Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * message.c - synchronous message handling | |
3 | */ | |
4 | ||
1da177e4 LT |
5 | #include <linux/pci.h> /* for scatterlist macros */ |
6 | #include <linux/usb.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/slab.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/timer.h> | |
12 | #include <linux/ctype.h> | |
a853a3d4 | 13 | #include <linux/nls.h> |
1da177e4 | 14 | #include <linux/device.h> |
11763609 | 15 | #include <linux/scatterlist.h> |
7ceec1f1 | 16 | #include <linux/usb/quirks.h> |
1da177e4 LT |
17 | #include <asm/byteorder.h> |
18 | ||
19 | #include "hcd.h" /* for usbcore internals */ | |
20 | #include "usb.h" | |
21 | ||
df718962 AS |
22 | static void cancel_async_set_config(struct usb_device *udev); |
23 | ||
67f5dde3 AS |
24 | struct api_context { |
25 | struct completion done; | |
26 | int status; | |
27 | }; | |
28 | ||
7d12e780 | 29 | static void usb_api_blocking_completion(struct urb *urb) |
1da177e4 | 30 | { |
67f5dde3 AS |
31 | struct api_context *ctx = urb->context; |
32 | ||
33 | ctx->status = urb->status; | |
34 | complete(&ctx->done); | |
1da177e4 LT |
35 | } |
36 | ||
37 | ||
ecdc0a59 FBH |
38 | /* |
39 | * Starts urb and waits for completion or timeout. Note that this call | |
40 | * is NOT interruptible. Many device driver i/o requests should be | |
41 | * interruptible and therefore these drivers should implement their | |
42 | * own interruptible routines. | |
43 | */ | |
44 | static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length) | |
3e35bf39 | 45 | { |
67f5dde3 | 46 | struct api_context ctx; |
ecdc0a59 | 47 | unsigned long expire; |
3fc3e826 | 48 | int retval; |
1da177e4 | 49 | |
67f5dde3 AS |
50 | init_completion(&ctx.done); |
51 | urb->context = &ctx; | |
1da177e4 | 52 | urb->actual_length = 0; |
3fc3e826 GKH |
53 | retval = usb_submit_urb(urb, GFP_NOIO); |
54 | if (unlikely(retval)) | |
ecdc0a59 | 55 | goto out; |
1da177e4 | 56 | |
ecdc0a59 | 57 | expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT; |
67f5dde3 AS |
58 | if (!wait_for_completion_timeout(&ctx.done, expire)) { |
59 | usb_kill_urb(urb); | |
60 | retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status); | |
ecdc0a59 FBH |
61 | |
62 | dev_dbg(&urb->dev->dev, | |
71d2718f | 63 | "%s timed out on ep%d%s len=%u/%u\n", |
ecdc0a59 | 64 | current->comm, |
5e60a161 AS |
65 | usb_endpoint_num(&urb->ep->desc), |
66 | usb_urb_dir_in(urb) ? "in" : "out", | |
ecdc0a59 FBH |
67 | urb->actual_length, |
68 | urb->transfer_buffer_length); | |
ecdc0a59 | 69 | } else |
67f5dde3 | 70 | retval = ctx.status; |
ecdc0a59 | 71 | out: |
1da177e4 LT |
72 | if (actual_length) |
73 | *actual_length = urb->actual_length; | |
ecdc0a59 | 74 | |
1da177e4 | 75 | usb_free_urb(urb); |
3fc3e826 | 76 | return retval; |
1da177e4 LT |
77 | } |
78 | ||
79 | /*-------------------------------------------------------------------*/ | |
3e35bf39 | 80 | /* returns status (negative) or length (positive) */ |
1da177e4 | 81 | static int usb_internal_control_msg(struct usb_device *usb_dev, |
3e35bf39 | 82 | unsigned int pipe, |
1da177e4 LT |
83 | struct usb_ctrlrequest *cmd, |
84 | void *data, int len, int timeout) | |
85 | { | |
86 | struct urb *urb; | |
87 | int retv; | |
88 | int length; | |
89 | ||
90 | urb = usb_alloc_urb(0, GFP_NOIO); | |
91 | if (!urb) | |
92 | return -ENOMEM; | |
3e35bf39 | 93 | |
1da177e4 LT |
94 | usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data, |
95 | len, usb_api_blocking_completion, NULL); | |
96 | ||
97 | retv = usb_start_wait_urb(urb, timeout, &length); | |
98 | if (retv < 0) | |
99 | return retv; | |
100 | else | |
101 | return length; | |
102 | } | |
103 | ||
104 | /** | |
3e35bf39 GKH |
105 | * usb_control_msg - Builds a control urb, sends it off and waits for completion |
106 | * @dev: pointer to the usb device to send the message to | |
107 | * @pipe: endpoint "pipe" to send the message to | |
108 | * @request: USB message request value | |
109 | * @requesttype: USB message request type value | |
110 | * @value: USB message value | |
111 | * @index: USB message index value | |
112 | * @data: pointer to the data to send | |
113 | * @size: length in bytes of the data to send | |
114 | * @timeout: time in msecs to wait for the message to complete before timing | |
115 | * out (if 0 the wait is forever) | |
116 | * | |
117 | * Context: !in_interrupt () | |
118 | * | |
119 | * This function sends a simple control message to a specified endpoint and | |
120 | * waits for the message to complete, or timeout. | |
121 | * | |
122 | * If successful, it returns the number of bytes transferred, otherwise a | |
123 | * negative error number. | |
124 | * | |
125 | * Don't use this function from within an interrupt context, like a bottom half | |
126 | * handler. If you need an asynchronous message, or need to send a message | |
127 | * from within interrupt context, use usb_submit_urb(). | |
128 | * If a thread in your driver uses this call, make sure your disconnect() | |
129 | * method can wait for it to complete. Since you don't have a handle on the | |
130 | * URB used, you can't cancel the request. | |
1da177e4 | 131 | */ |
3e35bf39 GKH |
132 | int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request, |
133 | __u8 requesttype, __u16 value, __u16 index, void *data, | |
134 | __u16 size, int timeout) | |
1da177e4 | 135 | { |
3e35bf39 | 136 | struct usb_ctrlrequest *dr; |
1da177e4 | 137 | int ret; |
3e35bf39 GKH |
138 | |
139 | dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO); | |
1da177e4 LT |
140 | if (!dr) |
141 | return -ENOMEM; | |
142 | ||
3e35bf39 | 143 | dr->bRequestType = requesttype; |
1da177e4 | 144 | dr->bRequest = request; |
da2bbdcc HH |
145 | dr->wValue = cpu_to_le16(value); |
146 | dr->wIndex = cpu_to_le16(index); | |
147 | dr->wLength = cpu_to_le16(size); | |
1da177e4 | 148 | |
3e35bf39 | 149 | /* dbg("usb_control_msg"); */ |
1da177e4 LT |
150 | |
151 | ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout); | |
152 | ||
153 | kfree(dr); | |
154 | ||
155 | return ret; | |
156 | } | |
782e70c6 | 157 | EXPORT_SYMBOL_GPL(usb_control_msg); |
1da177e4 | 158 | |
782a7a63 GKH |
159 | /** |
160 | * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion | |
161 | * @usb_dev: pointer to the usb device to send the message to | |
162 | * @pipe: endpoint "pipe" to send the message to | |
163 | * @data: pointer to the data to send | |
164 | * @len: length in bytes of the data to send | |
3e35bf39 GKH |
165 | * @actual_length: pointer to a location to put the actual length transferred |
166 | * in bytes | |
782a7a63 GKH |
167 | * @timeout: time in msecs to wait for the message to complete before |
168 | * timing out (if 0 the wait is forever) | |
3e35bf39 | 169 | * |
782a7a63 GKH |
170 | * Context: !in_interrupt () |
171 | * | |
172 | * This function sends a simple interrupt message to a specified endpoint and | |
173 | * waits for the message to complete, or timeout. | |
174 | * | |
175 | * If successful, it returns 0, otherwise a negative error number. The number | |
176 | * of actual bytes transferred will be stored in the actual_length paramater. | |
177 | * | |
178 | * Don't use this function from within an interrupt context, like a bottom half | |
179 | * handler. If you need an asynchronous message, or need to send a message | |
180 | * from within interrupt context, use usb_submit_urb() If a thread in your | |
181 | * driver uses this call, make sure your disconnect() method can wait for it to | |
182 | * complete. Since you don't have a handle on the URB used, you can't cancel | |
183 | * the request. | |
184 | */ | |
185 | int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe, | |
186 | void *data, int len, int *actual_length, int timeout) | |
187 | { | |
188 | return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout); | |
189 | } | |
190 | EXPORT_SYMBOL_GPL(usb_interrupt_msg); | |
191 | ||
1da177e4 | 192 | /** |
3e35bf39 GKH |
193 | * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion |
194 | * @usb_dev: pointer to the usb device to send the message to | |
195 | * @pipe: endpoint "pipe" to send the message to | |
196 | * @data: pointer to the data to send | |
197 | * @len: length in bytes of the data to send | |
198 | * @actual_length: pointer to a location to put the actual length transferred | |
199 | * in bytes | |
200 | * @timeout: time in msecs to wait for the message to complete before | |
201 | * timing out (if 0 the wait is forever) | |
202 | * | |
203 | * Context: !in_interrupt () | |
204 | * | |
205 | * This function sends a simple bulk message to a specified endpoint | |
206 | * and waits for the message to complete, or timeout. | |
207 | * | |
208 | * If successful, it returns 0, otherwise a negative error number. The number | |
209 | * of actual bytes transferred will be stored in the actual_length paramater. | |
210 | * | |
211 | * Don't use this function from within an interrupt context, like a bottom half | |
212 | * handler. If you need an asynchronous message, or need to send a message | |
213 | * from within interrupt context, use usb_submit_urb() If a thread in your | |
214 | * driver uses this call, make sure your disconnect() method can wait for it to | |
215 | * complete. Since you don't have a handle on the URB used, you can't cancel | |
216 | * the request. | |
217 | * | |
218 | * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl, | |
219 | * users are forced to abuse this routine by using it to submit URBs for | |
220 | * interrupt endpoints. We will take the liberty of creating an interrupt URB | |
221 | * (with the default interval) if the target is an interrupt endpoint. | |
1da177e4 | 222 | */ |
3e35bf39 GKH |
223 | int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe, |
224 | void *data, int len, int *actual_length, int timeout) | |
1da177e4 LT |
225 | { |
226 | struct urb *urb; | |
d09d36a9 | 227 | struct usb_host_endpoint *ep; |
1da177e4 | 228 | |
d09d36a9 AS |
229 | ep = (usb_pipein(pipe) ? usb_dev->ep_in : usb_dev->ep_out) |
230 | [usb_pipeendpoint(pipe)]; | |
231 | if (!ep || len < 0) | |
1da177e4 LT |
232 | return -EINVAL; |
233 | ||
d09d36a9 | 234 | urb = usb_alloc_urb(0, GFP_KERNEL); |
1da177e4 LT |
235 | if (!urb) |
236 | return -ENOMEM; | |
237 | ||
d09d36a9 AS |
238 | if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == |
239 | USB_ENDPOINT_XFER_INT) { | |
240 | pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30); | |
241 | usb_fill_int_urb(urb, usb_dev, pipe, data, len, | |
8d062b9a AS |
242 | usb_api_blocking_completion, NULL, |
243 | ep->desc.bInterval); | |
d09d36a9 AS |
244 | } else |
245 | usb_fill_bulk_urb(urb, usb_dev, pipe, data, len, | |
246 | usb_api_blocking_completion, NULL); | |
1da177e4 LT |
247 | |
248 | return usb_start_wait_urb(urb, timeout, actual_length); | |
249 | } | |
782e70c6 | 250 | EXPORT_SYMBOL_GPL(usb_bulk_msg); |
1da177e4 LT |
251 | |
252 | /*-------------------------------------------------------------------*/ | |
253 | ||
3e35bf39 | 254 | static void sg_clean(struct usb_sg_request *io) |
1da177e4 LT |
255 | { |
256 | if (io->urbs) { | |
257 | while (io->entries--) | |
3e35bf39 GKH |
258 | usb_free_urb(io->urbs [io->entries]); |
259 | kfree(io->urbs); | |
1da177e4 LT |
260 | io->urbs = NULL; |
261 | } | |
262 | if (io->dev->dev.dma_mask != NULL) | |
3e35bf39 GKH |
263 | usb_buffer_unmap_sg(io->dev, usb_pipein(io->pipe), |
264 | io->sg, io->nents); | |
1da177e4 LT |
265 | io->dev = NULL; |
266 | } | |
267 | ||
3e35bf39 | 268 | static void sg_complete(struct urb *urb) |
1da177e4 | 269 | { |
3e35bf39 | 270 | struct usb_sg_request *io = urb->context; |
3fc3e826 | 271 | int status = urb->status; |
1da177e4 | 272 | |
3e35bf39 | 273 | spin_lock(&io->lock); |
1da177e4 LT |
274 | |
275 | /* In 2.5 we require hcds' endpoint queues not to progress after fault | |
276 | * reports, until the completion callback (this!) returns. That lets | |
277 | * device driver code (like this routine) unlink queued urbs first, | |
278 | * if it needs to, since the HC won't work on them at all. So it's | |
279 | * not possible for page N+1 to overwrite page N, and so on. | |
280 | * | |
281 | * That's only for "hard" faults; "soft" faults (unlinks) sometimes | |
282 | * complete before the HCD can get requests away from hardware, | |
283 | * though never during cleanup after a hard fault. | |
284 | */ | |
285 | if (io->status | |
286 | && (io->status != -ECONNRESET | |
3fc3e826 | 287 | || status != -ECONNRESET) |
1da177e4 | 288 | && urb->actual_length) { |
3e35bf39 | 289 | dev_err(io->dev->bus->controller, |
1da177e4 LT |
290 | "dev %s ep%d%s scatterlist error %d/%d\n", |
291 | io->dev->devpath, | |
5e60a161 AS |
292 | usb_endpoint_num(&urb->ep->desc), |
293 | usb_urb_dir_in(urb) ? "in" : "out", | |
3fc3e826 | 294 | status, io->status); |
3e35bf39 | 295 | /* BUG (); */ |
1da177e4 LT |
296 | } |
297 | ||
3fc3e826 GKH |
298 | if (io->status == 0 && status && status != -ECONNRESET) { |
299 | int i, found, retval; | |
1da177e4 | 300 | |
3fc3e826 | 301 | io->status = status; |
1da177e4 LT |
302 | |
303 | /* the previous urbs, and this one, completed already. | |
304 | * unlink pending urbs so they won't rx/tx bad data. | |
305 | * careful: unlink can sometimes be synchronous... | |
306 | */ | |
3e35bf39 | 307 | spin_unlock(&io->lock); |
1da177e4 LT |
308 | for (i = 0, found = 0; i < io->entries; i++) { |
309 | if (!io->urbs [i] || !io->urbs [i]->dev) | |
310 | continue; | |
311 | if (found) { | |
3e35bf39 | 312 | retval = usb_unlink_urb(io->urbs [i]); |
3fc3e826 GKH |
313 | if (retval != -EINPROGRESS && |
314 | retval != -ENODEV && | |
315 | retval != -EBUSY) | |
3e35bf39 | 316 | dev_err(&io->dev->dev, |
1da177e4 | 317 | "%s, unlink --> %d\n", |
441b62c1 | 318 | __func__, retval); |
1da177e4 LT |
319 | } else if (urb == io->urbs [i]) |
320 | found = 1; | |
321 | } | |
3e35bf39 | 322 | spin_lock(&io->lock); |
1da177e4 LT |
323 | } |
324 | urb->dev = NULL; | |
325 | ||
326 | /* on the last completion, signal usb_sg_wait() */ | |
327 | io->bytes += urb->actual_length; | |
328 | io->count--; | |
329 | if (!io->count) | |
3e35bf39 | 330 | complete(&io->complete); |
1da177e4 | 331 | |
3e35bf39 | 332 | spin_unlock(&io->lock); |
1da177e4 LT |
333 | } |
334 | ||
335 | ||
336 | /** | |
337 | * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request | |
338 | * @io: request block being initialized. until usb_sg_wait() returns, | |
339 | * treat this as a pointer to an opaque block of memory, | |
340 | * @dev: the usb device that will send or receive the data | |
341 | * @pipe: endpoint "pipe" used to transfer the data | |
342 | * @period: polling rate for interrupt endpoints, in frames or | |
343 | * (for high speed endpoints) microframes; ignored for bulk | |
344 | * @sg: scatterlist entries | |
345 | * @nents: how many entries in the scatterlist | |
346 | * @length: how many bytes to send from the scatterlist, or zero to | |
347 | * send every byte identified in the list. | |
348 | * @mem_flags: SLAB_* flags affecting memory allocations in this call | |
349 | * | |
350 | * Returns zero for success, else a negative errno value. This initializes a | |
351 | * scatter/gather request, allocating resources such as I/O mappings and urb | |
352 | * memory (except maybe memory used by USB controller drivers). | |
353 | * | |
354 | * The request must be issued using usb_sg_wait(), which waits for the I/O to | |
355 | * complete (or to be canceled) and then cleans up all resources allocated by | |
356 | * usb_sg_init(). | |
357 | * | |
358 | * The request may be canceled with usb_sg_cancel(), either before or after | |
359 | * usb_sg_wait() is called. | |
360 | */ | |
3e35bf39 GKH |
361 | int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, |
362 | unsigned pipe, unsigned period, struct scatterlist *sg, | |
363 | int nents, size_t length, gfp_t mem_flags) | |
1da177e4 | 364 | { |
3e35bf39 GKH |
365 | int i; |
366 | int urb_flags; | |
367 | int dma; | |
e04748e3 | 368 | int use_sg; |
1da177e4 LT |
369 | |
370 | if (!io || !dev || !sg | |
3e35bf39 GKH |
371 | || usb_pipecontrol(pipe) |
372 | || usb_pipeisoc(pipe) | |
1da177e4 LT |
373 | || nents <= 0) |
374 | return -EINVAL; | |
375 | ||
3e35bf39 | 376 | spin_lock_init(&io->lock); |
1da177e4 LT |
377 | io->dev = dev; |
378 | io->pipe = pipe; | |
379 | io->sg = sg; | |
380 | io->nents = nents; | |
381 | ||
382 | /* not all host controllers use DMA (like the mainstream pci ones); | |
383 | * they can use PIO (sl811) or be software over another transport. | |
384 | */ | |
385 | dma = (dev->dev.dma_mask != NULL); | |
386 | if (dma) | |
5e60a161 | 387 | io->entries = usb_buffer_map_sg(dev, usb_pipein(pipe), |
3e35bf39 | 388 | sg, nents); |
1da177e4 LT |
389 | else |
390 | io->entries = nents; | |
391 | ||
392 | /* initialize all the urbs we'll use */ | |
393 | if (io->entries <= 0) | |
394 | return io->entries; | |
395 | ||
4c1bd3d7 | 396 | if (dev->bus->sg_tablesize > 0) { |
e04748e3 SS |
397 | io->urbs = kmalloc(sizeof *io->urbs, mem_flags); |
398 | use_sg = true; | |
399 | } else { | |
400 | io->urbs = kmalloc(io->entries * sizeof *io->urbs, mem_flags); | |
401 | use_sg = false; | |
402 | } | |
1da177e4 LT |
403 | if (!io->urbs) |
404 | goto nomem; | |
405 | ||
ed1db3ad | 406 | urb_flags = 0; |
e2722528 YS |
407 | if (dma) |
408 | urb_flags |= URB_NO_TRANSFER_DMA_MAP; | |
3e35bf39 | 409 | if (usb_pipein(pipe)) |
1da177e4 LT |
410 | urb_flags |= URB_SHORT_NOT_OK; |
411 | ||
e04748e3 SS |
412 | if (use_sg) { |
413 | io->urbs[0] = usb_alloc_urb(0, mem_flags); | |
414 | if (!io->urbs[0]) { | |
415 | io->entries = 0; | |
1da177e4 LT |
416 | goto nomem; |
417 | } | |
418 | ||
e04748e3 SS |
419 | io->urbs[0]->dev = NULL; |
420 | io->urbs[0]->pipe = pipe; | |
421 | io->urbs[0]->interval = period; | |
422 | io->urbs[0]->transfer_flags = urb_flags; | |
423 | ||
424 | io->urbs[0]->complete = sg_complete; | |
425 | io->urbs[0]->context = io; | |
426 | /* A length of zero means transfer the whole sg list */ | |
427 | io->urbs[0]->transfer_buffer_length = length; | |
428 | if (length == 0) { | |
429 | for_each_sg(sg, sg, io->entries, i) { | |
430 | io->urbs[0]->transfer_buffer_length += | |
431 | sg_dma_len(sg); | |
432 | } | |
433 | } | |
434 | io->urbs[0]->sg = io; | |
435 | io->urbs[0]->num_sgs = io->entries; | |
436 | io->entries = 1; | |
437 | } else { | |
ed1db3ad | 438 | urb_flags |= URB_NO_INTERRUPT; |
e04748e3 SS |
439 | for_each_sg(sg, sg, io->entries, i) { |
440 | unsigned len; | |
441 | ||
442 | io->urbs[i] = usb_alloc_urb(0, mem_flags); | |
443 | if (!io->urbs[i]) { | |
444 | io->entries = i; | |
445 | goto nomem; | |
446 | } | |
447 | ||
448 | io->urbs[i]->dev = NULL; | |
449 | io->urbs[i]->pipe = pipe; | |
450 | io->urbs[i]->interval = period; | |
451 | io->urbs[i]->transfer_flags = urb_flags; | |
452 | ||
453 | io->urbs[i]->complete = sg_complete; | |
454 | io->urbs[i]->context = io; | |
455 | ||
456 | /* | |
81bf46f3 PZ |
457 | * Some systems need to revert to PIO when DMA is temporarily |
458 | * unavailable. For their sakes, both transfer_buffer and | |
459 | * transfer_dma are set when possible. | |
e04748e3 | 460 | * |
81bf46f3 PZ |
461 | * Note that if IOMMU coalescing occurred, we cannot |
462 | * trust sg_page anymore, so check if S/G list shrunk. | |
e04748e3 | 463 | */ |
81bf46f3 PZ |
464 | if (io->nents == io->entries && !PageHighMem(sg_page(sg))) |
465 | io->urbs[i]->transfer_buffer = sg_virt(sg); | |
466 | else | |
467 | io->urbs[i]->transfer_buffer = NULL; | |
468 | ||
e04748e3 SS |
469 | if (dma) { |
470 | io->urbs[i]->transfer_dma = sg_dma_address(sg); | |
471 | len = sg_dma_len(sg); | |
e04748e3 SS |
472 | } else { |
473 | /* hc may use _only_ transfer_buffer */ | |
e04748e3 SS |
474 | len = sg->length; |
475 | } | |
476 | ||
477 | if (length) { | |
478 | len = min_t(unsigned, len, length); | |
479 | length -= len; | |
480 | if (length == 0) | |
481 | io->entries = i + 1; | |
482 | } | |
483 | io->urbs[i]->transfer_buffer_length = len; | |
1da177e4 | 484 | } |
e04748e3 | 485 | io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT; |
1da177e4 | 486 | } |
1da177e4 LT |
487 | |
488 | /* transaction state */ | |
580da348 | 489 | io->count = io->entries; |
1da177e4 LT |
490 | io->status = 0; |
491 | io->bytes = 0; | |
3e35bf39 | 492 | init_completion(&io->complete); |
1da177e4 LT |
493 | return 0; |
494 | ||
495 | nomem: | |
3e35bf39 | 496 | sg_clean(io); |
1da177e4 LT |
497 | return -ENOMEM; |
498 | } | |
782e70c6 | 499 | EXPORT_SYMBOL_GPL(usb_sg_init); |
1da177e4 LT |
500 | |
501 | /** | |
502 | * usb_sg_wait - synchronously execute scatter/gather request | |
503 | * @io: request block handle, as initialized with usb_sg_init(). | |
504 | * some fields become accessible when this call returns. | |
505 | * Context: !in_interrupt () | |
506 | * | |
507 | * This function blocks until the specified I/O operation completes. It | |
508 | * leverages the grouping of the related I/O requests to get good transfer | |
509 | * rates, by queueing the requests. At higher speeds, such queuing can | |
510 | * significantly improve USB throughput. | |
511 | * | |
512 | * There are three kinds of completion for this function. | |
513 | * (1) success, where io->status is zero. The number of io->bytes | |
514 | * transferred is as requested. | |
515 | * (2) error, where io->status is a negative errno value. The number | |
516 | * of io->bytes transferred before the error is usually less | |
517 | * than requested, and can be nonzero. | |
093cf723 | 518 | * (3) cancellation, a type of error with status -ECONNRESET that |
1da177e4 LT |
519 | * is initiated by usb_sg_cancel(). |
520 | * | |
521 | * When this function returns, all memory allocated through usb_sg_init() or | |
522 | * this call will have been freed. The request block parameter may still be | |
523 | * passed to usb_sg_cancel(), or it may be freed. It could also be | |
524 | * reinitialized and then reused. | |
525 | * | |
526 | * Data Transfer Rates: | |
527 | * | |
528 | * Bulk transfers are valid for full or high speed endpoints. | |
529 | * The best full speed data rate is 19 packets of 64 bytes each | |
530 | * per frame, or 1216 bytes per millisecond. | |
531 | * The best high speed data rate is 13 packets of 512 bytes each | |
532 | * per microframe, or 52 KBytes per millisecond. | |
533 | * | |
534 | * The reason to use interrupt transfers through this API would most likely | |
535 | * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond | |
536 | * could be transferred. That capability is less useful for low or full | |
537 | * speed interrupt endpoints, which allow at most one packet per millisecond, | |
538 | * of at most 8 or 64 bytes (respectively). | |
79abb1ab SS |
539 | * |
540 | * It is not necessary to call this function to reserve bandwidth for devices | |
541 | * under an xHCI host controller, as the bandwidth is reserved when the | |
542 | * configuration or interface alt setting is selected. | |
1da177e4 | 543 | */ |
3e35bf39 | 544 | void usb_sg_wait(struct usb_sg_request *io) |
1da177e4 | 545 | { |
3e35bf39 GKH |
546 | int i; |
547 | int entries = io->entries; | |
1da177e4 LT |
548 | |
549 | /* queue the urbs. */ | |
3e35bf39 | 550 | spin_lock_irq(&io->lock); |
8ccef0df AS |
551 | i = 0; |
552 | while (i < entries && !io->status) { | |
3e35bf39 | 553 | int retval; |
1da177e4 | 554 | |
3e35bf39 GKH |
555 | io->urbs[i]->dev = io->dev; |
556 | retval = usb_submit_urb(io->urbs [i], GFP_ATOMIC); | |
1da177e4 LT |
557 | |
558 | /* after we submit, let completions or cancelations fire; | |
559 | * we handshake using io->status. | |
560 | */ | |
3e35bf39 | 561 | spin_unlock_irq(&io->lock); |
1da177e4 LT |
562 | switch (retval) { |
563 | /* maybe we retrying will recover */ | |
3e35bf39 | 564 | case -ENXIO: /* hc didn't queue this one */ |
1da177e4 LT |
565 | case -EAGAIN: |
566 | case -ENOMEM: | |
567 | io->urbs[i]->dev = NULL; | |
568 | retval = 0; | |
3e35bf39 | 569 | yield(); |
1da177e4 LT |
570 | break; |
571 | ||
572 | /* no error? continue immediately. | |
573 | * | |
574 | * NOTE: to work better with UHCI (4K I/O buffer may | |
575 | * need 3K of TDs) it may be good to limit how many | |
576 | * URBs are queued at once; N milliseconds? | |
577 | */ | |
578 | case 0: | |
8ccef0df | 579 | ++i; |
3e35bf39 | 580 | cpu_relax(); |
1da177e4 LT |
581 | break; |
582 | ||
583 | /* fail any uncompleted urbs */ | |
584 | default: | |
3e35bf39 GKH |
585 | io->urbs[i]->dev = NULL; |
586 | io->urbs[i]->status = retval; | |
587 | dev_dbg(&io->dev->dev, "%s, submit --> %d\n", | |
441b62c1 | 588 | __func__, retval); |
3e35bf39 | 589 | usb_sg_cancel(io); |
1da177e4 | 590 | } |
3e35bf39 | 591 | spin_lock_irq(&io->lock); |
1da177e4 LT |
592 | if (retval && (io->status == 0 || io->status == -ECONNRESET)) |
593 | io->status = retval; | |
594 | } | |
595 | io->count -= entries - i; | |
596 | if (io->count == 0) | |
3e35bf39 GKH |
597 | complete(&io->complete); |
598 | spin_unlock_irq(&io->lock); | |
1da177e4 LT |
599 | |
600 | /* OK, yes, this could be packaged as non-blocking. | |
601 | * So could the submit loop above ... but it's easier to | |
602 | * solve neither problem than to solve both! | |
603 | */ | |
3e35bf39 | 604 | wait_for_completion(&io->complete); |
1da177e4 | 605 | |
3e35bf39 | 606 | sg_clean(io); |
1da177e4 | 607 | } |
782e70c6 | 608 | EXPORT_SYMBOL_GPL(usb_sg_wait); |
1da177e4 LT |
609 | |
610 | /** | |
611 | * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait() | |
612 | * @io: request block, initialized with usb_sg_init() | |
613 | * | |
614 | * This stops a request after it has been started by usb_sg_wait(). | |
615 | * It can also prevents one initialized by usb_sg_init() from starting, | |
616 | * so that call just frees resources allocated to the request. | |
617 | */ | |
3e35bf39 | 618 | void usb_sg_cancel(struct usb_sg_request *io) |
1da177e4 | 619 | { |
3e35bf39 | 620 | unsigned long flags; |
1da177e4 | 621 | |
3e35bf39 | 622 | spin_lock_irqsave(&io->lock, flags); |
1da177e4 LT |
623 | |
624 | /* shut everything down, if it didn't already */ | |
625 | if (!io->status) { | |
3e35bf39 | 626 | int i; |
1da177e4 LT |
627 | |
628 | io->status = -ECONNRESET; | |
3e35bf39 | 629 | spin_unlock(&io->lock); |
1da177e4 | 630 | for (i = 0; i < io->entries; i++) { |
3e35bf39 | 631 | int retval; |
1da177e4 LT |
632 | |
633 | if (!io->urbs [i]->dev) | |
634 | continue; | |
3e35bf39 | 635 | retval = usb_unlink_urb(io->urbs [i]); |
1da177e4 | 636 | if (retval != -EINPROGRESS && retval != -EBUSY) |
3e35bf39 | 637 | dev_warn(&io->dev->dev, "%s, unlink --> %d\n", |
441b62c1 | 638 | __func__, retval); |
1da177e4 | 639 | } |
3e35bf39 | 640 | spin_lock(&io->lock); |
1da177e4 | 641 | } |
3e35bf39 | 642 | spin_unlock_irqrestore(&io->lock, flags); |
1da177e4 | 643 | } |
782e70c6 | 644 | EXPORT_SYMBOL_GPL(usb_sg_cancel); |
1da177e4 LT |
645 | |
646 | /*-------------------------------------------------------------------*/ | |
647 | ||
648 | /** | |
649 | * usb_get_descriptor - issues a generic GET_DESCRIPTOR request | |
650 | * @dev: the device whose descriptor is being retrieved | |
651 | * @type: the descriptor type (USB_DT_*) | |
652 | * @index: the number of the descriptor | |
653 | * @buf: where to put the descriptor | |
654 | * @size: how big is "buf"? | |
655 | * Context: !in_interrupt () | |
656 | * | |
657 | * Gets a USB descriptor. Convenience functions exist to simplify | |
658 | * getting some types of descriptors. Use | |
659 | * usb_get_string() or usb_string() for USB_DT_STRING. | |
660 | * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG) | |
661 | * are part of the device structure. | |
662 | * In addition to a number of USB-standard descriptors, some | |
663 | * devices also use class-specific or vendor-specific descriptors. | |
664 | * | |
665 | * This call is synchronous, and may not be used in an interrupt context. | |
666 | * | |
667 | * Returns the number of bytes received on success, or else the status code | |
668 | * returned by the underlying usb_control_msg() call. | |
669 | */ | |
3e35bf39 GKH |
670 | int usb_get_descriptor(struct usb_device *dev, unsigned char type, |
671 | unsigned char index, void *buf, int size) | |
1da177e4 LT |
672 | { |
673 | int i; | |
674 | int result; | |
3e35bf39 GKH |
675 | |
676 | memset(buf, 0, size); /* Make sure we parse really received data */ | |
1da177e4 LT |
677 | |
678 | for (i = 0; i < 3; ++i) { | |
c39772d8 | 679 | /* retry on length 0 or error; some devices are flakey */ |
1da177e4 LT |
680 | result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), |
681 | USB_REQ_GET_DESCRIPTOR, USB_DIR_IN, | |
682 | (type << 8) + index, 0, buf, size, | |
683 | USB_CTRL_GET_TIMEOUT); | |
c39772d8 | 684 | if (result <= 0 && result != -ETIMEDOUT) |
1da177e4 LT |
685 | continue; |
686 | if (result > 1 && ((u8 *)buf)[1] != type) { | |
67f5a4ba | 687 | result = -ENODATA; |
1da177e4 LT |
688 | continue; |
689 | } | |
690 | break; | |
691 | } | |
692 | return result; | |
693 | } | |
782e70c6 | 694 | EXPORT_SYMBOL_GPL(usb_get_descriptor); |
1da177e4 LT |
695 | |
696 | /** | |
697 | * usb_get_string - gets a string descriptor | |
698 | * @dev: the device whose string descriptor is being retrieved | |
699 | * @langid: code for language chosen (from string descriptor zero) | |
700 | * @index: the number of the descriptor | |
701 | * @buf: where to put the string | |
702 | * @size: how big is "buf"? | |
703 | * Context: !in_interrupt () | |
704 | * | |
705 | * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character, | |
706 | * in little-endian byte order). | |
707 | * The usb_string() function will often be a convenient way to turn | |
708 | * these strings into kernel-printable form. | |
709 | * | |
710 | * Strings may be referenced in device, configuration, interface, or other | |
711 | * descriptors, and could also be used in vendor-specific ways. | |
712 | * | |
713 | * This call is synchronous, and may not be used in an interrupt context. | |
714 | * | |
715 | * Returns the number of bytes received on success, or else the status code | |
716 | * returned by the underlying usb_control_msg() call. | |
717 | */ | |
e266a124 AB |
718 | static int usb_get_string(struct usb_device *dev, unsigned short langid, |
719 | unsigned char index, void *buf, int size) | |
1da177e4 LT |
720 | { |
721 | int i; | |
722 | int result; | |
723 | ||
724 | for (i = 0; i < 3; ++i) { | |
725 | /* retry on length 0 or stall; some devices are flakey */ | |
726 | result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), | |
727 | USB_REQ_GET_DESCRIPTOR, USB_DIR_IN, | |
728 | (USB_DT_STRING << 8) + index, langid, buf, size, | |
729 | USB_CTRL_GET_TIMEOUT); | |
67f5a4ba AS |
730 | if (result == 0 || result == -EPIPE) |
731 | continue; | |
732 | if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) { | |
733 | result = -ENODATA; | |
734 | continue; | |
735 | } | |
736 | break; | |
1da177e4 LT |
737 | } |
738 | return result; | |
739 | } | |
740 | ||
741 | static void usb_try_string_workarounds(unsigned char *buf, int *length) | |
742 | { | |
743 | int newlength, oldlength = *length; | |
744 | ||
745 | for (newlength = 2; newlength + 1 < oldlength; newlength += 2) | |
746 | if (!isprint(buf[newlength]) || buf[newlength + 1]) | |
747 | break; | |
748 | ||
749 | if (newlength > 2) { | |
750 | buf[0] = newlength; | |
751 | *length = newlength; | |
752 | } | |
753 | } | |
754 | ||
755 | static int usb_string_sub(struct usb_device *dev, unsigned int langid, | |
3e35bf39 | 756 | unsigned int index, unsigned char *buf) |
1da177e4 LT |
757 | { |
758 | int rc; | |
759 | ||
760 | /* Try to read the string descriptor by asking for the maximum | |
761 | * possible number of bytes */ | |
7ceec1f1 ON |
762 | if (dev->quirks & USB_QUIRK_STRING_FETCH_255) |
763 | rc = -EIO; | |
764 | else | |
765 | rc = usb_get_string(dev, langid, index, buf, 255); | |
1da177e4 LT |
766 | |
767 | /* If that failed try to read the descriptor length, then | |
768 | * ask for just that many bytes */ | |
769 | if (rc < 2) { | |
770 | rc = usb_get_string(dev, langid, index, buf, 2); | |
771 | if (rc == 2) | |
772 | rc = usb_get_string(dev, langid, index, buf, buf[0]); | |
773 | } | |
774 | ||
775 | if (rc >= 2) { | |
776 | if (!buf[0] && !buf[1]) | |
777 | usb_try_string_workarounds(buf, &rc); | |
778 | ||
779 | /* There might be extra junk at the end of the descriptor */ | |
780 | if (buf[0] < rc) | |
781 | rc = buf[0]; | |
782 | ||
783 | rc = rc - (rc & 1); /* force a multiple of two */ | |
784 | } | |
785 | ||
786 | if (rc < 2) | |
787 | rc = (rc < 0 ? rc : -EINVAL); | |
788 | ||
789 | return rc; | |
790 | } | |
791 | ||
0cce2eda DM |
792 | static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf) |
793 | { | |
794 | int err; | |
795 | ||
796 | if (dev->have_langid) | |
797 | return 0; | |
798 | ||
799 | if (dev->string_langid < 0) | |
800 | return -EPIPE; | |
801 | ||
802 | err = usb_string_sub(dev, 0, 0, tbuf); | |
803 | ||
804 | /* If the string was reported but is malformed, default to english | |
805 | * (0x0409) */ | |
806 | if (err == -ENODATA || (err > 0 && err < 4)) { | |
807 | dev->string_langid = 0x0409; | |
808 | dev->have_langid = 1; | |
809 | dev_err(&dev->dev, | |
810 | "string descriptor 0 malformed (err = %d), " | |
811 | "defaulting to 0x%04x\n", | |
812 | err, dev->string_langid); | |
813 | return 0; | |
814 | } | |
815 | ||
816 | /* In case of all other errors, we assume the device is not able to | |
817 | * deal with strings at all. Set string_langid to -1 in order to | |
818 | * prevent any string to be retrieved from the device */ | |
819 | if (err < 0) { | |
820 | dev_err(&dev->dev, "string descriptor 0 read error: %d\n", | |
821 | err); | |
822 | dev->string_langid = -1; | |
823 | return -EPIPE; | |
824 | } | |
825 | ||
826 | /* always use the first langid listed */ | |
827 | dev->string_langid = tbuf[2] | (tbuf[3] << 8); | |
828 | dev->have_langid = 1; | |
829 | dev_dbg(&dev->dev, "default language 0x%04x\n", | |
830 | dev->string_langid); | |
831 | return 0; | |
832 | } | |
833 | ||
1da177e4 | 834 | /** |
a853a3d4 | 835 | * usb_string - returns UTF-8 version of a string descriptor |
1da177e4 LT |
836 | * @dev: the device whose string descriptor is being retrieved |
837 | * @index: the number of the descriptor | |
838 | * @buf: where to put the string | |
839 | * @size: how big is "buf"? | |
840 | * Context: !in_interrupt () | |
3e35bf39 | 841 | * |
1da177e4 | 842 | * This converts the UTF-16LE encoded strings returned by devices, from |
a853a3d4 CL |
843 | * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones |
844 | * that are more usable in most kernel contexts. Note that this function | |
1da177e4 LT |
845 | * chooses strings in the first language supported by the device. |
846 | * | |
1da177e4 LT |
847 | * This call is synchronous, and may not be used in an interrupt context. |
848 | * | |
849 | * Returns length of the string (>= 0) or usb_control_msg status (< 0). | |
850 | */ | |
851 | int usb_string(struct usb_device *dev, int index, char *buf, size_t size) | |
852 | { | |
853 | unsigned char *tbuf; | |
854 | int err; | |
1da177e4 LT |
855 | |
856 | if (dev->state == USB_STATE_SUSPENDED) | |
857 | return -EHOSTUNREACH; | |
858 | if (size <= 0 || !buf || !index) | |
859 | return -EINVAL; | |
860 | buf[0] = 0; | |
74675a58 | 861 | tbuf = kmalloc(256, GFP_NOIO); |
1da177e4 LT |
862 | if (!tbuf) |
863 | return -ENOMEM; | |
864 | ||
0cce2eda DM |
865 | err = usb_get_langid(dev, tbuf); |
866 | if (err < 0) | |
867 | goto errout; | |
3e35bf39 | 868 | |
1da177e4 LT |
869 | err = usb_string_sub(dev, dev->string_langid, index, tbuf); |
870 | if (err < 0) | |
871 | goto errout; | |
872 | ||
873 | size--; /* leave room for trailing NULL char in output buffer */ | |
74675a58 AS |
874 | err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2, |
875 | UTF16_LITTLE_ENDIAN, buf, size); | |
a853a3d4 | 876 | buf[err] = 0; |
1da177e4 LT |
877 | |
878 | if (tbuf[1] != USB_DT_STRING) | |
3e35bf39 GKH |
879 | dev_dbg(&dev->dev, |
880 | "wrong descriptor type %02x for string %d (\"%s\")\n", | |
881 | tbuf[1], index, buf); | |
1da177e4 LT |
882 | |
883 | errout: | |
884 | kfree(tbuf); | |
885 | return err; | |
886 | } | |
782e70c6 | 887 | EXPORT_SYMBOL_GPL(usb_string); |
1da177e4 | 888 | |
a853a3d4 CL |
889 | /* one UTF-8-encoded 16-bit character has at most three bytes */ |
890 | #define MAX_USB_STRING_SIZE (127 * 3 + 1) | |
891 | ||
4f62efe6 AS |
892 | /** |
893 | * usb_cache_string - read a string descriptor and cache it for later use | |
894 | * @udev: the device whose string descriptor is being read | |
895 | * @index: the descriptor index | |
896 | * | |
897 | * Returns a pointer to a kmalloc'ed buffer containing the descriptor string, | |
898 | * or NULL if the index is 0 or the string could not be read. | |
899 | */ | |
900 | char *usb_cache_string(struct usb_device *udev, int index) | |
901 | { | |
902 | char *buf; | |
903 | char *smallbuf = NULL; | |
904 | int len; | |
905 | ||
3e35bf39 GKH |
906 | if (index <= 0) |
907 | return NULL; | |
908 | ||
acbe2feb | 909 | buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO); |
3e35bf39 | 910 | if (buf) { |
a853a3d4 | 911 | len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE); |
3e35bf39 | 912 | if (len > 0) { |
acbe2feb | 913 | smallbuf = kmalloc(++len, GFP_NOIO); |
3e35bf39 | 914 | if (!smallbuf) |
4f62efe6 AS |
915 | return buf; |
916 | memcpy(smallbuf, buf, len); | |
917 | } | |
918 | kfree(buf); | |
919 | } | |
920 | return smallbuf; | |
921 | } | |
922 | ||
1da177e4 LT |
923 | /* |
924 | * usb_get_device_descriptor - (re)reads the device descriptor (usbcore) | |
925 | * @dev: the device whose device descriptor is being updated | |
926 | * @size: how much of the descriptor to read | |
927 | * Context: !in_interrupt () | |
928 | * | |
929 | * Updates the copy of the device descriptor stored in the device structure, | |
6ab16a90 | 930 | * which dedicates space for this purpose. |
1da177e4 LT |
931 | * |
932 | * Not exported, only for use by the core. If drivers really want to read | |
933 | * the device descriptor directly, they can call usb_get_descriptor() with | |
934 | * type = USB_DT_DEVICE and index = 0. | |
935 | * | |
936 | * This call is synchronous, and may not be used in an interrupt context. | |
937 | * | |
938 | * Returns the number of bytes received on success, or else the status code | |
939 | * returned by the underlying usb_control_msg() call. | |
940 | */ | |
941 | int usb_get_device_descriptor(struct usb_device *dev, unsigned int size) | |
942 | { | |
943 | struct usb_device_descriptor *desc; | |
944 | int ret; | |
945 | ||
946 | if (size > sizeof(*desc)) | |
947 | return -EINVAL; | |
948 | desc = kmalloc(sizeof(*desc), GFP_NOIO); | |
949 | if (!desc) | |
950 | return -ENOMEM; | |
951 | ||
952 | ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size); | |
3e35bf39 | 953 | if (ret >= 0) |
1da177e4 LT |
954 | memcpy(&dev->descriptor, desc, size); |
955 | kfree(desc); | |
956 | return ret; | |
957 | } | |
958 | ||
959 | /** | |
960 | * usb_get_status - issues a GET_STATUS call | |
961 | * @dev: the device whose status is being checked | |
962 | * @type: USB_RECIP_*; for device, interface, or endpoint | |
963 | * @target: zero (for device), else interface or endpoint number | |
964 | * @data: pointer to two bytes of bitmap data | |
965 | * Context: !in_interrupt () | |
966 | * | |
967 | * Returns device, interface, or endpoint status. Normally only of | |
968 | * interest to see if the device is self powered, or has enabled the | |
969 | * remote wakeup facility; or whether a bulk or interrupt endpoint | |
970 | * is halted ("stalled"). | |
971 | * | |
972 | * Bits in these status bitmaps are set using the SET_FEATURE request, | |
973 | * and cleared using the CLEAR_FEATURE request. The usb_clear_halt() | |
974 | * function should be used to clear halt ("stall") status. | |
975 | * | |
976 | * This call is synchronous, and may not be used in an interrupt context. | |
977 | * | |
978 | * Returns the number of bytes received on success, or else the status code | |
979 | * returned by the underlying usb_control_msg() call. | |
980 | */ | |
981 | int usb_get_status(struct usb_device *dev, int type, int target, void *data) | |
982 | { | |
983 | int ret; | |
984 | u16 *status = kmalloc(sizeof(*status), GFP_KERNEL); | |
985 | ||
986 | if (!status) | |
987 | return -ENOMEM; | |
988 | ||
989 | ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), | |
990 | USB_REQ_GET_STATUS, USB_DIR_IN | type, 0, target, status, | |
991 | sizeof(*status), USB_CTRL_GET_TIMEOUT); | |
992 | ||
993 | *(u16 *)data = *status; | |
994 | kfree(status); | |
995 | return ret; | |
996 | } | |
782e70c6 | 997 | EXPORT_SYMBOL_GPL(usb_get_status); |
1da177e4 LT |
998 | |
999 | /** | |
1000 | * usb_clear_halt - tells device to clear endpoint halt/stall condition | |
1001 | * @dev: device whose endpoint is halted | |
1002 | * @pipe: endpoint "pipe" being cleared | |
1003 | * Context: !in_interrupt () | |
1004 | * | |
1005 | * This is used to clear halt conditions for bulk and interrupt endpoints, | |
1006 | * as reported by URB completion status. Endpoints that are halted are | |
1007 | * sometimes referred to as being "stalled". Such endpoints are unable | |
1008 | * to transmit or receive data until the halt status is cleared. Any URBs | |
1009 | * queued for such an endpoint should normally be unlinked by the driver | |
1010 | * before clearing the halt condition, as described in sections 5.7.5 | |
1011 | * and 5.8.5 of the USB 2.0 spec. | |
1012 | * | |
1013 | * Note that control and isochronous endpoints don't halt, although control | |
1014 | * endpoints report "protocol stall" (for unsupported requests) using the | |
1015 | * same status code used to report a true stall. | |
1016 | * | |
1017 | * This call is synchronous, and may not be used in an interrupt context. | |
1018 | * | |
1019 | * Returns zero on success, or else the status code returned by the | |
1020 | * underlying usb_control_msg() call. | |
1021 | */ | |
1022 | int usb_clear_halt(struct usb_device *dev, int pipe) | |
1023 | { | |
1024 | int result; | |
1025 | int endp = usb_pipeendpoint(pipe); | |
3e35bf39 GKH |
1026 | |
1027 | if (usb_pipein(pipe)) | |
1da177e4 LT |
1028 | endp |= USB_DIR_IN; |
1029 | ||
1030 | /* we don't care if it wasn't halted first. in fact some devices | |
1031 | * (like some ibmcam model 1 units) seem to expect hosts to make | |
1032 | * this request for iso endpoints, which can't halt! | |
1033 | */ | |
1034 | result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), | |
1035 | USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT, | |
1036 | USB_ENDPOINT_HALT, endp, NULL, 0, | |
1037 | USB_CTRL_SET_TIMEOUT); | |
1038 | ||
1039 | /* don't un-halt or force to DATA0 except on success */ | |
1040 | if (result < 0) | |
1041 | return result; | |
1042 | ||
1043 | /* NOTE: seems like Microsoft and Apple don't bother verifying | |
1044 | * the clear "took", so some devices could lock up if you check... | |
1045 | * such as the Hagiwara FlashGate DUAL. So we won't bother. | |
1046 | * | |
1047 | * NOTE: make sure the logic here doesn't diverge much from | |
1048 | * the copy in usb-storage, for as long as we need two copies. | |
1049 | */ | |
1050 | ||
3444b26a | 1051 | usb_reset_endpoint(dev, endp); |
1da177e4 LT |
1052 | |
1053 | return 0; | |
1054 | } | |
782e70c6 | 1055 | EXPORT_SYMBOL_GPL(usb_clear_halt); |
1da177e4 | 1056 | |
3b23dd6f AS |
1057 | static int create_intf_ep_devs(struct usb_interface *intf) |
1058 | { | |
1059 | struct usb_device *udev = interface_to_usbdev(intf); | |
1060 | struct usb_host_interface *alt = intf->cur_altsetting; | |
1061 | int i; | |
1062 | ||
1063 | if (intf->ep_devs_created || intf->unregistering) | |
1064 | return 0; | |
1065 | ||
1066 | for (i = 0; i < alt->desc.bNumEndpoints; ++i) | |
1067 | (void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev); | |
1068 | intf->ep_devs_created = 1; | |
1069 | return 0; | |
1070 | } | |
1071 | ||
1072 | static void remove_intf_ep_devs(struct usb_interface *intf) | |
1073 | { | |
1074 | struct usb_host_interface *alt = intf->cur_altsetting; | |
1075 | int i; | |
1076 | ||
1077 | if (!intf->ep_devs_created) | |
1078 | return; | |
1079 | ||
1080 | for (i = 0; i < alt->desc.bNumEndpoints; ++i) | |
1081 | usb_remove_ep_devs(&alt->endpoint[i]); | |
1082 | intf->ep_devs_created = 0; | |
1083 | } | |
1084 | ||
1da177e4 LT |
1085 | /** |
1086 | * usb_disable_endpoint -- Disable an endpoint by address | |
1087 | * @dev: the device whose endpoint is being disabled | |
1088 | * @epaddr: the endpoint's address. Endpoint number for output, | |
1089 | * endpoint number + USB_DIR_IN for input | |
ddeac4e7 AS |
1090 | * @reset_hardware: flag to erase any endpoint state stored in the |
1091 | * controller hardware | |
1da177e4 | 1092 | * |
ddeac4e7 AS |
1093 | * Disables the endpoint for URB submission and nukes all pending URBs. |
1094 | * If @reset_hardware is set then also deallocates hcd/hardware state | |
1095 | * for the endpoint. | |
1da177e4 | 1096 | */ |
ddeac4e7 AS |
1097 | void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr, |
1098 | bool reset_hardware) | |
1da177e4 LT |
1099 | { |
1100 | unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK; | |
1101 | struct usb_host_endpoint *ep; | |
1102 | ||
1103 | if (!dev) | |
1104 | return; | |
1105 | ||
1106 | if (usb_endpoint_out(epaddr)) { | |
1107 | ep = dev->ep_out[epnum]; | |
ddeac4e7 AS |
1108 | if (reset_hardware) |
1109 | dev->ep_out[epnum] = NULL; | |
1da177e4 LT |
1110 | } else { |
1111 | ep = dev->ep_in[epnum]; | |
ddeac4e7 AS |
1112 | if (reset_hardware) |
1113 | dev->ep_in[epnum] = NULL; | |
1da177e4 | 1114 | } |
bdd016ba AS |
1115 | if (ep) { |
1116 | ep->enabled = 0; | |
95cf82f9 | 1117 | usb_hcd_flush_endpoint(dev, ep); |
ddeac4e7 AS |
1118 | if (reset_hardware) |
1119 | usb_hcd_disable_endpoint(dev, ep); | |
bdd016ba | 1120 | } |
1da177e4 LT |
1121 | } |
1122 | ||
3444b26a DV |
1123 | /** |
1124 | * usb_reset_endpoint - Reset an endpoint's state. | |
1125 | * @dev: the device whose endpoint is to be reset | |
1126 | * @epaddr: the endpoint's address. Endpoint number for output, | |
1127 | * endpoint number + USB_DIR_IN for input | |
1128 | * | |
1129 | * Resets any host-side endpoint state such as the toggle bit, | |
1130 | * sequence number or current window. | |
1131 | */ | |
1132 | void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr) | |
1133 | { | |
1134 | unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK; | |
1135 | struct usb_host_endpoint *ep; | |
1136 | ||
1137 | if (usb_endpoint_out(epaddr)) | |
1138 | ep = dev->ep_out[epnum]; | |
1139 | else | |
1140 | ep = dev->ep_in[epnum]; | |
1141 | if (ep) | |
1142 | usb_hcd_reset_endpoint(dev, ep); | |
1143 | } | |
1144 | EXPORT_SYMBOL_GPL(usb_reset_endpoint); | |
1145 | ||
1146 | ||
1da177e4 LT |
1147 | /** |
1148 | * usb_disable_interface -- Disable all endpoints for an interface | |
1149 | * @dev: the device whose interface is being disabled | |
1150 | * @intf: pointer to the interface descriptor | |
ddeac4e7 AS |
1151 | * @reset_hardware: flag to erase any endpoint state stored in the |
1152 | * controller hardware | |
1da177e4 LT |
1153 | * |
1154 | * Disables all the endpoints for the interface's current altsetting. | |
1155 | */ | |
ddeac4e7 AS |
1156 | void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf, |
1157 | bool reset_hardware) | |
1da177e4 LT |
1158 | { |
1159 | struct usb_host_interface *alt = intf->cur_altsetting; | |
1160 | int i; | |
1161 | ||
1162 | for (i = 0; i < alt->desc.bNumEndpoints; ++i) { | |
1163 | usb_disable_endpoint(dev, | |
ddeac4e7 AS |
1164 | alt->endpoint[i].desc.bEndpointAddress, |
1165 | reset_hardware); | |
1da177e4 LT |
1166 | } |
1167 | } | |
1168 | ||
3e35bf39 | 1169 | /** |
1da177e4 LT |
1170 | * usb_disable_device - Disable all the endpoints for a USB device |
1171 | * @dev: the device whose endpoints are being disabled | |
1172 | * @skip_ep0: 0 to disable endpoint 0, 1 to skip it. | |
1173 | * | |
1174 | * Disables all the device's endpoints, potentially including endpoint 0. | |
1175 | * Deallocates hcd/hardware state for the endpoints (nuking all or most | |
1176 | * pending urbs) and usbcore state for the interfaces, so that usbcore | |
1177 | * must usb_set_configuration() before any interfaces could be used. | |
1178 | */ | |
1179 | void usb_disable_device(struct usb_device *dev, int skip_ep0) | |
1180 | { | |
1181 | int i; | |
1182 | ||
441b62c1 | 1183 | dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__, |
3e35bf39 | 1184 | skip_ep0 ? "non-ep0" : "all"); |
1da177e4 | 1185 | for (i = skip_ep0; i < 16; ++i) { |
ddeac4e7 AS |
1186 | usb_disable_endpoint(dev, i, true); |
1187 | usb_disable_endpoint(dev, i + USB_DIR_IN, true); | |
1da177e4 | 1188 | } |
1da177e4 LT |
1189 | |
1190 | /* getting rid of interfaces will disconnect | |
1191 | * any drivers bound to them (a key side effect) | |
1192 | */ | |
1193 | if (dev->actconfig) { | |
1194 | for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) { | |
1195 | struct usb_interface *interface; | |
1196 | ||
86d30741 | 1197 | /* remove this interface if it has been registered */ |
1da177e4 | 1198 | interface = dev->actconfig->interface[i]; |
d305ef5d | 1199 | if (!device_is_registered(&interface->dev)) |
86d30741 | 1200 | continue; |
3e35bf39 | 1201 | dev_dbg(&dev->dev, "unregistering interface %s\n", |
7071a3ce | 1202 | dev_name(&interface->dev)); |
352d0263 | 1203 | interface->unregistering = 1; |
3b23dd6f | 1204 | remove_intf_ep_devs(interface); |
1a21175a | 1205 | device_del(&interface->dev); |
1da177e4 LT |
1206 | } |
1207 | ||
1208 | /* Now that the interfaces are unbound, nobody should | |
1209 | * try to access them. | |
1210 | */ | |
1211 | for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) { | |
3e35bf39 | 1212 | put_device(&dev->actconfig->interface[i]->dev); |
1da177e4 LT |
1213 | dev->actconfig->interface[i] = NULL; |
1214 | } | |
1215 | dev->actconfig = NULL; | |
1216 | if (dev->state == USB_STATE_CONFIGURED) | |
1217 | usb_set_device_state(dev, USB_STATE_ADDRESS); | |
1218 | } | |
1219 | } | |
1220 | ||
3e35bf39 | 1221 | /** |
1da177e4 LT |
1222 | * usb_enable_endpoint - Enable an endpoint for USB communications |
1223 | * @dev: the device whose interface is being enabled | |
1224 | * @ep: the endpoint | |
3444b26a | 1225 | * @reset_ep: flag to reset the endpoint state |
1da177e4 | 1226 | * |
3444b26a | 1227 | * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers. |
1da177e4 LT |
1228 | * For control endpoints, both the input and output sides are handled. |
1229 | */ | |
2caf7fcd | 1230 | void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep, |
3444b26a | 1231 | bool reset_ep) |
1da177e4 | 1232 | { |
bdd016ba AS |
1233 | int epnum = usb_endpoint_num(&ep->desc); |
1234 | int is_out = usb_endpoint_dir_out(&ep->desc); | |
1235 | int is_control = usb_endpoint_xfer_control(&ep->desc); | |
1da177e4 | 1236 | |
3444b26a DV |
1237 | if (reset_ep) |
1238 | usb_hcd_reset_endpoint(dev, ep); | |
1239 | if (is_out || is_control) | |
1da177e4 | 1240 | dev->ep_out[epnum] = ep; |
3444b26a | 1241 | if (!is_out || is_control) |
1da177e4 | 1242 | dev->ep_in[epnum] = ep; |
bdd016ba | 1243 | ep->enabled = 1; |
1da177e4 LT |
1244 | } |
1245 | ||
3e35bf39 | 1246 | /** |
1da177e4 LT |
1247 | * usb_enable_interface - Enable all the endpoints for an interface |
1248 | * @dev: the device whose interface is being enabled | |
1249 | * @intf: pointer to the interface descriptor | |
3444b26a | 1250 | * @reset_eps: flag to reset the endpoints' state |
1da177e4 LT |
1251 | * |
1252 | * Enables all the endpoints for the interface's current altsetting. | |
1253 | */ | |
2caf7fcd | 1254 | void usb_enable_interface(struct usb_device *dev, |
3444b26a | 1255 | struct usb_interface *intf, bool reset_eps) |
1da177e4 LT |
1256 | { |
1257 | struct usb_host_interface *alt = intf->cur_altsetting; | |
1258 | int i; | |
1259 | ||
1260 | for (i = 0; i < alt->desc.bNumEndpoints; ++i) | |
3444b26a | 1261 | usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps); |
1da177e4 LT |
1262 | } |
1263 | ||
1264 | /** | |
1265 | * usb_set_interface - Makes a particular alternate setting be current | |
1266 | * @dev: the device whose interface is being updated | |
1267 | * @interface: the interface being updated | |
1268 | * @alternate: the setting being chosen. | |
1269 | * Context: !in_interrupt () | |
1270 | * | |
1271 | * This is used to enable data transfers on interfaces that may not | |
1272 | * be enabled by default. Not all devices support such configurability. | |
1273 | * Only the driver bound to an interface may change its setting. | |
1274 | * | |
1275 | * Within any given configuration, each interface may have several | |
1276 | * alternative settings. These are often used to control levels of | |
1277 | * bandwidth consumption. For example, the default setting for a high | |
1278 | * speed interrupt endpoint may not send more than 64 bytes per microframe, | |
1279 | * while interrupt transfers of up to 3KBytes per microframe are legal. | |
1280 | * Also, isochronous endpoints may never be part of an | |
1281 | * interface's default setting. To access such bandwidth, alternate | |
1282 | * interface settings must be made current. | |
1283 | * | |
1284 | * Note that in the Linux USB subsystem, bandwidth associated with | |
1285 | * an endpoint in a given alternate setting is not reserved until an URB | |
1286 | * is submitted that needs that bandwidth. Some other operating systems | |
1287 | * allocate bandwidth early, when a configuration is chosen. | |
1288 | * | |
1289 | * This call is synchronous, and may not be used in an interrupt context. | |
1290 | * Also, drivers must not change altsettings while urbs are scheduled for | |
1291 | * endpoints in that interface; all such urbs must first be completed | |
1292 | * (perhaps forced by unlinking). | |
1293 | * | |
1294 | * Returns zero on success, or else the status code returned by the | |
1295 | * underlying usb_control_msg() call. | |
1296 | */ | |
1297 | int usb_set_interface(struct usb_device *dev, int interface, int alternate) | |
1298 | { | |
1299 | struct usb_interface *iface; | |
1300 | struct usb_host_interface *alt; | |
3f0479e0 | 1301 | struct usb_hcd *hcd = bus_to_hcd(dev->bus); |
1da177e4 LT |
1302 | int ret; |
1303 | int manual = 0; | |
3e35bf39 GKH |
1304 | unsigned int epaddr; |
1305 | unsigned int pipe; | |
1da177e4 LT |
1306 | |
1307 | if (dev->state == USB_STATE_SUSPENDED) | |
1308 | return -EHOSTUNREACH; | |
1309 | ||
1310 | iface = usb_ifnum_to_if(dev, interface); | |
1311 | if (!iface) { | |
1312 | dev_dbg(&dev->dev, "selecting invalid interface %d\n", | |
1313 | interface); | |
1314 | return -EINVAL; | |
1315 | } | |
1316 | ||
1317 | alt = usb_altnum_to_altsetting(iface, alternate); | |
1318 | if (!alt) { | |
3b6004f3 GKH |
1319 | dev_warn(&dev->dev, "selecting invalid altsetting %d", |
1320 | alternate); | |
1da177e4 LT |
1321 | return -EINVAL; |
1322 | } | |
1323 | ||
3f0479e0 SS |
1324 | /* Make sure we have enough bandwidth for this alternate interface. |
1325 | * Remove the current alt setting and add the new alt setting. | |
1326 | */ | |
1327 | mutex_lock(&hcd->bandwidth_mutex); | |
1328 | ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt); | |
1329 | if (ret < 0) { | |
1330 | dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n", | |
1331 | alternate); | |
1332 | mutex_unlock(&hcd->bandwidth_mutex); | |
1333 | return ret; | |
1334 | } | |
1335 | ||
392e1d98 AS |
1336 | if (dev->quirks & USB_QUIRK_NO_SET_INTF) |
1337 | ret = -EPIPE; | |
1338 | else | |
1339 | ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), | |
1da177e4 LT |
1340 | USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE, |
1341 | alternate, interface, NULL, 0, 5000); | |
1342 | ||
1343 | /* 9.4.10 says devices don't need this and are free to STALL the | |
1344 | * request if the interface only has one alternate setting. | |
1345 | */ | |
1346 | if (ret == -EPIPE && iface->num_altsetting == 1) { | |
1347 | dev_dbg(&dev->dev, | |
1348 | "manual set_interface for iface %d, alt %d\n", | |
1349 | interface, alternate); | |
1350 | manual = 1; | |
3f0479e0 SS |
1351 | } else if (ret < 0) { |
1352 | /* Re-instate the old alt setting */ | |
1353 | usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting); | |
1354 | mutex_unlock(&hcd->bandwidth_mutex); | |
1da177e4 | 1355 | return ret; |
3f0479e0 SS |
1356 | } |
1357 | mutex_unlock(&hcd->bandwidth_mutex); | |
1da177e4 LT |
1358 | |
1359 | /* FIXME drivers shouldn't need to replicate/bugfix the logic here | |
1360 | * when they implement async or easily-killable versions of this or | |
1361 | * other "should-be-internal" functions (like clear_halt). | |
1362 | * should hcd+usbcore postprocess control requests? | |
1363 | */ | |
1364 | ||
1365 | /* prevent submissions using previous endpoint settings */ | |
3b23dd6f AS |
1366 | if (iface->cur_altsetting != alt) { |
1367 | remove_intf_ep_devs(iface); | |
0e6c8e8d | 1368 | usb_remove_sysfs_intf_files(iface); |
3b23dd6f | 1369 | } |
ddeac4e7 | 1370 | usb_disable_interface(dev, iface, true); |
1da177e4 | 1371 | |
1da177e4 LT |
1372 | iface->cur_altsetting = alt; |
1373 | ||
1374 | /* If the interface only has one altsetting and the device didn't | |
a81e7ecc | 1375 | * accept the request, we attempt to carry out the equivalent action |
1da177e4 LT |
1376 | * by manually clearing the HALT feature for each endpoint in the |
1377 | * new altsetting. | |
1378 | */ | |
1379 | if (manual) { | |
1380 | int i; | |
1381 | ||
1382 | for (i = 0; i < alt->desc.bNumEndpoints; i++) { | |
3e35bf39 GKH |
1383 | epaddr = alt->endpoint[i].desc.bEndpointAddress; |
1384 | pipe = __create_pipe(dev, | |
1385 | USB_ENDPOINT_NUMBER_MASK & epaddr) | | |
1386 | (usb_endpoint_out(epaddr) ? | |
1387 | USB_DIR_OUT : USB_DIR_IN); | |
1da177e4 LT |
1388 | |
1389 | usb_clear_halt(dev, pipe); | |
1390 | } | |
1391 | } | |
1392 | ||
1393 | /* 9.1.1.5: reset toggles for all endpoints in the new altsetting | |
1394 | * | |
1395 | * Note: | |
1396 | * Despite EP0 is always present in all interfaces/AS, the list of | |
1397 | * endpoints from the descriptor does not contain EP0. Due to its | |
1398 | * omnipresence one might expect EP0 being considered "affected" by | |
1399 | * any SetInterface request and hence assume toggles need to be reset. | |
1400 | * However, EP0 toggles are re-synced for every individual transfer | |
1401 | * during the SETUP stage - hence EP0 toggles are "don't care" here. | |
1402 | * (Likewise, EP0 never "halts" on well designed devices.) | |
1403 | */ | |
2caf7fcd | 1404 | usb_enable_interface(dev, iface, true); |
3b23dd6f | 1405 | if (device_is_registered(&iface->dev)) { |
0e6c8e8d | 1406 | usb_create_sysfs_intf_files(iface); |
3b23dd6f AS |
1407 | create_intf_ep_devs(iface); |
1408 | } | |
1da177e4 LT |
1409 | return 0; |
1410 | } | |
782e70c6 | 1411 | EXPORT_SYMBOL_GPL(usb_set_interface); |
1da177e4 LT |
1412 | |
1413 | /** | |
1414 | * usb_reset_configuration - lightweight device reset | |
1415 | * @dev: the device whose configuration is being reset | |
1416 | * | |
1417 | * This issues a standard SET_CONFIGURATION request to the device using | |
1418 | * the current configuration. The effect is to reset most USB-related | |
1419 | * state in the device, including interface altsettings (reset to zero), | |
3444b26a | 1420 | * endpoint halts (cleared), and endpoint state (only for bulk and interrupt |
1da177e4 LT |
1421 | * endpoints). Other usbcore state is unchanged, including bindings of |
1422 | * usb device drivers to interfaces. | |
1423 | * | |
1424 | * Because this affects multiple interfaces, avoid using this with composite | |
1425 | * (multi-interface) devices. Instead, the driver for each interface may | |
a81e7ecc DB |
1426 | * use usb_set_interface() on the interfaces it claims. Be careful though; |
1427 | * some devices don't support the SET_INTERFACE request, and others won't | |
3444b26a | 1428 | * reset all the interface state (notably endpoint state). Resetting the whole |
1da177e4 LT |
1429 | * configuration would affect other drivers' interfaces. |
1430 | * | |
1431 | * The caller must own the device lock. | |
1432 | * | |
1433 | * Returns zero on success, else a negative error code. | |
1434 | */ | |
1435 | int usb_reset_configuration(struct usb_device *dev) | |
1436 | { | |
1437 | int i, retval; | |
1438 | struct usb_host_config *config; | |
3f0479e0 | 1439 | struct usb_hcd *hcd = bus_to_hcd(dev->bus); |
1da177e4 LT |
1440 | |
1441 | if (dev->state == USB_STATE_SUSPENDED) | |
1442 | return -EHOSTUNREACH; | |
1443 | ||
1444 | /* caller must have locked the device and must own | |
1445 | * the usb bus readlock (so driver bindings are stable); | |
1446 | * calls during probe() are fine | |
1447 | */ | |
1448 | ||
1449 | for (i = 1; i < 16; ++i) { | |
ddeac4e7 AS |
1450 | usb_disable_endpoint(dev, i, true); |
1451 | usb_disable_endpoint(dev, i + USB_DIR_IN, true); | |
1da177e4 LT |
1452 | } |
1453 | ||
1454 | config = dev->actconfig; | |
3f0479e0 SS |
1455 | retval = 0; |
1456 | mutex_lock(&hcd->bandwidth_mutex); | |
1457 | /* Make sure we have enough bandwidth for each alternate setting 0 */ | |
1458 | for (i = 0; i < config->desc.bNumInterfaces; i++) { | |
1459 | struct usb_interface *intf = config->interface[i]; | |
1460 | struct usb_host_interface *alt; | |
1461 | ||
1462 | alt = usb_altnum_to_altsetting(intf, 0); | |
1463 | if (!alt) | |
1464 | alt = &intf->altsetting[0]; | |
1465 | if (alt != intf->cur_altsetting) | |
1466 | retval = usb_hcd_alloc_bandwidth(dev, NULL, | |
1467 | intf->cur_altsetting, alt); | |
1468 | if (retval < 0) | |
1469 | break; | |
1470 | } | |
1471 | /* If not, reinstate the old alternate settings */ | |
1472 | if (retval < 0) { | |
1473 | reset_old_alts: | |
1474 | for (; i >= 0; i--) { | |
1475 | struct usb_interface *intf = config->interface[i]; | |
1476 | struct usb_host_interface *alt; | |
1477 | ||
1478 | alt = usb_altnum_to_altsetting(intf, 0); | |
1479 | if (!alt) | |
1480 | alt = &intf->altsetting[0]; | |
1481 | if (alt != intf->cur_altsetting) | |
1482 | usb_hcd_alloc_bandwidth(dev, NULL, | |
1483 | alt, intf->cur_altsetting); | |
1484 | } | |
1485 | mutex_unlock(&hcd->bandwidth_mutex); | |
1486 | return retval; | |
1487 | } | |
1da177e4 LT |
1488 | retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), |
1489 | USB_REQ_SET_CONFIGURATION, 0, | |
1490 | config->desc.bConfigurationValue, 0, | |
1491 | NULL, 0, USB_CTRL_SET_TIMEOUT); | |
0e6c8e8d | 1492 | if (retval < 0) |
3f0479e0 SS |
1493 | goto reset_old_alts; |
1494 | mutex_unlock(&hcd->bandwidth_mutex); | |
1da177e4 | 1495 | |
1da177e4 LT |
1496 | /* re-init hc/hcd interface/endpoint state */ |
1497 | for (i = 0; i < config->desc.bNumInterfaces; i++) { | |
1498 | struct usb_interface *intf = config->interface[i]; | |
1499 | struct usb_host_interface *alt; | |
1500 | ||
1501 | alt = usb_altnum_to_altsetting(intf, 0); | |
1502 | ||
1503 | /* No altsetting 0? We'll assume the first altsetting. | |
1504 | * We could use a GetInterface call, but if a device is | |
1505 | * so non-compliant that it doesn't have altsetting 0 | |
1506 | * then I wouldn't trust its reply anyway. | |
1507 | */ | |
1508 | if (!alt) | |
1509 | alt = &intf->altsetting[0]; | |
1510 | ||
3b23dd6f AS |
1511 | if (alt != intf->cur_altsetting) { |
1512 | remove_intf_ep_devs(intf); | |
1513 | usb_remove_sysfs_intf_files(intf); | |
1514 | } | |
1da177e4 | 1515 | intf->cur_altsetting = alt; |
2caf7fcd | 1516 | usb_enable_interface(dev, intf, true); |
3b23dd6f | 1517 | if (device_is_registered(&intf->dev)) { |
0e6c8e8d | 1518 | usb_create_sysfs_intf_files(intf); |
3b23dd6f AS |
1519 | create_intf_ep_devs(intf); |
1520 | } | |
1da177e4 LT |
1521 | } |
1522 | return 0; | |
1523 | } | |
782e70c6 | 1524 | EXPORT_SYMBOL_GPL(usb_reset_configuration); |
1da177e4 | 1525 | |
b0e396e3 | 1526 | static void usb_release_interface(struct device *dev) |
1da177e4 LT |
1527 | { |
1528 | struct usb_interface *intf = to_usb_interface(dev); | |
1529 | struct usb_interface_cache *intfc = | |
1530 | altsetting_to_usb_interface_cache(intf->altsetting); | |
1531 | ||
1532 | kref_put(&intfc->ref, usb_release_interface_cache); | |
1533 | kfree(intf); | |
1534 | } | |
1535 | ||
9f8b17e6 | 1536 | #ifdef CONFIG_HOTPLUG |
7eff2e7a | 1537 | static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env) |
9f8b17e6 KS |
1538 | { |
1539 | struct usb_device *usb_dev; | |
1540 | struct usb_interface *intf; | |
1541 | struct usb_host_interface *alt; | |
9f8b17e6 | 1542 | |
9f8b17e6 KS |
1543 | intf = to_usb_interface(dev); |
1544 | usb_dev = interface_to_usbdev(intf); | |
1545 | alt = intf->cur_altsetting; | |
1546 | ||
7eff2e7a | 1547 | if (add_uevent_var(env, "INTERFACE=%d/%d/%d", |
9f8b17e6 KS |
1548 | alt->desc.bInterfaceClass, |
1549 | alt->desc.bInterfaceSubClass, | |
1550 | alt->desc.bInterfaceProtocol)) | |
1551 | return -ENOMEM; | |
1552 | ||
7eff2e7a | 1553 | if (add_uevent_var(env, |
3e35bf39 GKH |
1554 | "MODALIAS=usb:" |
1555 | "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X", | |
9f8b17e6 KS |
1556 | le16_to_cpu(usb_dev->descriptor.idVendor), |
1557 | le16_to_cpu(usb_dev->descriptor.idProduct), | |
1558 | le16_to_cpu(usb_dev->descriptor.bcdDevice), | |
1559 | usb_dev->descriptor.bDeviceClass, | |
1560 | usb_dev->descriptor.bDeviceSubClass, | |
1561 | usb_dev->descriptor.bDeviceProtocol, | |
1562 | alt->desc.bInterfaceClass, | |
1563 | alt->desc.bInterfaceSubClass, | |
1564 | alt->desc.bInterfaceProtocol)) | |
1565 | return -ENOMEM; | |
1566 | ||
9f8b17e6 KS |
1567 | return 0; |
1568 | } | |
1569 | ||
1570 | #else | |
1571 | ||
7eff2e7a | 1572 | static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env) |
9f8b17e6 KS |
1573 | { |
1574 | return -ENODEV; | |
1575 | } | |
1576 | #endif /* CONFIG_HOTPLUG */ | |
1577 | ||
1578 | struct device_type usb_if_device_type = { | |
1579 | .name = "usb_interface", | |
1580 | .release = usb_release_interface, | |
1581 | .uevent = usb_if_uevent, | |
1582 | }; | |
1583 | ||
165fe97e | 1584 | static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev, |
3e35bf39 GKH |
1585 | struct usb_host_config *config, |
1586 | u8 inum) | |
165fe97e CN |
1587 | { |
1588 | struct usb_interface_assoc_descriptor *retval = NULL; | |
1589 | struct usb_interface_assoc_descriptor *intf_assoc; | |
1590 | int first_intf; | |
1591 | int last_intf; | |
1592 | int i; | |
1593 | ||
1594 | for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) { | |
1595 | intf_assoc = config->intf_assoc[i]; | |
1596 | if (intf_assoc->bInterfaceCount == 0) | |
1597 | continue; | |
1598 | ||
1599 | first_intf = intf_assoc->bFirstInterface; | |
1600 | last_intf = first_intf + (intf_assoc->bInterfaceCount - 1); | |
1601 | if (inum >= first_intf && inum <= last_intf) { | |
1602 | if (!retval) | |
1603 | retval = intf_assoc; | |
1604 | else | |
1605 | dev_err(&dev->dev, "Interface #%d referenced" | |
1606 | " by multiple IADs\n", inum); | |
1607 | } | |
1608 | } | |
1609 | ||
1610 | return retval; | |
1611 | } | |
1612 | ||
dc023dce IPG |
1613 | |
1614 | /* | |
1615 | * Internal function to queue a device reset | |
1616 | * | |
1617 | * This is initialized into the workstruct in 'struct | |
1618 | * usb_device->reset_ws' that is launched by | |
1619 | * message.c:usb_set_configuration() when initializing each 'struct | |
1620 | * usb_interface'. | |
1621 | * | |
1622 | * It is safe to get the USB device without reference counts because | |
1623 | * the life cycle of @iface is bound to the life cycle of @udev. Then, | |
1624 | * this function will be ran only if @iface is alive (and before | |
1625 | * freeing it any scheduled instances of it will have been cancelled). | |
1626 | * | |
1627 | * We need to set a flag (usb_dev->reset_running) because when we call | |
1628 | * the reset, the interfaces might be unbound. The current interface | |
1629 | * cannot try to remove the queued work as it would cause a deadlock | |
1630 | * (you cannot remove your work from within your executing | |
1631 | * workqueue). This flag lets it know, so that | |
1632 | * usb_cancel_queued_reset() doesn't try to do it. | |
1633 | * | |
1634 | * See usb_queue_reset_device() for more details | |
1635 | */ | |
09e81f3d | 1636 | static void __usb_queue_reset_device(struct work_struct *ws) |
dc023dce IPG |
1637 | { |
1638 | int rc; | |
1639 | struct usb_interface *iface = | |
1640 | container_of(ws, struct usb_interface, reset_ws); | |
1641 | struct usb_device *udev = interface_to_usbdev(iface); | |
1642 | ||
1643 | rc = usb_lock_device_for_reset(udev, iface); | |
1644 | if (rc >= 0) { | |
1645 | iface->reset_running = 1; | |
1646 | usb_reset_device(udev); | |
1647 | iface->reset_running = 0; | |
1648 | usb_unlock_device(udev); | |
1649 | } | |
1650 | } | |
1651 | ||
1652 | ||
1da177e4 LT |
1653 | /* |
1654 | * usb_set_configuration - Makes a particular device setting be current | |
1655 | * @dev: the device whose configuration is being updated | |
1656 | * @configuration: the configuration being chosen. | |
1657 | * Context: !in_interrupt(), caller owns the device lock | |
1658 | * | |
1659 | * This is used to enable non-default device modes. Not all devices | |
1660 | * use this kind of configurability; many devices only have one | |
1661 | * configuration. | |
1662 | * | |
3f141e2a AS |
1663 | * @configuration is the value of the configuration to be installed. |
1664 | * According to the USB spec (e.g. section 9.1.1.5), configuration values | |
1665 | * must be non-zero; a value of zero indicates that the device in | |
1666 | * unconfigured. However some devices erroneously use 0 as one of their | |
1667 | * configuration values. To help manage such devices, this routine will | |
1668 | * accept @configuration = -1 as indicating the device should be put in | |
1669 | * an unconfigured state. | |
1670 | * | |
1da177e4 LT |
1671 | * USB device configurations may affect Linux interoperability, |
1672 | * power consumption and the functionality available. For example, | |
1673 | * the default configuration is limited to using 100mA of bus power, | |
1674 | * so that when certain device functionality requires more power, | |
1675 | * and the device is bus powered, that functionality should be in some | |
1676 | * non-default device configuration. Other device modes may also be | |
1677 | * reflected as configuration options, such as whether two ISDN | |
1678 | * channels are available independently; and choosing between open | |
1679 | * standard device protocols (like CDC) or proprietary ones. | |
1680 | * | |
16bbab29 IPG |
1681 | * Note that a non-authorized device (dev->authorized == 0) will only |
1682 | * be put in unconfigured mode. | |
1683 | * | |
1da177e4 LT |
1684 | * Note that USB has an additional level of device configurability, |
1685 | * associated with interfaces. That configurability is accessed using | |
1686 | * usb_set_interface(). | |
1687 | * | |
1688 | * This call is synchronous. The calling context must be able to sleep, | |
1689 | * must own the device lock, and must not hold the driver model's USB | |
6d243e5c | 1690 | * bus mutex; usb interface driver probe() methods cannot use this routine. |
1da177e4 LT |
1691 | * |
1692 | * Returns zero on success, or else the status code returned by the | |
093cf723 | 1693 | * underlying call that failed. On successful completion, each interface |
1da177e4 LT |
1694 | * in the original device configuration has been destroyed, and each one |
1695 | * in the new configuration has been probed by all relevant usb device | |
1696 | * drivers currently known to the kernel. | |
1697 | */ | |
1698 | int usb_set_configuration(struct usb_device *dev, int configuration) | |
1699 | { | |
1700 | int i, ret; | |
1701 | struct usb_host_config *cp = NULL; | |
1702 | struct usb_interface **new_interfaces = NULL; | |
3f0479e0 | 1703 | struct usb_hcd *hcd = bus_to_hcd(dev->bus); |
1da177e4 LT |
1704 | int n, nintf; |
1705 | ||
16bbab29 | 1706 | if (dev->authorized == 0 || configuration == -1) |
3f141e2a AS |
1707 | configuration = 0; |
1708 | else { | |
1709 | for (i = 0; i < dev->descriptor.bNumConfigurations; i++) { | |
1710 | if (dev->config[i].desc.bConfigurationValue == | |
1711 | configuration) { | |
1712 | cp = &dev->config[i]; | |
1713 | break; | |
1714 | } | |
1da177e4 LT |
1715 | } |
1716 | } | |
1717 | if ((!cp && configuration != 0)) | |
1718 | return -EINVAL; | |
1719 | ||
1720 | /* The USB spec says configuration 0 means unconfigured. | |
1721 | * But if a device includes a configuration numbered 0, | |
1722 | * we will accept it as a correctly configured state. | |
3f141e2a | 1723 | * Use -1 if you really want to unconfigure the device. |
1da177e4 LT |
1724 | */ |
1725 | if (cp && configuration == 0) | |
1726 | dev_warn(&dev->dev, "config 0 descriptor??\n"); | |
1727 | ||
1da177e4 LT |
1728 | /* Allocate memory for new interfaces before doing anything else, |
1729 | * so that if we run out then nothing will have changed. */ | |
1730 | n = nintf = 0; | |
1731 | if (cp) { | |
1732 | nintf = cp->desc.bNumInterfaces; | |
1733 | new_interfaces = kmalloc(nintf * sizeof(*new_interfaces), | |
acbe2feb | 1734 | GFP_NOIO); |
1da177e4 | 1735 | if (!new_interfaces) { |
898eb71c | 1736 | dev_err(&dev->dev, "Out of memory\n"); |
1da177e4 LT |
1737 | return -ENOMEM; |
1738 | } | |
1739 | ||
1740 | for (; n < nintf; ++n) { | |
0a1ef3b5 | 1741 | new_interfaces[n] = kzalloc( |
1da177e4 | 1742 | sizeof(struct usb_interface), |
acbe2feb | 1743 | GFP_NOIO); |
1da177e4 | 1744 | if (!new_interfaces[n]) { |
898eb71c | 1745 | dev_err(&dev->dev, "Out of memory\n"); |
1da177e4 LT |
1746 | ret = -ENOMEM; |
1747 | free_interfaces: | |
1748 | while (--n >= 0) | |
1749 | kfree(new_interfaces[n]); | |
1750 | kfree(new_interfaces); | |
1751 | return ret; | |
1752 | } | |
1753 | } | |
1da177e4 | 1754 | |
f48219db HS |
1755 | i = dev->bus_mA - cp->desc.bMaxPower * 2; |
1756 | if (i < 0) | |
1757 | dev_warn(&dev->dev, "new config #%d exceeds power " | |
1758 | "limit by %dmA\n", | |
1759 | configuration, -i); | |
1760 | } | |
55c52718 | 1761 | |
01d883d4 | 1762 | /* Wake up the device so we can send it the Set-Config request */ |
94fcda1f | 1763 | ret = usb_autoresume_device(dev); |
01d883d4 AS |
1764 | if (ret) |
1765 | goto free_interfaces; | |
1766 | ||
79abb1ab SS |
1767 | /* Make sure we have bandwidth (and available HCD resources) for this |
1768 | * configuration. Remove endpoints from the schedule if we're dropping | |
1769 | * this configuration to set configuration 0. After this point, the | |
1770 | * host controller will not allow submissions to dropped endpoints. If | |
1771 | * this call fails, the device state is unchanged. | |
1772 | */ | |
3f0479e0 SS |
1773 | mutex_lock(&hcd->bandwidth_mutex); |
1774 | ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL); | |
79abb1ab SS |
1775 | if (ret < 0) { |
1776 | usb_autosuspend_device(dev); | |
3f0479e0 | 1777 | mutex_unlock(&hcd->bandwidth_mutex); |
79abb1ab SS |
1778 | goto free_interfaces; |
1779 | } | |
1780 | ||
6ad07129 AS |
1781 | /* if it's already configured, clear out old state first. |
1782 | * getting rid of old interfaces means unbinding their drivers. | |
1783 | */ | |
1784 | if (dev->state != USB_STATE_ADDRESS) | |
3e35bf39 | 1785 | usb_disable_device(dev, 1); /* Skip ep0 */ |
6ad07129 | 1786 | |
df718962 AS |
1787 | /* Get rid of pending async Set-Config requests for this device */ |
1788 | cancel_async_set_config(dev); | |
1789 | ||
3e35bf39 GKH |
1790 | ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), |
1791 | USB_REQ_SET_CONFIGURATION, 0, configuration, 0, | |
1792 | NULL, 0, USB_CTRL_SET_TIMEOUT); | |
1793 | if (ret < 0) { | |
6ad07129 AS |
1794 | /* All the old state is gone, so what else can we do? |
1795 | * The device is probably useless now anyway. | |
1796 | */ | |
1797 | cp = NULL; | |
1798 | } | |
1da177e4 LT |
1799 | |
1800 | dev->actconfig = cp; | |
6ad07129 | 1801 | if (!cp) { |
1da177e4 | 1802 | usb_set_device_state(dev, USB_STATE_ADDRESS); |
3f0479e0 | 1803 | usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL); |
94fcda1f | 1804 | usb_autosuspend_device(dev); |
3f0479e0 | 1805 | mutex_unlock(&hcd->bandwidth_mutex); |
6ad07129 AS |
1806 | goto free_interfaces; |
1807 | } | |
3f0479e0 | 1808 | mutex_unlock(&hcd->bandwidth_mutex); |
6ad07129 | 1809 | usb_set_device_state(dev, USB_STATE_CONFIGURED); |
1da177e4 | 1810 | |
6ad07129 AS |
1811 | /* Initialize the new interface structures and the |
1812 | * hc/hcd/usbcore interface/endpoint state. | |
1813 | */ | |
1814 | for (i = 0; i < nintf; ++i) { | |
1815 | struct usb_interface_cache *intfc; | |
1816 | struct usb_interface *intf; | |
1817 | struct usb_host_interface *alt; | |
1da177e4 | 1818 | |
6ad07129 AS |
1819 | cp->interface[i] = intf = new_interfaces[i]; |
1820 | intfc = cp->intf_cache[i]; | |
1821 | intf->altsetting = intfc->altsetting; | |
1822 | intf->num_altsetting = intfc->num_altsetting; | |
165fe97e | 1823 | intf->intf_assoc = find_iad(dev, cp, i); |
6ad07129 | 1824 | kref_get(&intfc->ref); |
1da177e4 | 1825 | |
6ad07129 AS |
1826 | alt = usb_altnum_to_altsetting(intf, 0); |
1827 | ||
1828 | /* No altsetting 0? We'll assume the first altsetting. | |
1829 | * We could use a GetInterface call, but if a device is | |
1830 | * so non-compliant that it doesn't have altsetting 0 | |
1831 | * then I wouldn't trust its reply anyway. | |
1da177e4 | 1832 | */ |
6ad07129 AS |
1833 | if (!alt) |
1834 | alt = &intf->altsetting[0]; | |
1835 | ||
1836 | intf->cur_altsetting = alt; | |
2caf7fcd | 1837 | usb_enable_interface(dev, intf, true); |
6ad07129 AS |
1838 | intf->dev.parent = &dev->dev; |
1839 | intf->dev.driver = NULL; | |
1840 | intf->dev.bus = &usb_bus_type; | |
9f8b17e6 | 1841 | intf->dev.type = &usb_if_device_type; |
2e5f10e4 | 1842 | intf->dev.groups = usb_interface_groups; |
6ad07129 | 1843 | intf->dev.dma_mask = dev->dev.dma_mask; |
dc023dce | 1844 | INIT_WORK(&intf->reset_ws, __usb_queue_reset_device); |
3e35bf39 | 1845 | device_initialize(&intf->dev); |
6ad07129 | 1846 | mark_quiesced(intf); |
0031a06e | 1847 | dev_set_name(&intf->dev, "%d-%s:%d.%d", |
3e35bf39 GKH |
1848 | dev->bus->busnum, dev->devpath, |
1849 | configuration, alt->desc.bInterfaceNumber); | |
6ad07129 AS |
1850 | } |
1851 | kfree(new_interfaces); | |
1852 | ||
1662e3a7 AS |
1853 | if (cp->string == NULL && |
1854 | !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS)) | |
6ad07129 AS |
1855 | cp->string = usb_cache_string(dev, cp->desc.iConfiguration); |
1856 | ||
1857 | /* Now that all the interfaces are set up, register them | |
1858 | * to trigger binding of drivers to interfaces. probe() | |
1859 | * routines may install different altsettings and may | |
1860 | * claim() any interfaces not yet bound. Many class drivers | |
1861 | * need that: CDC, audio, video, etc. | |
1862 | */ | |
1863 | for (i = 0; i < nintf; ++i) { | |
1864 | struct usb_interface *intf = cp->interface[i]; | |
1865 | ||
3e35bf39 | 1866 | dev_dbg(&dev->dev, |
6ad07129 | 1867 | "adding %s (config #%d, interface %d)\n", |
7071a3ce | 1868 | dev_name(&intf->dev), configuration, |
6ad07129 | 1869 | intf->cur_altsetting->desc.bInterfaceNumber); |
3e35bf39 | 1870 | ret = device_add(&intf->dev); |
6ad07129 AS |
1871 | if (ret != 0) { |
1872 | dev_err(&dev->dev, "device_add(%s) --> %d\n", | |
7071a3ce | 1873 | dev_name(&intf->dev), ret); |
6ad07129 | 1874 | continue; |
1da177e4 | 1875 | } |
3b23dd6f | 1876 | create_intf_ep_devs(intf); |
1da177e4 LT |
1877 | } |
1878 | ||
94fcda1f | 1879 | usb_autosuspend_device(dev); |
86d30741 | 1880 | return 0; |
1da177e4 LT |
1881 | } |
1882 | ||
df718962 AS |
1883 | static LIST_HEAD(set_config_list); |
1884 | static DEFINE_SPINLOCK(set_config_lock); | |
1885 | ||
088dc270 AS |
1886 | struct set_config_request { |
1887 | struct usb_device *udev; | |
1888 | int config; | |
1889 | struct work_struct work; | |
df718962 | 1890 | struct list_head node; |
088dc270 AS |
1891 | }; |
1892 | ||
1893 | /* Worker routine for usb_driver_set_configuration() */ | |
c4028958 | 1894 | static void driver_set_config_work(struct work_struct *work) |
088dc270 | 1895 | { |
c4028958 DH |
1896 | struct set_config_request *req = |
1897 | container_of(work, struct set_config_request, work); | |
df718962 | 1898 | struct usb_device *udev = req->udev; |
088dc270 | 1899 | |
df718962 AS |
1900 | usb_lock_device(udev); |
1901 | spin_lock(&set_config_lock); | |
1902 | list_del(&req->node); | |
1903 | spin_unlock(&set_config_lock); | |
1904 | ||
1905 | if (req->config >= -1) /* Is req still valid? */ | |
1906 | usb_set_configuration(udev, req->config); | |
1907 | usb_unlock_device(udev); | |
1908 | usb_put_dev(udev); | |
088dc270 AS |
1909 | kfree(req); |
1910 | } | |
1911 | ||
df718962 AS |
1912 | /* Cancel pending Set-Config requests for a device whose configuration |
1913 | * was just changed | |
1914 | */ | |
1915 | static void cancel_async_set_config(struct usb_device *udev) | |
1916 | { | |
1917 | struct set_config_request *req; | |
1918 | ||
1919 | spin_lock(&set_config_lock); | |
1920 | list_for_each_entry(req, &set_config_list, node) { | |
1921 | if (req->udev == udev) | |
1922 | req->config = -999; /* Mark as cancelled */ | |
1923 | } | |
1924 | spin_unlock(&set_config_lock); | |
1925 | } | |
1926 | ||
088dc270 AS |
1927 | /** |
1928 | * usb_driver_set_configuration - Provide a way for drivers to change device configurations | |
1929 | * @udev: the device whose configuration is being updated | |
1930 | * @config: the configuration being chosen. | |
1931 | * Context: In process context, must be able to sleep | |
1932 | * | |
1933 | * Device interface drivers are not allowed to change device configurations. | |
1934 | * This is because changing configurations will destroy the interface the | |
1935 | * driver is bound to and create new ones; it would be like a floppy-disk | |
1936 | * driver telling the computer to replace the floppy-disk drive with a | |
1937 | * tape drive! | |
1938 | * | |
1939 | * Still, in certain specialized circumstances the need may arise. This | |
1940 | * routine gets around the normal restrictions by using a work thread to | |
1941 | * submit the change-config request. | |
1942 | * | |
af901ca1 | 1943 | * Returns 0 if the request was successfully queued, error code otherwise. |
088dc270 AS |
1944 | * The caller has no way to know whether the queued request will eventually |
1945 | * succeed. | |
1946 | */ | |
1947 | int usb_driver_set_configuration(struct usb_device *udev, int config) | |
1948 | { | |
1949 | struct set_config_request *req; | |
1950 | ||
1951 | req = kmalloc(sizeof(*req), GFP_KERNEL); | |
1952 | if (!req) | |
1953 | return -ENOMEM; | |
1954 | req->udev = udev; | |
1955 | req->config = config; | |
c4028958 | 1956 | INIT_WORK(&req->work, driver_set_config_work); |
088dc270 | 1957 | |
df718962 AS |
1958 | spin_lock(&set_config_lock); |
1959 | list_add(&req->node, &set_config_list); | |
1960 | spin_unlock(&set_config_lock); | |
1961 | ||
088dc270 | 1962 | usb_get_dev(udev); |
1737bf2c | 1963 | schedule_work(&req->work); |
088dc270 AS |
1964 | return 0; |
1965 | } | |
1966 | EXPORT_SYMBOL_GPL(usb_driver_set_configuration); |