Commit e901b987 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

usb: core: Add a helper function to check the validity of EP type in URB 



This patch adds a new helper function to perform a sanity check of the
given URB to see whether it contains a valid endpoint.  It's a light-
weight version of what usb_submit_urb() does, but without the kernel
warning followed by the stack trace, just returns an error code.

Especially for a driver that doesn't parse the descriptor but fills
the URB with the fixed endpoint (e.g. some quirks for non-compliant
devices), this kind of check is preferable at the probe phase before
actually submitting the urb.

Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 8a5776a5

drivers/usb/core/urb.c

+26 −4
Original line number Diff line number Diff line
@@ -187,6 +187,31 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); 


/*-------------------------------------------------------------------*/



static const int pipetypes[4] = {

	PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT

};



/**

 * usb_urb_ep_type_check - sanity check of endpoint in the given urb

 * @urb: urb to be checked

 *

 * This performs a light-weight sanity check for the endpoint in the

 * given urb.  It returns 0 if the urb contains a valid endpoint, otherwise

 * a negative error code.

 */

int usb_urb_ep_type_check(const struct urb *urb)

{

	const struct usb_host_endpoint *ep;



	ep = usb_pipe_endpoint(urb->dev, urb->pipe);

	if (!ep)

		return -EINVAL;

	if (usb_pipetype(urb->pipe) != pipetypes[usb_endpoint_type(&ep->desc)])

		return -EINVAL;

	return 0;

}

EXPORT_SYMBOL_GPL(usb_urb_ep_type_check);



/**

 * usb_submit_urb - issue an asynchronous transfer request for an endpoint

 * @urb: pointer to the urb describing the request
@@ -326,9 +351,6 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); 
 */

int usb_submit_urb(struct urb *urb, gfp_t mem_flags)

{

	static int			pipetypes[4] = {

		PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT

	};

	int				xfertype, max;

	struct usb_device		*dev;

	struct usb_host_endpoint	*ep;
@@ -444,7 +466,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) 
	 */



	/* Check that the pipe's type matches the endpoint's type */

	if (usb_pipetype(urb->pipe) != pipetypes[xfertype])

	if (usb_urb_ep_type_check(urb))

		dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n",

			usb_pipetype(urb->pipe), pipetypes[xfertype]);

include/linux/usb.h

+2 −0
Original line number Diff line number Diff line
@@ -1728,6 +1728,8 @@ static inline int usb_urb_dir_out(struct urb *urb) 
	return (urb->transfer_flags & URB_DIR_MASK) == URB_DIR_OUT;

}



int usb_urb_ep_type_check(const struct urb *urb);



void *usb_alloc_coherent(struct usb_device *dev, size_t size,

	gfp_t mem_flags, dma_addr_t *dma);

void usb_free_coherent(struct usb_device *dev, size_t size,

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