From: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx> [ 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> --- drivers/staging/media/sunxi/cedrus/cedrus_video.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_video.c b/drivers/staging/media/sunxi/cedrus/cedrus_video.c index 911f607d9b09..16327be904d1 100644 --- a/drivers/staging/media/sunxi/cedrus/cedrus_video.c +++ b/drivers/staging/media/sunxi/cedrus/cedrus_video.c @@ -449,7 +449,13 @@ 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; } -- 2.30.2
