[ 062/108] [media] uvcvideo: Reset the bytesused field when recycling an erroneous buffer

From: Greg Kroah-Hartman
Date: Wed Sep 12 2012 - 20:32:37 EST

From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.5-stable review patch. If anyone has any objections, please let me know.


From: Jayakrishnan Memana <jayakrishnan.memana@xxxxxxxxxxxx>

commit 8a3f0ede2b3f5477122060af1a816c6bbf09fcd2 upstream.

Buffers marked as erroneous are recycled immediately by the driver if
the nodrop module parameter isn't set. The buffer payload size is reset
to 0, but the buffer bytesused field isn't. This results in the buffer
being immediately considered as complete, leading to an infinite loop in
interrupt context.

Fix the problem by resetting the bytesused field when recycling the

Signed-off-by: Jayakrishnan Memana <jayakrishnan.memana@xxxxxxxxxxxx>
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/media/video/uvc/uvc_queue.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -338,6 +338,7 @@ struct uvc_buffer *uvc_queue_next_buffer
if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
buf->error = 0;
buf->state = UVC_BUF_STATE_QUEUED;
+ buf->bytesused = 0;
vb2_set_plane_payload(&buf->buf, 0, 0);
return buf;

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