This is a note to let you know that I've just added the patch titled media: cedrus: Fix .buf_prepare to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-cedrus-fix-.buf_prepare.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit db8f592d46520d1c83383bcf3afae9eb3818f82b Author: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx> Date: Wed May 5 14:23:47 2021 +0200 media: cedrus: Fix .buf_prepare [ Upstream commit d84b9202d712309840f8b5abee0ed272506563bd ] The driver should only set the payload on .buf_prepare if the buffer is CAPTURE type. If an OUTPUT buffer has a zero bytesused set by userspace then v4l2-core will set it to buffer length. If we overwrite bytesused for OUTPUT buffers, too, then vb2_get_plane_payload() will return incorrect value which might be then written to hw registers by the driver in cedrus_h264.c or cedrus_vp8.c. Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_video.c b/drivers/staging/media/sunxi/cedrus/cedrus_video.c index b62eb8e84057..bf731caf2ed5 100644 --- a/drivers/staging/media/sunxi/cedrus/cedrus_video.c +++ b/drivers/staging/media/sunxi/cedrus/cedrus_video.c @@ -457,7 +457,13 @@ static int cedrus_buf_prepare(struct vb2_buffer *vb) if (vb2_plane_size(vb, 0) < pix_fmt->sizeimage) return -EINVAL; - vb2_set_plane_payload(vb, 0, pix_fmt->sizeimage); + /* + * Buffer's bytesused must be written by driver for CAPTURE buffers. + * (for OUTPUT buffers, if userspace passes 0 bytesused, v4l2-core sets + * it to buffer length). + */ + if (V4L2_TYPE_IS_CAPTURE(vq->type)) + vb2_set_plane_payload(vb, 0, pix_fmt->sizeimage); return 0; }