usb: gadget: uvc: mark incomplete frames with UVC_STREAM_ERR

[ Upstream commit 2a3b7af120477d0571b815ccb8600cafd5ebf02f ]

If an frame was transmitted incomplete to the host, we set the
UVC_STREAM_ERR bit in the header for the last request that is going
to be queued. This way the host will know that it should drop the
frame instead of trying to display the corrupted content.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20240214-uvc-error-tag-v1-2-37659a3877fe@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index dbdd9033c126819fcc88fafd60b772ffbf2b872c..53e4cd81ea4465299137db10f85a6f5d371bf879 100644 (file)
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -35,6 +35,9 @@ uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf,
 
        data[1] = UVC_STREAM_EOH | video->fid;
 
+       if (video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE)
+               data[1] |= UVC_STREAM_ERR;
+
        if (video->queue.buf_used == 0 && ts.tv_sec) {
                /* dwClockFrequency is 48 MHz */
                u32 pts = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48;