> On Apr 18, 2019, at 16:12, Guenter Roeck <[email protected]> wrote:
>
> That explains why the other drivers don't generate an error message.
> You might want to reconsider the dev_err() above; it appears it adds zero
> value.
>
>> If I am wrong, then pwm-fan.c should also be visited since my max6650_probe
>> code
>> was copy-pasted from it.
>>
>
> You are correct, that should not fail either. But two wrongs don't make it
> right.
So you think any fan chip driver probe function in hwmon should succeed even if
(devm_)thermal_of_cooling_device_register fails?. Mmmh... perhaps I am missing
something, but I tend to disagree. That means that for example my system boots
normally without any errors, yet the thermal-zone I defined, which is there to
prevent my system from burning out, would remain incomplete (without required
cooling device) and yet no errors came out of the kernel.
I just tested it and that's exactly what's happening! Yikes.
>
>>
>> On a related note, I am worried about everyone having to progressively add
>> thermal-zone support to each fan chip in drivers/hwmon. Would it not be
>> possible
>> for hwmon to detect, through `enum hwmon_sensor_types` set to `hwmon_fan` in
>> `struct hwmon_channel_info` to be registered as cooling device in thermal ?
>> Of
>> course for max665x to work, it would have to be modified to use
>> `devm_hwmon_device_register_with_info` instead of
>> `devm_hwmon_device_register_with_groups`
>>
>
> Yes, that would be desirable. Patches welcome. And, yes, the driver would have
> to be reworked to use the new API.
>
>> Another possiblity would be to create a new driver in drivers/thermal for
>> max665x as a thermal cooling device. Or even a
>
> Only if we also drop the existing driver from hwmon. Fine with me if others
> agree and let you do it (one less hwmon driver to maintain).
>
> Note that I just submitted a patch series to introduce
> devm_thermal_of_cooling_device_register(). We'll see if the thermal
> maintainers
> accept it.
Saw that. For a minute I really thought you pulled out a series which did
exactly
what I was talking about (i.e. auto-registering fans in thermal cooling)!!
Since my problem is fixed in the short term, and am very stretched for time with
our project, I will not have time to do this now. Perhaps one day... ;)
