V4L/DVB (13153): uvcvideo: Fix uvc_alloc_urb_buffers()
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.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index bb9fed6..3369200 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -770,8 +770,9 @@
/* Retry allocations until one succeed. */
for (; npackets > 1; npackets /= 2) {
for (i = 0; i < UVC_URBS; ++i) {
+ stream->urb_size = psize * npackets;
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);
@@ -780,7 +781,6 @@
}
if (i == UVC_URBS) {
- stream->urb_size = psize * npackets;
uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers "
"of %ux%u bytes each.\n", UVC_URBS, npackets,
psize);
