Re: [PATCH v5 01/10] media: rcar-vin: Link VINs on Gen3 to a single channel on each CSI-2

[Niklas Söderlund]

Hi Tomi,

Thanks for your work.

On 2026-03-11 15:53:14 +0200, Tomi Valkeinen wrote:
> The stream routing will be fully configurable when we add full streams
> support to the rcar pipeline. Thus there is no need for the user to be
> able to link VINs to different CSI-2 channels. In fact, allowing e.g.
> VIN0 to be connected to CSI-2 channel 3 would be wrong, as the hardware
> doesn't allow that.
> 
> Change rvin_csi2_create_link() so that it creates media links only
> between matching VINs and CSI-2 channels (VIN0 - channel 0, VIN1 -
> channel 1, etc.).
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>

I think you should break this out of the streams series so we can merge 
it before streams are enabled by default in the API.

> ---
>  .../media/platform/renesas/rcar-vin/rcar-core.c    | 27 ++++++++++++----------
>  1 file changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/rcar-vin/rcar-core.c b/drivers/media/platform/renesas/rcar-vin/rcar-core.c
> index c8d564aa1eba..2fcea715101c 100644
> --- a/drivers/media/platform/renesas/rcar-vin/rcar-core.c
> +++ b/drivers/media/platform/renesas/rcar-vin/rcar-core.c
> @@ -673,23 +673,26 @@ static int rvin_csi2_create_link(struct rvin_group *group, unsigned int id,
>  	struct media_entity *source = &group->remotes[route->csi].subdev->entity;
>  	struct media_entity *sink = &group->vin[id]->vdev.entity;
>  	struct media_pad *sink_pad = &sink->pads[0];
> +	struct media_pad *source_pad;
> +	unsigned int source_idx;
>  	unsigned int channel;
> -	int ret;
>  
> -	for (channel = 0; channel < 4; channel++) {
> -		unsigned int source_idx = rvin_group_csi_channel_to_pad(channel);
> -		struct media_pad *source_pad = &source->pads[source_idx];
> +	/*
> +	 * The channels from CSI-2 blocks and the VIN groups have a set of
> +	 * hardcoded routing options to choose from. We only support the routing
> +	 * where all VINs in a group are connected to the same CSI-2 block,
> +	 * and the Nth VIN in the group is connected to the Nth CSI-2 channel.
> +	 */
>  
> -		/* Skip if link already exists. */
> -		if (media_entity_find_link(source_pad, sink_pad))
> -			continue;
> +	channel = id % 4;
> +	source_idx = rvin_group_csi_channel_to_pad(channel);
> +	source_pad = &source->pads[source_idx];
>  
> -		ret = media_create_pad_link(source, source_idx, sink, 0, 0);
> -		if (ret)
> -			return ret;
> -	}
> +	/* Skip if link already exists. */
> +	if (media_entity_find_link(source_pad, sink_pad))
> +		return 0;
>  
> -	return 0;
> +	return media_create_pad_link(source, source_idx, sink, 0, 0);
>  }
>  
>  static int rvin_parallel_setup_links(struct rvin_group *group)
> 
> -- 
> 2.43.0
> 

-- 
Kind Regards,
Niklas Söderlund