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

Jernej Škrabec
2019-09-30T16:44:15Z

Dne ponedeljek, 30. september 2019 ob 10:14:32 CEST je Hans Verkuil
napisal(a):
> 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?

To prevent warnings on arm64 such as reported here:
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1620796.html

But I'm not sure if this aplies for this case. I compiled kernel for arm64 but
there is no warning without this cast with my configuration. I guess I can
remove it.

Best regards,
Jernej

>
> 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,
> >
> > };