Re: [PATCH 1/2] hwmon: gpio-fan: mark OF related data as maybe unused

[Guenter Roeck]

On 3/12/23 12:32, Krzysztof Kozlowski wrote:
> On 12/03/2023 19:48, Guenter Roeck wrote:
> > On 3/12/23 11:08, Krzysztof Kozlowski wrote:
> > > On 12/03/2023 19:06, Guenter Roeck wrote:
> > > > On Sat, Mar 11, 2023 at 12:16:09PM +0100, Krzysztof Kozlowski wrote:
> > > > > The driver can be compile tested with !CONFIG_OF making certain data
> > > > > unused:
> > > > >
> > > > >     drivers/hwmon/gpio-fan.c:484:34: error: ‘of_gpio_fan_match’ defined but not used [-Werror=unused-const-variable=]
> > > >
> > > > How do you trigger that ? The driver depends on OF_GPIO which
> > > > in turn depends on OF. Arguably that means that of_match_ptr()
> > > > doesnot really make sense, but still I don't see how you can
> > > > trigger the above error message.
> > >
> > > I can drop of_match_ptr, it's indeed in many cases not needed.
> > >
> > > I just build x86_64 allyesconfig minus OF, with W=1.
> >
> > x86_64 allyesconfig minus OF minus results in SENSORS_GPIO_FAN being
> > deselected (it doesn't show up in the configuration anymore at all
> > after "make olddefconfig").
> >
> > $ make allyesconfig
> > $ grep SENSORS_GPIO_FAN .config
> > CONFIG_SENSORS_GPIO_FAN=y
> > $ sed -i -e 's/CONFIG_OF=y/# CONFIG_OF is not set/' .config
> > $ make olddefconfig
> > #
> > # configuration written to .config
> > #
> > $ grep SENSORS_GPIO_FAN .config
> > $
> >
> > I suspect what you did is to disable CONFIG_OF, and then you built
> > the driver without realizing that is was deselected.
>
> The driver would not built. I mean, I did not cheat here to built it
> with incorrect config.
>
> I rather suspect that config is broken due to:
> WARNING: unmet direct dependencies detected for OF_GPIO
> WARNING: unmet direct dependencies detected for GPIO_SYSCON
> WARNING: unmet direct dependencies detected for MFD_STMFX
>
> This was next-20230308
Interesting. That has been fixed in next-20230310, where
SENSORS_GPIO_FAN is again deselected if CONFIG_OF is disabled.

> > > Do you want to me to drop of_match_ptr?
> >
> > Yes, sure, that makes more sense. The reason though is that the
> > driver depends on CONFIG_OF=y, not because of the build failure.
>
> I'll send v2 of both patches because anyway dropping of_match_ptr is
> preferred.
Ok.

Thanks,
Guenter