeups on | |
892 | * | |
893 | * Allow usb_wait_anchor_empty_timeout waiters to be woken up again, and | |
894 | * wake up any current waiters if the anchor is empty. | |
895 | */ | |
896 | void usb_anchor_resume_wakeups(struct usb_anchor *anchor) | |
897 | { | |
898 | if (!anchor) | |
899 | return; | |
900 | ||
901 | atomic_dec(&anchor->suspend_wakeups); | |
902 | if (usb_anchor_check_wakeup(anchor)) | |
903 | wake_up(&anchor->wait); | |
904 | } | |
905 | EXPORT_SYMBOL_GPL(usb_anchor_resume_wakeups); | |
906 | ||
51a2f077 ON |
907 | /** |
908 | * usb_wait_anchor_empty_timeout - wait for an anchor to be unused | |
909 | * @anchor: the anchor you want to become unused | |
910 | * @timeout: how long you are willing to wait in milliseconds | |
911 | * | |
912 | * Call this is you want to be sure all an anchor's | |
913 | * URBs have finished | |
626f090c YB |
914 | * |
915 | * Return: Non-zero if the anchor became unused. Zero on timeout. | |
51a2f077 ON |
916 | */ |
917 | int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, | |
918 | unsigned int timeout) | |
919 | { | |
6ec4147e HG |
920 | return wait_event_timeout(anchor->wait, |
921 | usb_anchor_check_wakeup(anchor), | |
51a2f077 ON |
922 | msecs_to_jiffies(timeout)); |
923 | } | |
924 | EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); | |
19876252 ON |
925 | |
926 | /** | |
927 | * usb_get_from_anchor - get an anchor's oldest urb | |
928 | * @anchor: the anchor whose urb you want | |
929 | * | |
626f090c | 930 | * This will take the oldest urb from an anchor, |
19876252 | 931 | * unanchor and return it |
626f090c YB |
932 | * |
933 | * Return: The oldest urb from @anchor, or %NULL if @anchor has no | |
934 | * urbs associated with it. | |
19876252 ON |
935 | */ |
936 | struct urb *usb_get_from_anchor(struct usb_anchor *anchor) | |
937 | { | |
938 | struct urb *victim; | |
939 | unsigned long flags; | |
940 | ||
941 | spin_lock_irqsave(&anchor->lock, flags); | |
942 | if (!list_empty(&anchor->urb_list)) { | |
943 | victim = list_entry(anchor->urb_list.next, struct urb, | |
944 | anchor_list); | |
945 | usb_get_urb(victim); | |
b3e67044 | 946 | __usb_unanchor_urb(victim, anchor); |
19876252 | 947 | } else { |
19876252 ON |
948 | victim = NULL; |
949 | } | |
b3e67044 | 950 | spin_unlock_irqrestore(&anchor->lock, flags); |
19876252 ON |
951 | |
952 | return victim; | |
953 | } | |
954 | ||
955 | EXPORT_SYMBOL_GPL(usb_get_from_anchor); | |
956 | ||
957 | /** | |
958 | * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs | |
959 | * @anchor: the anchor whose urbs you want to unanchor | |
960 | * | |
961 | * use this to get rid of all an anchor's urbs | |
962 | */ | |
963 | void usb_scuttle_anchored_urbs(struct usb_anchor *anchor) | |
964 | { | |
965 | struct urb *victim; | |
966 | unsigned long flags; | |
967 | ||
968 | spin_lock_irqsave(&anchor->lock, flags); | |
969 | while (!list_empty(&anchor->urb_list)) { | |
970 | victim = list_entry(anchor->urb_list.prev, struct urb, | |
971 | anchor_list); | |
b3e67044 | 972 | __usb_unanchor_urb(victim, anchor); |
19876252 ON |
973 | } |
974 | spin_unlock_irqrestore(&anchor->lock, flags); | |
975 | } | |
976 | ||
977 | EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); | |
978 | ||
979 | /** | |
980 | * usb_anchor_empty - is an anchor empty | |
981 | * @anchor: the anchor you want to query | |
982 | * | |
626f090c | 983 | * Return: 1 if the anchor has no urbs associated with it. |
19876252 ON |
984 | */ |
985 | int usb_anchor_empty(struct usb_anchor *anchor) | |
986 | { | |
987 | return list_empty(&anchor->urb_list); | |
988 | } | |
989 | ||
990 | EXPORT_SYMBOL_GPL(usb_anchor_empty); | |
991 |