On Wed, 11 Oct 2017 16:14:55 +0200, Johan Hovold wrote:
On Wed, Oct 11, 2017 at 12:36:38PM +0200, Takashi Iwai wrote:
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 Signed-off-by: Takashi Iwai tiwai@suse.de
v1->v2:
- Fix function name typos
- Call usb_urb_ep_type_check() in usb_submit_urb(), too
drivers/usb/core/urb.c | 30 ++++++++++++++++++++++++++---- include/linux/usb.h | 2 ++ 2 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 47903d510955..8b800e34407b 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -187,6 +187,31 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb);
/*-------------------------------------------------------------------*/
+static const int pipetypes[4] = {
- PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
+};
No this one is no longer used outside of usb_urb_ep_type_check().
It is used in the error message, so I kept it here.
+/**
- 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;And I know Greg asked you to call this function from usb_submit_urb() which have already done the above ep-lookup once. Maybe not that many extra cycles, but still seems unnecessary to me.
Yeah, we can do micro-optimization later if needed, e.g. splitting the function. It's a question of balance between code optimization and readability...
thanks,
Takashi
- 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]);
Johan