Re: [PATCH] media: i2c: imx274: implement enum_mbus_code

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Luca,

On Thu, Nov 18, 2021 at 06:11:35PM +0100, Luca Ceresoli wrote:
> Hi Eugen,
> 
> On 18/11/21 16:40, Eugen Hristev wrote:
> > Current driver supports only SRGGB 10 bit RAW bayer format.
> > Add the enum_mbus_code implementation to report this format supported.
> > 
> >  # v4l2-ctl -d /dev/v4l-subdev3 --list-subdev-mbus-codes
> > ioctl: VIDIOC_SUBDEV_ENUM_MBUS_CODE (pad=0)
> >         0x300f: MEDIA_BUS_FMT_SRGGB10_1X10
> >  #
> > 
> > Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> 
> Generally OK, but I have a few minor comments.
> 
> > ---
> >  drivers/media/i2c/imx274.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> > 
> > diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
> > index 2e804e3b70c4..25a4ef8f6187 100644
> > --- a/drivers/media/i2c/imx274.c
> > +++ b/drivers/media/i2c/imx274.c
> > @@ -1909,7 +1909,21 @@ static int imx274_set_frame_interval(struct stimx274 *priv,
> >  	return err;
> >  }
> >  
> > +static int imx274_enum_mbus_code(struct v4l2_subdev *sd,
> > +				 struct v4l2_subdev_state *sd_state,
> > +				 struct v4l2_subdev_mbus_code_enum *code)
> > +{
> > +	if (code->index > 0)
> > +		return -EINVAL;
> 
> Many driver do check code->pad too, so you might want to do
> 
> 	if (code->pad > 0 || code->index > 0)
> 		return -EINVAL;

The caller will have checked the pad exists, and there's a single one on
the subdev I suppose.

> 
> However I don't think it is strictly necessary, thus
> 
> > +
> > +	/* only supported format in the driver is Raw 10 bits SRGGB */
> > +	code->code = MEDIA_BUS_FMT_SRGGB10_1X10;
> 
> Maybe better:
> 
>   code->code =  to_imx274(sd)->format.code

Good idea.

> 
> just as a little guard for future format changes.
> 
> With or without these I'm OK anyway with the patch, so:
> 
> Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
> 
> -- 
> Luca

-- 
Sakari Ailus