Re: [PATCH v7 07/11] media: rkvdec: Add the VP9 backend - Chen-Yu Tsai

From: Chen-Yu Tsai <wenst@chromium.org>
To: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Cc: Linux Media Mailing List <linux-media@vger.kernel.org>,
	 "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
	<linux-arm-kernel@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	 "open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>,
	linux-staging@lists.linux.dev,
	 Benjamin Gaignard <benjamin.gaignard@collabora.com>,
	 Boris Brezillon <boris.brezillon@collabora.com>,
	 Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>,
	Fabio Estevam <festevam@gmail.com>,
	 Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	 Heiko Stuebner <heiko@sntech.de>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	 Mauro Carvalho Chehab <mchehab@kernel.org>,
	Nicolas Dufresne <nicolas.dufresne@collabora.com>,
	 NXP Linux Team <linux-imx@nxp.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	 Philipp Zabel <p.zabel@pengutronix.de>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	 Shawn Guo <shawnguo@kernel.org>,
	kernel@collabora.com,  Ezequiel Garcia <ezequiel@collabora.com>,
	Adrian Ratiu <adrian.ratiu@collabora.com>
Subject: Re: [PATCH v7 07/11] media: rkvdec: Add the VP9 backend
Date: Fri, 8 Oct 2021 18:30:26 +0800	[thread overview]
Message-ID: <CAGXv+5GU3f40BijQxazGVtJ0o9rZY_cux9mxRUEtXYHF2Oz-UQ@mail.gmail.com> (raw)
In-Reply-To: <20210929160439.6601-8-andrzej.p@collabora.com>

Hi,

On Thu, Sep 30, 2021 at 12:07 AM Andrzej Pietrasiewicz
<andrzej.p@collabora.com> wrote:
>
> From: Boris Brezillon <boris.brezillon@collabora.com>
>
> The Rockchip VDEC supports VP9 profile 0 up to 4096x2304@30fps. Add
> a backend for this new format.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
> Co-developed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
> ---
>  drivers/staging/media/rkvdec/Kconfig      |    1 +
>  drivers/staging/media/rkvdec/Makefile     |    2 +-
>  drivers/staging/media/rkvdec/rkvdec-vp9.c | 1078 +++++++++++++++++++++
>  drivers/staging/media/rkvdec/rkvdec.c     |   52 +-
>  drivers/staging/media/rkvdec/rkvdec.h     |   12 +-
>  5 files changed, 1137 insertions(+), 8 deletions(-)
>  create mode 100644 drivers/staging/media/rkvdec/rkvdec-vp9.c
>

[...]

> diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c
> index 7131156c1f2c..6aa8aca66547 100644
> --- a/drivers/staging/media/rkvdec/rkvdec.c
> +++ b/drivers/staging/media/rkvdec/rkvdec.c

[...]

> @@ -319,7 +354,7 @@ static int rkvdec_s_output_fmt(struct file *file, void *priv,
>         struct v4l2_m2m_ctx *m2m_ctx = ctx->fh.m2m_ctx;
>         const struct rkvdec_coded_fmt_desc *desc;
>         struct v4l2_format *cap_fmt;
> -       struct vb2_queue *peer_vq;
> +       struct vb2_queue *peer_vq, *vq;
>         int ret;
>
>         /*
> @@ -331,6 +366,15 @@ static int rkvdec_s_output_fmt(struct file *file, void *priv,
>         if (vb2_is_busy(peer_vq))
>                 return -EBUSY;
>
> +       /*
> +        * Some codecs like VP9 can contain dynamic resolution changes which
> +        * are currently not supported by the V4L2 API or driver, so return
> +        * an error if userspace tries to reconfigure the output format.
> +        */
> +       vq = v4l2_m2m_get_vq(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
> +       if (vb2_is_busy(vq))
> +               return -EINVAL;

This check is already done in rkvdec_s_fmt(), though it returns -EBUSY
instead. And I don't see similar changes to Hantro, so maybe this isn't
an API limitation as described in the comment? My recent patch [1] also
loosens the restrictions on this.

ChenYu

[1] https://lore.kernel.org/linux-media/20211008100423.739462-3-wenst@chromium.org/

> +
>         ret = rkvdec_s_fmt(file, priv, f, rkvdec_try_output_fmt);
>         if (ret)
>                 return ret;