From 309373a3571ef7175bd9da0c9b13476a718e8478 Mon Sep 17 00:00:00 2001
From: Chen-Yu Tsai <wenst@chromium.org>
Date: Thu, 31 Mar 2022 09:49:06 +0100
Subject: [PATCH] media: hantro: Empty encoder capture buffers by default
Git-commit: 309373a3571ef7175bd9da0c9b13476a718e8478
Patch-mainline: v5.19-rc1
References: git-fixes

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: 775fec69008d ("media: add Rockchip VPU JPEG encoder driver")
Fixes: 082aaecff35f ("media: hantro: Fix .buf_prepare")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/media/hantro/hantro_v4l2.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/hantro/hantro_v4l2.c b/drivers/staging/media/hantro/hantro_v4l2.c
index 8b8276ff7b28..71a6279750bf 100644
--- a/drivers/staging/media/hantro/hantro_v4l2.c
+++ b/drivers/staging/media/hantro/hantro_v4l2.c
@@ -768,8 +768,12 @@ 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;
 }
-- 
2.35.3