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Message-ID: <e716f649-dec7-ec71-8054-05f05167a042@xs4all.nl>
Date:   Thu, 18 Aug 2022 12:55:15 +0200
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Subject: Re: [PATCH v25 4/4] media: platform: mtk-mdp3: add MediaTek MDP3
 driver
Content-Language: en-US
To:     Moudy Ho <moudy.ho@mediatek.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc:     Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Rob Landley <rob@landley.net>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org,
        Alexandre Courbot <acourbot@chromium.org>, tfiga@chromium.org,
        drinkcat@chromium.org, pihsun@chromium.org, hsinyi@google.com,
        Benjamin Gaignard <benjamin.gaignard@collabora.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Project_Global_Chrome_Upstream_Group@mediatek.com,
        cellopoint.kai@gmail.com, Ping-Hsun Wu <ping-hsun.wu@mediatek.com>,
        daoyuan huang <daoyuan.huang@mediatek.com>
References: <20220817095629.29911-1-moudy.ho@mediatek.com>
 <20220817095629.29911-5-moudy.ho@mediatek.com>
From:   Hans Verkuil <hverkuil-cisco@xs4all.nl>
In-Reply-To: <20220817095629.29911-5-moudy.ho@mediatek.com>
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Precedence: bulk

Hi Moudy,

Just two nitpicks:

On 17/08/2022 11:56, Moudy Ho wrote:
> This patch adds driver for MediaTek's Media Data Path ver.3 (MDP3).
> It provides the following functions:
>   color transform, format conversion, resize, crop, rotate, flip
>   and additional image quality enhancement.
> 
> The MDP3 driver is mainly used for Google Chromebook products to
> import the new architecture to set the HW settings as shown below:
>   User -> V4L2 framework
>     -> MDP3 driver -> SCP (setting calculations)
>       -> MDP3 driver -> CMDQ (GCE driver) -> HW
> 
> Each modules' related operation control is sited in mtk-mdp3-comp.c
> Each modules' register table is defined in file with "mdp_reg_" prefix
> GCE related API, operation control  sited in mtk-mdp3-cmdq.c
> V4L2 m2m device functions are implemented in mtk-mdp3-m2m.c
> Probe, power, suspend/resume, system level functions are defined in
> mtk-mdp3-core.c

<snip>

> diff --git a/drivers/media/platform/mediatek/mdp3/Kconfig b/drivers/media/platform/mediatek/mdp3/Kconfig
> new file mode 100644
> index 000000000000..e8c593c1eb69
> --- /dev/null
> +++ b/drivers/media/platform/mediatek/mdp3/Kconfig
> @@ -0,0 +1,20 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +config VIDEO_MEDIATEK_MDP3
> +	tristate "MediaTek MDP v3 driver"
> +	depends on MTK_IOMMU || COMPILE_TEST
> +	depends on VIDEO_DEV
> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	depends on MTK_MMSYS

This needs to be MTK_MMSYS || COMPILE_TEST.

> +	depends on HAS_DMA
> +	select VIDEOBUF2_DMA_CONTIG
> +	select V4L2_MEM2MEM_DEV
> +	select VIDEO_MEDIATEK_VPU
> +	select MTK_CMDQ
> +	select MTK_SCP
> +	default n
> +	help
> +	    It is a v4l2 driver and present in MediaTek MT8183 SoC.
> +	    The driver supports scaling and color space conversion.
> +
> +	    To compile this driver as a module, choose M here: the
> +	    module will be called mtk-mdp3.

<snip>

> diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c
> new file mode 100644
> index 000000000000..0c1675c6dce2
> --- /dev/null
> +++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c
> @@ -0,0 +1,724 @@

<snip>

> +static int mdp_m2m_s_selection(struct file *file, void *fh,
> +			       struct v4l2_selection *s)
> +{
> +	struct mdp_m2m_ctx *ctx = fh_to_ctx(fh);
> +	struct mdp_frame *frame = ctx_get_frame(ctx, s->type);
> +	struct mdp_frame *capture;
> +	struct v4l2_rect r;
> +	struct device *dev = &ctx->mdp_dev->pdev->dev;
> +	bool valid = false;
> +	int ret;
> +
> +	if (s->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
> +		valid = (s->target == V4L2_SEL_TGT_CROP);
> +	else if (s->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		valid = (s->target == V4L2_SEL_TGT_COMPOSE);
> +
> +	if (!valid) {
> +		dev_err(dev, "[%s:%d] invalid type:%u target:%u", __func__,
> +			ctx->id, s->type, s->target);

This needs to be dev_dbg: you don't want to spam the kernel log for
userspace errors.

> +		return -EINVAL;
> +	}
> +
> +	ret = mdp_try_crop(ctx, &r, s, frame);
> +	if (ret)
> +		return ret;
> +	capture = ctx_get_frame(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
> +
> +	if (mdp_target_is_crop(s->target))
> +		capture->crop.c = r;
> +	else
> +		capture->compose = r;
> +
> +	s->r = r;
> +
> +	return 0;
> +}

I can modify these two changes myself if you are OK with that. Just let me know.

If you prefer to post a v26 that's OK too.

Regards,

	Hans