media: hantro: Empty encoder capture buffers by default

stable inclusion
from stable-v5.10.121
commit b6b70cd3ddfab2005771f81eb6a6f638b44d0e10
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b6b70cd3ddfab2005771f81eb6a6f638b44d0e10

--------------------------------

[ Upstream commit 309373a3 ]

The payload size for encoder capture buffers is set by the driver upon
finishing encoding each frame, based on the encoded length returned from
hardware, and whatever header and padding length used. Setting a
non-zero default serves no real purpose, and also causes issues if the
capture buffer is returned to userspace unused, confusing the
application.

Instead, always set the payload size to 0 for encoder capture buffers
when preparing them.

Fixes: 775fec69 ("media: add Rockchip VPU JPEG encoder driver")
Fixes: 082aaecf ("media: hantro: Fix .buf_prepare")
Signed-off-by: NChen-Yu Tsai <wenst@chromium.org>
Reviewed-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/staging/media/hantro/hantro_v4l2.c

@@ -644,8 +644,12 @@ static int hantro_buf_prepare(struct vb2_buffer *vb)
 	 * (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->plane_fmt[0].sizeimage);
+	if (V4L2_TYPE_IS_CAPTURE(vq->type)) {
+		if (ctx->is_encoder)
+			vb2_set_plane_payload(vb, 0, 0);
+		else
+			vb2_set_plane_payload(vb, 0, pix_fmt->plane_fmt[0].sizeimage);
+	}
 
 	return 0;
 }