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 * Don't use this function from within an interrupt context, like a bottom half
123 * handler. If you need an asynchronous message, or need to send a message
124 * from within interrupt context, use usb_submit_urb().
125 * If a thread in your driver uses this call, make sure your disconnect()
126 * method can wait for it to complete. Since you don't have a handle on the
127 * URB used, you can't cancel the request.
129 * Return: If successful, the number of bytes transferred. Otherwise, a negative
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 * Don't use this function from within an interrupt context, like a bottom half
174 * handler. If you need an asynchronous message, or need to send a message
175 * from within interrupt context, use usb_submit_urb() If a thread in your
176 * driver uses this call, make sure your disconnect() method can wait for it to
177 * complete. Since you don't have a handle on the URB used, you can't cancel
181 * If successful, 0. Otherwise a negative error number. The number of actual
182 * bytes transferred will be stored in the @actual_length parameter.
184 int usb_interrupt_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
185 void *data
, int len
, int *actual_length
, int timeout
)
187 return usb_bulk_msg(usb_dev
, pipe
, data
, len
, actual_length
, timeout
);
189 EXPORT_SYMBOL_GPL(usb_interrupt_msg
);
192 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
193 * @usb_dev: pointer to the usb device to send the message to
194 * @pipe: endpoint "pipe" to send the message to
195 * @data: pointer to the data to send
196 * @len: length in bytes of the data to send
197 * @actual_length: pointer to a location to put the actual length transferred
199 * @timeout: time in msecs to wait for the message to complete before
200 * timing out (if 0 the wait is forever)
202 * Context: !in_interrupt ()
204 * This function sends a simple bulk message to a specified endpoint
205 * and waits for the message to complete, or timeout.
207 * Don't use this function from within an interrupt context, like a bottom half
208 * handler. If you need an asynchronous message, or need to send a message
209 * from within interrupt context, use usb_submit_urb() If a thread in your
210 * driver uses this call, make sure your disconnect() method can wait for it to
211 * complete. Since you don't have a handle on the URB used, you can't cancel
214 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
215 * users are forced to abuse this routine by using it to submit URBs for
216 * interrupt endpoints. We will take the liberty of creating an interrupt URB
217 * (with the default interval) if the target is an interrupt endpoint.
220 * If successful, 0. Otherwise a negative error number. The number of actual
221 * bytes transferred will be stored in the @actual_length paramater.
224 int usb_bulk_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
225 void *data
, int len
, int *actual_length
, int timeout
)
228 struct usb_host_endpoint
*ep
;
230 ep
= usb_pipe_endpoint(usb_dev
, pipe
);
234 urb
= usb_alloc_urb(0, GFP_KERNEL
);
238 if ((ep
->desc
.bmAttributes
& USB_ENDPOINT_XFERTYPE_MASK
) ==
239 USB_ENDPOINT_XFER_INT
) {
240 pipe
= (pipe
& ~(3 << 30)) | (PIPE_INTERRUPT
<< 30);
241 usb_fill_int_urb(urb
, usb_dev
, pipe
, data
, len
,
242 usb_api_blocking_completion
, NULL
,
245 usb_fill_bulk_urb(urb
, usb_dev
, pipe
, data
, len
,
246 usb_api_blocking_completion
, NULL
);
248 return usb_start_wait_urb(urb
, timeout
, actual_length
);
250 EXPORT_SYMBOL_GPL(usb_bulk_msg
);
252 /*-------------------------------------------------------------------*/
254 static void sg_clean(struct usb_sg_request
*io
)
257 while (io
->entries
--)
258 usb_free_urb(io
->urbs
[io
->entries
]);
265 static void sg_complete(struct urb
*urb
)
267 struct usb_sg_request
*io
= urb
->context
;
268 int status
= urb
->status
;
270 spin_lock(&io
->lock
);
272 /* In 2.5 we require hcds' endpoint queues not to progress after fault
273 * reports, until the completion callback (this!) returns. That lets
274 * device driver code (like this routine) unlink queued urbs first,
275 * if it needs to, since the HC won't work on them at all. So it's
276 * not possible for page N+1 to overwrite page N, and so on.
278 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
279 * complete before the HCD can get requests away from hardware,
280 * though never during cleanup after a hard fault.
283 && (io
->status
!= -ECONNRESET
284 || status
!= -ECONNRESET
)
285 && urb
->actual_length
) {
286 dev_err(io
->dev
->bus
->controller
,
287 "dev %s ep%d%s scatterlist error %d/%d\n",
289 usb_endpoint_num(&urb
->ep
->desc
),
290 usb_urb_dir_in(urb
) ? "in" : "out",
295 if (io
->status
== 0 && status
&& status
!= -ECONNRESET
) {
296 int i
, found
, retval
;
300 /* the previous urbs, and this one, completed already.
301 * unlink pending urbs so they won't rx/tx bad data.
302 * careful: unlink can sometimes be synchronous...
304 spin_unlock(&io
->lock
);
305 for (i
= 0, found
= 0; i
< io
->entries
; i
++) {
306 if (!io
->urbs
[i
] || !io
->urbs
[i
]->dev
)
309 retval
= usb_unlink_urb(io
->urbs
[i
]);
310 if (retval
!= -EINPROGRESS
&&
314 dev_err(&io
->dev
->dev
,
315 "%s, unlink --> %d\n",
317 } else if (urb
== io
->urbs
[i
])
320 spin_lock(&io
->lock
);
323 /* on the last completion, signal usb_sg_wait() */
324 io
->bytes
+= urb
->actual_length
;
327 complete(&io
->complete
);
329 spin_unlock(&io
->lock
);
334 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
335 * @io: request block being initialized. until usb_sg_wait() returns,
336 * treat this as a pointer to an opaque block of memory,
337 * @dev: the usb device that will send or receive the data
338 * @pipe: endpoint "pipe" used to transfer the data
339 * @period: polling rate for interrupt endpoints, in frames or
340 * (for high speed endpoints) microframes; ignored for bulk
341 * @sg: scatterlist entries
342 * @nents: how many entries in the scatterlist
343 * @length: how many bytes to send from the scatterlist, or zero to
344 * send every byte identified in the list.
345 * @mem_flags: SLAB_* flags affecting memory allocations in this call
347 * This initializes a scatter/gather request, allocating resources such as
348 * I/O mappings and urb memory (except maybe memory used by USB controller
351 * The request must be issued using usb_sg_wait(), which waits for the I/O to
352 * complete (or to be canceled) and then cleans up all resources allocated by
355 * The request may be canceled with usb_sg_cancel(), either before or after
356 * usb_sg_wait() is called.
358 * Return: Zero for success, else a negative errno value.
360 int usb_sg_init(struct usb_sg_request
*io
, struct usb_device
*dev
,
361 unsigned pipe
, unsigned period
, struct scatterlist
*sg
,
362 int nents
, size_t length
, gfp_t mem_flags
)
368 if (!io
|| !dev
|| !sg
369 || usb_pipecontrol(pipe
)
370 || usb_pipeisoc(pipe
)
374 spin_lock_init(&io
->lock
);
378 if (dev
->bus
->sg_tablesize
> 0) {
386 /* initialize all the urbs we'll use */
387 io
->urbs
= kmalloc(io
->entries
* sizeof(*io
->urbs
), mem_flags
);
391 urb_flags
= URB_NO_INTERRUPT
;
392 if (usb_pipein(pipe
))
393 urb_flags
|= URB_SHORT_NOT_OK
;
395 for_each_sg(sg
, sg
, io
->entries
, i
) {
399 urb
= usb_alloc_urb(0, mem_flags
);
408 urb
->interval
= period
;
409 urb
->transfer_flags
= urb_flags
;
410 urb
->complete
= sg_complete
;
415 /* There is no single transfer buffer */
416 urb
->transfer_buffer
= NULL
;
417 urb
->num_sgs
= nents
;
419 /* A length of zero means transfer the whole sg list */
422 struct scatterlist
*sg2
;
425 for_each_sg(sg
, sg2
, nents
, j
)
430 * Some systems can't use DMA; they use PIO instead.
431 * For their sakes, transfer_buffer is set whenever
434 if (!PageHighMem(sg_page(sg
)))
435 urb
->transfer_buffer
= sg_virt(sg
);
437 urb
->transfer_buffer
= NULL
;
441 len
= min_t(size_t, len
, length
);
447 urb
->transfer_buffer_length
= len
;
449 io
->urbs
[--i
]->transfer_flags
&= ~URB_NO_INTERRUPT
;
451 /* transaction state */
452 io
->count
= io
->entries
;
455 init_completion(&io
->complete
);
462 EXPORT_SYMBOL_GPL(usb_sg_init
);
465 * usb_sg_wait - synchronously execute scatter/gather request
466 * @io: request block handle, as initialized with usb_sg_init().
467 * some fields become accessible when this call returns.
468 * Context: !in_interrupt ()
470 * This function blocks until the specified I/O operation completes. It
471 * leverages the grouping of the related I/O requests to get good transfer
472 * rates, by queueing the requests. At higher speeds, such queuing can
473 * significantly improve USB throughput.
475 * There are three kinds of completion for this function.
476 * (1) success, where io->status is zero. The number of io->bytes
477 * transferred is as requested.
478 * (2) error, where io->status is a negative errno value. The number
479 * of io->bytes transferred before the error is usually less
480 * than requested, and can be nonzero.
481 * (3) cancellation, a type of error with status -ECONNRESET that
482 * is initiated by usb_sg_cancel().
484 * When this function returns, all memory allocated through usb_sg_init() or
485 * this call will have been freed. The request block parameter may still be
486 * passed to usb_sg_cancel(), or it may be freed. It could also be
487 * reinitialized and then reused.
489 * Data Transfer Rates:
491 * Bulk transfers are valid for full or high speed endpoints.
492 * The best full speed data rate is 19 packets of 64 bytes each
493 * per frame, or 1216 bytes per millisecond.
494 * The best high speed data rate is 13 packets of 512 bytes each
495 * per microframe, or 52 KBytes per millisecond.
497 * The reason to use interrupt transfers through this API would most likely
498 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
499 * could be transferred. That capability is less useful for low or full
500 * speed interrupt endpoints, which allow at most one packet per millisecond,
501 * of at most 8 or 64 bytes (respectively).
503 * It is not necessary to call this function to reserve bandwidth for devices
504 * under an xHCI host controller, as the bandwidth is reserved when the
505 * configuration or interface alt setting is selected.
507 void usb_sg_wait(struct usb_sg_request
*io
)
510 int entries
= io
->entries
;
512 /* queue the urbs. */
513 spin_lock_irq(&io
->lock
);
515 while (i
< entries
&& !io
->status
) {
518 io
->urbs
[i
]->dev
= io
->dev
;
519 retval
= usb_submit_urb(io
->urbs
[i
], GFP_ATOMIC
);
521 /* after we submit, let completions or cancelations fire;
522 * we handshake using io->status.
524 spin_unlock_irq(&io
->lock
);
526 /* maybe we retrying will recover */
527 case -ENXIO
: /* hc didn't queue this one */
534 /* no error? continue immediately.
536 * NOTE: to work better with UHCI (4K I/O buffer may
537 * need 3K of TDs) it may be good to limit how many
538 * URBs are queued at once; N milliseconds?
545 /* fail any uncompleted urbs */
547 io
->urbs
[i
]->status
= retval
;
548 dev_dbg(&io
->dev
->dev
, "%s, submit --> %d\n",
552 spin_lock_irq(&io
->lock
);
553 if (retval
&& (io
->status
== 0 || io
->status
== -ECONNRESET
))
556 io
->count
-= entries
- i
;
558 complete(&io
->complete
);
559 spin_unlock_irq(&io
->lock
);
561 /* OK, yes, this could be packaged as non-blocking.
562 * So could the submit loop above ... but it's easier to
563 * solve neither problem than to solve both!
565 wait_for_completion(&io
->complete
);
569 EXPORT_SYMBOL_GPL(usb_sg_wait
);
572 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
573 * @io: request block, initialized with usb_sg_init()
575 * This stops a request after it has been started by usb_sg_wait().
576 * It can also prevents one initialized by usb_sg_init() from starting,
577 * so that call just frees resources allocated to the request.
579 void usb_sg_cancel(struct usb_sg_request
*io
)
583 spin_lock_irqsave(&io
->lock
, flags
);
585 /* shut everything down, if it didn't already */
589 io
->status
= -ECONNRESET
;
590 spin_unlock(&io
->lock
);
591 for (i
= 0; i
< io
->entries
; i
++) {
594 if (!io
->urbs
[i
]->dev
)
596 retval
= usb_unlink_urb(io
->urbs
[i
]);
597 if (retval
!= -EINPROGRESS
601 dev_warn(&io
->dev
->dev
, "%s, unlink --> %d\n",
604 spin_lock(&io
->lock
);
606 spin_unlock_irqrestore(&io
->lock
, flags
);
608 EXPORT_SYMBOL_GPL(usb_sg_cancel
);
610 /*-------------------------------------------------------------------*/
613 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
614 * @dev: the device whose descriptor is being retrieved
615 * @type: the descriptor type (USB_DT_*)
616 * @index: the number of the descriptor
617 * @buf: where to put the descriptor
618 * @size: how big is "buf"?
619 * Context: !in_interrupt ()
621 * Gets a USB descriptor. Convenience functions exist to simplify
622 * getting some types of descriptors. Use
623 * usb_get_string() or usb_string() for USB_DT_STRING.
624 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
625 * are part of the device structure.
626 * In addition to a number of USB-standard descriptors, some
627 * devices also use class-specific or vendor-specific descriptors.
629 * This call is synchronous, and may not be used in an interrupt context.
631 * Return: The number of bytes received on success, or else the status code
632 * returned by the underlying usb_control_msg() call.
634 int usb_get_descriptor(struct usb_device
*dev
, unsigned char type
,
635 unsigned char index
, void *buf
, int size
)
640 memset(buf
, 0, size
); /* Make sure we parse really received data */
642 for (i
= 0; i
< 3; ++i
) {
643 /* retry on length 0 or error; some devices are flakey */
644 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
645 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
646 (type
<< 8) + index
, 0, buf
, size
,
647 USB_CTRL_GET_TIMEOUT
);
648 if (result
<= 0 && result
!= -ETIMEDOUT
)
650 if (result
> 1 && ((u8
*)buf
)[1] != type
) {
658 EXPORT_SYMBOL_GPL(usb_get_descriptor
);
661 * usb_get_string - gets a string descriptor
662 * @dev: the device whose string descriptor is being retrieved
663 * @langid: code for language chosen (from string descriptor zero)
664 * @index: the number of the descriptor
665 * @buf: where to put the string
666 * @size: how big is "buf"?
667 * Context: !in_interrupt ()
669 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
670 * in little-endian byte order).
671 * The usb_string() function will often be a convenient way to turn
672 * these strings into kernel-printable form.
674 * Strings may be referenced in device, configuration, interface, or other
675 * descriptors, and could also be used in vendor-specific ways.
677 * This call is synchronous, and may not be used in an interrupt context.
679 * Return: The number of bytes received on success, or else the status code
680 * returned by the underlying usb_control_msg() call.
682 static int usb_get_string(struct usb_device
*dev
, unsigned short langid
,
683 unsigned char index
, void *buf
, int size
)
688 for (i
= 0; i
< 3; ++i
) {
689 /* retry on length 0 or stall; some devices are flakey */
690 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
691 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
692 (USB_DT_STRING
<< 8) + index
, langid
, buf
, size
,
693 USB_CTRL_GET_TIMEOUT
);
694 if (result
== 0 || result
== -EPIPE
)
696 if (result
> 1 && ((u8
*) buf
)[1] != USB_DT_STRING
) {
705 static void usb_try_string_workarounds(unsigned char *buf
, int *length
)
707 int newlength
, oldlength
= *length
;
709 for (newlength
= 2; newlength
+ 1 < oldlength
; newlength
+= 2)
710 if (!isprint(buf
[newlength
]) || buf
[newlength
+ 1])
719 static int usb_string_sub(struct usb_device
*dev
, unsigned int langid
,
720 unsigned int index
, unsigned char *buf
)
724 /* Try to read the string descriptor by asking for the maximum
725 * possible number of bytes */
726 if (dev
->quirks
& USB_QUIRK_STRING_FETCH_255
)
729 rc
= usb_get_string(dev
, langid
, index
, buf
, 255);
731 /* If that failed try to read the descriptor length, then
732 * ask for just that many bytes */
734 rc
= usb_get_string(dev
, langid
, index
, buf
, 2);
736 rc
= usb_get_string(dev
, langid
, index
, buf
, buf
[0]);
740 if (!buf
[0] && !buf
[1])
741 usb_try_string_workarounds(buf
, &rc
);
743 /* There might be extra junk at the end of the descriptor */
747 rc
= rc
- (rc
& 1); /* force a multiple of two */
751 rc
= (rc
< 0 ? rc
: -EINVAL
);
756 static int usb_get_langid(struct usb_device
*dev
, unsigned char *tbuf
)
760 if (dev
->have_langid
)
763 if (dev
->string_langid
< 0)
766 err
= usb_string_sub(dev
, 0, 0, tbuf
);
768 /* If the string was reported but is malformed, default to english
770 if (err
== -ENODATA
|| (err
> 0 && err
< 4)) {
771 dev
->string_langid
= 0x0409;
772 dev
->have_langid
= 1;
774 "string descriptor 0 malformed (err = %d), "
775 "defaulting to 0x%04x\n",
776 err
, dev
->string_langid
);
780 /* In case of all other errors, we assume the device is not able to
781 * deal with strings at all. Set string_langid to -1 in order to
782 * prevent any string to be retrieved from the device */
784 dev_err(&dev
->dev
, "string descriptor 0 read error: %d\n",
786 dev
->string_langid
= -1;
790 /* always use the first langid listed */
791 dev
->string_langid
= tbuf
[2] | (tbuf
[3] << 8);
792 dev
->have_langid
= 1;
793 dev_dbg(&dev
->dev
, "default language 0x%04x\n",
799 * usb_string - returns UTF-8 version of a string descriptor
800 * @dev: the device whose string descriptor is being retrieved
801 * @index: the number of the descriptor
802 * @buf: where to put the string
803 * @size: how big is "buf"?
804 * Context: !in_interrupt ()
806 * This converts the UTF-16LE encoded strings returned by devices, from
807 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
808 * that are more usable in most kernel contexts. Note that this function
809 * chooses strings in the first language supported by the device.
811 * This call is synchronous, and may not be used in an interrupt context.
813 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
815 int usb_string(struct usb_device
*dev
, int index
, char *buf
, size_t size
)
820 if (dev
->state
== USB_STATE_SUSPENDED
)
821 return -EHOSTUNREACH
;
822 if (size
<= 0 || !buf
|| !index
)
825 tbuf
= kmalloc(256, GFP_NOIO
);
829 err
= usb_get_langid(dev
, tbuf
);
833 err
= usb_string_sub(dev
, dev
->string_langid
, index
, tbuf
);
837 size
--; /* leave room for trailing NULL char in output buffer */
838 err
= utf16s_to_utf8s((wchar_t *) &tbuf
[2], (err
- 2) / 2,
839 UTF16_LITTLE_ENDIAN
, buf
, size
);
842 if (tbuf
[1] != USB_DT_STRING
)
844 "wrong descriptor type %02x for string %d (\"%s\")\n",
845 tbuf
[1], index
, buf
);
851 EXPORT_SYMBOL_GPL(usb_string
);
853 /* one UTF-8-encoded 16-bit character has at most three bytes */
854 #define MAX_USB_STRING_SIZE (127 * 3 + 1)
857 * usb_cache_string - read a string descriptor and cache it for later use
858 * @udev: the device whose string descriptor is being read
859 * @index: the descriptor index
861 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
862 * or %NULL if the index is 0 or the string could not be read.
864 char *usb_cache_string(struct usb_device
*udev
, int index
)
867 char *smallbuf
= NULL
;
873 buf
= kmalloc(MAX_USB_STRING_SIZE
, GFP_NOIO
);
875 len
= usb_string(udev
, index
, buf
, MAX_USB_STRING_SIZE
);
877 smallbuf
= kmalloc(++len
, GFP_NOIO
);
880 memcpy(smallbuf
, buf
, len
);
888 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
889 * @dev: the device whose device descriptor is being updated
890 * @size: how much of the descriptor to read
891 * Context: !in_interrupt ()
893 * Updates the copy of the device descriptor stored in the device structure,
894 * which dedicates space for this purpose.
896 * Not exported, only for use by the core. If drivers really want to read
897 * the device descriptor directly, they can call usb_get_descriptor() with
898 * type = USB_DT_DEVICE and index = 0.
900 * This call is synchronous, and may not be used in an interrupt context.
902 * Return: The number of bytes received on success, or else the status code
903 * returned by the underlying usb_control_msg() call.
905 int usb_get_device_descriptor(struct usb_device
*dev
, unsigned int size
)
907 struct usb_device_descriptor
*desc
;
910 if (size
> sizeof(*desc
))
912 desc
= kmalloc(sizeof(*desc
), GFP_NOIO
);
916 ret
= usb_get_descriptor(dev
, USB_DT_DEVICE
, 0, desc
, size
);
918 memcpy(&dev
->descriptor
, desc
, size
);
924 * usb_get_status - issues a GET_STATUS call
925 * @dev: the device whose status is being checked
926 * @type: USB_RECIP_*; for device, interface, or endpoint
927 * @target: zero (for device), else interface or endpoint number
928 * @data: pointer to two bytes of bitmap data
929 * Context: !in_interrupt ()
931 * Returns device, interface, or endpoint status. Normally only of
932 * interest to see if the device is self powered, or has enabled the
933 * remote wakeup facility; or whether a bulk or interrupt endpoint
934 * is halted ("stalled").
936 * Bits in these status bitmaps are set using the SET_FEATURE request,
937 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
938 * function should be used to clear halt ("stall") status.
940 * This call is synchronous, and may not be used in an interrupt context.
942 * Returns 0 and the status value in *@data (in host byte order) on success,
943 * or else the status code from the underlying usb_control_msg() call.
945 int usb_get_status(struct usb_device
*dev
, int type
, int target
, void *data
)
948 __le16
*status
= kmalloc(sizeof(*status
), GFP_KERNEL
);
953 ret
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
954 USB_REQ_GET_STATUS
, USB_DIR_IN
| type
, 0, target
, status
,
955 sizeof(*status
), USB_CTRL_GET_TIMEOUT
);
958 *(u16
*) data
= le16_to_cpu(*status
);
960 } else if (ret
>= 0) {
966 EXPORT_SYMBOL_GPL(usb_get_status
);
969 * usb_clear_halt - tells device to clear endpoint halt/stall condition
970 * @dev: device whose endpoint is halted
971 * @pipe: endpoint "pipe" being cleared
972 * Context: !in_interrupt ()
974 * This is used to clear halt conditions for bulk and interrupt endpoints,
975 * as reported by URB completion status. Endpoints that are halted are
976 * sometimes referred to as being "stalled". Such endpoints are unable
977 * to transmit or receive data until the halt status is cleared. Any URBs
978 * queued for such an endpoint should normally be unlinked by the driver
979 * before clearing the halt condition, as described in sections 5.7.5
980 * and 5.8.5 of the USB 2.0 spec.
982 * Note that control and isochronous endpoints don't halt, although control
983 * endpoints report "protocol stall" (for unsupported requests) using the
984 * same status code used to report a true stall.
986 * This call is synchronous, and may not be used in an interrupt context.
988 * Return: Zero on success, or else the status code returned by the
989 * underlying usb_control_msg() call.
991 int usb_clear_halt(struct usb_device
*dev
, int pipe
)
994 int endp
= usb_pipeendpoint(pipe
);
996 if (usb_pipein(pipe
))
999 /* we don't care if it wasn't halted first. in fact some devices
1000 * (like some ibmcam model 1 units) seem to expect hosts to make
1001 * this request for iso endpoints, which can't halt!
1003 result
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1004 USB_REQ_CLEAR_FEATURE
, USB_RECIP_ENDPOINT
,
1005 USB_ENDPOINT_HALT
, endp
, NULL
, 0,
1006 USB_CTRL_SET_TIMEOUT
);
1008 /* don't un-halt or force to DATA0 except on success */
1012 /* NOTE: seems like Microsoft and Apple don't bother verifying
1013 * the clear "took", so some devices could lock up if you check...
1014 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1016 * NOTE: make sure the logic here doesn't diverge much from
1017 * the copy in usb-storage, for as long as we need two copies.
1020 usb_reset_endpoint(dev
, endp
);
1024 EXPORT_SYMBOL_GPL(usb_clear_halt
);
1026 static int create_intf_ep_devs(struct usb_interface
*intf
)
1028 struct usb_device
*udev
= interface_to_usbdev(intf
);
1029 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1032 if (intf
->ep_devs_created
|| intf
->unregistering
)
1035 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1036 (void) usb_create_ep_devs(&intf
->dev
, &alt
->endpoint
[i
], udev
);
1037 intf
->ep_devs_created
= 1;
1041 static void remove_intf_ep_devs(struct usb_interface
*intf
)
1043 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1046 if (!intf
->ep_devs_created
)
1049 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1050 usb_remove_ep_devs(&alt
->endpoint
[i
]);
1051 intf
->ep_devs_created
= 0;
1055 * usb_disable_endpoint -- Disable an endpoint by address
1056 * @dev: the device whose endpoint is being disabled
1057 * @epaddr: the endpoint's address. Endpoint number for output,
1058 * endpoint number + USB_DIR_IN for input
1059 * @reset_hardware: flag to erase any endpoint state stored in the
1060 * controller hardware
1062 * Disables the endpoint for URB submission and nukes all pending URBs.
1063 * If @reset_hardware is set then also deallocates hcd/hardware state
1066 void usb_disable_endpoint(struct usb_device
*dev
, unsigned int epaddr
,
1067 bool reset_hardware
)
1069 unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
1070 struct usb_host_endpoint
*ep
;
1075 if (usb_endpoint_out(epaddr
)) {
1076 ep
= dev
->ep_out
[epnum
];
1078 dev
->ep_out
[epnum
] = NULL
;
1080 ep
= dev
->ep_in
[epnum
];
1082 dev
->ep_in
[epnum
] = NULL
;
1086 usb_hcd_flush_endpoint(dev
, ep
);
1088 usb_hcd_disable_endpoint(dev
, ep
);
1093 * usb_reset_endpoint - Reset an endpoint's state.
1094 * @dev: the device whose endpoint is to be reset
1095 * @epaddr: the endpoint's address. Endpoint number for output,
1096 * endpoint number + USB_DIR_IN for input
1098 * Resets any host-side endpoint state such as the toggle bit,
1099 * sequence number or current window.
1101 void usb_reset_endpoint(struct usb_device
*dev
, unsigned int epaddr
)
1103 unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
1104 struct usb_host_endpoint
*ep
;
1106 if (usb_endpoint_out(epaddr
))
1107 ep
= dev
->ep_out
[epnum
];
1109 ep
= dev
->ep_in
[epnum
];
1111 usb_hcd_reset_endpoint(dev
, ep
);
1113 EXPORT_SYMBOL_GPL(usb_reset_endpoint
);
1117 * usb_disable_interface -- Disable all endpoints for an interface
1118 * @dev: the device whose interface is being disabled
1119 * @intf: pointer to the interface descriptor
1120 * @reset_hardware: flag to erase any endpoint state stored in the
1121 * controller hardware
1123 * Disables all the endpoints for the interface's current altsetting.
1125 void usb_disable_interface(struct usb_device
*dev
, struct usb_interface
*intf
,
1126 bool reset_hardware
)
1128 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1131 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
) {
1132 usb_disable_endpoint(dev
,
1133 alt
->endpoint
[i
].desc
.bEndpointAddress
,
1139 * usb_disable_device - Disable all the endpoints for a USB device
1140 * @dev: the device whose endpoints are being disabled
1141 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1143 * Disables all the device's endpoints, potentially including endpoint 0.
1144 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1145 * pending urbs) and usbcore state for the interfaces, so that usbcore
1146 * must usb_set_configuration() before any interfaces could be used.
1148 void usb_disable_device(struct usb_device
*dev
, int skip_ep0
)
1151 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1153 /* getting rid of interfaces will disconnect
1154 * any drivers bound to them (a key side effect)
1156 if (dev
->actconfig
) {
1158 * FIXME: In order to avoid self-deadlock involving the
1159 * bandwidth_mutex, we have to mark all the interfaces
1160 * before unregistering any of them.
1162 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++)
1163 dev
->actconfig
->interface
[i
]->unregistering
= 1;
1165 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1166 struct usb_interface
*interface
;
1168 /* remove this interface if it has been registered */
1169 interface
= dev
->actconfig
->interface
[i
];
1170 if (!device_is_registered(&interface
->dev
))
1172 dev_dbg(&dev
->dev
, "unregistering interface %s\n",
1173 dev_name(&interface
->dev
));
1174 remove_intf_ep_devs(interface
);
1175 device_del(&interface
->dev
);
1178 /* Now that the interfaces are unbound, nobody should
1179 * try to access them.
1181 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1182 put_device(&dev
->actconfig
->interface
[i
]->dev
);
1183 dev
->actconfig
->interface
[i
] = NULL
;
1186 if (dev
->usb2_hw_lpm_enabled
== 1)
1187 usb_set_usb2_hardware_lpm(dev
, 0);
1188 usb_unlocked_disable_lpm(dev
);
1189 usb_disable_ltm(dev
);
1191 dev
->actconfig
= NULL
;
1192 if (dev
->state
== USB_STATE_CONFIGURED
)
1193 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1196 dev_dbg(&dev
->dev
, "%s nuking %s URBs\n", __func__
,
1197 skip_ep0
? "non-ep0" : "all");
1198 if (hcd
->driver
->check_bandwidth
) {
1199 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1200 for (i
= skip_ep0
; i
< 16; ++i
) {
1201 usb_disable_endpoint(dev
, i
, false);
1202 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, false);
1204 /* Remove endpoints from the host controller internal state */
1205 mutex_lock(hcd
->bandwidth_mutex
);
1206 usb_hcd_alloc_bandwidth(dev
, NULL
, NULL
, NULL
);
1207 mutex_unlock(hcd
->bandwidth_mutex
);
1208 /* Second pass: remove endpoint pointers */
1210 for (i
= skip_ep0
; i
< 16; ++i
) {
1211 usb_disable_endpoint(dev
, i
, true);
1212 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, true);
1217 * usb_enable_endpoint - Enable an endpoint for USB communications
1218 * @dev: the device whose interface is being enabled
1220 * @reset_ep: flag to reset the endpoint state
1222 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1223 * For control endpoints, both the input and output sides are handled.
1225 void usb_enable_endpoint(struct usb_device
*dev
, struct usb_host_endpoint
*ep
,
1228 int epnum
= usb_endpoint_num(&ep
->desc
);
1229 int is_out
= usb_endpoint_dir_out(&ep
->desc
);
1230 int is_control
= usb_endpoint_xfer_control(&ep
->desc
);
1233 usb_hcd_reset_endpoint(dev
, ep
);
1234 if (is_out
|| is_control
)
1235 dev
->ep_out
[epnum
] = ep
;
1236 if (!is_out
|| is_control
)
1237 dev
->ep_in
[epnum
] = ep
;
1242 * usb_enable_interface - Enable all the endpoints for an interface
1243 * @dev: the device whose interface is being enabled
1244 * @intf: pointer to the interface descriptor
1245 * @reset_eps: flag to reset the endpoints' state
1247 * Enables all the endpoints for the interface's current altsetting.
1249 void usb_enable_interface(struct usb_device
*dev
,
1250 struct usb_interface
*intf
, bool reset_eps
)
1252 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1255 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1256 usb_enable_endpoint(dev
, &alt
->endpoint
[i
], reset_eps
);
1260 * usb_set_interface - Makes a particular alternate setting be current
1261 * @dev: the device whose interface is being updated
1262 * @interface: the interface being updated
1263 * @alternate: the setting being chosen.
1264 * Context: !in_interrupt ()
1266 * This is used to enable data transfers on interfaces that may not
1267 * be enabled by default. Not all devices support such configurability.
1268 * Only the driver bound to an interface may change its setting.
1270 * Within any given configuration, each interface may have several
1271 * alternative settings. These are often used to control levels of
1272 * bandwidth consumption. For example, the default setting for a high
1273 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1274 * while interrupt transfers of up to 3KBytes per microframe are legal.
1275 * Also, isochronous endpoints may never be part of an
1276 * interface's default setting. To access such bandwidth, alternate
1277 * interface settings must be made current.
1279 * Note that in the Linux USB subsystem, bandwidth associated with
1280 * an endpoint in a given alternate setting is not reserved until an URB
1281 * is submitted that needs that bandwidth. Some other operating systems
1282 * allocate bandwidth early, when a configuration is chosen.
1284 * This call is synchronous, and may not be used in an interrupt context.
1285 * Also, drivers must not change altsettings while urbs are scheduled for
1286 * endpoints in that interface; all such urbs must first be completed
1287 * (perhaps forced by unlinking).
1289 * Return: Zero on success, or else the status code returned by the
1290 * underlying usb_control_msg() call.
1292 int usb_set_interface(struct usb_device
*dev
, int interface
, int alternate
)
1294 struct usb_interface
*iface
;
1295 struct usb_host_interface
*alt
;
1296 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1299 unsigned int epaddr
;
1302 if (dev
->state
== USB_STATE_SUSPENDED
)
1303 return -EHOSTUNREACH
;
1305 iface
= usb_ifnum_to_if(dev
, interface
);
1307 dev_dbg(&dev
->dev
, "selecting invalid interface %d\n",
1311 if (iface
->unregistering
)
1314 alt
= usb_altnum_to_altsetting(iface
, alternate
);
1316 dev_warn(&dev
->dev
, "selecting invalid altsetting %d\n",
1321 /* Make sure we have enough bandwidth for this alternate interface.
1322 * Remove the current alt setting and add the new alt setting.
1324 mutex_lock(hcd
->bandwidth_mutex
);
1325 /* Disable LPM, and re-enable it once the new alt setting is installed,
1326 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1328 if (usb_disable_lpm(dev
)) {
1329 dev_err(&iface
->dev
, "%s Failed to disable LPM\n.", __func__
);
1330 mutex_unlock(hcd
->bandwidth_mutex
);
1333 ret
= usb_hcd_alloc_bandwidth(dev
, NULL
, iface
->cur_altsetting
, alt
);
1335 dev_info(&dev
->dev
, "Not enough bandwidth for altsetting %d\n",
1337 usb_enable_lpm(dev
);
1338 mutex_unlock(hcd
->bandwidth_mutex
);
1342 if (dev
->quirks
& USB_QUIRK_NO_SET_INTF
)
1345 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1346 USB_REQ_SET_INTERFACE
, USB_RECIP_INTERFACE
,
1347 alternate
, interface
, NULL
, 0, 5000);
1349 /* 9.4.10 says devices don't need this and are free to STALL the
1350 * request if the interface only has one alternate setting.
1352 if (ret
== -EPIPE
&& iface
->num_altsetting
== 1) {
1354 "manual set_interface for iface %d, alt %d\n",
1355 interface
, alternate
);
1357 } else if (ret
< 0) {
1358 /* Re-instate the old alt setting */
1359 usb_hcd_alloc_bandwidth(dev
, NULL
, alt
, iface
->cur_altsetting
);
1360 usb_enable_lpm(dev
);
1361 mutex_unlock(hcd
->bandwidth_mutex
);
1364 mutex_unlock(hcd
->bandwidth_mutex
);
1366 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1367 * when they implement async or easily-killable versions of this or
1368 * other "should-be-internal" functions (like clear_halt).
1369 * should hcd+usbcore postprocess control requests?
1372 /* prevent submissions using previous endpoint settings */
1373 if (iface
->cur_altsetting
!= alt
) {
1374 remove_intf_ep_devs(iface
);
1375 usb_remove_sysfs_intf_files(iface
);
1377 usb_disable_interface(dev
, iface
, true);
1379 iface
->cur_altsetting
= alt
;
1381 /* Now that the interface is installed, re-enable LPM. */
1382 usb_unlocked_enable_lpm(dev
);
1384 /* If the interface only has one altsetting and the device didn't
1385 * accept the request, we attempt to carry out the equivalent action
1386 * by manually clearing the HALT feature for each endpoint in the
1392 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; i
++) {
1393 epaddr
= alt
->endpoint
[i
].desc
.bEndpointAddress
;
1394 pipe
= __create_pipe(dev
,
1395 USB_ENDPOINT_NUMBER_MASK
& epaddr
) |
1396 (usb_endpoint_out(epaddr
) ?
1397 USB_DIR_OUT
: USB_DIR_IN
);
1399 usb_clear_halt(dev
, pipe
);
1403 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1406 * Despite EP0 is always present in all interfaces/AS, the list of
1407 * endpoints from the descriptor does not contain EP0. Due to its
1408 * omnipresence one might expect EP0 being considered "affected" by
1409 * any SetInterface request and hence assume toggles need to be reset.
1410 * However, EP0 toggles are re-synced for every individual transfer
1411 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1412 * (Likewise, EP0 never "halts" on well designed devices.)
1414 usb_enable_interface(dev
, iface
, true);
1415 if (device_is_registered(&iface
->dev
)) {
1416 usb_create_sysfs_intf_files(iface
);
1417 create_intf_ep_devs(iface
);
1421 EXPORT_SYMBOL_GPL(usb_set_interface
);
1424 * usb_reset_configuration - lightweight device reset
1425 * @dev: the device whose configuration is being reset
1427 * This issues a standard SET_CONFIGURATION request to the device using
1428 * the current configuration. The effect is to reset most USB-related
1429 * state in the device, including interface altsettings (reset to zero),
1430 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1431 * endpoints). Other usbcore state is unchanged, including bindings of
1432 * usb device drivers to interfaces.
1434 * Because this affects multiple interfaces, avoid using this with composite
1435 * (multi-interface) devices. Instead, the driver for each interface may
1436 * use usb_set_interface() on the interfaces it claims. Be careful though;
1437 * some devices don't support the SET_INTERFACE request, and others won't
1438 * reset all the interface state (notably endpoint state). Resetting the whole
1439 * configuration would affect other drivers' interfaces.
1441 * The caller must own the device lock.
1443 * Return: Zero on success, else a negative error code.
1445 int usb_reset_configuration(struct usb_device
*dev
)
1448 struct usb_host_config
*config
;
1449 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1451 if (dev
->state
== USB_STATE_SUSPENDED
)
1452 return -EHOSTUNREACH
;
1454 /* caller must have locked the device and must own
1455 * the usb bus readlock (so driver bindings are stable);
1456 * calls during probe() are fine
1459 for (i
= 1; i
< 16; ++i
) {
1460 usb_disable_endpoint(dev
, i
, true);
1461 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, true);
1464 config
= dev
->actconfig
;
1466 mutex_lock(hcd
->bandwidth_mutex
);
1467 /* Disable LPM, and re-enable it once the configuration is reset, so
1468 * that the xHCI driver can recalculate the U1/U2 timeouts.
1470 if (usb_disable_lpm(dev
)) {
1471 dev_err(&dev
->dev
, "%s Failed to disable LPM\n.", __func__
);
1472 mutex_unlock(hcd
->bandwidth_mutex
);
1475 /* Make sure we have enough bandwidth for each alternate setting 0 */
1476 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
1477 struct usb_interface
*intf
= config
->interface
[i
];
1478 struct usb_host_interface
*alt
;
1480 alt
= usb_altnum_to_altsetting(intf
, 0);
1482 alt
= &intf
->altsetting
[0];
1483 if (alt
!= intf
->cur_altsetting
)
1484 retval
= usb_hcd_alloc_bandwidth(dev
, NULL
,
1485 intf
->cur_altsetting
, alt
);
1489 /* If not, reinstate the old alternate settings */
1492 for (i
--; i
>= 0; i
--) {
1493 struct usb_interface
*intf
= config
->interface
[i
];
1494 struct usb_host_interface
*alt
;
1496 alt
= usb_altnum_to_altsetting(intf
, 0);
1498 alt
= &intf
->altsetting
[0];
1499 if (alt
!= intf
->cur_altsetting
)
1500 usb_hcd_alloc_bandwidth(dev
, NULL
,
1501 alt
, intf
->cur_altsetting
);
1503 usb_enable_lpm(dev
);
1504 mutex_unlock(hcd
->bandwidth_mutex
);
1507 retval
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1508 USB_REQ_SET_CONFIGURATION
, 0,
1509 config
->desc
.bConfigurationValue
, 0,
1510 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1512 goto reset_old_alts
;
1513 mutex_unlock(hcd
->bandwidth_mutex
);
1515 /* re-init hc/hcd interface/endpoint state */
1516 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
1517 struct usb_interface
*intf
= config
->interface
[i
];
1518 struct usb_host_interface
*alt
;
1520 alt
= usb_altnum_to_altsetting(intf
, 0);
1522 /* No altsetting 0? We'll assume the first altsetting.
1523 * We could use a GetInterface call, but if a device is
1524 * so non-compliant that it doesn't have altsetting 0
1525 * then I wouldn't trust its reply anyway.
1528 alt
= &intf
->altsetting
[0];
1530 if (alt
!= intf
->cur_altsetting
) {
1531 remove_intf_ep_devs(intf
);
1532 usb_remove_sysfs_intf_files(intf
);
1534 intf
->cur_altsetting
= alt
;
1535 usb_enable_interface(dev
, intf
, true);
1536 if (device_is_registered(&intf
->dev
)) {
1537 usb_create_sysfs_intf_files(intf
);
1538 create_intf_ep_devs(intf
);
1541 /* Now that the interfaces are installed, re-enable LPM. */
1542 usb_unlocked_enable_lpm(dev
);
1545 EXPORT_SYMBOL_GPL(usb_reset_configuration
);
1547 static void usb_release_interface(struct device
*dev
)
1549 struct usb_interface
*intf
= to_usb_interface(dev
);
1550 struct usb_interface_cache
*intfc
=
1551 altsetting_to_usb_interface_cache(intf
->altsetting
);
1553 kref_put(&intfc
->ref
, usb_release_interface_cache
);
1557 static int usb_if_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1559 struct usb_device
*usb_dev
;
1560 struct usb_interface
*intf
;
1561 struct usb_host_interface
*alt
;
1563 intf
= to_usb_interface(dev
);
1564 usb_dev
= interface_to_usbdev(intf
);
1565 alt
= intf
->cur_altsetting
;
1567 if (add_uevent_var(env
, "INTERFACE=%d/%d/%d",
1568 alt
->desc
.bInterfaceClass
,
1569 alt
->desc
.bInterfaceSubClass
,
1570 alt
->desc
.bInterfaceProtocol
))
1573 if (add_uevent_var(env
,
1575 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1576 le16_to_cpu(usb_dev
->descriptor
.idVendor
),
1577 le16_to_cpu(usb_dev
->descriptor
.idProduct
),
1578 le16_to_cpu(usb_dev
->descriptor
.bcdDevice
),
1579 usb_dev
->descriptor
.bDeviceClass
,
1580 usb_dev
->descriptor
.bDeviceSubClass
,
1581 usb_dev
->descriptor
.bDeviceProtocol
,
1582 alt
->desc
.bInterfaceClass
,
1583 alt
->desc
.bInterfaceSubClass
,
1584 alt
->desc
.bInterfaceProtocol
,
1585 alt
->desc
.bInterfaceNumber
))
1591 struct device_type usb_if_device_type
= {
1592 .name
= "usb_interface",
1593 .release
= usb_release_interface
,
1594 .uevent
= usb_if_uevent
,
1597 static struct usb_interface_assoc_descriptor
*find_iad(struct usb_device
*dev
,
1598 struct usb_host_config
*config
,
1601 struct usb_interface_assoc_descriptor
*retval
= NULL
;
1602 struct usb_interface_assoc_descriptor
*intf_assoc
;
1607 for (i
= 0; (i
< USB_MAXIADS
&& config
->intf_assoc
[i
]); i
++) {
1608 intf_assoc
= config
->intf_assoc
[i
];
1609 if (intf_assoc
->bInterfaceCount
== 0)
1612 first_intf
= intf_assoc
->bFirstInterface
;
1613 last_intf
= first_intf
+ (intf_assoc
->bInterfaceCount
- 1);
1614 if (inum
>= first_intf
&& inum
<= last_intf
) {
1616 retval
= intf_assoc
;
1618 dev_err(&dev
->dev
, "Interface #%d referenced"
1619 " by multiple IADs\n", inum
);
1628 * Internal function to queue a device reset
1630 * This is initialized into the workstruct in 'struct
1631 * usb_device->reset_ws' that is launched by
1632 * message.c:usb_set_configuration() when initializing each 'struct
1635 * It is safe to get the USB device without reference counts because
1636 * the life cycle of @iface is bound to the life cycle of @udev. Then,
1637 * this function will be ran only if @iface is alive (and before
1638 * freeing it any scheduled instances of it will have been cancelled).
1640 * We need to set a flag (usb_dev->reset_running) because when we call
1641 * the reset, the interfaces might be unbound. The current interface
1642 * cannot try to remove the queued work as it would cause a deadlock
1643 * (you cannot remove your work from within your executing
1644 * workqueue). This flag lets it know, so that
1645 * usb_cancel_queued_reset() doesn't try to do it.
1647 * See usb_queue_reset_device() for more details
1649 static void __usb_queue_reset_device(struct work_struct
*ws
)
1652 struct usb_interface
*iface
=
1653 container_of(ws
, struct usb_interface
, reset_ws
);
1654 struct usb_device
*udev
= interface_to_usbdev(iface
);
1656 rc
= usb_lock_device_for_reset(udev
, iface
);
1658 iface
->reset_running
= 1;
1659 usb_reset_device(udev
);
1660 iface
->reset_running
= 0;
1661 usb_unlock_device(udev
);
1667 * usb_set_configuration - Makes a particular device setting be current
1668 * @dev: the device whose configuration is being updated
1669 * @configuration: the configuration being chosen.
1670 * Context: !in_interrupt(), caller owns the device lock
1672 * This is used to enable non-default device modes. Not all devices
1673 * use this kind of configurability; many devices only have one
1676 * @configuration is the value of the configuration to be installed.
1677 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1678 * must be non-zero; a value of zero indicates that the device in
1679 * unconfigured. However some devices erroneously use 0 as one of their
1680 * configuration values. To help manage such devices, this routine will
1681 * accept @configuration = -1 as indicating the device should be put in
1682 * an unconfigured state.
1684 * USB device configurations may affect Linux interoperability,
1685 * power consumption and the functionality available. For example,
1686 * the default configuration is limited to using 100mA of bus power,
1687 * so that when certain device functionality requires more power,
1688 * and the device is bus powered, that functionality should be in some
1689 * non-default device configuration. Other device modes may also be
1690 * reflected as configuration options, such as whether two ISDN
1691 * channels are available independently; and choosing between open
1692 * standard device protocols (like CDC) or proprietary ones.
1694 * Note that a non-authorized device (dev->authorized == 0) will only
1695 * be put in unconfigured mode.
1697 * Note that USB has an additional level of device configurability,
1698 * associated with interfaces. That configurability is accessed using
1699 * usb_set_interface().
1701 * This call is synchronous. The calling context must be able to sleep,
1702 * must own the device lock, and must not hold the driver model's USB
1703 * bus mutex; usb interface driver probe() methods cannot use this routine.
1705 * Returns zero on success, or else the status code returned by the
1706 * underlying call that failed. On successful completion, each interface
1707 * in the original device configuration has been destroyed, and each one
1708 * in the new configuration has been probed by all relevant usb device
1709 * drivers currently known to the kernel.
1711 int usb_set_configuration(struct usb_device
*dev
, int configuration
)
1714 struct usb_host_config
*cp
= NULL
;
1715 struct usb_interface
**new_interfaces
= NULL
;
1716 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1719 if (dev
->authorized
== 0 || configuration
== -1)
1722 for (i
= 0; i
< dev
->descriptor
.bNumConfigurations
; i
++) {
1723 if (dev
->config
[i
].desc
.bConfigurationValue
==
1725 cp
= &dev
->config
[i
];
1730 if ((!cp
&& configuration
!= 0))
1733 /* The USB spec says configuration 0 means unconfigured.
1734 * But if a device includes a configuration numbered 0,
1735 * we will accept it as a correctly configured state.
1736 * Use -1 if you really want to unconfigure the device.
1738 if (cp
&& configuration
== 0)
1739 dev_warn(&dev
->dev
, "config 0 descriptor??\n");
1741 /* Allocate memory for new interfaces before doing anything else,
1742 * so that if we run out then nothing will have changed. */
1745 nintf
= cp
->desc
.bNumInterfaces
;
1746 new_interfaces
= kmalloc(nintf
* sizeof(*new_interfaces
),
1748 if (!new_interfaces
) {
1749 dev_err(&dev
->dev
, "Out of memory\n");
1753 for (; n
< nintf
; ++n
) {
1754 new_interfaces
[n
] = kzalloc(
1755 sizeof(struct usb_interface
),
1757 if (!new_interfaces
[n
]) {
1758 dev_err(&dev
->dev
, "Out of memory\n");
1762 kfree(new_interfaces
[n
]);
1763 kfree(new_interfaces
);
1768 i
= dev
->bus_mA
- usb_get_max_power(dev
, cp
);
1770 dev_warn(&dev
->dev
, "new config #%d exceeds power "
1775 /* Wake up the device so we can send it the Set-Config request */
1776 ret
= usb_autoresume_device(dev
);
1778 goto free_interfaces
;
1780 /* if it's already configured, clear out old state first.
1781 * getting rid of old interfaces means unbinding their drivers.
1783 if (dev
->state
!= USB_STATE_ADDRESS
)
1784 usb_disable_device(dev
, 1); /* Skip ep0 */
1786 /* Get rid of pending async Set-Config requests for this device */
1787 cancel_async_set_config(dev
);
1789 /* Make sure we have bandwidth (and available HCD resources) for this
1790 * configuration. Remove endpoints from the schedule if we're dropping
1791 * this configuration to set configuration 0. After this point, the
1792 * host controller will not allow submissions to dropped endpoints. If
1793 * this call fails, the device state is unchanged.
1795 mutex_lock(hcd
->bandwidth_mutex
);
1796 /* Disable LPM, and re-enable it once the new configuration is
1797 * installed, so that the xHCI driver can recalculate the U1/U2
1800 if (dev
->actconfig
&& usb_disable_lpm(dev
)) {
1801 dev_err(&dev
->dev
, "%s Failed to disable LPM\n.", __func__
);
1802 mutex_unlock(hcd
->bandwidth_mutex
);
1804 goto free_interfaces
;
1806 ret
= usb_hcd_alloc_bandwidth(dev
, cp
, NULL
, NULL
);
1809 usb_enable_lpm(dev
);
1810 mutex_unlock(hcd
->bandwidth_mutex
);
1811 usb_autosuspend_device(dev
);
1812 goto free_interfaces
;
1816 * Initialize the new interface structures and the
1817 * hc/hcd/usbcore interface/endpoint state.
1819 for (i
= 0; i
< nintf
; ++i
) {
1820 struct usb_interface_cache
*intfc
;
1821 struct usb_interface
*intf
;
1822 struct usb_host_interface
*alt
;
1824 cp
->interface
[i
] = intf
= new_interfaces
[i
];
1825 intfc
= cp
->intf_cache
[i
];
1826 intf
->altsetting
= intfc
->altsetting
;
1827 intf
->num_altsetting
= intfc
->num_altsetting
;
1828 kref_get(&intfc
->ref
);
1830 alt
= usb_altnum_to_altsetting(intf
, 0);
1832 /* No altsetting 0? We'll assume the first altsetting.
1833 * We could use a GetInterface call, but if a device is
1834 * so non-compliant that it doesn't have altsetting 0
1835 * then I wouldn't trust its reply anyway.
1838 alt
= &intf
->altsetting
[0];
1841 find_iad(dev
, cp
, alt
->desc
.bInterfaceNumber
);
1842 intf
->cur_altsetting
= alt
;
1843 usb_enable_interface(dev
, intf
, true);
1844 intf
->dev
.parent
= &dev
->dev
;
1845 intf
->dev
.driver
= NULL
;
1846 intf
->dev
.bus
= &usb_bus_type
;
1847 intf
->dev
.type
= &usb_if_device_type
;
1848 intf
->dev
.groups
= usb_interface_groups
;
1849 intf
->dev
.dma_mask
= dev
->dev
.dma_mask
;
1850 INIT_WORK(&intf
->reset_ws
, __usb_queue_reset_device
);
1852 device_initialize(&intf
->dev
);
1853 pm_runtime_no_callbacks(&intf
->dev
);
1854 dev_set_name(&intf
->dev
, "%d-%s:%d.%d",
1855 dev
->bus
->busnum
, dev
->devpath
,
1856 configuration
, alt
->desc
.bInterfaceNumber
);
1858 kfree(new_interfaces
);
1860 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1861 USB_REQ_SET_CONFIGURATION
, 0, configuration
, 0,
1862 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1863 if (ret
< 0 && cp
) {
1865 * All the old state is gone, so what else can we do?
1866 * The device is probably useless now anyway.
1868 usb_hcd_alloc_bandwidth(dev
, NULL
, NULL
, NULL
);
1869 for (i
= 0; i
< nintf
; ++i
) {
1870 usb_disable_interface(dev
, cp
->interface
[i
], true);
1871 put_device(&cp
->interface
[i
]->dev
);
1872 cp
->interface
[i
] = NULL
;
1877 dev
->actconfig
= cp
;
1878 mutex_unlock(hcd
->bandwidth_mutex
);
1881 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1883 /* Leave LPM disabled while the device is unconfigured. */
1884 usb_autosuspend_device(dev
);
1887 usb_set_device_state(dev
, USB_STATE_CONFIGURED
);
1889 if (cp
->string
== NULL
&&
1890 !(dev
->quirks
& USB_QUIRK_CONFIG_INTF_STRINGS
))
1891 cp
->string
= usb_cache_string(dev
, cp
->desc
.iConfiguration
);
1893 /* Now that the interfaces are installed, re-enable LPM. */
1894 usb_unlocked_enable_lpm(dev
);
1895 /* Enable LTM if it was turned off by usb_disable_device. */
1896 usb_enable_ltm(dev
);
1898 /* Now that all the interfaces are set up, register them
1899 * to trigger binding of drivers to interfaces. probe()
1900 * routines may install different altsettings and may
1901 * claim() any interfaces not yet bound. Many class drivers
1902 * need that: CDC, audio, video, etc.
1904 for (i
= 0; i
< nintf
; ++i
) {
1905 struct usb_interface
*intf
= cp
->interface
[i
];
1908 "adding %s (config #%d, interface %d)\n",
1909 dev_name(&intf
->dev
), configuration
,
1910 intf
->cur_altsetting
->desc
.bInterfaceNumber
);
1911 device_enable_async_suspend(&intf
->dev
);
1912 ret
= device_add(&intf
->dev
);
1914 dev_err(&dev
->dev
, "device_add(%s) --> %d\n",
1915 dev_name(&intf
->dev
), ret
);
1918 create_intf_ep_devs(intf
);
1921 usb_autosuspend_device(dev
);
1925 static LIST_HEAD(set_config_list
);
1926 static DEFINE_SPINLOCK(set_config_lock
);
1928 struct set_config_request
{
1929 struct usb_device
*udev
;
1931 struct work_struct work
;
1932 struct list_head node
;
1935 /* Worker routine for usb_driver_set_configuration() */
1936 static void driver_set_config_work(struct work_struct
*work
)
1938 struct set_config_request
*req
=
1939 container_of(work
, struct set_config_request
, work
);
1940 struct usb_device
*udev
= req
->udev
;
1942 usb_lock_device(udev
);
1943 spin_lock(&set_config_lock
);
1944 list_del(&req
->node
);
1945 spin_unlock(&set_config_lock
);
1947 if (req
->config
>= -1) /* Is req still valid? */
1948 usb_set_configuration(udev
, req
->config
);
1949 usb_unlock_device(udev
);
1954 /* Cancel pending Set-Config requests for a device whose configuration
1957 static void cancel_async_set_config(struct usb_device
*udev
)
1959 struct set_config_request
*req
;
1961 spin_lock(&set_config_lock
);
1962 list_for_each_entry(req
, &set_config_list
, node
) {
1963 if (req
->udev
== udev
)
1964 req
->config
= -999; /* Mark as cancelled */
1966 spin_unlock(&set_config_lock
);
1970 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
1971 * @udev: the device whose configuration is being updated
1972 * @config: the configuration being chosen.
1973 * Context: In process context, must be able to sleep
1975 * Device interface drivers are not allowed to change device configurations.
1976 * This is because changing configurations will destroy the interface the
1977 * driver is bound to and create new ones; it would be like a floppy-disk
1978 * driver telling the computer to replace the floppy-disk drive with a
1981 * Still, in certain specialized circumstances the need may arise. This
1982 * routine gets around the normal restrictions by using a work thread to
1983 * submit the change-config request.
1985 * Return: 0 if the request was successfully queued, error code otherwise.
1986 * The caller has no way to know whether the queued request will eventually
1989 int usb_driver_set_configuration(struct usb_device
*udev
, int config
)
1991 struct set_config_request
*req
;
1993 req
= kmalloc(sizeof(*req
), GFP_KERNEL
);
1997 req
->config
= config
;
1998 INIT_WORK(&req
->work
, driver_set_config_work
);
2000 spin_lock(&set_config_lock
);
2001 list_add(&req
->node
, &set_config_list
);
2002 spin_unlock(&set_config_lock
);
2005 schedule_work(&req
->work
);
2008 EXPORT_SYMBOL_GPL(usb_driver_set_configuration
);