1 // SPDX-License-Identifier: GPL-2.0
3 * message.c - synchronous message handling
5 * Released under the GPLv2 only.
8 #include <linux/acpi.h>
9 #include <linux/pci.h> /* for scatterlist macros */
10 #include <linux/usb.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
14 #include <linux/timer.h>
15 #include <linux/ctype.h>
16 #include <linux/nls.h>
17 #include <linux/device.h>
18 #include <linux/scatterlist.h>
19 #include <linux/usb/cdc.h>
20 #include <linux/usb/quirks.h>
21 #include <linux/usb/hcd.h> /* for usbcore internals */
22 #include <linux/usb/of.h>
23 #include <asm/byteorder.h>
27 static void cancel_async_set_config(struct usb_device *udev);
30 struct completion done;
34 static void usb_api_blocking_completion(struct urb *urb)
36 struct api_context *ctx = urb->context;
38 ctx->status = urb->status;
44 * Starts urb and waits for completion or timeout. Note that this call
45 * is NOT interruptible. Many device driver i/o requests should be
46 * interruptible and therefore these drivers should implement their
47 * own interruptible routines.
49 static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
51 struct api_context ctx;
55 init_completion(&ctx.done);
57 urb->actual_length = 0;
58 retval = usb_submit_urb(urb, GFP_NOIO);
62 expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
63 if (!wait_for_completion_timeout(&ctx.done, expire)) {
65 retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
67 dev_dbg(&urb->dev->dev,
68 "%s timed out on ep%d%s len=%u/%u\n",
70 usb_endpoint_num(&urb->ep->desc),
71 usb_urb_dir_in(urb) ? "in" : "out",
73 urb->transfer_buffer_length);
78 *actual_length = urb->actual_length;
84 /*-------------------------------------------------------------------*/
85 /* returns status (negative) or length (positive) */
86 static int usb_internal_control_msg(struct usb_device *usb_dev,
88 struct usb_ctrlrequest *cmd,
89 void *data, int len, int timeout)
95 urb = usb_alloc_urb(0, GFP_NOIO);
99 usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
100 len, usb_api_blocking_completion, NULL);
102 retv = usb_start_wait_urb(urb, timeout, &length);
110 * usb_control_msg - Builds a control urb, sends it off and waits for completion
111 * @dev: pointer to the usb device to send the message to
112 * @pipe: endpoint "pipe" to send the message to
113 * @request: USB message request value
114 * @requesttype: USB message request type value
115 * @value: USB message value
116 * @index: USB message index value
117 * @data: pointer to the data to send
118 * @size: length in bytes of the data to send
119 * @timeout: time in msecs to wait for the message to complete before timing
120 * out (if 0 the wait is forever)
122 * Context: task context, might sleep.
124 * This function sends a simple control message to a specified endpoint and
125 * waits for the message to complete, or timeout.
127 * Don't use this function from within an interrupt context. If you need
128 * an asynchronous message, or need to send a message from within interrupt
129 * context, use usb_submit_urb(). If a thread in your driver uses this call,
130 * make sure your disconnect() method can wait for it to complete. Since you
131 * don't have a handle on the URB used, you can't cancel the request.
133 * Return: If successful, the number of bytes transferred. Otherwise, a negative
136 int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
137 __u8 requesttype, __u16 value, __u16 index, void *data,
138 __u16 size, int timeout)
140 struct usb_ctrlrequest *dr;
143 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
147 dr->bRequestType = requesttype;
148 dr->bRequest = request;
149 dr->wValue = cpu_to_le16(value);
150 dr->wIndex = cpu_to_le16(index);
151 dr->wLength = cpu_to_le16(size);
153 ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
155 /* Linger a bit, prior to the next control message. */
156 if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
163 EXPORT_SYMBOL_GPL(usb_control_msg);
166 * usb_control_msg_send - Builds a control "send" message, sends it off and waits for completion
167 * @dev: pointer to the usb device to send the message to
168 * @endpoint: endpoint to send the message to
169 * @request: USB message request value
170 * @requesttype: USB message request type value
171 * @value: USB message value
172 * @index: USB message index value
173 * @driver_data: pointer to the data to send
174 * @size: length in bytes of the data to send
175 * @timeout: time in msecs to wait for the message to complete before timing
176 * out (if 0 the wait is forever)
177 * @memflags: the flags for memory allocation for buffers
179 * Context: !in_interrupt ()
181 * This function sends a control message to a specified endpoint that is not
182 * expected to fill in a response (i.e. a "send message") and waits for the
183 * message to complete, or timeout.
185 * Do not use this function from within an interrupt context. If you need
186 * an asynchronous message, or need to send a message from within interrupt
187 * context, use usb_submit_urb(). If a thread in your driver uses this call,
188 * make sure your disconnect() method can wait for it to complete. Since you
189 * don't have a handle on the URB used, you can't cancel the request.
191 * The data pointer can be made to a reference on the stack, or anywhere else,
192 * as it will not be modified at all. This does not have the restriction that
193 * usb_control_msg() has where the data pointer must be to dynamically allocated
194 * memory (i.e. memory that can be successfully DMAed to a device).
196 * Return: If successful, 0 is returned, Otherwise, a negative error number.
198 int usb_control_msg_send(struct usb_device *dev, __u8 endpoint, __u8 request,
199 __u8 requesttype, __u16 value, __u16 index,
200 const void *driver_data, __u16 size, int timeout,
203 unsigned int pipe = usb_sndctrlpipe(dev, endpoint);
208 data = kmemdup(driver_data, size, memflags);
213 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
214 data, size, timeout);
222 EXPORT_SYMBOL_GPL(usb_control_msg_send);
225 * usb_control_msg_recv - Builds a control "receive" message, sends it off and waits for completion
226 * @dev: pointer to the usb device to send the message to
227 * @endpoint: endpoint to send the message to
228 * @request: USB message request value
229 * @requesttype: USB message request type value
230 * @value: USB message value
231 * @index: USB message index value
232 * @driver_data: pointer to the data to be filled in by the message
233 * @size: length in bytes of the data to be received
234 * @timeout: time in msecs to wait for the message to complete before timing
235 * out (if 0 the wait is forever)
236 * @memflags: the flags for memory allocation for buffers
238 * Context: !in_interrupt ()
240 * This function sends a control message to a specified endpoint that is
241 * expected to fill in a response (i.e. a "receive message") and waits for the
242 * message to complete, or timeout.
244 * Do not use this function from within an interrupt context. If you need
245 * an asynchronous message, or need to send a message from within interrupt
246 * context, use usb_submit_urb(). If a thread in your driver uses this call,
247 * make sure your disconnect() method can wait for it to complete. Since you
248 * don't have a handle on the URB used, you can't cancel the request.
250 * The data pointer can be made to a reference on the stack, or anywhere else
251 * that can be successfully written to. This function does not have the
252 * restriction that usb_control_msg() has where the data pointer must be to
253 * dynamically allocated memory (i.e. memory that can be successfully DMAed to a
256 * The "whole" message must be properly received from the device in order for
257 * this function to be successful. If a device returns less than the expected
258 * amount of data, then the function will fail. Do not use this for messages
259 * where a variable amount of data might be returned.
261 * Return: If successful, 0 is returned, Otherwise, a negative error number.
263 int usb_control_msg_recv(struct usb_device *dev, __u8 endpoint, __u8 request,
264 __u8 requesttype, __u16 value, __u16 index,
265 void *driver_data, __u16 size, int timeout,
268 unsigned int pipe = usb_rcvctrlpipe(dev, endpoint);
272 if (!size || !driver_data)
275 data = kmalloc(size, memflags);
279 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
280 data, size, timeout);
286 memcpy(driver_data, data, size);
296 EXPORT_SYMBOL_GPL(usb_control_msg_recv);
299 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
300 * @usb_dev: pointer to the usb device to send the message to
301 * @pipe: endpoint "pipe" to send the message to
302 * @data: pointer to the data to send
303 * @len: length in bytes of the data to send
304 * @actual_length: pointer to a location to put the actual length transferred
306 * @timeout: time in msecs to wait for the message to complete before
307 * timing out (if 0 the wait is forever)
309 * Context: task context, might sleep.
311 * This function sends a simple interrupt message to a specified endpoint and
312 * waits for the message to complete, or timeout.
314 * Don't use this function from within an interrupt context. If you need
315 * an asynchronous message, or need to send a message from within interrupt
316 * context, use usb_submit_urb() If a thread in your driver uses this call,
317 * make sure your disconnect() method can wait for it to complete. Since you
318 * don't have a handle on the URB used, you can't cancel the request.
321 * If successful, 0. Otherwise a negative error number. The number of actual
322 * bytes transferred will be stored in the @actual_length parameter.
324 int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
325 void *data, int len, int *actual_length, int timeout)
327 return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
329 EXPORT_SYMBOL_GPL(usb_interrupt_msg);
332 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
333 * @usb_dev: pointer to the usb device to send the message to
334 * @pipe: endpoint "pipe" to send the message to
335 * @data: pointer to the data to send
336 * @len: length in bytes of the data to send
337 * @actual_length: pointer to a location to put the actual length transferred
339 * @timeout: time in msecs to wait for the message to complete before
340 * timing out (if 0 the wait is forever)
342 * Context: task context, might sleep.
344 * This function sends a simple bulk message to a specified endpoint
345 * and waits for the message to complete, or timeout.
347 * Don't use this function from within an interrupt context. If you need
348 * an asynchronous message, or need to send a message from within interrupt
349 * context, use usb_submit_urb() If a thread in your driver uses this call,
350 * make sure your disconnect() method can wait for it to complete. Since you
351 * don't have a handle on the URB used, you can't cancel the request.
353 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
354 * users are forced to abuse this routine by using it to submit URBs for
355 * interrupt endpoints. We will take the liberty of creating an interrupt URB
356 * (with the default interval) if the target is an interrupt endpoint.
359 * If successful, 0. Otherwise a negative error number. The number of actual
360 * bytes transferred will be stored in the @actual_length parameter.
363 int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
364 void *data, int len, int *actual_length, int timeout)
367 struct usb_host_endpoint *ep;
369 ep = usb_pipe_endpoint(usb_dev, pipe);
373 urb = usb_alloc_urb(0, GFP_KERNEL);
377 if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
378 USB_ENDPOINT_XFER_INT) {
379 pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
380 usb_fill_int_urb(urb, usb_dev, pipe, data, len,
381 usb_api_blocking_completion, NULL,
384 usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
385 usb_api_blocking_completion, NULL);
387 return usb_start_wait_urb(urb, timeout, actual_length);
389 EXPORT_SYMBOL_GPL(usb_bulk_msg);
391 /*-------------------------------------------------------------------*/
393 static void sg_clean(struct usb_sg_request *io)
396 while (io->entries--)
397 usb_free_urb(io->urbs[io->entries]);
404 static void sg_complete(struct urb *urb)
407 struct usb_sg_request *io = urb->context;
408 int status = urb->status;
410 spin_lock_irqsave(&io->lock, flags);
412 /* In 2.5 we require hcds' endpoint queues not to progress after fault
413 * reports, until the completion callback (this!) returns. That lets
414 * device driver code (like this routine) unlink queued urbs first,
415 * if it needs to, since the HC won't work on them at all. So it's
416 * not possible for page N+1 to overwrite page N, and so on.
418 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
419 * complete before the HCD can get requests away from hardware,
420 * though never during cleanup after a hard fault.
423 && (io->status != -ECONNRESET
424 || status != -ECONNRESET)
425 && urb->actual_length) {
426 dev_err(io->dev->bus->controller,
427 "dev %s ep%d%s scatterlist error %d/%d\n",
429 usb_endpoint_num(&urb->ep->desc),
430 usb_urb_dir_in(urb) ? "in" : "out",
435 if (io->status == 0 && status && status != -ECONNRESET) {
436 int i, found, retval;
440 /* the previous urbs, and this one, completed already.
441 * unlink pending urbs so they won't rx/tx bad data.
442 * careful: unlink can sometimes be synchronous...
444 spin_unlock_irqrestore(&io->lock, flags);
445 for (i = 0, found = 0; i < io->entries; i++) {
449 usb_block_urb(io->urbs[i]);
450 retval = usb_unlink_urb(io->urbs[i]);
451 if (retval != -EINPROGRESS &&
455 dev_err(&io->dev->dev,
456 "%s, unlink --> %d\n",
458 } else if (urb == io->urbs[i])
461 spin_lock_irqsave(&io->lock, flags);
464 /* on the last completion, signal usb_sg_wait() */
465 io->bytes += urb->actual_length;
468 complete(&io->complete);
470 spin_unlock_irqrestore(&io->lock, flags);
475 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
476 * @io: request block being initialized. until usb_sg_wait() returns,
477 * treat this as a pointer to an opaque block of memory,
478 * @dev: the usb device that will send or receive the data
479 * @pipe: endpoint "pipe" used to transfer the data
480 * @period: polling rate for interrupt endpoints, in frames or
481 * (for high speed endpoints) microframes; ignored for bulk
482 * @sg: scatterlist entries
483 * @nents: how many entries in the scatterlist
484 * @length: how many bytes to send from the scatterlist, or zero to
485 * send every byte identified in the list.
486 * @mem_flags: SLAB_* flags affecting memory allocations in this call
488 * This initializes a scatter/gather request, allocating resources such as
489 * I/O mappings and urb memory (except maybe memory used by USB controller
492 * The request must be issued using usb_sg_wait(), which waits for the I/O to
493 * complete (or to be canceled) and then cleans up all resources allocated by
496 * The request may be canceled with usb_sg_cancel(), either before or after
497 * usb_sg_wait() is called.
499 * Return: Zero for success, else a negative errno value.
501 int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
502 unsigned pipe, unsigned period, struct scatterlist *sg,
503 int nents, size_t length, gfp_t mem_flags)
509 if (!io || !dev || !sg
510 || usb_pipecontrol(pipe)
511 || usb_pipeisoc(pipe)
515 spin_lock_init(&io->lock);
519 if (dev->bus->sg_tablesize > 0) {
527 /* initialize all the urbs we'll use */
528 io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
532 urb_flags = URB_NO_INTERRUPT;
533 if (usb_pipein(pipe))
534 urb_flags |= URB_SHORT_NOT_OK;
536 for_each_sg(sg, sg, io->entries, i) {
540 urb = usb_alloc_urb(0, mem_flags);
549 urb->interval = period;
550 urb->transfer_flags = urb_flags;
551 urb->complete = sg_complete;
556 /* There is no single transfer buffer */
557 urb->transfer_buffer = NULL;
558 urb->num_sgs = nents;
560 /* A length of zero means transfer the whole sg list */
563 struct scatterlist *sg2;
566 for_each_sg(sg, sg2, nents, j)
571 * Some systems can't use DMA; they use PIO instead.
572 * For their sakes, transfer_buffer is set whenever
575 if (!PageHighMem(sg_page(sg)))
576 urb->transfer_buffer = sg_virt(sg);
578 urb->transfer_buffer = NULL;
582 len = min_t(size_t, len, length);
588 urb->transfer_buffer_length = len;
590 io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
592 /* transaction state */
593 io->count = io->entries;
596 init_completion(&io->complete);
603 EXPORT_SYMBOL_GPL(usb_sg_init);
606 * usb_sg_wait - synchronously execute scatter/gather request
607 * @io: request block handle, as initialized with usb_sg_init().
608 * some fields become accessible when this call returns.
610 * Context: task context, might sleep.
612 * This function blocks until the specified I/O operation completes. It
613 * leverages the grouping of the related I/O requests to get good transfer
614 * rates, by queueing the requests. At higher speeds, such queuing can
615 * significantly improve USB throughput.
617 * There are three kinds of completion for this function.
619 * (1) success, where io->status is zero. The number of io->bytes
620 * transferred is as requested.
621 * (2) error, where io->status is a negative errno value. The number
622 * of io->bytes transferred before the error is usually less
623 * than requested, and can be nonzero.
624 * (3) cancellation, a type of error with status -ECONNRESET that
625 * is initiated by usb_sg_cancel().
627 * When this function returns, all memory allocated through usb_sg_init() or
628 * this call will have been freed. The request block parameter may still be
629 * passed to usb_sg_cancel(), or it may be freed. It could also be
630 * reinitialized and then reused.
632 * Data Transfer Rates:
634 * Bulk transfers are valid for full or high speed endpoints.
635 * The best full speed data rate is 19 packets of 64 bytes each
636 * per frame, or 1216 bytes per millisecond.
637 * The best high speed data rate is 13 packets of 512 bytes each
638 * per microframe, or 52 KBytes per millisecond.
640 * The reason to use interrupt transfers through this API would most likely
641 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
642 * could be transferred. That capability is less useful for low or full
643 * speed interrupt endpoints, which allow at most one packet per millisecond,
644 * of at most 8 or 64 bytes (respectively).
646 * It is not necessary to call this function to reserve bandwidth for devices
647 * under an xHCI host controller, as the bandwidth is reserved when the
648 * configuration or interface alt setting is selected.
650 void usb_sg_wait(struct usb_sg_request *io)
653 int entries = io->entries;
655 /* queue the urbs. */
656 spin_lock_irq(&io->lock);
658 while (i < entries && !io->status) {
661 io->urbs[i]->dev = io->dev;
662 spin_unlock_irq(&io->lock);
664 retval = usb_submit_urb(io->urbs[i], GFP_NOIO);
667 /* maybe we retrying will recover */
668 case -ENXIO: /* hc didn't queue this one */
675 /* no error? continue immediately.
677 * NOTE: to work better with UHCI (4K I/O buffer may
678 * need 3K of TDs) it may be good to limit how many
679 * URBs are queued at once; N milliseconds?
686 /* fail any uncompleted urbs */
688 io->urbs[i]->status = retval;
689 dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
693 spin_lock_irq(&io->lock);
694 if (retval && (io->status == 0 || io->status == -ECONNRESET))
697 io->count -= entries - i;
699 complete(&io->complete);
700 spin_unlock_irq(&io->lock);
702 /* OK, yes, this could be packaged as non-blocking.
703 * So could the submit loop above ... but it's easier to
704 * solve neither problem than to solve both!
706 wait_for_completion(&io->complete);
710 EXPORT_SYMBOL_GPL(usb_sg_wait);
713 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
714 * @io: request block, initialized with usb_sg_init()
716 * This stops a request after it has been started by usb_sg_wait().
717 * It can also prevents one initialized by usb_sg_init() from starting,
718 * so that call just frees resources allocated to the request.
720 void usb_sg_cancel(struct usb_sg_request *io)
725 spin_lock_irqsave(&io->lock, flags);
726 if (io->status || io->count == 0) {
727 spin_unlock_irqrestore(&io->lock, flags);
730 /* shut everything down */
731 io->status = -ECONNRESET;
732 io->count++; /* Keep the request alive until we're done */
733 spin_unlock_irqrestore(&io->lock, flags);
735 for (i = io->entries - 1; i >= 0; --i) {
736 usb_block_urb(io->urbs[i]);
738 retval = usb_unlink_urb(io->urbs[i]);
739 if (retval != -EINPROGRESS
743 dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
747 spin_lock_irqsave(&io->lock, flags);
750 complete(&io->complete);
751 spin_unlock_irqrestore(&io->lock, flags);
753 EXPORT_SYMBOL_GPL(usb_sg_cancel);
755 /*-------------------------------------------------------------------*/
758 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
759 * @dev: the device whose descriptor is being retrieved
760 * @type: the descriptor type (USB_DT_*)
761 * @index: the number of the descriptor
762 * @buf: where to put the descriptor
763 * @size: how big is "buf"?
765 * Context: task context, might sleep.
767 * Gets a USB descriptor. Convenience functions exist to simplify
768 * getting some types of descriptors. Use
769 * usb_get_string() or usb_string() for USB_DT_STRING.
770 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
771 * are part of the device structure.
772 * In addition to a number of USB-standard descriptors, some
773 * devices also use class-specific or vendor-specific descriptors.
775 * This call is synchronous, and may not be used in an interrupt context.
777 * Return: The number of bytes received on success, or else the status code
778 * returned by the underlying usb_control_msg() call.
780 int usb_get_descriptor(struct usb_device *dev, unsigned char type,
781 unsigned char index, void *buf, int size)
786 if (size <= 0) /* No point in asking for no data */
789 memset(buf, 0, size); /* Make sure we parse really received data */
791 for (i = 0; i < 3; ++i) {
792 /* retry on length 0 or error; some devices are flakey */
793 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
794 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
795 (type << 8) + index, 0, buf, size,
796 USB_CTRL_GET_TIMEOUT);
797 if (result <= 0 && result != -ETIMEDOUT)
799 if (result > 1 && ((u8 *)buf)[1] != type) {
807 EXPORT_SYMBOL_GPL(usb_get_descriptor);
810 * usb_get_string - gets a string descriptor
811 * @dev: the device whose string descriptor is being retrieved
812 * @langid: code for language chosen (from string descriptor zero)
813 * @index: the number of the descriptor
814 * @buf: where to put the string
815 * @size: how big is "buf"?
817 * Context: task context, might sleep.
819 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
820 * in little-endian byte order).
821 * The usb_string() function will often be a convenient way to turn
822 * these strings into kernel-printable form.
824 * Strings may be referenced in device, configuration, interface, or other
825 * descriptors, and could also be used in vendor-specific ways.
827 * This call is synchronous, and may not be used in an interrupt context.
829 * Return: The number of bytes received on success, or else the status code
830 * returned by the underlying usb_control_msg() call.
832 static int usb_get_string(struct usb_device *dev, unsigned short langid,
833 unsigned char index, void *buf, int size)
838 if (size <= 0) /* No point in asking for no data */
841 for (i = 0; i < 3; ++i) {
842 /* retry on length 0 or stall; some devices are flakey */
843 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
844 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
845 (USB_DT_STRING << 8) + index, langid, buf, size,
846 USB_CTRL_GET_TIMEOUT);
847 if (result == 0 || result == -EPIPE)
849 if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
858 static void usb_try_string_workarounds(unsigned char *buf, int *length)
860 int newlength, oldlength = *length;
862 for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
863 if (!isprint(buf[newlength]) || buf[newlength + 1])
872 static int usb_string_sub(struct usb_device *dev, unsigned int langid,
873 unsigned int index, unsigned char *buf)
877 /* Try to read the string descriptor by asking for the maximum
878 * possible number of bytes */
879 if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
882 rc = usb_get_string(dev, langid, index, buf, 255);
884 /* If that failed try to read the descriptor length, then
885 * ask for just that many bytes */
887 rc = usb_get_string(dev, langid, index, buf, 2);
889 rc = usb_get_string(dev, langid, index, buf, buf[0]);
893 if (!buf[0] && !buf[1])
894 usb_try_string_workarounds(buf, &rc);
896 /* There might be extra junk at the end of the descriptor */
900 rc = rc - (rc & 1); /* force a multiple of two */
904 rc = (rc < 0 ? rc : -EINVAL);
909 static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
913 if (dev->have_langid)
916 if (dev->string_langid < 0)
919 err = usb_string_sub(dev, 0, 0, tbuf);
921 /* If the string was reported but is malformed, default to english
923 if (err == -ENODATA || (err > 0 && err < 4)) {
924 dev->string_langid = 0x0409;
925 dev->have_langid = 1;
927 "language id specifier not provided by device, defaulting to English\n");
931 /* In case of all other errors, we assume the device is not able to
932 * deal with strings at all. Set string_langid to -1 in order to
933 * prevent any string to be retrieved from the device */
935 dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
937 dev->string_langid = -1;
941 /* always use the first langid listed */
942 dev->string_langid = tbuf[2] | (tbuf[3] << 8);
943 dev->have_langid = 1;
944 dev_dbg(&dev->dev, "default language 0x%04x\n",
950 * usb_string - returns UTF-8 version of a string descriptor
951 * @dev: the device whose string descriptor is being retrieved
952 * @index: the number of the descriptor
953 * @buf: where to put the string
954 * @size: how big is "buf"?
956 * Context: task context, might sleep.
958 * This converts the UTF-16LE encoded strings returned by devices, from
959 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
960 * that are more usable in most kernel contexts. Note that this function
961 * chooses strings in the first language supported by the device.
963 * This call is synchronous, and may not be used in an interrupt context.
965 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
967 int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
972 if (dev->state == USB_STATE_SUSPENDED)
973 return -EHOSTUNREACH;
974 if (size <= 0 || !buf)
977 if (index <= 0 || index >= 256)
979 tbuf = kmalloc(256, GFP_NOIO);
983 err = usb_get_langid(dev, tbuf);
987 err = usb_string_sub(dev, dev->string_langid, index, tbuf);
991 size--; /* leave room for trailing NULL char in output buffer */
992 err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
993 UTF16_LITTLE_ENDIAN, buf, size);
996 if (tbuf[1] != USB_DT_STRING)
998 "wrong descriptor type %02x for string %d (\"%s\")\n",
999 tbuf[1], index, buf);
1005 EXPORT_SYMBOL_GPL(usb_string);
1007 /* one UTF-8-encoded 16-bit character has at most three bytes */
1008 #define MAX_USB_STRING_SIZE (127 * 3 + 1)
1011 * usb_cache_string - read a string descriptor and cache it for later use
1012 * @udev: the device whose string descriptor is being read
1013 * @index: the descriptor index
1015 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
1016 * or %NULL if the index is 0 or the string could not be read.
1018 char *usb_cache_string(struct usb_device *udev, int index)
1021 char *smallbuf = NULL;
1027 buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
1029 len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
1031 smallbuf = kmalloc(++len, GFP_NOIO);
1034 memcpy(smallbuf, buf, len);
1042 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
1043 * @dev: the device whose device descriptor is being updated
1044 * @size: how much of the descriptor to read
1046 * Context: task context, might sleep.
1048 * Updates the copy of the device descriptor stored in the device structure,
1049 * which dedicates space for this purpose.
1051 * Not exported, only for use by the core. If drivers really want to read
1052 * the device descriptor directly, they can call usb_get_descriptor() with
1053 * type = USB_DT_DEVICE and index = 0.
1055 * This call is synchronous, and may not be used in an interrupt context.
1057 * Return: The number of bytes received on success, or else the status code
1058 * returned by the underlying usb_control_msg() call.
1060 int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
1062 struct usb_device_descriptor *desc;
1065 if (size > sizeof(*desc))
1067 desc = kmalloc(sizeof(*desc), GFP_NOIO);
1071 ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
1073 memcpy(&dev->descriptor, desc, size);
1079 * usb_set_isoch_delay - informs the device of the packet transmit delay
1080 * @dev: the device whose delay is to be informed
1081 * Context: task context, might sleep
1083 * Since this is an optional request, we don't bother if it fails.
1085 int usb_set_isoch_delay(struct usb_device *dev)
1087 /* skip hub devices */
1088 if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
1091 /* skip non-SS/non-SSP devices */
1092 if (dev->speed < USB_SPEED_SUPER)
1095 return usb_control_msg_send(dev, 0,
1096 USB_REQ_SET_ISOCH_DELAY,
1097 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
1098 dev->hub_delay, 0, NULL, 0,
1099 USB_CTRL_SET_TIMEOUT,
1104 * usb_get_status - issues a GET_STATUS call
1105 * @dev: the device whose status is being checked
1106 * @recip: USB_RECIP_*; for device, interface, or endpoint
1107 * @type: USB_STATUS_TYPE_*; for standard or PTM status types
1108 * @target: zero (for device), else interface or endpoint number
1109 * @data: pointer to two bytes of bitmap data
1111 * Context: task context, might sleep.
1113 * Returns device, interface, or endpoint status. Normally only of
1114 * interest to see if the device is self powered, or has enabled the
1115 * remote wakeup facility; or whether a bulk or interrupt endpoint
1116 * is halted ("stalled").
1118 * Bits in these status bitmaps are set using the SET_FEATURE request,
1119 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
1120 * function should be used to clear halt ("stall") status.
1122 * This call is synchronous, and may not be used in an interrupt context.
1124 * Returns 0 and the status value in *@data (in host byte order) on success,
1125 * or else the status code from the underlying usb_control_msg() call.
1127 int usb_get_status(struct usb_device *dev, int recip, int type, int target,
1135 case USB_STATUS_TYPE_STANDARD:
1138 case USB_STATUS_TYPE_PTM:
1139 if (recip != USB_RECIP_DEVICE)
1148 status = kmalloc(length, GFP_KERNEL);
1152 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1153 USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1154 target, status, length, USB_CTRL_GET_TIMEOUT);
1158 if (type != USB_STATUS_TYPE_PTM) {
1163 *(u32 *) data = le32_to_cpu(*(__le32 *) status);
1167 if (type != USB_STATUS_TYPE_STANDARD) {
1172 *(u16 *) data = le16_to_cpu(*(__le16 *) status);
1182 EXPORT_SYMBOL_GPL(usb_get_status);
1185 * usb_clear_halt - tells device to clear endpoint halt/stall condition
1186 * @dev: device whose endpoint is halted
1187 * @pipe: endpoint "pipe" being cleared
1189 * Context: task context, might sleep.
1191 * This is used to clear halt conditions for bulk and interrupt endpoints,
1192 * as reported by URB completion status. Endpoints that are halted are
1193 * sometimes referred to as being "stalled". Such endpoints are unable
1194 * to transmit or receive data until the halt status is cleared. Any URBs
1195 * queued for such an endpoint should normally be unlinked by the driver
1196 * before clearing the halt condition, as described in sections 5.7.5
1197 * and 5.8.5 of the USB 2.0 spec.
1199 * Note that control and isochronous endpoints don't halt, although control
1200 * endpoints report "protocol stall" (for unsupported requests) using the
1201 * same status code used to report a true stall.
1203 * This call is synchronous, and may not be used in an interrupt context.
1205 * Return: Zero on success, or else the status code returned by the
1206 * underlying usb_control_msg() call.
1208 int usb_clear_halt(struct usb_device *dev, int pipe)
1211 int endp = usb_pipeendpoint(pipe);
1213 if (usb_pipein(pipe))
1216 /* we don't care if it wasn't halted first. in fact some devices
1217 * (like some ibmcam model 1 units) seem to expect hosts to make
1218 * this request for iso endpoints, which can't halt!
1220 result = usb_control_msg_send(dev, 0,
1221 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1222 USB_ENDPOINT_HALT, endp, NULL, 0,
1223 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
1225 /* don't un-halt or force to DATA0 except on success */
1229 /* NOTE: seems like Microsoft and Apple don't bother verifying
1230 * the clear "took", so some devices could lock up if you check...
1231 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1233 * NOTE: make sure the logic here doesn't diverge much from
1234 * the copy in usb-storage, for as long as we need two copies.
1237 usb_reset_endpoint(dev, endp);
1241 EXPORT_SYMBOL_GPL(usb_clear_halt);
1243 static int create_intf_ep_devs(struct usb_interface *intf)
1245 struct usb_device *udev = interface_to_usbdev(intf);
1246 struct usb_host_interface *alt = intf->cur_altsetting;
1249 if (intf->ep_devs_created || intf->unregistering)
1252 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1253 (void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
1254 intf->ep_devs_created = 1;
1258 static void remove_intf_ep_devs(struct usb_interface *intf)
1260 struct usb_host_interface *alt = intf->cur_altsetting;
1263 if (!intf->ep_devs_created)
1266 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1267 usb_remove_ep_devs(&alt->endpoint[i]);
1268 intf->ep_devs_created = 0;
1272 * usb_disable_endpoint -- Disable an endpoint by address
1273 * @dev: the device whose endpoint is being disabled
1274 * @epaddr: the endpoint's address. Endpoint number for output,
1275 * endpoint number + USB_DIR_IN for input
1276 * @reset_hardware: flag to erase any endpoint state stored in the
1277 * controller hardware
1279 * Disables the endpoint for URB submission and nukes all pending URBs.
1280 * If @reset_hardware is set then also deallocates hcd/hardware state
1283 void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1284 bool reset_hardware)
1286 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1287 struct usb_host_endpoint *ep;
1292 if (usb_endpoint_out(epaddr)) {
1293 ep = dev->ep_out[epnum];
1294 if (reset_hardware && epnum != 0)
1295 dev->ep_out[epnum] = NULL;
1297 ep = dev->ep_in[epnum];
1298 if (reset_hardware && epnum != 0)
1299 dev->ep_in[epnum] = NULL;
1303 usb_hcd_flush_endpoint(dev, ep);
1305 usb_hcd_disable_endpoint(dev, ep);
1310 * usb_reset_endpoint - Reset an endpoint's state.
1311 * @dev: the device whose endpoint is to be reset
1312 * @epaddr: the endpoint's address. Endpoint number for output,
1313 * endpoint number + USB_DIR_IN for input
1315 * Resets any host-side endpoint state such as the toggle bit,
1316 * sequence number or current window.
1318 void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1320 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1321 struct usb_host_endpoint *ep;
1323 if (usb_endpoint_out(epaddr))
1324 ep = dev->ep_out[epnum];
1326 ep = dev->ep_in[epnum];
1328 usb_hcd_reset_endpoint(dev, ep);
1330 EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1334 * usb_disable_interface -- Disable all endpoints for an interface
1335 * @dev: the device whose interface is being disabled
1336 * @intf: pointer to the interface descriptor
1337 * @reset_hardware: flag to erase any endpoint state stored in the
1338 * controller hardware
1340 * Disables all the endpoints for the interface's current altsetting.
1342 void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1343 bool reset_hardware)
1345 struct usb_host_interface *alt = intf->cur_altsetting;
1348 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1349 usb_disable_endpoint(dev,
1350 alt->endpoint[i].desc.bEndpointAddress,
1356 * usb_disable_device_endpoints -- Disable all endpoints for a device
1357 * @dev: the device whose endpoints are being disabled
1358 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1360 static void usb_disable_device_endpoints(struct usb_device *dev, int skip_ep0)
1362 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1365 if (hcd->driver->check_bandwidth) {
1366 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1367 for (i = skip_ep0; i < 16; ++i) {
1368 usb_disable_endpoint(dev, i, false);
1369 usb_disable_endpoint(dev, i + USB_DIR_IN, false);
1371 /* Remove endpoints from the host controller internal state */
1372 mutex_lock(hcd->bandwidth_mutex);
1373 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1374 mutex_unlock(hcd->bandwidth_mutex);
1376 /* Second pass: remove endpoint pointers */
1377 for (i = skip_ep0; i < 16; ++i) {
1378 usb_disable_endpoint(dev, i, true);
1379 usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1384 * usb_disable_device - Disable all the endpoints for a USB device
1385 * @dev: the device whose endpoints are being disabled
1386 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1388 * Disables all the device's endpoints, potentially including endpoint 0.
1389 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1390 * pending urbs) and usbcore state for the interfaces, so that usbcore
1391 * must usb_set_configuration() before any interfaces could be used.
1393 void usb_disable_device(struct usb_device *dev, int skip_ep0)
1397 /* getting rid of interfaces will disconnect
1398 * any drivers bound to them (a key side effect)
1400 if (dev->actconfig) {
1402 * FIXME: In order to avoid self-deadlock involving the
1403 * bandwidth_mutex, we have to mark all the interfaces
1404 * before unregistering any of them.
1406 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1407 dev->actconfig->interface[i]->unregistering = 1;
1409 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1410 struct usb_interface *interface;
1412 /* remove this interface if it has been registered */
1413 interface = dev->actconfig->interface[i];
1414 if (!device_is_registered(&interface->dev))
1416 dev_dbg(&dev->dev, "unregistering interface %s\n",
1417 dev_name(&interface->dev));
1418 remove_intf_ep_devs(interface);
1419 device_del(&interface->dev);
1422 /* Now that the interfaces are unbound, nobody should
1423 * try to access them.
1425 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1426 put_device(&dev->actconfig->interface[i]->dev);
1427 dev->actconfig->interface[i] = NULL;
1430 usb_disable_usb2_hardware_lpm(dev);
1431 usb_unlocked_disable_lpm(dev);
1432 usb_disable_ltm(dev);
1434 dev->actconfig = NULL;
1435 if (dev->state == USB_STATE_CONFIGURED)
1436 usb_set_device_state(dev, USB_STATE_ADDRESS);
1439 dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1440 skip_ep0 ? "non-ep0" : "all");
1442 usb_disable_device_endpoints(dev, skip_ep0);
1446 * usb_enable_endpoint - Enable an endpoint for USB communications
1447 * @dev: the device whose interface is being enabled
1449 * @reset_ep: flag to reset the endpoint state
1451 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1452 * For control endpoints, both the input and output sides are handled.
1454 void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1457 int epnum = usb_endpoint_num(&ep->desc);
1458 int is_out = usb_endpoint_dir_out(&ep->desc);
1459 int is_control = usb_endpoint_xfer_control(&ep->desc);
1462 usb_hcd_reset_endpoint(dev, ep);
1463 if (is_out || is_control)
1464 dev->ep_out[epnum] = ep;
1465 if (!is_out || is_control)
1466 dev->ep_in[epnum] = ep;
1471 * usb_enable_interface - Enable all the endpoints for an interface
1472 * @dev: the device whose interface is being enabled
1473 * @intf: pointer to the interface descriptor
1474 * @reset_eps: flag to reset the endpoints' state
1476 * Enables all the endpoints for the interface's current altsetting.
1478 void usb_enable_interface(struct usb_device *dev,
1479 struct usb_interface *intf, bool reset_eps)
1481 struct usb_host_interface *alt = intf->cur_altsetting;
1484 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1485 usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
1489 * usb_set_interface - Makes a particular alternate setting be current
1490 * @dev: the device whose interface is being updated
1491 * @interface: the interface being updated
1492 * @alternate: the setting being chosen.
1494 * Context: task context, might sleep.
1496 * This is used to enable data transfers on interfaces that may not
1497 * be enabled by default. Not all devices support such configurability.
1498 * Only the driver bound to an interface may change its setting.
1500 * Within any given configuration, each interface may have several
1501 * alternative settings. These are often used to control levels of
1502 * bandwidth consumption. For example, the default setting for a high
1503 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1504 * while interrupt transfers of up to 3KBytes per microframe are legal.
1505 * Also, isochronous endpoints may never be part of an
1506 * interface's default setting. To access such bandwidth, alternate
1507 * interface settings must be made current.
1509 * Note that in the Linux USB subsystem, bandwidth associated with
1510 * an endpoint in a given alternate setting is not reserved until an URB
1511 * is submitted that needs that bandwidth. Some other operating systems
1512 * allocate bandwidth early, when a configuration is chosen.
1514 * xHCI reserves bandwidth and configures the alternate setting in
1515 * usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1516 * may be disabled. Drivers cannot rely on any particular alternate
1517 * setting being in effect after a failure.
1519 * This call is synchronous, and may not be used in an interrupt context.
1520 * Also, drivers must not change altsettings while urbs are scheduled for
1521 * endpoints in that interface; all such urbs must first be completed
1522 * (perhaps forced by unlinking).
1524 * Return: Zero on success, or else the status code returned by the
1525 * underlying usb_control_msg() call.
1527 int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1529 struct usb_interface *iface;
1530 struct usb_host_interface *alt;
1531 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1532 int i, ret, manual = 0;
1533 unsigned int epaddr;
1536 if (dev->state == USB_STATE_SUSPENDED)
1537 return -EHOSTUNREACH;
1539 iface = usb_ifnum_to_if(dev, interface);
1541 dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1545 if (iface->unregistering)
1548 alt = usb_altnum_to_altsetting(iface, alternate);
1550 dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1555 * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1556 * including freeing dropped endpoint ring buffers.
1557 * Make sure the interface endpoints are flushed before that
1559 usb_disable_interface(dev, iface, false);
1561 /* Make sure we have enough bandwidth for this alternate interface.
1562 * Remove the current alt setting and add the new alt setting.
1564 mutex_lock(hcd->bandwidth_mutex);
1565 /* Disable LPM, and re-enable it once the new alt setting is installed,
1566 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1568 if (usb_disable_lpm(dev)) {
1569 dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1570 mutex_unlock(hcd->bandwidth_mutex);
1573 /* Changing alt-setting also frees any allocated streams */
1574 for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1575 iface->cur_altsetting->endpoint[i].streams = 0;
1577 ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
1579 dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1581 usb_enable_lpm(dev);
1582 mutex_unlock(hcd->bandwidth_mutex);
1586 if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1589 ret = usb_control_msg_send(dev, 0,
1590 USB_REQ_SET_INTERFACE,
1591 USB_RECIP_INTERFACE, alternate,
1592 interface, NULL, 0, 5000,
1595 /* 9.4.10 says devices don't need this and are free to STALL the
1596 * request if the interface only has one alternate setting.
1598 if (ret == -EPIPE && iface->num_altsetting == 1) {
1600 "manual set_interface for iface %d, alt %d\n",
1601 interface, alternate);
1604 /* Re-instate the old alt setting */
1605 usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
1606 usb_enable_lpm(dev);
1607 mutex_unlock(hcd->bandwidth_mutex);
1610 mutex_unlock(hcd->bandwidth_mutex);
1612 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1613 * when they implement async or easily-killable versions of this or
1614 * other "should-be-internal" functions (like clear_halt).
1615 * should hcd+usbcore postprocess control requests?
1618 /* prevent submissions using previous endpoint settings */
1619 if (iface->cur_altsetting != alt) {
1620 remove_intf_ep_devs(iface);
1621 usb_remove_sysfs_intf_files(iface);
1623 usb_disable_interface(dev, iface, true);
1625 iface->cur_altsetting = alt;
1627 /* Now that the interface is installed, re-enable LPM. */
1628 usb_unlocked_enable_lpm(dev);
1630 /* If the interface only has one altsetting and the device didn't
1631 * accept the request, we attempt to carry out the equivalent action
1632 * by manually clearing the HALT feature for each endpoint in the
1636 for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1637 epaddr = alt->endpoint[i].desc.bEndpointAddress;
1638 pipe = __create_pipe(dev,
1639 USB_ENDPOINT_NUMBER_MASK & epaddr) |
1640 (usb_endpoint_out(epaddr) ?
1641 USB_DIR_OUT : USB_DIR_IN);
1643 usb_clear_halt(dev, pipe);
1647 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1650 * Despite EP0 is always present in all interfaces/AS, the list of
1651 * endpoints from the descriptor does not contain EP0. Due to its
1652 * omnipresence one might expect EP0 being considered "affected" by
1653 * any SetInterface request and hence assume toggles need to be reset.
1654 * However, EP0 toggles are re-synced for every individual transfer
1655 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1656 * (Likewise, EP0 never "halts" on well designed devices.)
1658 usb_enable_interface(dev, iface, true);
1659 if (device_is_registered(&iface->dev)) {
1660 usb_create_sysfs_intf_files(iface);
1661 create_intf_ep_devs(iface);
1665 EXPORT_SYMBOL_GPL(usb_set_interface);
1668 * usb_reset_configuration - lightweight device reset
1669 * @dev: the device whose configuration is being reset
1671 * This issues a standard SET_CONFIGURATION request to the device using
1672 * the current configuration. The effect is to reset most USB-related
1673 * state in the device, including interface altsettings (reset to zero),
1674 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1675 * endpoints). Other usbcore state is unchanged, including bindings of
1676 * usb device drivers to interfaces.
1678 * Because this affects multiple interfaces, avoid using this with composite
1679 * (multi-interface) devices. Instead, the driver for each interface may
1680 * use usb_set_interface() on the interfaces it claims. Be careful though;
1681 * some devices don't support the SET_INTERFACE request, and others won't
1682 * reset all the interface state (notably endpoint state). Resetting the whole
1683 * configuration would affect other drivers' interfaces.
1685 * The caller must own the device lock.
1687 * Return: Zero on success, else a negative error code.
1689 * If this routine fails the device will probably be in an unusable state
1690 * with endpoints disabled, and interfaces only partially enabled.
1692 int usb_reset_configuration(struct usb_device *dev)
1695 struct usb_host_config *config;
1696 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1698 if (dev->state == USB_STATE_SUSPENDED)
1699 return -EHOSTUNREACH;
1701 /* caller must have locked the device and must own
1702 * the usb bus readlock (so driver bindings are stable);
1703 * calls during probe() are fine
1706 usb_disable_device_endpoints(dev, 1); /* skip ep0*/
1708 config = dev->actconfig;
1710 mutex_lock(hcd->bandwidth_mutex);
1711 /* Disable LPM, and re-enable it once the configuration is reset, so
1712 * that the xHCI driver can recalculate the U1/U2 timeouts.
1714 if (usb_disable_lpm(dev)) {
1715 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1716 mutex_unlock(hcd->bandwidth_mutex);
1720 /* xHCI adds all endpoints in usb_hcd_alloc_bandwidth */
1721 retval = usb_hcd_alloc_bandwidth(dev, config, NULL, NULL);
1723 usb_enable_lpm(dev);
1724 mutex_unlock(hcd->bandwidth_mutex);
1727 retval = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
1728 config->desc.bConfigurationValue, 0,
1729 NULL, 0, USB_CTRL_SET_TIMEOUT,
1732 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1733 usb_enable_lpm(dev);
1734 mutex_unlock(hcd->bandwidth_mutex);
1737 mutex_unlock(hcd->bandwidth_mutex);
1739 /* re-init hc/hcd interface/endpoint state */
1740 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1741 struct usb_interface *intf = config->interface[i];
1742 struct usb_host_interface *alt;
1744 alt = usb_altnum_to_altsetting(intf, 0);
1746 /* No altsetting 0? We'll assume the first altsetting.
1747 * We could use a GetInterface call, but if a device is
1748 * so non-compliant that it doesn't have altsetting 0
1749 * then I wouldn't trust its reply anyway.
1752 alt = &intf->altsetting[0];
1754 if (alt != intf->cur_altsetting) {
1755 remove_intf_ep_devs(intf);
1756 usb_remove_sysfs_intf_files(intf);
1758 intf->cur_altsetting = alt;
1759 usb_enable_interface(dev, intf, true);
1760 if (device_is_registered(&intf->dev)) {
1761 usb_create_sysfs_intf_files(intf);
1762 create_intf_ep_devs(intf);
1765 /* Now that the interfaces are installed, re-enable LPM. */
1766 usb_unlocked_enable_lpm(dev);
1769 EXPORT_SYMBOL_GPL(usb_reset_configuration);
1771 static void usb_release_interface(struct device *dev)
1773 struct usb_interface *intf = to_usb_interface(dev);
1774 struct usb_interface_cache *intfc =
1775 altsetting_to_usb_interface_cache(intf->altsetting);
1777 kref_put(&intfc->ref, usb_release_interface_cache);
1778 usb_put_dev(interface_to_usbdev(intf));
1779 of_node_put(dev->of_node);
1784 * usb_deauthorize_interface - deauthorize an USB interface
1786 * @intf: USB interface structure
1788 void usb_deauthorize_interface(struct usb_interface *intf)
1790 struct device *dev = &intf->dev;
1792 device_lock(dev->parent);
1794 if (intf->authorized) {
1796 intf->authorized = 0;
1799 usb_forced_unbind_intf(intf);
1802 device_unlock(dev->parent);
1806 * usb_authorize_interface - authorize an USB interface
1808 * @intf: USB interface structure
1810 void usb_authorize_interface(struct usb_interface *intf)
1812 struct device *dev = &intf->dev;
1814 if (!intf->authorized) {
1816 intf->authorized = 1; /* authorize interface */
1821 static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
1823 struct usb_device *usb_dev;
1824 struct usb_interface *intf;
1825 struct usb_host_interface *alt;
1827 intf = to_usb_interface(dev);
1828 usb_dev = interface_to_usbdev(intf);
1829 alt = intf->cur_altsetting;
1831 if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
1832 alt->desc.bInterfaceClass,
1833 alt->desc.bInterfaceSubClass,
1834 alt->desc.bInterfaceProtocol))
1837 if (add_uevent_var(env,
1839 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1840 le16_to_cpu(usb_dev->descriptor.idVendor),
1841 le16_to_cpu(usb_dev->descriptor.idProduct),
1842 le16_to_cpu(usb_dev->descriptor.bcdDevice),
1843 usb_dev->descriptor.bDeviceClass,
1844 usb_dev->descriptor.bDeviceSubClass,
1845 usb_dev->descriptor.bDeviceProtocol,
1846 alt->desc.bInterfaceClass,
1847 alt->desc.bInterfaceSubClass,
1848 alt->desc.bInterfaceProtocol,
1849 alt->desc.bInterfaceNumber))
1855 struct device_type usb_if_device_type = {
1856 .name = "usb_interface",
1857 .release = usb_release_interface,
1858 .uevent = usb_if_uevent,
1861 static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1862 struct usb_host_config *config,
1865 struct usb_interface_assoc_descriptor *retval = NULL;
1866 struct usb_interface_assoc_descriptor *intf_assoc;
1871 for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1872 intf_assoc = config->intf_assoc[i];
1873 if (intf_assoc->bInterfaceCount == 0)
1876 first_intf = intf_assoc->bFirstInterface;
1877 last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1878 if (inum >= first_intf && inum <= last_intf) {
1880 retval = intf_assoc;
1882 dev_err(&dev->dev, "Interface #%d referenced"
1883 " by multiple IADs\n", inum);
1892 * Internal function to queue a device reset
1893 * See usb_queue_reset_device() for more details
1895 static void __usb_queue_reset_device(struct work_struct *ws)
1898 struct usb_interface *iface =
1899 container_of(ws, struct usb_interface, reset_ws);
1900 struct usb_device *udev = interface_to_usbdev(iface);
1902 rc = usb_lock_device_for_reset(udev, iface);
1904 usb_reset_device(udev);
1905 usb_unlock_device(udev);
1907 usb_put_intf(iface); /* Undo _get_ in usb_queue_reset_device() */
1912 * usb_set_configuration - Makes a particular device setting be current
1913 * @dev: the device whose configuration is being updated
1914 * @configuration: the configuration being chosen.
1916 * Context: task context, might sleep. Caller holds device lock.
1918 * This is used to enable non-default device modes. Not all devices
1919 * use this kind of configurability; many devices only have one
1922 * @configuration is the value of the configuration to be installed.
1923 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1924 * must be non-zero; a value of zero indicates that the device in
1925 * unconfigured. However some devices erroneously use 0 as one of their
1926 * configuration values. To help manage such devices, this routine will
1927 * accept @configuration = -1 as indicating the device should be put in
1928 * an unconfigured state.
1930 * USB device configurations may affect Linux interoperability,
1931 * power consumption and the functionality available. For example,
1932 * the default configuration is limited to using 100mA of bus power,
1933 * so that when certain device functionality requires more power,
1934 * and the device is bus powered, that functionality should be in some
1935 * non-default device configuration. Other device modes may also be
1936 * reflected as configuration options, such as whether two ISDN
1937 * channels are available independently; and choosing between open
1938 * standard device protocols (like CDC) or proprietary ones.
1940 * Note that a non-authorized device (dev->authorized == 0) will only
1941 * be put in unconfigured mode.
1943 * Note that USB has an additional level of device configurability,
1944 * associated with interfaces. That configurability is accessed using
1945 * usb_set_interface().
1947 * This call is synchronous. The calling context must be able to sleep,
1948 * must own the device lock, and must not hold the driver model's USB
1949 * bus mutex; usb interface driver probe() methods cannot use this routine.
1951 * Returns zero on success, or else the status code returned by the
1952 * underlying call that failed. On successful completion, each interface
1953 * in the original device configuration has been destroyed, and each one
1954 * in the new configuration has been probed by all relevant usb device
1955 * drivers currently known to the kernel.
1957 int usb_set_configuration(struct usb_device *dev, int configuration)
1960 struct usb_host_config *cp = NULL;
1961 struct usb_interface **new_interfaces = NULL;
1962 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1965 if (dev->authorized == 0 || configuration == -1)
1968 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
1969 if (dev->config[i].desc.bConfigurationValue ==
1971 cp = &dev->config[i];
1976 if ((!cp && configuration != 0))
1979 /* The USB spec says configuration 0 means unconfigured.
1980 * But if a device includes a configuration numbered 0,
1981 * we will accept it as a correctly configured state.
1982 * Use -1 if you really want to unconfigure the device.
1984 if (cp && configuration == 0)
1985 dev_warn(&dev->dev, "config 0 descriptor??\n");
1987 /* Allocate memory for new interfaces before doing anything else,
1988 * so that if we run out then nothing will have changed. */
1991 nintf = cp->desc.bNumInterfaces;
1992 new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
1994 if (!new_interfaces)
1997 for (; n < nintf; ++n) {
1998 new_interfaces[n] = kzalloc(
1999 sizeof(struct usb_interface),
2001 if (!new_interfaces[n]) {
2005 kfree(new_interfaces[n]);
2006 kfree(new_interfaces);
2011 i = dev->bus_mA - usb_get_max_power(dev, cp);
2013 dev_warn(&dev->dev, "new config #%d exceeds power "
2018 /* Wake up the device so we can send it the Set-Config request */
2019 ret = usb_autoresume_device(dev);
2021 goto free_interfaces;
2023 /* if it's already configured, clear out old state first.
2024 * getting rid of old interfaces means unbinding their drivers.
2026 if (dev->state != USB_STATE_ADDRESS)
2027 usb_disable_device(dev, 1); /* Skip ep0 */
2029 /* Get rid of pending async Set-Config requests for this device */
2030 cancel_async_set_config(dev);
2032 /* Make sure we have bandwidth (and available HCD resources) for this
2033 * configuration. Remove endpoints from the schedule if we're dropping
2034 * this configuration to set configuration 0. After this point, the
2035 * host controller will not allow submissions to dropped endpoints. If
2036 * this call fails, the device state is unchanged.
2038 mutex_lock(hcd->bandwidth_mutex);
2039 /* Disable LPM, and re-enable it once the new configuration is
2040 * installed, so that the xHCI driver can recalculate the U1/U2
2043 if (dev->actconfig && usb_disable_lpm(dev)) {
2044 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
2045 mutex_unlock(hcd->bandwidth_mutex);
2047 goto free_interfaces;
2049 ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
2052 usb_enable_lpm(dev);
2053 mutex_unlock(hcd->bandwidth_mutex);
2054 usb_autosuspend_device(dev);
2055 goto free_interfaces;
2059 * Initialize the new interface structures and the
2060 * hc/hcd/usbcore interface/endpoint state.
2062 for (i = 0; i < nintf; ++i) {
2063 struct usb_interface_cache *intfc;
2064 struct usb_interface *intf;
2065 struct usb_host_interface *alt;
2068 cp->interface[i] = intf = new_interfaces[i];
2069 intfc = cp->intf_cache[i];
2070 intf->altsetting = intfc->altsetting;
2071 intf->num_altsetting = intfc->num_altsetting;
2072 intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
2073 kref_get(&intfc->ref);
2075 alt = usb_altnum_to_altsetting(intf, 0);
2077 /* No altsetting 0? We'll assume the first altsetting.
2078 * We could use a GetInterface call, but if a device is
2079 * so non-compliant that it doesn't have altsetting 0
2080 * then I wouldn't trust its reply anyway.
2083 alt = &intf->altsetting[0];
2085 ifnum = alt->desc.bInterfaceNumber;
2086 intf->intf_assoc = find_iad(dev, cp, ifnum);
2087 intf->cur_altsetting = alt;
2088 usb_enable_interface(dev, intf, true);
2089 intf->dev.parent = &dev->dev;
2090 if (usb_of_has_combined_node(dev)) {
2091 device_set_of_node_from_dev(&intf->dev, &dev->dev);
2093 intf->dev.of_node = usb_of_get_interface_node(dev,
2094 configuration, ifnum);
2096 ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev));
2097 intf->dev.driver = NULL;
2098 intf->dev.bus = &usb_bus_type;
2099 intf->dev.type = &usb_if_device_type;
2100 intf->dev.groups = usb_interface_groups;
2101 INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
2103 device_initialize(&intf->dev);
2104 pm_runtime_no_callbacks(&intf->dev);
2105 dev_set_name(&intf->dev, "%d-%s:%d.%d", dev->bus->busnum,
2106 dev->devpath, configuration, ifnum);
2109 kfree(new_interfaces);
2111 ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
2112 configuration, 0, NULL, 0,
2113 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
2116 * All the old state is gone, so what else can we do?
2117 * The device is probably useless now anyway.
2119 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
2120 for (i = 0; i < nintf; ++i) {
2121 usb_disable_interface(dev, cp->interface[i], true);
2122 put_device(&cp->interface[i]->dev);
2123 cp->interface[i] = NULL;
2128 dev->actconfig = cp;
2129 mutex_unlock(hcd->bandwidth_mutex);
2132 usb_set_device_state(dev, USB_STATE_ADDRESS);
2134 /* Leave LPM disabled while the device is unconfigured. */
2135 usb_autosuspend_device(dev);
2138 usb_set_device_state(dev, USB_STATE_CONFIGURED);
2140 if (cp->string == NULL &&
2141 !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
2142 cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
2144 /* Now that the interfaces are installed, re-enable LPM. */
2145 usb_unlocked_enable_lpm(dev);
2146 /* Enable LTM if it was turned off by usb_disable_device. */
2147 usb_enable_ltm(dev);
2149 /* Now that all the interfaces are set up, register them
2150 * to trigger binding of drivers to interfaces. probe()
2151 * routines may install different altsettings and may
2152 * claim() any interfaces not yet bound. Many class drivers
2153 * need that: CDC, audio, video, etc.
2155 for (i = 0; i < nintf; ++i) {
2156 struct usb_interface *intf = cp->interface[i];
2158 if (intf->dev.of_node &&
2159 !of_device_is_available(intf->dev.of_node)) {
2160 dev_info(&dev->dev, "skipping disabled interface %d\n",
2161 intf->cur_altsetting->desc.bInterfaceNumber);
2166 "adding %s (config #%d, interface %d)\n",
2167 dev_name(&intf->dev), configuration,
2168 intf->cur_altsetting->desc.bInterfaceNumber);
2169 device_enable_async_suspend(&intf->dev);
2170 ret = device_add(&intf->dev);
2172 dev_err(&dev->dev, "device_add(%s) --> %d\n",
2173 dev_name(&intf->dev), ret);
2176 create_intf_ep_devs(intf);
2179 usb_autosuspend_device(dev);
2182 EXPORT_SYMBOL_GPL(usb_set_configuration);
2184 static LIST_HEAD(set_config_list);
2185 static DEFINE_SPINLOCK(set_config_lock);
2187 struct set_config_request {
2188 struct usb_device *udev;
2190 struct work_struct work;
2191 struct list_head node;
2194 /* Worker routine for usb_driver_set_configuration() */
2195 static void driver_set_config_work(struct work_struct *work)
2197 struct set_config_request *req =
2198 container_of(work, struct set_config_request, work);
2199 struct usb_device *udev = req->udev;
2201 usb_lock_device(udev);
2202 spin_lock(&set_config_lock);
2203 list_del(&req->node);
2204 spin_unlock(&set_config_lock);
2206 if (req->config >= -1) /* Is req still valid? */
2207 usb_set_configuration(udev, req->config);
2208 usb_unlock_device(udev);
2213 /* Cancel pending Set-Config requests for a device whose configuration
2216 static void cancel_async_set_config(struct usb_device *udev)
2218 struct set_config_request *req;
2220 spin_lock(&set_config_lock);
2221 list_for_each_entry(req, &set_config_list, node) {
2222 if (req->udev == udev)
2223 req->config = -999; /* Mark as cancelled */
2225 spin_unlock(&set_config_lock);
2229 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
2230 * @udev: the device whose configuration is being updated
2231 * @config: the configuration being chosen.
2232 * Context: In process context, must be able to sleep
2234 * Device interface drivers are not allowed to change device configurations.
2235 * This is because changing configurations will destroy the interface the
2236 * driver is bound to and create new ones; it would be like a floppy-disk
2237 * driver telling the computer to replace the floppy-disk drive with a
2240 * Still, in certain specialized circumstances the need may arise. This
2241 * routine gets around the normal restrictions by using a work thread to
2242 * submit the change-config request.
2244 * Return: 0 if the request was successfully queued, error code otherwise.
2245 * The caller has no way to know whether the queued request will eventually
2248 int usb_driver_set_configuration(struct usb_device *udev, int config)
2250 struct set_config_request *req;
2252 req = kmalloc(sizeof(*req), GFP_KERNEL);
2256 req->config = config;
2257 INIT_WORK(&req->work, driver_set_config_work);
2259 spin_lock(&set_config_lock);
2260 list_add(&req->node, &set_config_list);
2261 spin_unlock(&set_config_lock);
2264 schedule_work(&req->work);
2267 EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2270 * cdc_parse_cdc_header - parse the extra headers present in CDC devices
2271 * @hdr: the place to put the results of the parsing
2272 * @intf: the interface for which parsing is requested
2273 * @buffer: pointer to the extra headers to be parsed
2274 * @buflen: length of the extra headers
2276 * This evaluates the extra headers present in CDC devices which
2277 * bind the interfaces for data and control and provide details
2278 * about the capabilities of the device.
2280 * Return: number of descriptors parsed or -EINVAL
2281 * if the header is contradictory beyond salvage
2284 int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2285 struct usb_interface *intf,
2289 /* duplicates are ignored */
2290 struct usb_cdc_union_desc *union_header = NULL;
2292 /* duplicates are not tolerated */
2293 struct usb_cdc_header_desc *header = NULL;
2294 struct usb_cdc_ether_desc *ether = NULL;
2295 struct usb_cdc_mdlm_detail_desc *detail = NULL;
2296 struct usb_cdc_mdlm_desc *desc = NULL;
2298 unsigned int elength;
2301 memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2302 hdr->phonet_magic_present = false;
2303 while (buflen > 0) {
2304 elength = buffer[0];
2306 dev_err(&intf->dev, "skipping garbage byte\n");
2310 if ((buflen < elength) || (elength < 3)) {
2311 dev_err(&intf->dev, "invalid descriptor buffer length\n");
2314 if (buffer[1] != USB_DT_CS_INTERFACE) {
2315 dev_err(&intf->dev, "skipping garbage\n");
2319 switch (buffer[2]) {
2320 case USB_CDC_UNION_TYPE: /* we've found it */
2321 if (elength < sizeof(struct usb_cdc_union_desc))
2324 dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2327 union_header = (struct usb_cdc_union_desc *)buffer;
2329 case USB_CDC_COUNTRY_TYPE:
2330 if (elength < sizeof(struct usb_cdc_country_functional_desc))
2332 hdr->usb_cdc_country_functional_desc =
2333 (struct usb_cdc_country_functional_desc *)buffer;
2335 case USB_CDC_HEADER_TYPE:
2336 if (elength != sizeof(struct usb_cdc_header_desc))
2340 header = (struct usb_cdc_header_desc *)buffer;
2342 case USB_CDC_ACM_TYPE:
2343 if (elength < sizeof(struct usb_cdc_acm_descriptor))
2345 hdr->usb_cdc_acm_descriptor =
2346 (struct usb_cdc_acm_descriptor *)buffer;
2348 case USB_CDC_ETHERNET_TYPE:
2349 if (elength != sizeof(struct usb_cdc_ether_desc))
2353 ether = (struct usb_cdc_ether_desc *)buffer;
2355 case USB_CDC_CALL_MANAGEMENT_TYPE:
2356 if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2358 hdr->usb_cdc_call_mgmt_descriptor =
2359 (struct usb_cdc_call_mgmt_descriptor *)buffer;
2361 case USB_CDC_DMM_TYPE:
2362 if (elength < sizeof(struct usb_cdc_dmm_desc))
2364 hdr->usb_cdc_dmm_desc =
2365 (struct usb_cdc_dmm_desc *)buffer;
2367 case USB_CDC_MDLM_TYPE:
2368 if (elength < sizeof(struct usb_cdc_mdlm_desc))
2372 desc = (struct usb_cdc_mdlm_desc *)buffer;
2374 case USB_CDC_MDLM_DETAIL_TYPE:
2375 if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2379 detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2381 case USB_CDC_NCM_TYPE:
2382 if (elength < sizeof(struct usb_cdc_ncm_desc))
2384 hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2386 case USB_CDC_MBIM_TYPE:
2387 if (elength < sizeof(struct usb_cdc_mbim_desc))
2390 hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2392 case USB_CDC_MBIM_EXTENDED_TYPE:
2393 if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2395 hdr->usb_cdc_mbim_extended_desc =
2396 (struct usb_cdc_mbim_extended_desc *)buffer;
2398 case CDC_PHONET_MAGIC_NUMBER:
2399 hdr->phonet_magic_present = true;
2403 * there are LOTS more CDC descriptors that
2404 * could legitimately be found here.
2406 dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2407 buffer[2], elength);
2415 hdr->usb_cdc_union_desc = union_header;
2416 hdr->usb_cdc_header_desc = header;
2417 hdr->usb_cdc_mdlm_detail_desc = detail;
2418 hdr->usb_cdc_mdlm_desc = desc;
2419 hdr->usb_cdc_ether_desc = ether;
2423 EXPORT_SYMBOL(cdc_parse_cdc_header);