V4L/DVB (10651): uvcvideo: Ignore empty bulk URBs

Devices may send a zero-length packet to signal the end of a bulk payload. If
the payload size is a multiple of the URB size the zero-length packet will be
received by the URB completion handler. Handle this by ignoring all empty URBs.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 9139086f940a..0789ba381fc1 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -540,6 +540,9 @@ static void uvc_video_decode_bulk(struct urb *urb,
         u8 *mem;
         int len, ret;
 
+        if (urb->actual_length == 0)
+                return;
+
         mem = urb->transfer_buffer;
         len = urb->actual_length;
         video->bulk.payload_size += len;