diff options
| author | chenchangcheng <chenchangcheng@kylinos.cn> | 2025-05-10 14:18:03 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 18:41:27 +0200 |
| commit | 7a73a083dd847edb91b6b04d5d289f37be688bfc (patch) | |
| tree | 32dc8e4ae64edeed25f1d966717d4a7e963fa58b | |
| parent | 455fe47d9ffb1fbdad1ea587f341bc4f2a6f48c8 (diff) | |
media: uvcvideo: Fix bandwidth issue for Alcor camera
[ Upstream commit 9764401bf6f8a20eb11c2e78470f20fee91a9ea7 ]
Some broken device return wrong dwMaxPayloadTransferSize fields as
follows:
[ 218.632537] uvcvideo: Device requested 2752512 B/frame bandwidth.
[ 218.632598] uvcvideo: No fast enough alt setting for requested bandwidth.
When dwMaxPayloadTransferSize is greater than maxpsize, it will prevent
the camera from starting. So use the bandwidth of maxpsize.
Signed-off-by: chenchangcheng <chenchangcheng@kylinos.cn>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20250510061803.811433-1-ccc194101@163.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/media/usb/uvc/uvc_video.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index e3567aeb0007..11769a1832d2 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -262,6 +262,15 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, ctrl->dwMaxPayloadTransferSize = bandwidth; } + + if (stream->intf->num_altsetting > 1 && + ctrl->dwMaxPayloadTransferSize > stream->maxpsize) { + dev_warn_ratelimited(&stream->intf->dev, + "UVC non compliance: the max payload transmission size (%u) exceeds the size of the ep max packet (%u). Using the max size.\n", + ctrl->dwMaxPayloadTransferSize, + stream->maxpsize); + ctrl->dwMaxPayloadTransferSize = stream->maxpsize; + } } static size_t uvc_video_ctrl_size(struct uvc_streaming *stream) |