[PATCH AUTOSEL 6.8 09/28] usb: gadget: uvc: mark incomplete frames with UVC_STREAM_ERR

Sasha Levin
2024-04-03T17:17:13Z

From: Michael Grzeschik <m.grzeschik@pengutronix.de>

[ 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>
---
drivers/usb/gadget/function/uvc_video.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index dbdd9033c1268..53e4cd81ea446 100644
--- 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;
--
2.43.0