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 91af3b1ef0d412e9d71720afb38f24a703ec4e6e..281e75027b34426d07536c3966ceb820b24e8a38 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;