[PATCH v2 6/6] media: cedrus: Add support for holding capture buffer

[Jernej Skrabec]

When frame contains multiple slices and driver works in slice mode, it's
more efficient to hold capture buffer in queue until all slices of a
same frame are decoded.

Add support for that to Cedrus driver by exposing and implementing
V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF capability.

Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
---
 drivers/staging/media/sunxi/cedrus/cedrus_dec.c   |  9 +++++++++
 drivers/staging/media/sunxi/cedrus/cedrus_hw.c    |  8 +++++---
 drivers/staging/media/sunxi/cedrus/cedrus_video.c | 14 ++++++++++++++
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c
index e49c3396ca4d..67f7d4326fc1 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c
@@ -31,6 +31,14 @@ void cedrus_device_run(void *priv)
 
 	run.src = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
 	run.dst = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
+
+	if (v4l2_m2m_release_capture_buf(run.src, run.dst)) {
+		v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
+		v4l2_m2m_buf_done(run.dst, VB2_BUF_STATE_DONE);
+		run.dst = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
+	}
+	run.dst->is_held = run.src->flags & V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF;
+
 	run.first_slice = !run.dst->vb2_buf.copied_timestamp ||
 		run.src->vb2_buf.timestamp != run.dst->vb2_buf.timestamp;
 
@@ -46,6 +54,7 @@ void cedrus_device_run(void *priv)
 			V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS);
 		run.mpeg2.quantization = cedrus_find_control_data(ctx,
 			V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION);
+		run.dst->is_held = false;
 		break;
 
 	case V4L2_PIX_FMT_H264_SLICE:
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
index fc8579b90dab..b466041c25db 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
@@ -122,7 +122,7 @@ static irqreturn_t cedrus_irq(int irq, void *data)
 	dev->dec_ops[ctx->current_codec]->irq_clear(ctx);
 
 	src_buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
-	dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
+	dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
 
 	if (!src_buf || !dst_buf) {
 		v4l2_err(&dev->v4l2_dev,
@@ -136,8 +136,10 @@ static irqreturn_t cedrus_irq(int irq, void *data)
 		state = VB2_BUF_STATE_DONE;
 
 	v4l2_m2m_buf_done(src_buf, state);
-	v4l2_m2m_buf_done(dst_buf, state);
-
+	if (!dst_buf->is_held) {
+		v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
+		v4l2_m2m_buf_done(dst_buf, state);
+	}
 	v4l2_m2m_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx);
 
 	return IRQ_HANDLED;
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_video.c b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
index 3ec3a2db790c..82198b2bb081 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_video.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
@@ -303,6 +303,17 @@ static int cedrus_s_fmt_vid_out(struct file *file, void *priv,
 
 	ctx->src_fmt = f->fmt.pix;
 
+	switch (ctx->src_fmt.pixelformat) {
+	case V4L2_PIX_FMT_H264_SLICE:
+		vq->subsystem_flags |=
+			VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
+		break;
+	default:
+		vq->subsystem_flags &=
+			(u32)~VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
+		break;
+	}
+
 	/* Propagate colorspace information to capture. */
 	ctx->dst_fmt.colorspace = f->fmt.pix.colorspace;
 	ctx->dst_fmt.xfer_func = f->fmt.pix.xfer_func;
@@ -336,6 +347,9 @@ const struct v4l2_ioctl_ops cedrus_ioctl_ops = {
 	.vidioc_streamon		= v4l2_m2m_ioctl_streamon,
 	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,
 
+	.vidioc_try_decoder_cmd		= v4l2_m2m_ioctl_stateless_try_decoder_cmd,
+	.vidioc_decoder_cmd		= v4l2_m2m_ioctl_stateless_decoder_cmd,
+
 	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
 	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
 };
-- 
2.23.0