2 * message.c - synchronous message handling
5 #include <linux/pci.h> /* for scatterlist macros */
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/init.h>
11 #include <linux/timer.h>
12 #include <linux/ctype.h>
13 #include <linux/nls.h>
14 #include <linux/device.h>
15 #include <linux/scatterlist.h>
16 #include <linux/usb/quirks.h>
17 #include <linux/usb/hcd.h> /* for usbcore internals */
18 #include <asm/byteorder.h>
22 static void cancel_async_set_config(struct usb_device
*udev
);
25 struct completion done
;
29 static void usb_api_blocking_completion(struct urb
*urb
)
31 struct api_context
*ctx
= urb
->context
;
33 ctx
->status
= urb
->status
;
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.
44 static int usb_start_wait_urb(struct urb
*urb
, int timeout
, int *actual_length
)
46 struct api_context ctx
;
50 init_completion(&ctx
.done
);
52 urb
->actual_length
= 0;
53 retval
= usb_submit_urb(urb
, GFP_NOIO
);
57 expire
= timeout
? msecs_to_jiffies(timeout
) : MAX_SCHEDULE_TIMEOUT
;
58 if (!wait_for_completion_timeout(&ctx
.done
, expire
)) {
60 retval
= (ctx
.status
== -ENOENT
? -ETIMEDOUT
: ctx
.status
);
62 dev_dbg(&urb
->dev
->dev
,
63 "%s timed out on ep%d%s len=%u/%u\n",
65 usb_endpoint_num(&urb
->ep
->desc
),
66 usb_urb_dir_in(urb
) ? "in" : "out",
68 urb
->transfer_buffer_length
);
73 *actual_length
= urb
->actual_length
;
79 /*-------------------------------------------------------------------*/
80 /* returns status (negative) or length (positive) */
81 static int usb_internal_control_msg(struct usb_device
*usb_dev
,
83 struct usb_ctrlrequest
*cmd
,
84 void *data
, int len
, int timeout
)
90 urb
= usb_alloc_urb(0, GFP_NOIO
);
94 usb_fill_control_urb(urb
, usb_dev
, pipe
, (unsigned char *)cmd
, data
,
95 len
, usb_api_blocking_completion
, NULL
);
97 retv
= usb_start_wait_urb(urb
, timeout
, &length
);
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)
117 * Context: !in_interrupt ()
119 * This function sends a simple control message to a specified endpoint and
120 * waits for the message to complete, or timeout.
122 * If successful, it returns the number of bytes transferred, otherwise a
123 * negative error number.
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.
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
)
136 struct usb_ctrlrequest
*dr
;
139 dr
= kmalloc(sizeof(struct usb_ctrlrequest
), GFP_NOIO
);
143 dr
->bRequestType
= requesttype
;
144 dr
->bRequest
= request
;
145 dr
->wValue
= cpu_to_le16(value
);
146 dr
->wIndex
= cpu_to_le16(index
);
147 dr
->wLength
= cpu_to_le16(size
);
149 ret
= usb_internal_control_msg(dev
, pipe
, dr
, data
, size
, timeout
);
155 EXPORT_SYMBOL_GPL(usb_control_msg
);
158 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
159 * @usb_dev: pointer to the usb device to send the message to
160 * @pipe: endpoint "pipe" to send the message to
161 * @data: pointer to the data to send
162 * @len: length in bytes of the data to send
163 * @actual_length: pointer to a location to put the actual length transferred
165 * @timeout: time in msecs to wait for the message to complete before
166 * timing out (if 0 the wait is forever)
168 * Context: !in_interrupt ()
170 * This function sends a simple interrupt message to a specified endpoint and
171 * waits for the message to complete, or timeout.
173 * If successful, it returns 0, otherwise a negative error number. The number
174 * of actual bytes transferred will be stored in the actual_length paramater.
176 * Don't use this function from within an interrupt context, like a bottom half
177 * handler. If you need an asynchronous message, or need to send a message
178 * from within interrupt context, use usb_submit_urb() If a thread in your
179 * driver uses this call, make sure your disconnect() method can wait for it to
180 * complete. Since you don't have a handle on the URB used, you can't cancel
183 int usb_interrupt_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
184 void *data
, int len
, int *actual_length
, int timeout
)
186 return usb_bulk_msg(usb_dev
, pipe
, data
, len
, actual_length
, timeout
);
188 EXPORT_SYMBOL_GPL(usb_interrupt_msg
);
191 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
192 * @usb_dev: pointer to the usb device to send the message to
193 * @pipe: endpoint "pipe" to send the message to
194 * @data: pointer to the data to send
195 * @len: length in bytes of the data to send
196 * @actual_length: pointer to a location to put the actual length transferred
198 * @timeout: time in msecs to wait for the message to complete before
199 * timing out (if 0 the wait is forever)
201 * Context: !in_interrupt ()
203 * This function sends a simple bulk message to a specified endpoint
204 * and waits for the message to complete, or timeout.
206 * If successful, it returns 0, otherwise a negative error number. The number
207 * of actual bytes transferred will be stored in the actual_length paramater.
209 * Don't use this function from within an interrupt context, like a bottom half
210 * handler. If you need an asynchronous message, or need to send a message
211 * from within interrupt context, use usb_submit_urb() If a thread in your
212 * driver uses this call, make sure your disconnect() method can wait for it to
213 * complete. Since you don't have a handle on the URB used, you can't cancel
216 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
217 * users are forced to abuse this routine by using it to submit URBs for
218 * interrupt endpoints. We will take the liberty of creating an interrupt URB
219 * (with the default interval) if the target is an interrupt endpoint.
221 int usb_bulk_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
222 void *data
, int len
, int *actual_length
, int timeout
)
225 struct usb_host_endpoint
*ep
;
227 ep
= usb_pipe_endpoint(usb_dev
, pipe
);
231 urb
= usb_alloc_urb(0, GFP_KERNEL
);
235 if ((ep
->desc
.bmAttributes
& USB_ENDPOINT_XFERTYPE_MASK
) ==
236 USB_ENDPOINT_XFER_INT
) {
237 pipe
= (pipe
& ~(3 << 30)) | (PIPE_INTERRUPT
<< 30);
238 usb_fill_int_urb(urb
, usb_dev
, pipe
, data
, len
,
239 usb_api_blocking_completion
, NULL
,
242 usb_fill_bulk_urb(urb
, usb_dev
, pipe
, data
, len
,
243 usb_api_blocking_completion
, NULL
);
245 return usb_start_wait_urb(urb
, timeout
, actual_length
);
247 EXPORT_SYMBOL_GPL(usb_bulk_msg
);
249 /*-------------------------------------------------------------------*/
251 static void sg_clean(struct usb_sg_request
*io
)
254 while (io
->entries
--)
255 usb_free_urb(io
->urbs
[io
->entries
]);
262 static void sg_complete(struct urb
*urb
)
264 struct usb_sg_request
*io
= urb
->context
;
265 int status
= urb
->status
;
267 spin_lock(&io
->lock
);
269 /* In 2.5 we require hcds' endpoint queues not to progress after fault
270 * reports, until the completion callback (this!) returns. That lets
271 * device driver code (like this routine) unlink queued urbs first,
272 * if it needs to, since the HC won't work on them at all. So it's
273 * not possible for page N+1 to overwrite page N, and so on.
275 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
276 * complete before the HCD can get requests away from hardware,
277 * though never during cleanup after a hard fault.
280 && (io
->status
!= -ECONNRESET
281 || status
!= -ECONNRESET
)
282 && urb
->actual_length
) {
283 dev_err(io
->dev
->bus
->controller
,
284 "dev %s ep%d%s scatterlist error %d/%d\n",
286 usb_endpoint_num(&urb
->ep
->desc
),
287 usb_urb_dir_in(urb
) ? "in" : "out",
292 if (io
->status
== 0 && status
&& status
!= -ECONNRESET
) {
293 int i
, found
, retval
;
297 /* the previous urbs, and this one, completed already.
298 * unlink pending urbs so they won't rx/tx bad data.
299 * careful: unlink can sometimes be synchronous...
301 spin_unlock(&io
->lock
);
302 for (i
= 0, found
= 0; i
< io
->entries
; i
++) {
303 if (!io
->urbs
[i
] || !io
->urbs
[i
]->dev
)
306 retval
= usb_unlink_urb(io
->urbs
[i
]);
307 if (retval
!= -EINPROGRESS
&&
311 dev_err(&io
->dev
->dev
,
312 "%s, unlink --> %d\n",
314 } else if (urb
== io
->urbs
[i
])
317 spin_lock(&io
->lock
);
320 /* on the last completion, signal usb_sg_wait() */
321 io
->bytes
+= urb
->actual_length
;
324 complete(&io
->complete
);
326 spin_unlock(&io
->lock
);
331 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
332 * @io: request block being initialized. until usb_sg_wait() returns,
333 * treat this as a pointer to an opaque block of memory,
334 * @dev: the usb device that will send or receive the data
335 * @pipe: endpoint "pipe" used to transfer the data
336 * @period: polling rate for interrupt endpoints, in frames or
337 * (for high speed endpoints) microframes; ignored for bulk
338 * @sg: scatterlist entries
339 * @nents: how many entries in the scatterlist
340 * @length: how many bytes to send from the scatterlist, or zero to
341 * send every byte identified in the list.
342 * @mem_flags: SLAB_* flags affecting memory allocations in this call
344 * Returns zero for success, else a negative errno value. This initializes a
345 * scatter/gather request, allocating resources such as I/O mappings and urb
346 * memory (except maybe memory used by USB controller drivers).
348 * The request must be issued using usb_sg_wait(), which waits for the I/O to
349 * complete (or to be canceled) and then cleans up all resources allocated by
352 * The request may be canceled with usb_sg_cancel(), either before or after
353 * usb_sg_wait() is called.
355 int usb_sg_init(struct usb_sg_request
*io
, struct usb_device
*dev
,
356 unsigned pipe
, unsigned period
, struct scatterlist
*sg
,
357 int nents
, size_t length
, gfp_t mem_flags
)
363 if (!io
|| !dev
|| !sg
364 || usb_pipecontrol(pipe
)
365 || usb_pipeisoc(pipe
)
369 spin_lock_init(&io
->lock
);
373 if (dev
->bus
->sg_tablesize
> 0) {
381 /* initialize all the urbs we'll use */
382 io
->urbs
= kmalloc(io
->entries
* sizeof *io
->urbs
, mem_flags
);
386 urb_flags
= URB_NO_INTERRUPT
;
387 if (usb_pipein(pipe
))
388 urb_flags
|= URB_SHORT_NOT_OK
;
390 for_each_sg(sg
, sg
, io
->entries
, i
) {
394 urb
= usb_alloc_urb(0, mem_flags
);
403 urb
->interval
= period
;
404 urb
->transfer_flags
= urb_flags
;
405 urb
->complete
= sg_complete
;
410 /* There is no single transfer buffer */
411 urb
->transfer_buffer
= NULL
;
412 urb
->num_sgs
= nents
;
414 /* A length of zero means transfer the whole sg list */
417 struct scatterlist
*sg2
;
420 for_each_sg(sg
, sg2
, nents
, j
)
425 * Some systems can't use DMA; they use PIO instead.
426 * For their sakes, transfer_buffer is set whenever
429 if (!PageHighMem(sg_page(sg
)))
430 urb
->transfer_buffer
= sg_virt(sg
);
432 urb
->transfer_buffer
= NULL
;
436 len
= min_t(size_t, len
, length
);
442 urb
->transfer_buffer_length
= len
;
444 io
->urbs
[--i
]->transfer_flags
&= ~URB_NO_INTERRUPT
;
446 /* transaction state */
447 io
->count
= io
->entries
;
450 init_completion(&io
->complete
);
457 EXPORT_SYMBOL_GPL(usb_sg_init
);
460 * usb_sg_wait - synchronously execute scatter/gather request
461 * @io: request block handle, as initialized with usb_sg_init().
462 * some fields become accessible when this call returns.
463 * Context: !in_interrupt ()
465 * This function blocks until the specified I/O operation completes. It
466 * leverages the grouping of the related I/O requests to get good transfer
467 * rates, by queueing the requests. At higher speeds, such queuing can
468 * significantly improve USB throughput.
470 * There are three kinds of completion for this function.
471 * (1) success, where io->status is zero. The number of io->bytes
472 * transferred is as requested.
473 * (2) error, where io->status is a negative errno value. The number
474 * of io->bytes transferred before the error is usually less
475 * than requested, and can be nonzero.
476 * (3) cancellation, a type of error with status -ECONNRESET that
477 * is initiated by usb_sg_cancel().
479 * When this function returns, all memory allocated through usb_sg_init() or
480 * this call will have been freed. The request block parameter may still be
481 * passed to usb_sg_cancel(), or it may be freed. It could also be
482 * reinitialized and then reused.
484 * Data Transfer Rates:
486 * Bulk transfers are valid for full or high speed endpoints.
487 * The best full speed data rate is 19 packets of 64 bytes each
488 * per frame, or 1216 bytes per millisecond.
489 * The best high speed data rate is 13 packets of 512 bytes each
490 * per microframe, or 52 KBytes per millisecond.
492 * The reason to use interrupt transfers through this API would most likely
493 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
494 * could be transferred. That capability is less useful for low or full
495 * speed interrupt endpoints, which allow at most one packet per millisecond,
496 * of at most 8 or 64 bytes (respectively).
498 * It is not necessary to call this function to reserve bandwidth for devices
499 * under an xHCI host controller, as the bandwidth is reserved when the
500 * configuration or interface alt setting is selected.
502 void usb_sg_wait(struct usb_sg_request
*io
)
505 int entries
= io
->entries
;
507 /* queue the urbs. */
508 spin_lock_irq(&io
->lock
);
510 while (i
< entries
&& !io
->status
) {
513 io
->urbs
[i
]->dev
= io
->dev
;
514 retval
= usb_submit_urb(io
->urbs
[i
], GFP_ATOMIC
);
516 /* after we submit, let completions or cancelations fire;
517 * we handshake using io->status.
519 spin_unlock_irq(&io
->lock
);
521 /* maybe we retrying will recover */
522 case -ENXIO
: /* hc didn't queue this one */
529 /* no error? continue immediately.
531 * NOTE: to work better with UHCI (4K I/O buffer may
532 * need 3K of TDs) it may be good to limit how many
533 * URBs are queued at once; N milliseconds?
540 /* fail any uncompleted urbs */
542 io
->urbs
[i
]->status
= retval
;
543 dev_dbg(&io
->dev
->dev
, "%s, submit --> %d\n",
547 spin_lock_irq(&io
->lock
);
548 if (retval
&& (io
->status
== 0 || io
->status
== -ECONNRESET
))
551 io
->count
-= entries
- i
;
553 complete(&io
->complete
);
554 spin_unlock_irq(&io
->lock
);
556 /* OK, yes, this could be packaged as non-blocking.
557 * So could the submit loop above ... but it's easier to
558 * solve neither problem than to solve both!
560 wait_for_completion(&io
->complete
);
564 EXPORT_SYMBOL_GPL(usb_sg_wait
);
567 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
568 * @io: request block, initialized with usb_sg_init()
570 * This stops a request after it has been started by usb_sg_wait().
571 * It can also prevents one initialized by usb_sg_init() from starting,
572 * so that call just frees resources allocated to the request.
574 void usb_sg_cancel(struct usb_sg_request
*io
)
578 spin_lock_irqsave(&io
->lock
, flags
);
580 /* shut everything down, if it didn't already */
584 io
->status
= -ECONNRESET
;
585 spin_unlock(&io
->lock
);
586 for (i
= 0; i
< io
->entries
; i
++) {
589 if (!io
->urbs
[i
]->dev
)
591 retval
= usb_unlink_urb(io
->urbs
[i
]);
592 if (retval
!= -EINPROGRESS
596 dev_warn(&io
->dev
->dev
, "%s, unlink --> %d\n",
599 spin_lock(&io
->lock
);
601 spin_unlock_irqrestore(&io
->lock
, flags
);
603 EXPORT_SYMBOL_GPL(usb_sg_cancel
);
605 /*-------------------------------------------------------------------*/
608 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
609 * @dev: the device whose descriptor is being retrieved
610 * @type: the descriptor type (USB_DT_*)
611 * @index: the number of the descriptor
612 * @buf: where to put the descriptor
613 * @size: how big is "buf"?
614 * Context: !in_interrupt ()
616 * Gets a USB descriptor. Convenience functions exist to simplify
617 * getting some types of descriptors. Use
618 * usb_get_string() or usb_string() for USB_DT_STRING.
619 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
620 * are part of the device structure.
621 * In addition to a number of USB-standard descriptors, some
622 * devices also use class-specific or vendor-specific descriptors.
624 * This call is synchronous, and may not be used in an interrupt context.
626 * Returns the number of bytes received on success, or else the status code
627 * returned by the underlying usb_control_msg() call.
629 int usb_get_descriptor(struct usb_device
*dev
, unsigned char type
,
630 unsigned char index
, void *buf
, int size
)
635 memset(buf
, 0, size
); /* Make sure we parse really received data */
637 for (i
= 0; i
< 3; ++i
) {
638 /* retry on length 0 or error; some devices are flakey */
639 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
640 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
641 (type
<< 8) + index
, 0, buf
, size
,
642 USB_CTRL_GET_TIMEOUT
);
643 if (result
<= 0 && result
!= -ETIMEDOUT
)
645 if (result
> 1 && ((u8
*)buf
)[1] != type
) {
653 EXPORT_SYMBOL_GPL(usb_get_descriptor
);
656 * usb_get_string - gets a string descriptor
657 * @dev: the device whose string descriptor is being retrieved
658 * @langid: code for language chosen (from string descriptor zero)
659 * @index: the number of the descriptor
660 * @buf: where to put the string
661 * @size: how big is "buf"?
662 * Context: !in_interrupt ()
664 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
665 * in little-endian byte order).
666 * The usb_string() function will often be a convenient way to turn
667 * these strings into kernel-printable form.
669 * Strings may be referenced in device, configuration, interface, or other
670 * descriptors, and could also be used in vendor-specific ways.
672 * This call is synchronous, and may not be used in an interrupt context.
674 * Returns the number of bytes received on success, or else the status code
675 * returned by the underlying usb_control_msg() call.
677 static int usb_get_string(struct usb_device
*dev
, unsigned short langid
,
678 unsigned char index
, void *buf
, int size
)
683 for (i
= 0; i
< 3; ++i
) {
684 /* retry on length 0 or stall; some devices are flakey */
685 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
686 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
687 (USB_DT_STRING
<< 8) + index
, langid
, buf
, size
,
688 USB_CTRL_GET_TIMEOUT
);
689 if (result
== 0 || result
== -EPIPE
)
691 if (result
> 1 && ((u8
*) buf
)[1] != USB_DT_STRING
) {
700 static void usb_try_string_workarounds(unsigned char *buf
, int *length
)
702 int newlength
, oldlength
= *length
;
704 for (newlength
= 2; newlength
+ 1 < oldlength
; newlength
+= 2)
705 if (!isprint(buf
[newlength
]) || buf
[newlength
+ 1])
714 static int usb_string_sub(struct usb_device
*dev
, unsigned int langid
,
715 unsigned int index
, unsigned char *buf
)
719 /* Try to read the string descriptor by asking for the maximum
720 * possible number of bytes */
721 if (dev
->quirks
& USB_QUIRK_STRING_FETCH_255
)
724 rc
= usb_get_string(dev
, langid
, index
, buf
, 255);
726 /* If that failed try to read the descriptor length, then
727 * ask for just that many bytes */
729 rc
= usb_get_string(dev
, langid
, index
, buf
, 2);
731 rc
= usb_get_string(dev
, langid
, index
, buf
, buf
[0]);
735 if (!buf
[0] && !buf
[1])
736 usb_try_string_workarounds(buf
, &rc
);
738 /* There might be extra junk at the end of the descriptor */
742 rc
= rc
- (rc
& 1); /* force a multiple of two */
746 rc
= (rc
< 0 ? rc
: -EINVAL
);
751 static int usb_get_langid(struct usb_device
*dev
, unsigned char *tbuf
)
755 if (dev
->have_langid
)
758 if (dev
->string_langid
< 0)
761 err
= usb_string_sub(dev
, 0, 0, tbuf
);
763 /* If the string was reported but is malformed, default to english
765 if (err
== -ENODATA
|| (err
> 0 && err
< 4)) {
766 dev
->string_langid
= 0x0409;
767 dev
->have_langid
= 1;
769 "string descriptor 0 malformed (err = %d), "
770 "defaulting to 0x%04x\n",
771 err
, dev
->string_langid
);
775 /* In case of all other errors, we assume the device is not able to
776 * deal with strings at all. Set string_langid to -1 in order to
777 * prevent any string to be retrieved from the device */
779 dev_err(&dev
->dev
, "string descriptor 0 read error: %d\n",
781 dev
->string_langid
= -1;
785 /* always use the first langid listed */
786 dev
->string_langid
= tbuf
[2] | (tbuf
[3] << 8);
787 dev
->have_langid
= 1;
788 dev_dbg(&dev
->dev
, "default language 0x%04x\n",
794 * usb_string - returns UTF-8 version of a string descriptor
795 * @dev: the device whose string descriptor is being retrieved
796 * @index: the number of the descriptor
797 * @buf: where to put the string
798 * @size: how big is "buf"?
799 * Context: !in_interrupt ()
801 * This converts the UTF-16LE encoded strings returned by devices, from
802 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
803 * that are more usable in most kernel contexts. Note that this function
804 * chooses strings in the first language supported by the device.
806 * This call is synchronous, and may not be used in an interrupt context.
808 * Returns length of the string (>= 0) or usb_control_msg status (< 0).
810 int usb_string(struct usb_device
*dev
, int index
, char *buf
, size_t size
)
815 if (dev
->state
== USB_STATE_SUSPENDED
)
816 return -EHOSTUNREACH
;
817 if (size
<= 0 || !buf
|| !index
)
820 tbuf
= kmalloc(256, GFP_NOIO
);
824 err
= usb_get_langid(dev
, tbuf
);
828 err
= usb_string_sub(dev
, dev
->string_langid
, index
, tbuf
);
832 size
--; /* leave room for trailing NULL char in output buffer */
833 err
= utf16s_to_utf8s((wchar_t *) &tbuf
[2], (err
- 2) / 2,
834 UTF16_LITTLE_ENDIAN
, buf
, size
);
837 if (tbuf
[1] != USB_DT_STRING
)
839 "wrong descriptor type %02x for string %d (\"%s\")\n",
840 tbuf
[1], index
, buf
);
846 EXPORT_SYMBOL_GPL(usb_string
);
848 /* one UTF-8-encoded 16-bit character has at most three bytes */
849 #define MAX_USB_STRING_SIZE (127 * 3 + 1)
852 * usb_cache_string - read a string descriptor and cache it for later use
853 * @udev: the device whose string descriptor is being read
854 * @index: the descriptor index
856 * Returns a pointer to a kmalloc'ed buffer containing the descriptor string,
857 * or NULL if the index is 0 or the string could not be read.
859 char *usb_cache_string(struct usb_device
*udev
, int index
)
862 char *smallbuf
= NULL
;
868 buf
= kmalloc(MAX_USB_STRING_SIZE
, GFP_NOIO
);
870 len
= usb_string(udev
, index
, buf
, MAX_USB_STRING_SIZE
);
872 smallbuf
= kmalloc(++len
, GFP_NOIO
);
875 memcpy(smallbuf
, buf
, len
);
883 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
884 * @dev: the device whose device descriptor is being updated
885 * @size: how much of the descriptor to read
886 * Context: !in_interrupt ()
888 * Updates the copy of the device descriptor stored in the device structure,
889 * which dedicates space for this purpose.
891 * Not exported, only for use by the core. If drivers really want to read
892 * the device descriptor directly, they can call usb_get_descriptor() with
893 * type = USB_DT_DEVICE and index = 0.
895 * This call is synchronous, and may not be used in an interrupt context.
897 * Returns the number of bytes received on success, or else the status code
898 * returned by the underlying usb_control_msg() call.
900 int usb_get_device_descriptor(struct usb_device
*dev
, unsigned int size
)
902 struct usb_device_descriptor
*desc
;
905 if (size
> sizeof(*desc
))
907 desc
= kmalloc(sizeof(*desc
), GFP_NOIO
);
911 ret
= usb_get_descriptor(dev
, USB_DT_DEVICE
, 0, desc
, size
);
913 memcpy(&dev
->descriptor
, desc
, size
);
919 * usb_get_status - issues a GET_STATUS call
920 * @dev: the device whose status is being checked
921 * @type: USB_RECIP_*; for device, interface, or endpoint
922 * @target: zero (for device), else interface or endpoint number
923 * @data: pointer to two bytes of bitmap data
924 * Context: !in_interrupt ()
926 * Returns device, interface, or endpoint status. Normally only of
927 * interest to see if the device is self powered, or has enabled the
928 * remote wakeup facility; or whether a bulk or interrupt endpoint
929 * is halted ("stalled").
931 * Bits in these status bitmaps are set using the SET_FEATURE request,
932 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
933 * function should be used to clear halt ("stall") status.
935 * This call is synchronous, and may not be used in an interrupt context.
937 * Returns the number of bytes received on success, or else the status code
938 * returned by the underlying usb_control_msg() call.
940 int usb_get_status(struct usb_device
*dev
, int type
, int target
, void *data
)
943 u16
*status
= kmalloc(sizeof(*status
), GFP_KERNEL
);
948 ret
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
949 USB_REQ_GET_STATUS
, USB_DIR_IN
| type
, 0, target
, status
,
950 sizeof(*status
), USB_CTRL_GET_TIMEOUT
);
952 *(u16
*)data
= *status
;
956 EXPORT_SYMBOL_GPL(usb_get_status
);
959 * usb_clear_halt - tells device to clear endpoint halt/stall condition
960 * @dev: device whose endpoint is halted
961 * @pipe: endpoint "pipe" being cleared
962 * Context: !in_interrupt ()
964 * This is used to clear halt conditions for bulk and interrupt endpoints,
965 * as reported by URB completion status. Endpoints that are halted are
966 * sometimes referred to as being "stalled". Such endpoints are unable
967 * to transmit or receive data until the halt status is cleared. Any URBs
968 * queued for such an endpoint should normally be unlinked by the driver
969 * before clearing the halt condition, as described in sections 5.7.5
970 * and 5.8.5 of the USB 2.0 spec.
972 * Note that control and isochronous endpoints don't halt, although control
973 * endpoints report "protocol stall" (for unsupported requests) using the
974 * same status code used to report a true stall.
976 * This call is synchronous, and may not be used in an interrupt context.
978 * Returns zero on success, or else the status code returned by the
979 * underlying usb_control_msg() call.
981 int usb_clear_halt(struct usb_device
*dev
, int pipe
)
984 int endp
= usb_pipeendpoint(pipe
);
986 if (usb_pipein(pipe
))
989 /* we don't care if it wasn't halted first. in fact some devices
990 * (like some ibmcam model 1 units) seem to expect hosts to make
991 * this request for iso endpoints, which can't halt!
993 result
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
994 USB_REQ_CLEAR_FEATURE
, USB_RECIP_ENDPOINT
,
995 USB_ENDPOINT_HALT
, endp
, NULL
, 0,
996 USB_CTRL_SET_TIMEOUT
);
998 /* don't un-halt or force to DATA0 except on success */
1002 /* NOTE: seems like Microsoft and Apple don't bother verifying
1003 * the clear "took", so some devices could lock up if you check...
1004 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1006 * NOTE: make sure the logic here doesn't diverge much from
1007 * the copy in usb-storage, for as long as we need two copies.
1010 usb_reset_endpoint(dev
, endp
);
1014 EXPORT_SYMBOL_GPL(usb_clear_halt
);
1016 static int create_intf_ep_devs(struct usb_interface
*intf
)
1018 struct usb_device
*udev
= interface_to_usbdev(intf
);
1019 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1022 if (intf
->ep_devs_created
|| intf
->unregistering
)
1025 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1026 (void) usb_create_ep_devs(&intf
->dev
, &alt
->endpoint
[i
], udev
);
1027 intf
->ep_devs_created
= 1;
1031 static void remove_intf_ep_devs(struct usb_interface
*intf
)
1033 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1036 if (!intf
->ep_devs_created
)
1039 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1040 usb_remove_ep_devs(&alt
->endpoint
[i
]);
1041 intf
->ep_devs_created
= 0;
1045 * usb_disable_endpoint -- Disable an endpoint by address
1046 * @dev: the device whose endpoint is being disabled
1047 * @epaddr: the endpoint's address. Endpoint number for output,
1048 * endpoint number + USB_DIR_IN for input
1049 * @reset_hardware: flag to erase any endpoint state stored in the
1050 * controller hardware
1052 * Disables the endpoint for URB submission and nukes all pending URBs.
1053 * If @reset_hardware is set then also deallocates hcd/hardware state
1056 void usb_disable_endpoint(struct usb_device
*dev
, unsigned int epaddr
,
1057 bool reset_hardware
)
1059 unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
1060 struct usb_host_endpoint
*ep
;
1065 if (usb_endpoint_out(epaddr
)) {
1066 ep
= dev
->ep_out
[epnum
];
1068 dev
->ep_out
[epnum
] = NULL
;
1070 ep
= dev
->ep_in
[epnum
];
1072 dev
->ep_in
[epnum
] = NULL
;
1076 usb_hcd_flush_endpoint(dev
, ep
);
1078 usb_hcd_disable_endpoint(dev
, ep
);
1083 * usb_reset_endpoint - Reset an endpoint's state.
1084 * @dev: the device whose endpoint is to be reset
1085 * @epaddr: the endpoint's address. Endpoint number for output,
1086 * endpoint number + USB_DIR_IN for input
1088 * Resets any host-side endpoint state such as the toggle bit,
1089 * sequence number or current window.
1091 void usb_reset_endpoint(struct usb_device
*dev
, unsigned int epaddr
)
1093 unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
1094 struct usb_host_endpoint
*ep
;
1096 if (usb_endpoint_out(epaddr
))
1097 ep
= dev
->ep_out
[epnum
];
1099 ep
= dev
->ep_in
[epnum
];
1101 usb_hcd_reset_endpoint(dev
, ep
);
1103 EXPORT_SYMBOL_GPL(usb_reset_endpoint
);
1107 * usb_disable_interface -- Disable all endpoints for an interface
1108 * @dev: the device whose interface is being disabled
1109 * @intf: pointer to the interface descriptor
1110 * @reset_hardware: flag to erase any endpoint state stored in the
1111 * controller hardware
1113 * Disables all the endpoints for the interface's current altsetting.
1115 void usb_disable_interface(struct usb_device
*dev
, struct usb_interface
*intf
,
1116 bool reset_hardware
)
1118 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1121 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
) {
1122 usb_disable_endpoint(dev
,
1123 alt
->endpoint
[i
].desc
.bEndpointAddress
,
1129 * usb_disable_device - Disable all the endpoints for a USB device
1130 * @dev: the device whose endpoints are being disabled
1131 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1133 * Disables all the device's endpoints, potentially including endpoint 0.
1134 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1135 * pending urbs) and usbcore state for the interfaces, so that usbcore
1136 * must usb_set_configuration() before any interfaces could be used.
1138 void usb_disable_device(struct usb_device
*dev
, int skip_ep0
)
1141 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1143 /* getting rid of interfaces will disconnect
1144 * any drivers bound to them (a key side effect)
1146 if (dev
->actconfig
) {
1148 * FIXME: In order to avoid self-deadlock involving the
1149 * bandwidth_mutex, we have to mark all the interfaces
1150 * before unregistering any of them.
1152 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++)
1153 dev
->actconfig
->interface
[i
]->unregistering
= 1;
1155 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1156 struct usb_interface
*interface
;
1158 /* remove this interface if it has been registered */
1159 interface
= dev
->actconfig
->interface
[i
];
1160 if (!device_is_registered(&interface
->dev
))
1162 dev_dbg(&dev
->dev
, "unregistering interface %s\n",
1163 dev_name(&interface
->dev
));
1164 remove_intf_ep_devs(interface
);
1165 device_del(&interface
->dev
);
1168 /* Now that the interfaces are unbound, nobody should
1169 * try to access them.
1171 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1172 put_device(&dev
->actconfig
->interface
[i
]->dev
);
1173 dev
->actconfig
->interface
[i
] = NULL
;
1175 usb_unlocked_disable_lpm(dev
);
1176 usb_disable_ltm(dev
);
1177 dev
->actconfig
= NULL
;
1178 if (dev
->state
== USB_STATE_CONFIGURED
)
1179 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1182 dev_dbg(&dev
->dev
, "%s nuking %s URBs\n", __func__
,
1183 skip_ep0
? "non-ep0" : "all");
1184 if (hcd
->driver
->check_bandwidth
) {
1185 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1186 for (i
= skip_ep0
; i
< 16; ++i
) {
1187 usb_disable_endpoint(dev
, i
, false);
1188 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, false);
1190 /* Remove endpoints from the host controller internal state */
1191 mutex_lock(hcd
->bandwidth_mutex
);
1192 usb_hcd_alloc_bandwidth(dev
, NULL
, NULL
, NULL
);
1193 mutex_unlock(hcd
->bandwidth_mutex
);
1194 /* Second pass: remove endpoint pointers */
1196 for (i
= skip_ep0
; i
< 16; ++i
) {
1197 usb_disable_endpoint(dev
, i
, true);
1198 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, true);
1203 * usb_enable_endpoint - Enable an endpoint for USB communications
1204 * @dev: the device whose interface is being enabled
1206 * @reset_ep: flag to reset the endpoint state
1208 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1209 * For control endpoints, both the input and output sides are handled.
1211 void usb_enable_endpoint(struct usb_device
*dev
, struct usb_host_endpoint
*ep
,
1214 int epnum
= usb_endpoint_num(&ep
->desc
);
1215 int is_out
= usb_endpoint_dir_out(&ep
->desc
);
1216 int is_control
= usb_endpoint_xfer_control(&ep
->desc
);
1219 usb_hcd_reset_endpoint(dev
, ep
);
1220 if (is_out
|| is_control
)
1221 dev
->ep_out
[epnum
] = ep
;
1222 if (!is_out
|| is_control
)
1223 dev
->ep_in
[epnum
] = ep
;
1228 * usb_enable_interface - Enable all the endpoints for an interface
1229 * @dev: the device whose interface is being enabled
1230 * @intf: pointer to the interface descriptor
1231 * @reset_eps: flag to reset the endpoints' state
1233 * Enables all the endpoints for the interface's current altsetting.
1235 void usb_enable_interface(struct usb_device
*dev
,
1236 struct usb_interface
*intf
, bool reset_eps
)
1238 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1241 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1242 usb_enable_endpoint(dev
, &alt
->endpoint
[i
], reset_eps
);
1246 * usb_set_interface - Makes a particular alternate setting be current
1247 * @dev: the device whose interface is being updated
1248 * @interface: the interface being updated
1249 * @alternate: the setting being chosen.
1250 * Context: !in_interrupt ()
1252 * This is used to enable data transfers on interfaces that may not
1253 * be enabled by default. Not all devices support such configurability.
1254 * Only the driver bound to an interface may change its setting.
1256 * Within any given configuration, each interface may have several
1257 * alternative settings. These are often used to control levels of
1258 * bandwidth consumption. For example, the default setting for a high
1259 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1260 * while interrupt transfers of up to 3KBytes per microframe are legal.
1261 * Also, isochronous endpoints may never be part of an
1262 * interface's default setting. To access such bandwidth, alternate
1263 * interface settings must be made current.
1265 * Note that in the Linux USB subsystem, bandwidth associated with
1266 * an endpoint in a given alternate setting is not reserved until an URB
1267 * is submitted that needs that bandwidth. Some other operating systems
1268 * allocate bandwidth early, when a configuration is chosen.
1270 * This call is synchronous, and may not be used in an interrupt context.
1271 * Also, drivers must not change altsettings while urbs are scheduled for
1272 * endpoints in that interface; all such urbs must first be completed
1273 * (perhaps forced by unlinking).
1275 * Returns zero on success, or else the status code returned by the
1276 * underlying usb_control_msg() call.
1278 int usb_set_interface(struct usb_device
*dev
, int interface
, int alternate
)
1280 struct usb_interface
*iface
;
1281 struct usb_host_interface
*alt
;
1282 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1285 unsigned int epaddr
;
1288 if (dev
->state
== USB_STATE_SUSPENDED
)
1289 return -EHOSTUNREACH
;
1291 iface
= usb_ifnum_to_if(dev
, interface
);
1293 dev_dbg(&dev
->dev
, "selecting invalid interface %d\n",
1297 if (iface
->unregistering
)
1300 alt
= usb_altnum_to_altsetting(iface
, alternate
);
1302 dev_warn(&dev
->dev
, "selecting invalid altsetting %d\n",
1307 /* Make sure we have enough bandwidth for this alternate interface.
1308 * Remove the current alt setting and add the new alt setting.
1310 mutex_lock(hcd
->bandwidth_mutex
);
1311 /* Disable LPM, and re-enable it once the new alt setting is installed,
1312 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1314 if (usb_disable_lpm(dev
)) {
1315 dev_err(&iface
->dev
, "%s Failed to disable LPM\n.", __func__
);
1316 mutex_unlock(hcd
->bandwidth_mutex
);
1319 ret
= usb_hcd_alloc_bandwidth(dev
, NULL
, iface
->cur_altsetting
, alt
);
1321 dev_info(&dev
->dev
, "Not enough bandwidth for altsetting %d\n",
1323 usb_enable_lpm(dev
);
1324 mutex_unlock(hcd
->bandwidth_mutex
);
1328 if (dev
->quirks
& USB_QUIRK_NO_SET_INTF
)
1331 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1332 USB_REQ_SET_INTERFACE
, USB_RECIP_INTERFACE
,
1333 alternate
, interface
, NULL
, 0, 5000);
1335 /* 9.4.10 says devices don't need this and are free to STALL the
1336 * request if the interface only has one alternate setting.
1338 if (ret
== -EPIPE
&& iface
->num_altsetting
== 1) {
1340 "manual set_interface for iface %d, alt %d\n",
1341 interface
, alternate
);
1343 } else if (ret
< 0) {
1344 /* Re-instate the old alt setting */
1345 usb_hcd_alloc_bandwidth(dev
, NULL
, alt
, iface
->cur_altsetting
);
1346 usb_enable_lpm(dev
);
1347 mutex_unlock(hcd
->bandwidth_mutex
);
1350 mutex_unlock(hcd
->bandwidth_mutex
);
1352 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1353 * when they implement async or easily-killable versions of this or
1354 * other "should-be-internal" functions (like clear_halt).
1355 * should hcd+usbcore postprocess control requests?
1358 /* prevent submissions using previous endpoint settings */
1359 if (iface
->cur_altsetting
!= alt
) {
1360 remove_intf_ep_devs(iface
);
1361 usb_remove_sysfs_intf_files(iface
);
1363 usb_disable_interface(dev
, iface
, true);
1365 iface
->cur_altsetting
= alt
;
1367 /* Now that the interface is installed, re-enable LPM. */
1368 usb_unlocked_enable_lpm(dev
);
1370 /* If the interface only has one altsetting and the device didn't
1371 * accept the request, we attempt to carry out the equivalent action
1372 * by manually clearing the HALT feature for each endpoint in the
1378 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; i
++) {
1379 epaddr
= alt
->endpoint
[i
].desc
.bEndpointAddress
;
1380 pipe
= __create_pipe(dev
,
1381 USB_ENDPOINT_NUMBER_MASK
& epaddr
) |
1382 (usb_endpoint_out(epaddr
) ?
1383 USB_DIR_OUT
: USB_DIR_IN
);
1385 usb_clear_halt(dev
, pipe
);
1389 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1392 * Despite EP0 is always present in all interfaces/AS, the list of
1393 * endpoints from the descriptor does not contain EP0. Due to its
1394 * omnipresence one might expect EP0 being considered "affected" by
1395 * any SetInterface request and hence assume toggles need to be reset.
1396 * However, EP0 toggles are re-synced for every individual transfer
1397 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1398 * (Likewise, EP0 never "halts" on well designed devices.)
1400 usb_enable_interface(dev
, iface
, true);
1401 if (device_is_registered(&iface
->dev
)) {
1402 usb_create_sysfs_intf_files(iface
);
1403 create_intf_ep_devs(iface
);
1407 EXPORT_SYMBOL_GPL(usb_set_interface
);
1410 * usb_reset_configuration - lightweight device reset
1411 * @dev: the device whose configuration is being reset
1413 * This issues a standard SET_CONFIGURATION request to the device using
1414 * the current configuration. The effect is to reset most USB-related
1415 * state in the device, including interface altsettings (reset to zero),
1416 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1417 * endpoints). Other usbcore state is unchanged, including bindings of
1418 * usb device drivers to interfaces.
1420 * Because this affects multiple interfaces, avoid using this with composite
1421 * (multi-interface) devices. Instead, the driver for each interface may
1422 * use usb_set_interface() on the interfaces it claims. Be careful though;
1423 * some devices don't support the SET_INTERFACE request, and others won't
1424 * reset all the interface state (notably endpoint state). Resetting the whole
1425 * configuration would affect other drivers' interfaces.
1427 * The caller must own the device lock.
1429 * Returns zero on success, else a negative error code.
1431 int usb_reset_configuration(struct usb_device
*dev
)
1434 struct usb_host_config
*config
;
1435 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1437 if (dev
->state
== USB_STATE_SUSPENDED
)
1438 return -EHOSTUNREACH
;
1440 /* caller must have locked the device and must own
1441 * the usb bus readlock (so driver bindings are stable);
1442 * calls during probe() are fine
1445 for (i
= 1; i
< 16; ++i
) {
1446 usb_disable_endpoint(dev
, i
, true);
1447 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, true);
1450 config
= dev
->actconfig
;
1452 mutex_lock(hcd
->bandwidth_mutex
);
1453 /* Disable LPM, and re-enable it once the configuration is reset, so
1454 * that the xHCI driver can recalculate the U1/U2 timeouts.
1456 if (usb_disable_lpm(dev
)) {
1457 dev_err(&dev
->dev
, "%s Failed to disable LPM\n.", __func__
);
1458 mutex_unlock(hcd
->bandwidth_mutex
);
1461 /* Make sure we have enough bandwidth for each alternate setting 0 */
1462 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
1463 struct usb_interface
*intf
= config
->interface
[i
];
1464 struct usb_host_interface
*alt
;
1466 alt
= usb_altnum_to_altsetting(intf
, 0);
1468 alt
= &intf
->altsetting
[0];
1469 if (alt
!= intf
->cur_altsetting
)
1470 retval
= usb_hcd_alloc_bandwidth(dev
, NULL
,
1471 intf
->cur_altsetting
, alt
);
1475 /* If not, reinstate the old alternate settings */
1478 for (i
--; i
>= 0; i
--) {
1479 struct usb_interface
*intf
= config
->interface
[i
];
1480 struct usb_host_interface
*alt
;
1482 alt
= usb_altnum_to_altsetting(intf
, 0);
1484 alt
= &intf
->altsetting
[0];
1485 if (alt
!= intf
->cur_altsetting
)
1486 usb_hcd_alloc_bandwidth(dev
, NULL
,
1487 alt
, intf
->cur_altsetting
);
1489 usb_enable_lpm(dev
);
1490 mutex_unlock(hcd
->bandwidth_mutex
);
1493 retval
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1494 USB_REQ_SET_CONFIGURATION
, 0,
1495 config
->desc
.bConfigurationValue
, 0,
1496 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1498 goto reset_old_alts
;
1499 mutex_unlock(hcd
->bandwidth_mutex
);
1501 /* re-init hc/hcd interface/endpoint state */
1502 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
1503 struct usb_interface
*intf
= config
->interface
[i
];
1504 struct usb_host_interface
*alt
;
1506 alt
= usb_altnum_to_altsetting(intf
, 0);
1508 /* No altsetting 0? We'll assume the first altsetting.
1509 * We could use a GetInterface call, but if a device is
1510 * so non-compliant that it doesn't have altsetting 0
1511 * then I wouldn't trust its reply anyway.
1514 alt
= &intf
->altsetting
[0];
1516 if (alt
!= intf
->cur_altsetting
) {
1517 remove_intf_ep_devs(intf
);
1518 usb_remove_sysfs_intf_files(intf
);
1520 intf
->cur_altsetting
= alt
;
1521 usb_enable_interface(dev
, intf
, true);
1522 if (device_is_registered(&intf
->dev
)) {
1523 usb_create_sysfs_intf_files(intf
);
1524 create_intf_ep_devs(intf
);
1527 /* Now that the interfaces are installed, re-enable LPM. */
1528 usb_unlocked_enable_lpm(dev
);
1531 EXPORT_SYMBOL_GPL(usb_reset_configuration
);
1533 static void usb_release_interface(struct device
*dev
)
1535 struct usb_interface
*intf
= to_usb_interface(dev
);
1536 struct usb_interface_cache
*intfc
=
1537 altsetting_to_usb_interface_cache(intf
->altsetting
);
1539 kref_put(&intfc
->ref
, usb_release_interface_cache
);
1543 static int usb_if_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1545 struct usb_device
*usb_dev
;
1546 struct usb_interface
*intf
;
1547 struct usb_host_interface
*alt
;
1549 intf
= to_usb_interface(dev
);
1550 usb_dev
= interface_to_usbdev(intf
);
1551 alt
= intf
->cur_altsetting
;
1553 if (add_uevent_var(env
, "INTERFACE=%d/%d/%d",
1554 alt
->desc
.bInterfaceClass
,
1555 alt
->desc
.bInterfaceSubClass
,
1556 alt
->desc
.bInterfaceProtocol
))
1559 if (add_uevent_var(env
,
1561 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1562 le16_to_cpu(usb_dev
->descriptor
.idVendor
),
1563 le16_to_cpu(usb_dev
->descriptor
.idProduct
),
1564 le16_to_cpu(usb_dev
->descriptor
.bcdDevice
),
1565 usb_dev
->descriptor
.bDeviceClass
,
1566 usb_dev
->descriptor
.bDeviceSubClass
,
1567 usb_dev
->descriptor
.bDeviceProtocol
,
1568 alt
->desc
.bInterfaceClass
,
1569 alt
->desc
.bInterfaceSubClass
,
1570 alt
->desc
.bInterfaceProtocol
,
1571 alt
->desc
.bInterfaceNumber
))
1577 struct device_type usb_if_device_type
= {
1578 .name
= "usb_interface",
1579 .release
= usb_release_interface
,
1580 .uevent
= usb_if_uevent
,
1583 static struct usb_interface_assoc_descriptor
*find_iad(struct usb_device
*dev
,
1584 struct usb_host_config
*config
,
1587 struct usb_interface_assoc_descriptor
*retval
= NULL
;
1588 struct usb_interface_assoc_descriptor
*intf_assoc
;
1593 for (i
= 0; (i
< USB_MAXIADS
&& config
->intf_assoc
[i
]); i
++) {
1594 intf_assoc
= config
->intf_assoc
[i
];
1595 if (intf_assoc
->bInterfaceCount
== 0)
1598 first_intf
= intf_assoc
->bFirstInterface
;
1599 last_intf
= first_intf
+ (intf_assoc
->bInterfaceCount
- 1);
1600 if (inum
>= first_intf
&& inum
<= last_intf
) {
1602 retval
= intf_assoc
;
1604 dev_err(&dev
->dev
, "Interface #%d referenced"
1605 " by multiple IADs\n", inum
);
1614 * Internal function to queue a device reset
1616 * This is initialized into the workstruct in 'struct
1617 * usb_device->reset_ws' that is launched by
1618 * message.c:usb_set_configuration() when initializing each 'struct
1621 * It is safe to get the USB device without reference counts because
1622 * the life cycle of @iface is bound to the life cycle of @udev. Then,
1623 * this function will be ran only if @iface is alive (and before
1624 * freeing it any scheduled instances of it will have been cancelled).
1626 * We need to set a flag (usb_dev->reset_running) because when we call
1627 * the reset, the interfaces might be unbound. The current interface
1628 * cannot try to remove the queued work as it would cause a deadlock
1629 * (you cannot remove your work from within your executing
1630 * workqueue). This flag lets it know, so that
1631 * usb_cancel_queued_reset() doesn't try to do it.
1633 * See usb_queue_reset_device() for more details
1635 static void __usb_queue_reset_device(struct work_struct
*ws
)
1638 struct usb_interface
*iface
=
1639 container_of(ws
, struct usb_interface
, reset_ws
);
1640 struct usb_device
*udev
= interface_to_usbdev(iface
);
1642 rc
= usb_lock_device_for_reset(udev
, iface
);
1644 iface
->reset_running
= 1;
1645 usb_reset_device(udev
);
1646 iface
->reset_running
= 0;
1647 usb_unlock_device(udev
);
1653 * usb_set_configuration - Makes a particular device setting be current
1654 * @dev: the device whose configuration is being updated
1655 * @configuration: the configuration being chosen.
1656 * Context: !in_interrupt(), caller owns the device lock
1658 * This is used to enable non-default device modes. Not all devices
1659 * use this kind of configurability; many devices only have one
1662 * @configuration is the value of the configuration to be installed.
1663 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1664 * must be non-zero; a value of zero indicates that the device in
1665 * unconfigured. However some devices erroneously use 0 as one of their
1666 * configuration values. To help manage such devices, this routine will
1667 * accept @configuration = -1 as indicating the device should be put in
1668 * an unconfigured state.
1670 * USB device configurations may affect Linux interoperability,
1671 * power consumption and the functionality available. For example,
1672 * the default configuration is limited to using 100mA of bus power,
1673 * so that when certain device functionality requires more power,
1674 * and the device is bus powered, that functionality should be in some
1675 * non-default device configuration. Other device modes may also be
1676 * reflected as configuration options, such as whether two ISDN
1677 * channels are available independently; and choosing between open
1678 * standard device protocols (like CDC) or proprietary ones.
1680 * Note that a non-authorized device (dev->authorized == 0) will only
1681 * be put in unconfigured mode.
1683 * Note that USB has an additional level of device configurability,
1684 * associated with interfaces. That configurability is accessed using
1685 * usb_set_interface().
1687 * This call is synchronous. The calling context must be able to sleep,
1688 * must own the device lock, and must not hold the driver model's USB
1689 * bus mutex; usb interface driver probe() methods cannot use this routine.
1691 * Returns zero on success, or else the status code returned by the
1692 * underlying call that failed. On successful completion, each interface
1693 * in the original device configuration has been destroyed, and each one
1694 * in the new configuration has been probed by all relevant usb device
1695 * drivers currently known to the kernel.
1697 int usb_set_configuration(struct usb_device
*dev
, int configuration
)
1700 struct usb_host_config
*cp
= NULL
;
1701 struct usb_interface
**new_interfaces
= NULL
;
1702 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1705 if (dev
->authorized
== 0 || configuration
== -1)
1708 for (i
= 0; i
< dev
->descriptor
.bNumConfigurations
; i
++) {
1709 if (dev
->config
[i
].desc
.bConfigurationValue
==
1711 cp
= &dev
->config
[i
];
1716 if ((!cp
&& configuration
!= 0))
1719 /* The USB spec says configuration 0 means unconfigured.
1720 * But if a device includes a configuration numbered 0,
1721 * we will accept it as a correctly configured state.
1722 * Use -1 if you really want to unconfigure the device.
1724 if (cp
&& configuration
== 0)
1725 dev_warn(&dev
->dev
, "config 0 descriptor??\n");
1727 /* Allocate memory for new interfaces before doing anything else,
1728 * so that if we run out then nothing will have changed. */
1731 nintf
= cp
->desc
.bNumInterfaces
;
1732 new_interfaces
= kmalloc(nintf
* sizeof(*new_interfaces
),
1734 if (!new_interfaces
) {
1735 dev_err(&dev
->dev
, "Out of memory\n");
1739 for (; n
< nintf
; ++n
) {
1740 new_interfaces
[n
] = kzalloc(
1741 sizeof(struct usb_interface
),
1743 if (!new_interfaces
[n
]) {
1744 dev_err(&dev
->dev
, "Out of memory\n");
1748 kfree(new_interfaces
[n
]);
1749 kfree(new_interfaces
);
1754 i
= dev
->bus_mA
- usb_get_max_power(dev
, cp
);
1756 dev_warn(&dev
->dev
, "new config #%d exceeds power "
1761 /* Wake up the device so we can send it the Set-Config request */
1762 ret
= usb_autoresume_device(dev
);
1764 goto free_interfaces
;
1766 /* if it's already configured, clear out old state first.
1767 * getting rid of old interfaces means unbinding their drivers.
1769 if (dev
->state
!= USB_STATE_ADDRESS
)
1770 usb_disable_device(dev
, 1); /* Skip ep0 */
1772 /* Get rid of pending async Set-Config requests for this device */
1773 cancel_async_set_config(dev
);
1775 /* Make sure we have bandwidth (and available HCD resources) for this
1776 * configuration. Remove endpoints from the schedule if we're dropping
1777 * this configuration to set configuration 0. After this point, the
1778 * host controller will not allow submissions to dropped endpoints. If
1779 * this call fails, the device state is unchanged.
1781 mutex_lock(hcd
->bandwidth_mutex
);
1782 /* Disable LPM, and re-enable it once the new configuration is
1783 * installed, so that the xHCI driver can recalculate the U1/U2
1786 if (dev
->actconfig
&& usb_disable_lpm(dev
)) {
1787 dev_err(&dev
->dev
, "%s Failed to disable LPM\n.", __func__
);
1788 mutex_unlock(hcd
->bandwidth_mutex
);
1790 goto free_interfaces
;
1792 ret
= usb_hcd_alloc_bandwidth(dev
, cp
, NULL
, NULL
);
1795 usb_enable_lpm(dev
);
1796 mutex_unlock(hcd
->bandwidth_mutex
);
1797 usb_autosuspend_device(dev
);
1798 goto free_interfaces
;
1802 * Initialize the new interface structures and the
1803 * hc/hcd/usbcore interface/endpoint state.
1805 for (i
= 0; i
< nintf
; ++i
) {
1806 struct usb_interface_cache
*intfc
;
1807 struct usb_interface
*intf
;
1808 struct usb_host_interface
*alt
;
1810 cp
->interface
[i
] = intf
= new_interfaces
[i
];
1811 intfc
= cp
->intf_cache
[i
];
1812 intf
->altsetting
= intfc
->altsetting
;
1813 intf
->num_altsetting
= intfc
->num_altsetting
;
1814 kref_get(&intfc
->ref
);
1816 alt
= usb_altnum_to_altsetting(intf
, 0);
1818 /* No altsetting 0? We'll assume the first altsetting.
1819 * We could use a GetInterface call, but if a device is
1820 * so non-compliant that it doesn't have altsetting 0
1821 * then I wouldn't trust its reply anyway.
1824 alt
= &intf
->altsetting
[0];
1827 find_iad(dev
, cp
, alt
->desc
.bInterfaceNumber
);
1828 intf
->cur_altsetting
= alt
;
1829 usb_enable_interface(dev
, intf
, true);
1830 intf
->dev
.parent
= &dev
->dev
;
1831 intf
->dev
.driver
= NULL
;
1832 intf
->dev
.bus
= &usb_bus_type
;
1833 intf
->dev
.type
= &usb_if_device_type
;
1834 intf
->dev
.groups
= usb_interface_groups
;
1835 intf
->dev
.dma_mask
= dev
->dev
.dma_mask
;
1836 INIT_WORK(&intf
->reset_ws
, __usb_queue_reset_device
);
1838 device_initialize(&intf
->dev
);
1839 pm_runtime_no_callbacks(&intf
->dev
);
1840 dev_set_name(&intf
->dev
, "%d-%s:%d.%d",
1841 dev
->bus
->busnum
, dev
->devpath
,
1842 configuration
, alt
->desc
.bInterfaceNumber
);
1844 kfree(new_interfaces
);
1846 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1847 USB_REQ_SET_CONFIGURATION
, 0, configuration
, 0,
1848 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1849 if (ret
< 0 && cp
) {
1851 * All the old state is gone, so what else can we do?
1852 * The device is probably useless now anyway.
1854 usb_hcd_alloc_bandwidth(dev
, NULL
, NULL
, NULL
);
1855 for (i
= 0; i
< nintf
; ++i
) {
1856 usb_disable_interface(dev
, cp
->interface
[i
], true);
1857 put_device(&cp
->interface
[i
]->dev
);
1858 cp
->interface
[i
] = NULL
;
1863 dev
->actconfig
= cp
;
1864 mutex_unlock(hcd
->bandwidth_mutex
);
1867 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1869 /* Leave LPM disabled while the device is unconfigured. */
1870 usb_autosuspend_device(dev
);
1873 usb_set_device_state(dev
, USB_STATE_CONFIGURED
);
1875 if (cp
->string
== NULL
&&
1876 !(dev
->quirks
& USB_QUIRK_CONFIG_INTF_STRINGS
))
1877 cp
->string
= usb_cache_string(dev
, cp
->desc
.iConfiguration
);
1879 /* Now that the interfaces are installed, re-enable LPM. */
1880 usb_unlocked_enable_lpm(dev
);
1881 /* Enable LTM if it was turned off by usb_disable_device. */
1882 usb_enable_ltm(dev
);
1884 /* Now that all the interfaces are set up, register them
1885 * to trigger binding of drivers to interfaces. probe()
1886 * routines may install different altsettings and may
1887 * claim() any interfaces not yet bound. Many class drivers
1888 * need that: CDC, audio, video, etc.
1890 for (i
= 0; i
< nintf
; ++i
) {
1891 struct usb_interface
*intf
= cp
->interface
[i
];
1894 "adding %s (config #%d, interface %d)\n",
1895 dev_name(&intf
->dev
), configuration
,
1896 intf
->cur_altsetting
->desc
.bInterfaceNumber
);
1897 device_enable_async_suspend(&intf
->dev
);
1898 ret
= device_add(&intf
->dev
);
1900 dev_err(&dev
->dev
, "device_add(%s) --> %d\n",
1901 dev_name(&intf
->dev
), ret
);
1904 create_intf_ep_devs(intf
);
1907 usb_autosuspend_device(dev
);
1911 static LIST_HEAD(set_config_list
);
1912 static DEFINE_SPINLOCK(set_config_lock
);
1914 struct set_config_request
{
1915 struct usb_device
*udev
;
1917 struct work_struct work
;
1918 struct list_head node
;
1921 /* Worker routine for usb_driver_set_configuration() */
1922 static void driver_set_config_work(struct work_struct
*work
)
1924 struct set_config_request
*req
=
1925 container_of(work
, struct set_config_request
, work
);
1926 struct usb_device
*udev
= req
->udev
;
1928 usb_lock_device(udev
);
1929 spin_lock(&set_config_lock
);
1930 list_del(&req
->node
);
1931 spin_unlock(&set_config_lock
);
1933 if (req
->config
>= -1) /* Is req still valid? */
1934 usb_set_configuration(udev
, req
->config
);
1935 usb_unlock_device(udev
);
1940 /* Cancel pending Set-Config requests for a device whose configuration
1943 static void cancel_async_set_config(struct usb_device
*udev
)
1945 struct set_config_request
*req
;
1947 spin_lock(&set_config_lock
);
1948 list_for_each_entry(req
, &set_config_list
, node
) {
1949 if (req
->udev
== udev
)
1950 req
->config
= -999; /* Mark as cancelled */
1952 spin_unlock(&set_config_lock
);
1956 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
1957 * @udev: the device whose configuration is being updated
1958 * @config: the configuration being chosen.
1959 * Context: In process context, must be able to sleep
1961 * Device interface drivers are not allowed to change device configurations.
1962 * This is because changing configurations will destroy the interface the
1963 * driver is bound to and create new ones; it would be like a floppy-disk
1964 * driver telling the computer to replace the floppy-disk drive with a
1967 * Still, in certain specialized circumstances the need may arise. This
1968 * routine gets around the normal restrictions by using a work thread to
1969 * submit the change-config request.
1971 * Returns 0 if the request was successfully queued, error code otherwise.
1972 * The caller has no way to know whether the queued request will eventually
1975 int usb_driver_set_configuration(struct usb_device
*udev
, int config
)
1977 struct set_config_request
*req
;
1979 req
= kmalloc(sizeof(*req
), GFP_KERNEL
);
1983 req
->config
= config
;
1984 INIT_WORK(&req
->work
, driver_set_config_work
);
1986 spin_lock(&set_config_lock
);
1987 list_add(&req
->node
, &set_config_list
);
1988 spin_unlock(&set_config_lock
);
1991 schedule_work(&req
->work
);
1994 EXPORT_SYMBOL_GPL(usb_driver_set_configuration
);