Hi,
On Sunday 27 September 2009 10:30:34 tom.leiming@xxxxxxxxx wrote:
> From: Ming Lei <tom.leiming@xxxxxxxxx>
>
> This patch sets stream->urb_size as psize*npackets
> before calling uvc_alloc_urb_buffers, which may fix
> a possible failure of usb_buffer_free in case usb_buffer_alloc
> returns NULL. The patch is based on the ideas below:
>
> 1,If usb_buffer_alloc can't allocate a buffer sucessfully,
> uvc_free_urb_buffers will be called to free the allocated
> buffers, and stream->urb_size is required to be passed to
> usb_buffer_free;
>
> 2,uvc_free_urb_buffers can reset stream->urb_size.
>
> This patch is against linux-v2.6.31-next-20090926.
Good catch, thanks.
> Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
I've applied the patch to my tree and I'll send a pull request.
> ---
> drivers/media/video/uvc/uvc_video.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/video/uvc/uvc_video.c
> b/drivers/media/video/uvc/uvc_video.c index f960e8e..31dba66 100644
> --- a/drivers/media/video/uvc/uvc_video.c
> +++ b/drivers/media/video/uvc/uvc_video.c
> @@ -768,9 +768,10 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming
> *stream,
>
> /* Retry allocations until one succeed. */
> for (; npackets > 1; npackets /= 2) {
> + stream->urb_size = psize * npackets;
> for (i = 0; i < UVC_URBS; ++i) {
> stream->urb_buffer[i] = usb_buffer_alloc(
> - stream->dev->udev, psize * npackets,
> + stream->dev->udev, stream->urb_size,
> gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
> if (!stream->urb_buffer[i]) {
> uvc_free_urb_buffers(stream);
> @@ -779,7 +780,6 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming
> *stream, }
>
> if (i == UVC_URBS) {
> - stream->urb_size = psize * npackets;
> return npackets;
> }
> }
>
--
Regards,
Laurent Pinchart
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