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1da177e4 LT |
1 | #include <linux/module.h> |
2 | #include <linux/string.h> | |
3 | #include <linux/bitops.h> | |
4 | #include <linux/slab.h> | |
d617bc83 | 5 | #include <linux/log2.h> |
1da177e4 | 6 | #include <linux/usb.h> |
51a2f077 | 7 | #include <linux/wait.h> |
27729aad | 8 | #include <linux/usb/hcd.h> |
10e232c5 | 9 | #include <linux/scatterlist.h> |
1da177e4 LT |
10 | |
11 | #define to_urb(d) container_of(d, struct urb, kref) | |
12 | ||
6a2839be | 13 | |
1da177e4 LT |
14 | static void urb_destroy(struct kref *kref) |
15 | { | |
16 | struct urb *urb = to_urb(kref); | |
51a2f077 | 17 | |
8b3b01c8 MH |
18 | if (urb->transfer_flags & URB_FREE_BUFFER) |
19 | kfree(urb->transfer_buffer); | |
20 | ||
1da177e4 LT |
21 | kfree(urb); |
22 | } | |
23 | ||
24 | /** | |
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 | |
27 | * | |
28 | * Initializes a urb so that the USB subsystem can use it properly. | |
29 | * | |
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. | |
35 | * | |
36 | * Only use this function if you _really_ understand what you are doing. | |
37 | */ | |
38 | void usb_init_urb(struct urb *urb) | |
39 | { | |
40 | if (urb) { | |
41 | memset(urb, 0, sizeof(*urb)); | |
42 | kref_init(&urb->kref); | |
51a2f077 | 43 | INIT_LIST_HEAD(&urb->anchor_list); |
1da177e4 LT |
44 | } |
45 | } | |
782e70c6 | 46 | EXPORT_SYMBOL_GPL(usb_init_urb); |
1da177e4 LT |
47 | |
48 | /** | |
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. | |
53 | * | |
54 | * Creates an urb for the USB driver to use, initializes a few internal | |
025d4430 | 55 | * structures, increments the usage counter, and returns a pointer to it. |
1da177e4 | 56 | * |
1da177e4 LT |
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. | |
626f090c YB |
61 | * |
62 | * Return: A pointer to the new urb, or %NULL if no memory is available. | |
1da177e4 | 63 | */ |
55016f10 | 64 | struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) |
1da177e4 LT |
65 | { |
66 | struct urb *urb; | |
67 | ||
ec17cf1c | 68 | urb = kmalloc(sizeof(struct urb) + |
1da177e4 LT |
69 | iso_packets * sizeof(struct usb_iso_packet_descriptor), |
70 | mem_flags); | |
71 | if (!urb) { | |
69a85942 | 72 | printk(KERN_ERR "alloc_urb: kmalloc failed\n"); |
1da177e4 LT |
73 | return NULL; |
74 | } | |
75 | usb_init_urb(urb); | |
76 | return urb; | |
77 | } | |
782e70c6 | 78 | EXPORT_SYMBOL_GPL(usb_alloc_urb); |
1da177e4 LT |
79 | |
80 | /** | |
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 | |
83 | * | |
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. | |
86 | * | |
2870fde7 RV |
87 | * Note: The transfer buffer associated with the urb is not freed unless the |
88 | * URB_FREE_BUFFER transfer flag is set. | |
1da177e4 LT |
89 | */ |
90 | void usb_free_urb(struct urb *urb) | |
91 | { | |
92 | if (urb) | |
93 | kref_put(&urb->kref, urb_destroy); | |
94 | } | |
782e70c6 | 95 | EXPORT_SYMBOL_GPL(usb_free_urb); |
1da177e4 LT |
96 | |
97 | /** | |
98 | * usb_get_urb - increments the reference count of the urb | |
99 | * @urb: pointer to the urb to modify, may be NULL | |
100 | * | |
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 | |
103 | * for urbs. | |
104 | * | |
626f090c | 105 | * Return: A pointer to the urb with the incremented reference counter. |
1da177e4 | 106 | */ |
2c044a48 | 107 | struct urb *usb_get_urb(struct urb *urb) |
1da177e4 LT |
108 | { |
109 | if (urb) | |
110 | kref_get(&urb->kref); | |
111 | return urb; | |
112 | } | |
782e70c6 | 113 | EXPORT_SYMBOL_GPL(usb_get_urb); |
51a2f077 ON |
114 | |
115 | /** | |
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 | |
119 | * | |
120 | * This can be called to have access to URBs which are to be executed | |
121 | * without bothering to track them | |
122 | */ | |
123 | void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) | |
124 | { | |
125 | unsigned long flags; | |
126 | ||
127 | spin_lock_irqsave(&anchor->lock, flags); | |
128 | usb_get_urb(urb); | |
129 | list_add_tail(&urb->anchor_list, &anchor->urb_list); | |
130 | urb->anchor = anchor; | |
6a2839be | 131 | |
ae416ba4 | 132 | if (unlikely(anchor->poisoned)) |
49367d8f | 133 | atomic_inc(&urb->reject); |
6a2839be | 134 | |
51a2f077 ON |
135 | spin_unlock_irqrestore(&anchor->lock, flags); |
136 | } | |
137 | EXPORT_SYMBOL_GPL(usb_anchor_urb); | |
138 | ||
6ec4147e HG |
139 | static int usb_anchor_check_wakeup(struct usb_anchor *anchor) |
140 | { | |
141 | return atomic_read(&anchor->suspend_wakeups) == 0 && | |
142 | list_empty(&anchor->urb_list); | |
143 | } | |
144 | ||
b3e67044 CL |
145 | /* Callers must hold anchor->lock */ |
146 | static void __usb_unanchor_urb(struct urb *urb, struct usb_anchor *anchor) | |
147 | { | |
148 | urb->anchor = NULL; | |
149 | list_del(&urb->anchor_list); | |
150 | usb_put_urb(urb); | |
6ec4147e | 151 | if (usb_anchor_check_wakeup(anchor)) |
b3e67044 CL |
152 | wake_up(&anchor->wait); |
153 | } | |
154 | ||
51a2f077 ON |
155 | /** |
156 | * usb_unanchor_urb - unanchors an URB | |
157 | * @urb: pointer to the urb to anchor | |
158 | * | |
159 | * Call this to stop the system keeping track of this URB | |
160 | */ | |
161 | void usb_unanchor_urb(struct urb *urb) | |
162 | { | |
163 | unsigned long flags; | |
164 | struct usb_anchor *anchor; | |
165 | ||
166 | if (!urb) | |
167 | return; | |
168 | ||
169 | anchor = urb->anchor; | |
170 | if (!anchor) | |
171 | return; | |
172 | ||
173 | spin_lock_irqsave(&anchor->lock, flags); | |
b3e67044 CL |
174 | /* |
175 | * At this point, we could be competing with another thread which | |
176 | * has the same intention. To protect the urb from being unanchored | |
177 | * twice, only the winner of the race gets the job. | |
178 | */ | |
179 | if (likely(anchor == urb->anchor)) | |
180 | __usb_unanchor_urb(urb, anchor); | |
51a2f077 | 181 | spin_unlock_irqrestore(&anchor->lock, flags); |
51a2f077 ON |
182 | } |
183 | EXPORT_SYMBOL_GPL(usb_unanchor_urb); | |
184 | ||
1da177e4 LT |
185 | /*-------------------------------------------------------------------*/ |
186 | ||
187 | /** | |
188 | * usb_submit_urb - issue an asynchronous transfer request for an endpoint | |
189 | * @urb: pointer to the urb describing the request | |
190 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list | |
191 | * of valid options for this. | |
192 | * | |
193 | * This submits a transfer request, and transfers control of the URB | |
194 | * describing that request to the USB subsystem. Request completion will | |
195 | * be indicated later, asynchronously, by calling the completion handler. | |
196 | * The three types of completion are success, error, and unlink | |
2c044a48 | 197 | * (a software-induced fault, also called "request cancellation"). |
1da177e4 LT |
198 | * |
199 | * URBs may be submitted in interrupt context. | |
200 | * | |
201 | * The caller must have correctly initialized the URB before submitting | |
202 | * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are | |
203 | * available to ensure that most fields are correctly initialized, for | |
204 | * the particular kind of transfer, although they will not initialize | |
205 | * any transfer flags. | |
206 | * | |
626f090c YB |
207 | * If the submission is successful, the complete() callback from the URB |
208 | * will be called exactly once, when the USB core and Host Controller Driver | |
209 | * (HCD) are finished with the URB. When the completion function is called, | |
210 | * control of the URB is returned to the device driver which issued the | |
211 | * request. The completion handler may then immediately free or reuse that | |
212 | * URB. | |
1da177e4 LT |
213 | * |
214 | * With few exceptions, USB device drivers should never access URB fields | |
215 | * provided by usbcore or the HCD until its complete() is called. | |
216 | * The exceptions relate to periodic transfer scheduling. For both | |
217 | * interrupt and isochronous urbs, as part of successful URB submission | |
218 | * urb->interval is modified to reflect the actual transfer period used | |
219 | * (normally some power of two units). And for isochronous urbs, | |
220 | * urb->start_frame is modified to reflect when the URB's transfers were | |
a03bede5 AS |
221 | * scheduled to start. |
222 | * | |
223 | * Not all isochronous transfer scheduling policies will work, but most | |
224 | * host controller drivers should easily handle ISO queues going from now | |
225 | * until 10-200 msec into the future. Drivers should try to keep at | |
226 | * least one or two msec of data in the queue; many controllers require | |
227 | * that new transfers start at least 1 msec in the future when they are | |
228 | * added. If the driver is unable to keep up and the queue empties out, | |
229 | * the behavior for new submissions is governed by the URB_ISO_ASAP flag. | |
230 | * If the flag is set, or if the queue is idle, then the URB is always | |
231 | * assigned to the first available (and not yet expired) slot in the | |
232 | * endpoint's schedule. If the flag is not set and the queue is active | |
233 | * then the URB is always assigned to the next slot in the schedule | |
234 | * following the end of the endpoint's previous URB, even if that slot is | |
235 | * in the past. When a packet is assigned in this way to a slot that has | |
236 | * already expired, the packet is not transmitted and the corresponding | |
237 | * usb_iso_packet_descriptor's status field will return -EXDEV. If this | |
238 | * would happen to all the packets in the URB, submission fails with a | |
239 | * -EXDEV error code. | |
1da177e4 LT |
240 | * |
241 | * For control endpoints, the synchronous usb_control_msg() call is | |
242 | * often used (in non-interrupt context) instead of this call. | |
243 | * That is often used through convenience wrappers, for the requests | |
244 | * that are standardized in the USB 2.0 specification. For bulk | |
245 | * endpoints, a synchronous usb_bulk_msg() call is available. | |
246 | * | |
626f090c YB |
247 | * Return: |
248 | * 0 on successful submissions. A negative error number otherwise. | |
249 | * | |
1da177e4 LT |
250 | * Request Queuing: |
251 | * | |
252 | * URBs may be submitted to endpoints before previous ones complete, to | |
253 | * minimize the impact of interrupt latencies and system overhead on data | |
254 | * throughput. With that queuing policy, an endpoint's queue would never | |
255 | * be empty. This is required for continuous isochronous data streams, | |
256 | * and may also be required for some kinds of interrupt transfers. Such | |
257 | * queuing also maximizes bandwidth utilization by letting USB controllers | |
258 | * start work on later requests before driver software has finished the | |
259 | * completion processing for earlier (successful) requests. | |
260 | * | |
261 | * As of Linux 2.6, all USB endpoint transfer queues support depths greater | |
262 | * than one. This was previously a HCD-specific behavior, except for ISO | |
263 | * transfers. Non-isochronous endpoint queues are inactive during cleanup | |
093cf723 | 264 | * after faults (transfer errors or cancellation). |
1da177e4 LT |
265 | * |
266 | * Reserved Bandwidth Transfers: | |
267 | * | |
268 | * Periodic transfers (interrupt or isochronous) are performed repeatedly, | |
269 | * using the interval specified in the urb. Submitting the first urb to | |
270 | * the endpoint reserves the bandwidth necessary to make those transfers. | |
271 | * If the USB subsystem can't allocate sufficient bandwidth to perform | |
272 | * the periodic request, submitting such a periodic request should fail. | |
273 | * | |
79abb1ab SS |
274 | * For devices under xHCI, the bandwidth is reserved at configuration time, or |
275 | * when the alt setting is selected. If there is not enough bus bandwidth, the | |
276 | * configuration/alt setting request will fail. Therefore, submissions to | |
277 | * periodic endpoints on devices under xHCI should never fail due to bandwidth | |
278 | * constraints. | |
279 | * | |
1da177e4 LT |
280 | * Device drivers must explicitly request that repetition, by ensuring that |
281 | * some URB is always on the endpoint's queue (except possibly for short | |
025d4430 | 282 | * periods during completion callbacks). When there is no longer an urb |
1da177e4 LT |
283 | * queued, the endpoint's bandwidth reservation is canceled. This means |
284 | * drivers can use their completion handlers to ensure they keep bandwidth | |
285 | * they need, by reinitializing and resubmitting the just-completed urb | |
286 | * until the driver longer needs that periodic bandwidth. | |
287 | * | |
288 | * Memory Flags: | |
289 | * | |
290 | * The general rules for how to decide which mem_flags to use | |
291 | * are the same as for kmalloc. There are four | |
292 | * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and | |
293 | * GFP_ATOMIC. | |
294 | * | |
295 | * GFP_NOFS is not ever used, as it has not been implemented yet. | |
296 | * | |
297 | * GFP_ATOMIC is used when | |
298 | * (a) you are inside a completion handler, an interrupt, bottom half, | |
299 | * tasklet or timer, or | |
300 | * (b) you are holding a spinlock or rwlock (does not apply to | |
301 | * semaphores), or | |
302 | * (c) current->state != TASK_RUNNING, this is the case only after | |
303 | * you've changed it. | |
2c044a48 | 304 | * |
1da177e4 LT |
305 | * GFP_NOIO is used in the block io path and error handling of storage |
306 | * devices. | |
307 | * | |
308 | * All other situations use GFP_KERNEL. | |
309 | * | |
310 | * Some more specific rules for mem_flags can be inferred, such as | |
311 | * (1) start_xmit, timeout, and receive methods of network drivers must | |
312 | * use GFP_ATOMIC (they are called with a spinlock held); | |
313 | * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also | |
314 | * called with a spinlock held); | |
315 | * (3) If you use a kernel thread with a network driver you must use | |
316 | * GFP_NOIO, unless (b) or (c) apply; | |
317 | * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c) | |
318 | * apply or your are in a storage driver's block io path; | |
319 | * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and | |
320 | * (6) changing firmware on a running storage or net device uses | |
321 | * GFP_NOIO, unless b) or c) apply | |
322 | * | |
323 | */ | |
55016f10 | 324 | int usb_submit_urb(struct urb *urb, gfp_t mem_flags) |
1da177e4 | 325 | { |
3482528e GKH |
326 | static int pipetypes[4] = { |
327 | PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT | |
328 | }; | |
5b653c79 AS |
329 | int xfertype, max; |
330 | struct usb_device *dev; | |
331 | struct usb_host_endpoint *ep; | |
332 | int is_out; | |
3482528e | 333 | unsigned int allowed; |
1da177e4 | 334 | |
2f02bc8a | 335 | if (!urb || !urb->complete) |
1da177e4 | 336 | return -EINVAL; |
2f02bc8a AS |
337 | if (urb->hcpriv) { |
338 | WARN_ONCE(1, "URB %p submitted while active\n", urb); | |
339 | return -EBUSY; | |
340 | } | |
341 | ||
2c044a48 | 342 | dev = urb->dev; |
6da9c990 | 343 | if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED)) |
1da177e4 | 344 | return -ENODEV; |
1da177e4 | 345 | |
5b653c79 AS |
346 | /* For now, get the endpoint from the pipe. Eventually drivers |
347 | * will be required to set urb->ep directly and we will eliminate | |
348 | * urb->pipe. | |
349 | */ | |
fe54b058 | 350 | ep = usb_pipe_endpoint(dev, urb->pipe); |
5b653c79 AS |
351 | if (!ep) |
352 | return -ENOENT; | |
353 | ||
354 | urb->ep = ep; | |
1da177e4 LT |
355 | urb->status = -EINPROGRESS; |
356 | urb->actual_length = 0; | |
1da177e4 LT |
357 | |
358 | /* Lots of sanity checks, so HCDs can rely on clean data | |
359 | * and don't need to duplicate tests | |
360 | */ | |
5b653c79 | 361 | xfertype = usb_endpoint_type(&ep->desc); |
fea34091 AS |
362 | if (xfertype == USB_ENDPOINT_XFER_CONTROL) { |
363 | struct usb_ctrlrequest *setup = | |
364 | (struct usb_ctrlrequest *) urb->setup_packet; | |
365 | ||
366 | if (!setup) | |
367 | return -ENOEXEC; | |
368 | is_out = !(setup->bRequestType & USB_DIR_IN) || | |
369 | !setup->wLength; | |
370 | } else { | |
371 | is_out = usb_endpoint_dir_out(&ep->desc); | |
372 | } | |
373 | ||
ff9c895f AS |
374 | /* Clear the internal flags and cache the direction for later use */ |
375 | urb->transfer_flags &= ~(URB_DIR_MASK | URB_DMA_MAP_SINGLE | | |
376 | URB_DMA_MAP_PAGE | URB_DMA_MAP_SG | URB_MAP_LOCAL | | |
377 | URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL | | |
378 | URB_DMA_SG_COMBINED); | |
379 | urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN); | |
1da177e4 | 380 | |
5b653c79 AS |
381 | if (xfertype != USB_ENDPOINT_XFER_CONTROL && |
382 | dev->state < USB_STATE_CONFIGURED) | |
1da177e4 LT |
383 | return -ENODEV; |
384 | ||
29cc8897 | 385 | max = usb_endpoint_maxp(&ep->desc); |
1da177e4 LT |
386 | if (max <= 0) { |
387 | dev_dbg(&dev->dev, | |
388 | "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n", | |
5b653c79 | 389 | usb_endpoint_num(&ep->desc), is_out ? "out" : "in", |
441b62c1 | 390 | __func__, max); |
1da177e4 LT |
391 | return -EMSGSIZE; |
392 | } | |
393 | ||
394 | /* periodic transfers limit size per frame/uframe, | |
395 | * but drivers only control those sizes for ISO. | |
396 | * while we're checking, initialize return status. | |
397 | */ | |
5b653c79 | 398 | if (xfertype == USB_ENDPOINT_XFER_ISOC) { |
1da177e4 LT |
399 | int n, len; |
400 | ||
500132a0 PZ |
401 | /* SuperSpeed isoc endpoints have up to 16 bursts of up to |
402 | * 3 packets each | |
403 | */ | |
404 | if (dev->speed == USB_SPEED_SUPER) { | |
405 | int burst = 1 + ep->ss_ep_comp.bMaxBurst; | |
406 | int mult = USB_SS_MULT(ep->ss_ep_comp.bmAttributes); | |
407 | max *= burst; | |
408 | max *= mult; | |
409 | } | |
410 | ||
1da177e4 LT |
411 | /* "high bandwidth" mode, 1-3 packets/uframe? */ |
412 | if (dev->speed == USB_SPEED_HIGH) { | |
413 | int mult = 1 + ((max >> 11) & 0x03); | |
414 | max &= 0x07ff; | |
415 | max *= mult; | |
416 | } | |
417 | ||
2c044a48 | 418 | if (urb->number_of_packets <= 0) |
1da177e4 LT |
419 | return -EINVAL; |
420 | for (n = 0; n < urb->number_of_packets; n++) { | |
9251644a | 421 | len = urb->iso_frame_desc[n].length; |
2c044a48 | 422 | if (len < 0 || len > max) |
1da177e4 | 423 | return -EMSGSIZE; |
9251644a ON |
424 | urb->iso_frame_desc[n].status = -EXDEV; |
425 | urb->iso_frame_desc[n].actual_length = 0; | |
1da177e4 | 426 | } |
bcc48f1a ML |
427 | } else if (urb->num_sgs && !urb->dev->bus->no_sg_constraint && |
428 | dev->speed != USB_SPEED_WIRELESS) { | |
10e232c5 ML |
429 | struct scatterlist *sg; |
430 | int i; | |
431 | ||
432 | for_each_sg(urb->sg, sg, urb->num_sgs - 1, i) | |
433 | if (sg->length % max) | |
434 | return -EINVAL; | |
1da177e4 LT |
435 | } |
436 | ||
437 | /* the I/O buffer must be mapped/unmapped, except when length=0 */ | |
71d2718f | 438 | if (urb->transfer_buffer_length > INT_MAX) |
1da177e4 LT |
439 | return -EMSGSIZE; |
440 | ||
3482528e GKH |
441 | /* |
442 | * stuff that drivers shouldn't do, but which shouldn't | |
1da177e4 LT |
443 | * cause problems in HCDs if they get it wrong. |
444 | */ | |
f661c6f8 AS |
445 | |
446 | /* Check that the pipe's type matches the endpoint's type */ | |
0cb54a3e AS |
447 | if (usb_pipetype(urb->pipe) != pipetypes[xfertype]) |
448 | dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n", | |
f7dd6491 | 449 | usb_pipetype(urb->pipe), pipetypes[xfertype]); |
1da177e4 | 450 | |
0cb54a3e | 451 | /* Check against a simple/standard policy */ |
0ede76fc AS |
452 | allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK | |
453 | URB_FREE_BUFFER); | |
5b653c79 AS |
454 | switch (xfertype) { |
455 | case USB_ENDPOINT_XFER_BULK: | |
9672f0fe | 456 | case USB_ENDPOINT_XFER_INT: |
1da177e4 LT |
457 | if (is_out) |
458 | allowed |= URB_ZERO_PACKET; | |
459 | /* FALLTHROUGH */ | |
5b653c79 | 460 | case USB_ENDPOINT_XFER_CONTROL: |
1da177e4 LT |
461 | allowed |= URB_NO_FSBR; /* only affects UHCI */ |
462 | /* FALLTHROUGH */ | |
463 | default: /* all non-iso endpoints */ | |
464 | if (!is_out) | |
465 | allowed |= URB_SHORT_NOT_OK; | |
466 | break; | |
5b653c79 | 467 | case USB_ENDPOINT_XFER_ISOC: |
1da177e4 LT |
468 | allowed |= URB_ISO_ASAP; |
469 | break; | |
470 | } | |
0cb54a3e | 471 | allowed &= urb->transfer_flags; |
1da177e4 | 472 | |
0cb54a3e AS |
473 | /* warn if submitter gave bogus flags */ |
474 | if (allowed != urb->transfer_flags) | |
475 | dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n", | |
476 | urb->transfer_flags, allowed); | |
3482528e | 477 | |
1da177e4 LT |
478 | /* |
479 | * Force periodic transfer intervals to be legal values that are | |
480 | * a power of two (so HCDs don't need to). | |
481 | * | |
482 | * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC | |
483 | * supports different values... this uses EHCI/UHCI defaults (and | |
484 | * EHCI can use smaller non-default values). | |
485 | */ | |
5b653c79 AS |
486 | switch (xfertype) { |
487 | case USB_ENDPOINT_XFER_ISOC: | |
488 | case USB_ENDPOINT_XFER_INT: | |
1da177e4 | 489 | /* too small? */ |
8e08b976 | 490 | switch (dev->speed) { |
551cdbbe | 491 | case USB_SPEED_WIRELESS: |
a2cd612d TP |
492 | if ((urb->interval < 6) |
493 | && (xfertype == USB_ENDPOINT_XFER_INT)) | |
8e08b976 | 494 | return -EINVAL; |
8e08b976 DV |
495 | default: |
496 | if (urb->interval <= 0) | |
497 | return -EINVAL; | |
498 | break; | |
499 | } | |
1da177e4 LT |
500 | /* too big? */ |
501 | switch (dev->speed) { | |
6b403b02 SS |
502 | case USB_SPEED_SUPER: /* units are 125us */ |
503 | /* Handle up to 2^(16-1) microframes */ | |
504 | if (urb->interval > (1 << 15)) | |
505 | return -EINVAL; | |
506 | max = 1 << 15; | |
f09a15e6 | 507 | break; |
551cdbbe | 508 | case USB_SPEED_WIRELESS: |
8e08b976 DV |
509 | if (urb->interval > 16) |
510 | return -EINVAL; | |
511 | break; | |
1da177e4 | 512 | case USB_SPEED_HIGH: /* units are microframes */ |
2c044a48 | 513 | /* NOTE usb handles 2^15 */ |
1da177e4 LT |
514 | if (urb->interval > (1024 * 8)) |
515 | urb->interval = 1024 * 8; | |
5b653c79 | 516 | max = 1024 * 8; |
1da177e4 LT |
517 | break; |
518 | case USB_SPEED_FULL: /* units are frames/msec */ | |
519 | case USB_SPEED_LOW: | |
5b653c79 | 520 | if (xfertype == USB_ENDPOINT_XFER_INT) { |
1da177e4 LT |
521 | if (urb->interval > 255) |
522 | return -EINVAL; | |
2c044a48 | 523 | /* NOTE ohci only handles up to 32 */ |
5b653c79 | 524 | max = 128; |
1da177e4 LT |
525 | } else { |
526 | if (urb->interval > 1024) | |
527 | urb->interval = 1024; | |
2c044a48 | 528 | /* NOTE usb and ohci handle up to 2^15 */ |
5b653c79 | 529 | max = 1024; |
1da177e4 LT |
530 | } |
531 | break; | |
532 | default: | |
533 | return -EINVAL; | |
534 | } | |
551cdbbe | 535 | if (dev->speed != USB_SPEED_WIRELESS) { |
8e08b976 DV |
536 | /* Round down to a power of 2, no more than max */ |
537 | urb->interval = min(max, 1 << ilog2(urb->interval)); | |
538 | } | |
1da177e4 LT |
539 | } |
540 | ||
9251644a | 541 | return usb_hcd_submit_urb(urb, mem_flags); |
1da177e4 | 542 | } |
782e70c6 | 543 | EXPORT_SYMBOL_GPL(usb_submit_urb); |
1da177e4 LT |
544 | |
545 | /*-------------------------------------------------------------------*/ | |
546 | ||
547 | /** | |
548 | * usb_unlink_urb - abort/cancel a transfer request for an endpoint | |
549 | * @urb: pointer to urb describing a previously submitted request, | |
550 | * may be NULL | |
551 | * | |
beafef07 AS |
552 | * This routine cancels an in-progress request. URBs complete only once |
553 | * per submission, and may be canceled only once per submission. | |
554 | * Successful cancellation means termination of @urb will be expedited | |
555 | * and the completion handler will be called with a status code | |
556 | * indicating that the request has been canceled (rather than any other | |
557 | * code). | |
558 | * | |
cde217a5 AS |
559 | * Drivers should not call this routine or related routines, such as |
560 | * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect | |
561 | * method has returned. The disconnect function should synchronize with | |
562 | * a driver's I/O routines to insure that all URB-related activity has | |
563 | * completed before it returns. | |
564 | * | |
371f3b49 SAS |
565 | * This request is asynchronous, however the HCD might call the ->complete() |
566 | * callback during unlink. Therefore when drivers call usb_unlink_urb(), they | |
567 | * must not hold any locks that may be taken by the completion function. | |
568 | * Success is indicated by returning -EINPROGRESS, at which time the URB will | |
569 | * probably not yet have been given back to the device driver. When it is | |
570 | * eventually called, the completion function will see @urb->status == | |
571 | * -ECONNRESET. | |
beafef07 AS |
572 | * Failure is indicated by usb_unlink_urb() returning any other value. |
573 | * Unlinking will fail when @urb is not currently "linked" (i.e., it was | |
574 | * never submitted, or it was unlinked before, or the hardware is already | |
575 | * finished with it), even if the completion handler has not yet run. | |
1da177e4 | 576 | * |
da8bfb09 AS |
577 | * The URB must not be deallocated while this routine is running. In |
578 | * particular, when a driver calls this routine, it must insure that the | |
579 | * completion handler cannot deallocate the URB. | |
580 | * | |
626f090c YB |
581 | * Return: -EINPROGRESS on success. See description for other values on |
582 | * failure. | |
583 | * | |
1da177e4 LT |
584 | * Unlinking and Endpoint Queues: |
585 | * | |
beafef07 AS |
586 | * [The behaviors and guarantees described below do not apply to virtual |
587 | * root hubs but only to endpoint queues for physical USB devices.] | |
588 | * | |
1da177e4 LT |
589 | * Host Controller Drivers (HCDs) place all the URBs for a particular |
590 | * endpoint in a queue. Normally the queue advances as the controller | |
8835f665 | 591 | * hardware processes each request. But when an URB terminates with an |
beafef07 AS |
592 | * error its queue generally stops (see below), at least until that URB's |
593 | * completion routine returns. It is guaranteed that a stopped queue | |
594 | * will not restart until all its unlinked URBs have been fully retired, | |
595 | * with their completion routines run, even if that's not until some time | |
596 | * after the original completion handler returns. The same behavior and | |
597 | * guarantee apply when an URB terminates because it was unlinked. | |
598 | * | |
599 | * Bulk and interrupt endpoint queues are guaranteed to stop whenever an | |
600 | * URB terminates with any sort of error, including -ECONNRESET, -ENOENT, | |
601 | * and -EREMOTEIO. Control endpoint queues behave the same way except | |
602 | * that they are not guaranteed to stop for -EREMOTEIO errors. Queues | |
603 | * for isochronous endpoints are treated differently, because they must | |
604 | * advance at fixed rates. Such queues do not stop when an URB | |
605 | * encounters an error or is unlinked. An unlinked isochronous URB may | |
606 | * leave a gap in the stream of packets; it is undefined whether such | |
607 | * gaps can be filled in. | |
608 | * | |
609 | * Note that early termination of an URB because a short packet was | |
610 | * received will generate a -EREMOTEIO error if and only if the | |
611 | * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device | |
612 | * drivers can build deep queues for large or complex bulk transfers | |
613 | * and clean them up reliably after any sort of aborted transfer by | |
614 | * unlinking all pending URBs at the first fault. | |
615 | * | |
616 | * When a control URB terminates with an error other than -EREMOTEIO, it | |
617 | * is quite likely that the status stage of the transfer will not take | |
618 | * place. | |
1da177e4 LT |
619 | */ |
620 | int usb_unlink_urb(struct urb *urb) | |
621 | { | |
622 | if (!urb) | |
623 | return -EINVAL; | |
d617bc83 | 624 | if (!urb->dev) |
1da177e4 | 625 | return -ENODEV; |
d617bc83 AS |
626 | if (!urb->ep) |
627 | return -EIDRM; | |
a6d2bb9f | 628 | return usb_hcd_unlink_urb(urb, -ECONNRESET); |
1da177e4 | 629 | } |
782e70c6 | 630 | EXPORT_SYMBOL_GPL(usb_unlink_urb); |
1da177e4 LT |
631 | |
632 | /** | |
633 | * usb_kill_urb - cancel a transfer request and wait for it to finish | |
634 | * @urb: pointer to URB describing a previously submitted request, | |
635 | * may be NULL | |
636 | * | |
637 | * This routine cancels an in-progress request. It is guaranteed that | |
638 | * upon return all completion handlers will have finished and the URB | |
639 | * will be totally idle and available for reuse. These features make | |
640 | * this an ideal way to stop I/O in a disconnect() callback or close() | |
641 | * function. If the request has not already finished or been unlinked | |
642 | * the completion handler will see urb->status == -ENOENT. | |
643 | * | |
644 | * While the routine is running, attempts to resubmit the URB will fail | |
645 | * with error -EPERM. Thus even if the URB's completion handler always | |
646 | * tries to resubmit, it will not succeed and the URB will become idle. | |
647 | * | |
da8bfb09 AS |
648 | * The URB must not be deallocated while this routine is running. In |
649 | * particular, when a driver calls this routine, it must insure that the | |
650 | * completion handler cannot deallocate the URB. | |
651 | * | |
1da177e4 LT |
652 | * This routine may not be used in an interrupt context (such as a bottom |
653 | * half or a completion handler), or when holding a spinlock, or in other | |
654 | * situations where the caller can't schedule(). | |
cde217a5 AS |
655 | * |
656 | * This routine should not be called by a driver after its disconnect | |
657 | * method has returned. | |
1da177e4 LT |
658 | */ |
659 | void usb_kill_urb(struct urb *urb) | |
660 | { | |
e9aa795a | 661 | might_sleep(); |
d617bc83 | 662 | if (!(urb && urb->dev && urb->ep)) |
1da177e4 | 663 | return; |
49367d8f | 664 | atomic_inc(&urb->reject); |
1da177e4 | 665 | |
a6d2bb9f | 666 | usb_hcd_unlink_urb(urb, -ENOENT); |
1da177e4 LT |
667 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); |
668 | ||
49367d8f | 669 | atomic_dec(&urb->reject); |
1da177e4 | 670 | } |
782e70c6 | 671 | EXPORT_SYMBOL_GPL(usb_kill_urb); |
1da177e4 | 672 | |
55b447bf ON |
673 | /** |
674 | * usb_poison_urb - reliably kill a transfer and prevent further use of an URB | |
675 | * @urb: pointer to URB describing a previously submitted request, | |
676 | * may be NULL | |
677 | * | |
678 | * This routine cancels an in-progress request. It is guaranteed that | |
679 | * upon return all completion handlers will have finished and the URB | |
680 | * will be totally idle and cannot be reused. These features make | |
681 | * this an ideal way to stop I/O in a disconnect() callback. | |
682 | * If the request has not already finished or been unlinked | |
683 | * the completion handler will see urb->status == -ENOENT. | |
684 | * | |
685 | * After and while the routine runs, attempts to resubmit the URB will fail | |
686 | * with error -EPERM. Thus even if the URB's completion handler always | |
687 | * tries to resubmit, it will not succeed and the URB will become idle. | |
688 | * | |
da8bfb09 AS |
689 | * The URB must not be deallocated while this routine is running. In |
690 | * particular, when a driver calls this routine, it must insure that the | |
691 | * completion handler cannot deallocate the URB. | |
692 | * | |
55b447bf ON |
693 | * This routine may not be used in an interrupt context (such as a bottom |
694 | * half or a completion handler), or when holding a spinlock, or in other | |
695 | * situations where the caller can't schedule(). | |
cde217a5 AS |
696 | * |
697 | * This routine should not be called by a driver after its disconnect | |
698 | * method has returned. | |
55b447bf ON |
699 | */ |
700 | void usb_poison_urb(struct urb *urb) | |
701 | { | |
702 | might_sleep(); | |
68a2bed1 | 703 | if (!urb) |
55b447bf | 704 | return; |
49367d8f | 705 | atomic_inc(&urb->reject); |
55b447bf | 706 | |
68a2bed1 JH |
707 | if (!urb->dev || !urb->ep) |
708 | return; | |
709 | ||
55b447bf ON |
710 | usb_hcd_unlink_urb(urb, -ENOENT); |
711 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); | |
712 | } | |
713 | EXPORT_SYMBOL_GPL(usb_poison_urb); | |
714 | ||
715 | void usb_unpoison_urb(struct urb *urb) | |
716 | { | |
717 | if (!urb) | |
718 | return; | |
719 | ||
49367d8f | 720 | atomic_dec(&urb->reject); |
55b447bf ON |
721 | } |
722 | EXPORT_SYMBOL_GPL(usb_unpoison_urb); | |
723 | ||
8815bb09 ON |
724 | /** |
725 | * usb_block_urb - reliably prevent further use of an URB | |
726 | * @urb: pointer to URB to be blocked, may be NULL | |
727 | * | |
728 | * After the routine has run, attempts to resubmit the URB will fail | |
729 | * with error -EPERM. Thus even if the URB's completion handler always | |
730 | * tries to resubmit, it will not succeed and the URB will become idle. | |
731 | * | |
732 | * The URB must not be deallocated while this routine is running. In | |
733 | * particular, when a driver calls this routine, it must insure that the | |
734 | * completion handler cannot deallocate the URB. | |
735 | */ | |
736 | void usb_block_urb(struct urb *urb) | |
737 | { | |
738 | if (!urb) | |
739 | return; | |
740 | ||
741 | atomic_inc(&urb->reject); | |
742 | } | |
743 | EXPORT_SYMBOL_GPL(usb_block_urb); | |
744 | ||
51a2f077 ON |
745 | /** |
746 | * usb_kill_anchored_urbs - cancel transfer requests en masse | |
747 | * @anchor: anchor the requests are bound to | |
748 | * | |
749 | * this allows all outstanding URBs to be killed starting | |
750 | * from the back of the queue | |
cde217a5 AS |
751 | * |
752 | * This routine should not be called by a driver after its disconnect | |
753 | * method has returned. | |
51a2f077 ON |
754 | */ |
755 | void usb_kill_anchored_urbs(struct usb_anchor *anchor) | |
756 | { | |
757 | struct urb *victim; | |
758 | ||
759 | spin_lock_irq(&anchor->lock); | |
760 | while (!list_empty(&anchor->urb_list)) { | |
2c044a48 GKH |
761 | victim = list_entry(anchor->urb_list.prev, struct urb, |
762 | anchor_list); | |
51a2f077 ON |
763 | /* we must make sure the URB isn't freed before we kill it*/ |
764 | usb_get_urb(victim); | |
765 | spin_unlock_irq(&anchor->lock); | |
766 | /* this will unanchor the URB */ | |
767 | usb_kill_urb(victim); | |
768 | usb_put_urb(victim); | |
769 | spin_lock_irq(&anchor->lock); | |
770 | } | |
771 | spin_unlock_irq(&anchor->lock); | |
772 | } | |
773 | EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); | |
774 | ||
6a2839be ON |
775 | |
776 | /** | |
777 | * usb_poison_anchored_urbs - cease all traffic from an anchor | |
778 | * @anchor: anchor the requests are bound to | |
779 | * | |
780 | * this allows all outstanding URBs to be poisoned starting | |
781 | * from the back of the queue. Newly added URBs will also be | |
782 | * poisoned | |
cde217a5 AS |
783 | * |
784 | * This routine should not be called by a driver after its disconnect | |
785 | * method has returned. | |
6a2839be ON |
786 | */ |
787 | void usb_poison_anchored_urbs(struct usb_anchor *anchor) | |
788 | { | |
789 | struct urb *victim; | |
790 | ||
791 | spin_lock_irq(&anchor->lock); | |
792 | anchor->poisoned = 1; | |
793 | while (!list_empty(&anchor->urb_list)) { | |
794 | victim = list_entry(anchor->urb_list.prev, struct urb, | |
795 | anchor_list); | |
796 | /* we must make sure the URB isn't freed before we kill it*/ | |
797 | usb_get_urb(victim); | |
798 | spin_unlock_irq(&anchor->lock); | |
799 | /* this will unanchor the URB */ | |
800 | usb_poison_urb(victim); | |
801 | usb_put_urb(victim); | |
802 | spin_lock_irq(&anchor->lock); | |
803 | } | |
804 | spin_unlock_irq(&anchor->lock); | |
805 | } | |
806 | EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs); | |
cde217a5 | 807 | |
856395d6 ON |
808 | /** |
809 | * usb_unpoison_anchored_urbs - let an anchor be used successfully again | |
810 | * @anchor: anchor the requests are bound to | |
811 | * | |
812 | * Reverses the effect of usb_poison_anchored_urbs | |
813 | * the anchor can be used normally after it returns | |
814 | */ | |
815 | void usb_unpoison_anchored_urbs(struct usb_anchor *anchor) | |
816 | { | |
817 | unsigned long flags; | |
818 | struct urb *lazarus; | |
819 | ||
820 | spin_lock_irqsave(&anchor->lock, flags); | |
821 | list_for_each_entry(lazarus, &anchor->urb_list, anchor_list) { | |
822 | usb_unpoison_urb(lazarus); | |
823 | } | |
824 | anchor->poisoned = 0; | |
825 | spin_unlock_irqrestore(&anchor->lock, flags); | |
826 | } | |
827 | EXPORT_SYMBOL_GPL(usb_unpoison_anchored_urbs); | |
eda76959 ON |
828 | /** |
829 | * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse | |
830 | * @anchor: anchor the requests are bound to | |
831 | * | |
832 | * this allows all outstanding URBs to be unlinked starting | |
833 | * from the back of the queue. This function is asynchronous. | |
e227867f | 834 | * The unlinking is just triggered. It may happen after this |
eda76959 | 835 | * function has returned. |
cde217a5 AS |
836 | * |
837 | * This routine should not be called by a driver after its disconnect | |
838 | * method has returned. | |
eda76959 ON |
839 | */ |
840 | void usb_unlink_anchored_urbs(struct usb_anchor *anchor) | |
841 | { | |
842 | struct urb *victim; | |
843 | ||
b3e67044 | 844 | while ((victim = usb_get_from_anchor(anchor)) != NULL) { |
eda76959 | 845 | usb_unlink_urb(victim); |
77571f05 | 846 | usb_put_urb(victim); |
eda76959 | 847 | } |
eda76959 ON |
848 | } |
849 | EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); | |
850 | ||
6ec4147e HG |
851 | /** |
852 | * usb_anchor_suspend_wakeups | |
853 | * @anchor: the anchor you want to suspend wakeups on | |
854 | * | |
855 | * Call this to stop the last urb being unanchored from waking up any | |
856 | * usb_wait_anchor_empty_timeout waiters. This is used in the hcd urb give- | |
857 | * back path to delay waking up until after the completion handler has run. | |
858 | */ | |
859 | void usb_anchor_suspend_wakeups(struct usb_anchor *anchor) | |
860 | { | |
861 | if (anchor) | |
862 | atomic_inc(&anchor->suspend_wakeups); | |
863 | } | |
864 | EXPORT_SYMBOL_GPL(usb_anchor_suspend_wakeups); | |
865 | ||
866 | /** | |
867 | * usb_anchor_resume_wakeups | |
868 | * @anchor: the anchor you want to resume wakeups on | |
869 | * | |
870 | * Allow usb_wait_anchor_empty_timeout waiters to be woken up again, and | |
871 | * wake up any current waiters if the anchor is empty. | |
872 | */ | |
873 | void usb_anchor_resume_wakeups(struct usb_anchor *anchor) | |
874 | { | |
875 | if (!anchor) | |
876 | return; | |
877 | ||
878 | atomic_dec(&anchor->suspend_wakeups); | |
879 | if (usb_anchor_check_wakeup(anchor)) | |
880 | wake_up(&anchor->wait); | |
881 | } | |
882 | EXPORT_SYMBOL_GPL(usb_anchor_resume_wakeups); | |
883 | ||
51a2f077 ON |
884 | /** |
885 | * usb_wait_anchor_empty_timeout - wait for an anchor to be unused | |
886 | * @anchor: the anchor you want to become unused | |
887 | * @timeout: how long you are willing to wait in milliseconds | |
888 | * | |
889 | * Call this is you want to be sure all an anchor's | |
890 | * URBs have finished | |
626f090c YB |
891 | * |
892 | * Return: Non-zero if the anchor became unused. Zero on timeout. | |
51a2f077 ON |
893 | */ |
894 | int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, | |
895 | unsigned int timeout) | |
896 | { | |
6ec4147e HG |
897 | return wait_event_timeout(anchor->wait, |
898 | usb_anchor_check_wakeup(anchor), | |
51a2f077 ON |
899 | msecs_to_jiffies(timeout)); |
900 | } | |
901 | EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); | |
19876252 ON |
902 | |
903 | /** | |
904 | * usb_get_from_anchor - get an anchor's oldest urb | |
905 | * @anchor: the anchor whose urb you want | |
906 | * | |
626f090c | 907 | * This will take the oldest urb from an anchor, |
19876252 | 908 | * unanchor and return it |
626f090c YB |
909 | * |
910 | * Return: The oldest urb from @anchor, or %NULL if @anchor has no | |
911 | * urbs associated with it. | |
19876252 ON |
912 | */ |
913 | struct urb *usb_get_from_anchor(struct usb_anchor *anchor) | |
914 | { | |
915 | struct urb *victim; | |
916 | unsigned long flags; | |
917 | ||
918 | spin_lock_irqsave(&anchor->lock, flags); | |
919 | if (!list_empty(&anchor->urb_list)) { | |
920 | victim = list_entry(anchor->urb_list.next, struct urb, | |
921 | anchor_list); | |
922 | usb_get_urb(victim); | |
b3e67044 | 923 | __usb_unanchor_urb(victim, anchor); |
19876252 | 924 | } else { |
19876252 ON |
925 | victim = NULL; |
926 | } | |
b3e67044 | 927 | spin_unlock_irqrestore(&anchor->lock, flags); |
19876252 ON |
928 | |
929 | return victim; | |
930 | } | |
931 | ||
932 | EXPORT_SYMBOL_GPL(usb_get_from_anchor); | |
933 | ||
934 | /** | |
935 | * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs | |
936 | * @anchor: the anchor whose urbs you want to unanchor | |
937 | * | |
938 | * use this to get rid of all an anchor's urbs | |
939 | */ | |
940 | void usb_scuttle_anchored_urbs(struct usb_anchor *anchor) | |
941 | { | |
942 | struct urb *victim; | |
943 | unsigned long flags; | |
944 | ||
945 | spin_lock_irqsave(&anchor->lock, flags); | |
946 | while (!list_empty(&anchor->urb_list)) { | |
947 | victim = list_entry(anchor->urb_list.prev, struct urb, | |
948 | anchor_list); | |
b3e67044 | 949 | __usb_unanchor_urb(victim, anchor); |
19876252 ON |
950 | } |
951 | spin_unlock_irqrestore(&anchor->lock, flags); | |
952 | } | |
953 | ||
954 | EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); | |
955 | ||
956 | /** | |
957 | * usb_anchor_empty - is an anchor empty | |
958 | * @anchor: the anchor you want to query | |
959 | * | |
626f090c | 960 | * Return: 1 if the anchor has no urbs associated with it. |
19876252 ON |
961 | */ |
962 | int usb_anchor_empty(struct usb_anchor *anchor) | |
963 | { | |
964 | return list_empty(&anchor->urb_list); | |
965 | } | |
966 | ||
967 | EXPORT_SYMBOL_GPL(usb_anchor_empty); | |
968 |