linux-kernel - Re: [PATCH v2 1/9] thermal: cpu_cooling: Require thermal core to be compiled in

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Message-ID: <CAP245DWTyaOFhS3SYwAmLGpczQo9JR+gsDbGdHAnoxpTWayjgg@mail.gmail.com>
Date:   Wed, 23 Jan 2019 16:22:40 +0530
From:   Amit Kucheria <amit.kucheria@...aro.org>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        Eduardo Valentin <edubezval@...il.com>,
        Stephen Boyd <swboyd@...omium.org>,
        Doug Anderson <dianders@...omium.org>,
        Matthias Kaehlcke <mka@...omium.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Linux PM list <linux-pm@...r.kernel.org>
Subject: Re: [PATCH v2 1/9] thermal: cpu_cooling: Require thermal core to be
 compiled in

On Wed, Jan 23, 2019 at 4:04 PM Viresh Kumar <viresh.kumar@...aro.org> wrote:
>
> On 21-01-19, 21:10, Amit Kucheria wrote:
> > The CPU cooling driver (cpu_cooling.c) allows the platform's cpufreq
> > driver to register as a cooling device and cool down the platform by
> > throttling the CPU frequency. In order to be able to auto-register a
> > cpufreq driver as a cooling device from the cpufreq core, we need access
> > to code inside cpu_cooling.c which, in turn, accesses code inside
> > thermal core.
> >
> > CPU_FREQ is a bool while THERMAL is tristate.  In some configurations
> > (e.g. allmodconfig), CONFIG_THERMAL ends up as a module while
> > CONFIG_CPU_FREQ is compiled in. This leads to following error:
> >
> > drivers/cpufreq/cpufreq.o: In function `cpufreq_offline':
> > cpufreq.c:(.text+0x407c): undefined reference to `cpufreq_cooling_unregister'
> > drivers/cpufreq/cpufreq.o: In function `cpufreq_online':
> > cpufreq.c:(.text+0x70c0): undefined reference to `of_cpufreq_cooling_register'
> >
> > Given that platforms using CPU_THERMAL usually want it compiled-in so it
> > is available early in boot, make CPU_THERMAL depend on THERMAL being
> > compiled-in instead of allowing it to be a module.
> >
> > Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > Signed-off-by: Amit Kucheria <amit.kucheria@...aro.org>
> > ---
> >  drivers/thermal/Kconfig | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> > index 30323426902e..58bb7d72dc2b 100644
> > --- a/drivers/thermal/Kconfig
> > +++ b/drivers/thermal/Kconfig
> > @@ -152,6 +152,7 @@ config CPU_THERMAL
> >       bool "generic cpu cooling support"
> >       depends on CPU_FREQ
> >       depends on THERMAL_OF
> > +     depends on THERMAL=y
> >       help
> >         This implements the generic cpu cooling mechanism through frequency
> >         reduction. An ACPI version of this already exists
>
> Please remove all Kconfig crap, which gets fixed with this, as well in
> this patch itself. Like:

OK, I planned to if/when this series was accepted. Will send out a patch.


> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index 10bc5c798d17..40f8cc323996 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -40,8 +40,6 @@ config ARM_ARMADA_8K_CPUFREQ
>  config ARM_BIG_LITTLE_CPUFREQ
>         tristate "Generic ARM big LITTLE CPUfreq driver"
>         depends on ARM_CPU_TOPOLOGY && HAVE_CLK
> -       # if CPU_THERMAL is on and THERMAL=m, ARM_BIT_LITTLE_CPUFREQ cannot be =y
> -       depends on !CPU_THERMAL || THERMAL
>         select PM_OPP
>         help
>           This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.
>
> --
> viresh