Re: [PATCH v2] hwmon: max6650: add thermal cooling device capability

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Apr 18, 2019 at 02:02:48PM -0400, Jean-Francois Dagenais wrote:
> 
> > On Apr 18, 2019, at 13:38, Guenter Roeck <linux@roeck-us.net> wrote:
> > 
> >> +#if IS_ENABLED(CONFIG_THERMAL)
> > 
> > This will result in missing symbols if THERMAL is built as module
> > and this driver is built into the kernel. You'll have to adjust
> > Kconfig dependencies accordingly. See other drivers for examples.
> 
> Right! Was not a problem for me, but I do remember seing the "funny"
> ifdefs around.
> 

I know, it is annoying. There was an effort to make THERMAL boolean
instead of tristate, but it looks like that has stalled or was
rejected.

> > 
> >> +	data->cooling_dev =
> >> +		thermal_of_cooling_device_register(client->dev.of_node,
> >> +						   id->name, data,
> >> +						   &max6650_cooling_ops);
> >> +	if (IS_ERR(data->cooling_dev)) {
> >> +		err = PTR_ERR(data->cooling_dev);
> >> +		dev_err(&client->dev,
> >> +			"Failed to register as cooling device (%d)\n", err);
> >> +		return err;
> > 
> > Why would it be fatal for the driver if this fails ? It wasn't
> > fatal before.
> 
> Mmmh, you are right. This assumes that all users of max6650 would now require to
> be referred to in some thermal zone. Again, this was not a problem for my test
> environment.
> 
> Wow, two very egocentric issues. Will fix and send V3, thanks for the review!

Not really egocentric. Just keep in mind that there are existing use cases.

Thanks,
Guenter