Re: [PATCH v3 3/5] ARM: Exynos: switch to using generic cpufreq driver for Exynos4x12

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

On Monday, August 03, 2015 03:59:26 PM Viresh Kumar wrote:
> On 03-08-15, 12:17, Bartlomiej Zolnierkiewicz wrote:
> > 
> > Hi,
> > 
> > On Saturday, August 01, 2015 04:47:21 PM Viresh Kumar wrote:
> > > On 31-07-15, 20:49, Bartlomiej Zolnierkiewicz wrote:
> > > > diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
> > > > index 659879a..bf6d596 100644
> > > > --- a/drivers/cpufreq/Kconfig
> > > > +++ b/drivers/cpufreq/Kconfig
> > > > @@ -191,6 +191,7 @@ config CPUFREQ_DT
> > > >  	# if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
> > > >  	depends on !CPU_THERMAL || THERMAL
> > > >  	select PM_OPP
> > > > +	select EXYNOS_THERMAL if ARCH_EXYNOS
> > > >  	help
> > > >  	  This adds a generic DT based cpufreq driver for frequency management.
> > > >  	  It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
> > > 
> > > No, we shouldn't pollute generic Kconfig options with platform specific stuff.
> > 
> > The old code depended on this.  You couldn't enable boost support
> > without enabling thermal support (ARM_EXYNOS_CPU_FREQ_BOOST_SW
> > config option selected EXYNOS_THERMAL).
> > 
> > > Why don't you enable thermal in your .config?
> > 
> > It is enabled in exynos_defconfig but without the above change it
> > can disabled manually which is something that we don't want.
> 
> You are not getting it. I am not asking you to not select thermal, but
> to select it from within your architecture Kconfig option if you want.

OK.  Krzysztof/Kukjin do you agree with selecting EXYNOS_THERMAL
from ARCH_EXYNOS in the platform code?

> Over that, thermal is really an option, not a dependency. So, if
> someone manually disables it, its his problem not yours :)

I would really like it to be dependency not an option (+ I think
that ideally it should be checked at runtime, IOW we should be
checking from cpufreq-dt driver if the thermal support is enabled
before enabling boost support).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics