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

Hans Verkuil
2019-09-30T08:14:47Z

On 9/29/19 10:00 PM, Jernej Skrabec wrote:
> 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@siol.net>
> ---
> 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;

Why the u32 cast?

Regards,

Hans

> + 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,
> };