Re: [PATCH 2/2] media: v4l2-common: simplify v4l2_i2c_subdev_init name generation

[Philippe De Muyter <phdm@macqel.be>]

Hi Sakari,

On Fri, Aug 03, 2018 at 03:43:15PM +0300, Sakari Ailus wrote:
> Hi Philippe,
> 
> On Wed, Aug 01, 2018 at 11:20:57PM +0200, Philippe De Muyter wrote:
> > When v4l2_i2c_subdev_init is called, dev_name(&client->dev) has already
> > been set.  Use it to generate subdev's name instead of recreating it
> > with "%d-%04x".  This improves the similarity in subdev's name creation
> > between v4l2_i2c_subdev_init and v4l2_spi_subdev_init.
> > 
> > Signed-off-by: Philippe De Muyter <phdm@macqel.be>
> > ---
> >  drivers/media/v4l2-core/v4l2-common.c | 5 ++---
> >  1 file changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> > index 5471c6d..b062111 100644
> > --- a/drivers/media/v4l2-core/v4l2-common.c
> > +++ b/drivers/media/v4l2-core/v4l2-common.c
> > @@ -121,9 +121,8 @@ void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
> >  	v4l2_set_subdevdata(sd, client);
> >  	i2c_set_clientdata(client, sd);
> >  	/* initialize name */
> > -	snprintf(sd->name, sizeof(sd->name), "%s %d-%04x",
> > -		client->dev.driver->name, i2c_adapter_id(client->adapter),
> > -		client->addr);
> > +	snprintf(sd->name, sizeof(sd->name), "%s %s",
> > +		client->dev.driver->name, dev_name(&client->dev));
> >  }
> >  EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
> >  
> 
> I like the patch in principle. But what's the effect of this on the actual
> sub-device (and entity) names? Looking at i2c_dev_set_name(), this will be
> different. We can't change the existing entity naming in drivers, this will
> break applications that expect them to be named in a certain way.

Yeah.  I am 10 years too late.

Maybe adding for a long transition period a kernel message giving the new
name and the old one if they are different ?

Thank you

Philippe

-- 
Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles