Re: [PATCH v5 09/14] media: cadence: csi2rx: Add link validation

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Pratyush Yadav <p.yadav@ti.com>
Cc: "Mauro Carvalho Chehab" <mchehab@kernel.org>,
	"Nikhil Devshatwar" <nikhil.nd@ti.com>,
	"Tomi Valkeinen" <tomi.valkeinen@ideasonboard.com>,
	"Vignesh Raghavendra" <vigneshr@ti.com>,
	"Benoit Parrot" <bparrot@ti.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Sakari Ailus" <sakari.ailus@linux.intel.com>,
	"Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-media@vger.kernel.org
Subject: Re: [PATCH v5 09/14] media: cadence: csi2rx: Add link validation
Date: Thu, 30 Dec 2021 06:47:04 +0200	[thread overview]
Message-ID: <Yc05yD/P/UQlSG8B@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20211223191615.17803-10-p.yadav@ti.com>

Hi Pratyush,

Thank you for the patch.

On Fri, Dec 24, 2021 at 12:46:10AM +0530, Pratyush Yadav wrote:
> Add media link validation to make sure incorrectly configured pipelines
> are caught. Since there is no support for transcoding, rely on the
> default link validation function to make sure formats across source and
> sink pads are the same.

I think the commit message is a bit misleading. The default link
validation function ensures that formats on the source and sink sides of
a link match. It doesn't compare the formats on the sink and source pads
of the subdev. Whether the subdev can transcode or not is thus not
relevant here.

> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> 
> ---
> 
> Changes in v5:
> - New in v5.
> 
>  drivers/media/platform/cadence/cdns-csi2rx.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 53659776a906..119c7540c75a 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -492,6 +492,10 @@ static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
>  	.pad		= &csi2rx_pad_ops,
>  };
>  
> +static struct media_entity_operations csi2rx_media_ops = {

static const

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	.link_validate = v4l2_subdev_link_validate,
> +};
> +
>  static int csi2rx_async_bound(struct v4l2_async_notifier *notifier,
>  			      struct v4l2_subdev *s_subdev,
>  			      struct v4l2_async_subdev *asd)
> @@ -691,6 +695,7 @@ static int csi2rx_probe(struct platform_device *pdev)
>  	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
>  		csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
>  	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	csi2rx->subdev.entity.ops = &csi2rx_media_ops;
>  
>  	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,
>  				     csi2rx->pads);

-- 
Regards,

Laurent Pinchart