media: mtk-vcodec: make flush buffer reusable by encoder

The flush buffer is a special buffer that tells the decoder driver to
send an empty CAPTURE frame to the client with V4L2_BUF_FLAG_LAST set.

We need similar functionality for the encoder ; however currently the
flush buffer depends on decoder-specific structures and thus cannot be
reused with the encoder.

Fix this by testing for this buffer by its VB2 address, and not through
a dedicated flag stored in a higher-level decoder structure. This also
allows us to remove said flag and simplify the code a bit.

Since the flush buffer should never be used in the stateless decoder,
also add safeguards to check against it.

Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
index 3f83710b4fa5..1d64c8e84168 100644
--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
@@ -13,6 +13,7 @@
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ioctl.h>
+#include <media/v4l2-mem2mem.h>
 #include <media/videobuf2-core.h>
 #include "mtk_vcodec_util.h"
 
@@ -249,7 +250,8 @@ struct vdec_pic_info {
  * @decode_work: worker for the decoding
  * @encode_work: worker for the encoding
  * @last_decoded_picinfo: pic information get from latest decode
- * @empty_flush_buf: a fake size-0 capture buffer that indicates flush
+ * @empty_flush_buf: a fake size-0 capture buffer that indicates flush. Only
+ *		     to be used with encoder and stateful decoder.
  *
  * @colorspace: enum v4l2_colorspace; supplemental to pixelformat
  * @ycbcr_enc: enum v4l2_ycbcr_encoding, Y'CbCr encoding
@@ -288,7 +290,7 @@ struct mtk_vcodec_ctx {
 	struct work_struct decode_work;
 	struct work_struct encode_work;
 	struct vdec_pic_info last_decoded_picinfo;
-	struct mtk_video_dec_buf *empty_flush_buf;
+	struct v4l2_m2m_buffer empty_flush_buf;
 
 	enum v4l2_colorspace colorspace;
 	enum v4l2_ycbcr_encoding ycbcr_enc;