V4L/DVB: uvcvideo: Drop corrupted compressed frames

Corrupted video frames are dropped by default by the driver for
uncompressed formats. Data corruption is not less problematic for
compressed formats, so frame drop should be enabled by default for those
formats as well.

Mark buffers as faulty when an isochronous packet loss is detected for
any format, or when the buffer length doesn't match the image size for
uncompressed formats. Drop erroneous buffers regardless of whether the
format is compressed or uncompressed.

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

1 files changed, 11 insertions, 8 deletions

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 53f3ef4..e27cf0d 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -555,6 +555,9 @@ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 		if (urb->iso_frame_desc[i].status < 0) {
 			uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
 				"lost (%d).\n", urb->iso_frame_desc[i].status);
+			/* Mark the buffer as faulty. */
+			if (buf != NULL)
+				buf->error = 1;
 			continue;
 		}
 
@@ -579,8 +582,14 @@ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 		uvc_video_decode_end(stream, buf, mem,
 			urb->iso_frame_desc[i].actual_length);
 
-		if (buf->state == UVC_BUF_STATE_READY)
+		if (buf->state == UVC_BUF_STATE_READY) {
+			if (buf->buf.length != buf->buf.bytesused &&
+			    !(stream->cur_format->flags &
+			      UVC_FMT_FLAG_COMPRESSED))
+				buf->error = 1;
+
 			buf = uvc_queue_next_buffer(&stream->queue, buf);
+		}
 	}
 }
 
@@ -1104,7 +1113,7 @@ int uvc_video_init(struct uvc_streaming *stream)
 	atomic_set(&stream->active, 0);
 
 	/* Initialize the video buffers queue. */
-	uvc_queue_init(&stream->queue, stream->type);
+	uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param);
 
 	/* Alternate setting 0 should be the default, yet the XBox Live Vision
 	 * Cam (and possibly other devices) crash or otherwise misbehave if
@@ -1197,12 +1206,6 @@ int uvc_video_enable(struct uvc_streaming *stream, int enable)
 		return 0;
 	}
 
-	if ((stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED) ||
-	    uvc_no_drop_param)
-		stream->queue.flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
-	else
-		stream->queue.flags |= UVC_QUEUE_DROP_INCOMPLETE;
-
 	ret = uvc_queue_enable(&stream->queue, 1);
 	if (ret < 0)
 		return ret;