Re: [PATCH v3 1/2] watchdog: xen_wdt: use the watchdog subsystem

[Radu Rendec <rrendec@arista.com>]

On Wed, 2017-11-15 at 08:26 -0800, Guenter Roeck wrote:
> On Wed, Nov 15, 2017 at 03:34:40PM +0000, Radu Rendec wrote:
> > On Wed, 2017-11-15 at 06:58 -0800, Guenter Roeck wrote:
> > > On Tue, Nov 14, 2017 at 04:23:49PM +0000, Radu Rendec wrote:
> > > > diff --git a/drivers/watchdog/xen_wdt.c b/drivers/watchdog/xen_wdt.c
> > > > index 5dd5c3494d55..4e00419bd47d 100644
> > > > --- a/drivers/watchdog/xen_wdt.c
> > > > +++ b/drivers/watchdog/xen_wdt.c
> > > > @@ -9,9 +9,8 @@
> > > >   *	2 of the License, or (at your option) any later version.
> > > >   */
> > > >  
> > > > -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > > > -
> > > > -#define DRV_NAME	"wdt"
> > > > +#define DRV_NAME	"xen_wdt"
> > > > +#define DEV_NAME	"watchdog"
> > > 
> > > [ ... ]
> > > 
> > > >  
> > > > +static const struct platform_device_id xen_wdt_id_table[] = {
> > > > +	{ .name	= DEV_NAME },
> > > 
> > > I understand we are way into bikeshedding territory, and I was inclined
> > > to let this just go, but this is way too generic for a platform device
> > > ID, sorry.
> > 
> > Yes, that's the part I don't like about it either. So I think we're on
> > the same page here :)
> > 
> > FWIW, the old (current) version has the same problem, because in the
> > absence of an id_table (or a matching entry), platform_match() matches
> > against the driver name, which is just "wdt".
> > 
> > Anyway, how about using "xwdt0" for DEV_NAME? The driver supports only
> > one device by design, so adding "0" should be fine.
> > 
> 
> A numeric suffix to the device name suggests that there can be more than one,
> which would be misleading.
> 
> And all that because you don't like the output of dev_info(). Hope you don't
> start to mess with all the other drivers having the same "problem" of a less
> than perfect output from dev_ functions.

I was merely trying to make the output look better than just a repeated
string (which doesn't make much sense, IMHO).

At this point I see the following options:

   1. Revert to the previous patch version, but use dev_ instead of pr_ as
      you suggested. Messages would look like "wdt wdt: ...". Note that
      this still has the problem of registering a platform "id" of "wdt"
      which *is* quite generic and may collide with other drivers.
   2. Same as above, but change DRV_NAME to "xen_wdt", which is less
      generic. Messages would look like "xen_wdt xen_wdt: ...".
   3. Keep the id_table and change DEV_NAME to something without a numeric
      suffix, e.g. "xwdt".

At the end of the day, what I really want is to port the xen_wdt driver
to use the watchdog subsystem.

Please let me know which of the above options you prefer and I will
send an updated v4.

Thanks,
Radu