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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: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
hifive-unleashed-5.1
Takashi Iwai 2017-10-04 16:15:59 +02:00
parent 8a5776a5f4
commit e901b98738
2 changed files with 28 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
drivers/usb/core/urb.c
View File

@ -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]);

2
include/linux/usb.h
View File

@ -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,