diff options
| author | chenchangcheng <chenchangcheng@kylinos.cn> | 2025-05-10 14:18:03 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 18:30:45 +0200 |
| commit | 55dc87dc2ac18e33ba2fbe74861f7af68cfdd62d (patch) | |
| tree | 6aafb7f285257dd35e2634e7e8b6bec7cf0a8b15 | |
| parent | ea955d78bbc4dec4fe1fcf05331a0b40237e2638 (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 eab7b8f55730..17ec298ee4f7 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -258,6 +258,15 @@ 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) |