6.6-stable review patch. If anyone has any objections, please let me know.
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From: chenchangcheng chenchangcheng@kylinos.cn
[ 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 --- drivers/media/usb/uvc/uvc_video.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index 9572fdfe74f2..83abca42c5f1 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)