Re: [PATCH v9 07/28] rcar-vin: change name of video device

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

Hi Sakari,

On Thursday, 14 December 2017 16:25:00 EET Sakari Ailus wrote:
> On Fri, Dec 08, 2017 at 10:17:36AM +0200, Laurent Pinchart wrote:
> > On Friday, 8 December 2017 03:08:21 EET Niklas Söderlund wrote:
> > > The rcar-vin driver needs to be part of a media controller to support
> > > Gen3. Give each VIN instance a unique name so it can be referenced from
> > > userspace.
> > > 
> > > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > > Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
> > > ---
> > > 
> > >  drivers/media/platform/rcar-vin/rcar-v4l2.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > > b/drivers/media/platform/rcar-vin/rcar-v4l2.c index
> > > 59ec6d3d119590aa..19de99133f048960 100644
> > > --- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > > +++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > > @@ -876,7 +876,8 @@ int rvin_v4l2_register(struct rvin_dev *vin)
> > > 
> > >  	vdev->fops = &rvin_fops;
> > >  	vdev->v4l2_dev = &vin->v4l2_dev;
> > >  	vdev->queue = &vin->queue;
> > > 
> > > -	strlcpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name));
> > > +	snprintf(vdev->name, sizeof(vdev->name), "%s %s", KBUILD_MODNAME,
> > > +		 dev_name(vin->dev));
> > 
> > Do we need the module name here ? How about calling them "%s output",
> > dev_name(vin->dev) to emphasize the fact that this is a video node and not
> > a VIN subdev ? This is what the omap3isp and vsp1 drivers do.
> > 
> > We're suffering a bit from the fact that V4L2 has never standardized a
> > naming scheme for the devices. It wouldn't be fair to ask you to fix that
> > as a prerequisite to get the VIN driver merged, but we clearly have to
> > work on that at some point.
> 
> Agreed, this needs to be stable and I think aligning to what omap3isp or
> vsp1 do would be a good fix here.

Even omap3isp and vsp1 are not fully aligned, so I think we need to design a 
naming policy and document it.

-- 
Regards,

Laurent Pinchart