media: uvcvideo: Allow userspace to increase the meta buffersize

media: uvcvideo: Allow userspace to increase the meta buffersize

Now we have the metadata size hardcoded to 10 KiB, this is a value that
works fine for bulk cameras or frames with no extra metadata. But not
for all usecases.

We have seen some cameras that produce more metadata per frame. Eg:
Frame 1 captured (Bytes: 11154)
Frame 2 captured (Bytes: 11616)
Frame 3 captured (Bytes: 11374)
Frame 4 captured (Bytes: 11132)
Frame 5 captured (Bytes: 11594)
Frame 6 captured (Bytes: 11352)
Frame 7 captured (Bytes: 11110)
Frame 8 captured (Bytes: 11572)
Frame 9 captured (Bytes: 11308)

When this happens, the driver (correctly) marks the metadata as ERROR.

This patch let userspace set bigger buffersize via S_FMT.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patch.msgid.link/20260309-uvc-metadata-dmabuf-v1-3-fc8b87bd29c5@chromium.org
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>