Re: [PATCH] media: rcar-vin: require master VIN only for CSI source

["Niklas Söderlund" <niklas.soderlund@ragnatech.se>]

Hi Nikita,

Thanks for your work.

On 2022-02-02 13:47:00 +0300, Nikita Yushchenko wrote:
> Hardware limitations on VINs that can be used at the same time cover only
> CSI data source. For parallel source, any single VIN can work.
> 
> This patch moves check for master VIN availability in
> rvin_csi2_link_notify() below processing the parallel case.
> 
> This fixes media-ctl usage on KF board when both CSI and parallel cameras
> are in use on the same system. In such a setup, VINs 0-3 are used for
> CSI cameras and VIN5 is used for parallel camera.

I agree this issue needs to be addressed and I think the use-case is 
covered in the patch 1/3 in the VIN routing series [1]. I don't have 
access to King Fisher hardware so I can't test it, if you do could you 
test that series and see if it fix the issue?

1. [PATCH v3 0/3] media: rcar-{csi2,vin}: Move to full Virtual Channel routing per CSI-2 IP
   https://lore.kernel.org/linux-renesas-soc/20220124124858.571363-4-niklas.soderlund+renesas@ragnatech.se/T/

> 
> Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
> ---
>  drivers/media/platform/rcar-vin/rcar-core.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
> index 0186ae235113..038ee187f95a 100644
> --- a/drivers/media/platform/rcar-vin/rcar-core.c
> +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> @@ -826,11 +826,6 @@ static int rvin_csi2_link_notify(struct media_link *link, u32 flags,
>  	vin = container_of(vdev, struct rvin_dev, vdev);
>  	master_id = rvin_group_id_to_master(vin->id);
>  
> -	if (WARN_ON(!group->vin[master_id])) {
> -		ret = -ENODEV;
> -		goto out;
> -	}
> -
>  	/* Build a mask for already enabled links. */
>  	for (i = master_id; i < master_id + 4; i++) {
>  		if (!group->vin[i])
> @@ -878,6 +873,11 @@ static int rvin_csi2_link_notify(struct media_link *link, u32 flags,
>  		goto out;
>  	}
>  
> +	if (WARN_ON(!group->vin[master_id])) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
>  	channel = rvin_group_csi_pad_to_channel(link->source->index);
>  	mask_new = mask & rvin_csi2_get_mask(vin, csi_id, channel);
>  	vin_dbg(vin, "Try link change mask: 0x%x new: 0x%x\n", mask, mask_new);
> -- 
> 2.30.2
> 

-- 
Kind Regards,
Niklas Söderlund