Re: [PATCH] rcar_vin: propagate querystd() error upstream

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Sergei,

Thank you for the patch.

On Thursday 20 August 2015 00:02:17 Sergei Shtylyov wrote:
> rcar_vin_set_fmt() defaults to  PAL when the subdevice's querystd() method
> call fails (e.g. due to I2C error).  This doesn't work very well when a
> camera being used  outputs NTSC which has different order of fields and
> resolution.  Let  us stop  pretending and return the actual error (which
> would prevent video capture on at least Renesas Henninger/Porter board
> where I2C seems particularly buggy).
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 
> ---
> The patch is against the 'media_tree.git' repo's 'fixes' branch.
> 
>  drivers/media/platform/soc_camera/rcar_vin.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: media_tree/drivers/media/platform/soc_camera/rcar_vin.c
> ===================================================================
> --- media_tree.orig/drivers/media/platform/soc_camera/rcar_vin.c
> +++ media_tree/drivers/media/platform/soc_camera/rcar_vin.c
> @@ -1592,7 +1592,7 @@ static int rcar_vin_set_fmt(struct soc_c
>  		/* Query for standard if not explicitly mentioned _TB/_BT */
>  		ret = v4l2_subdev_call(sd, video, querystd, &std);
>  		if (ret < 0)
> -			std = V4L2_STD_625_50;
> +			return ret;

What if the subdev doesn't implement querystd ? That's the case of camera 
sensors for instance. In that case we should default to V4L2_FIELD_NONE.

>  		field = std & V4L2_STD_625_50 ? V4L2_FIELD_INTERLACED_TB :
>  						V4L2_FIELD_INTERLACED_BT;

-- 
Regards,

Laurent Pinchart