linux-kernel - Re: [PATCH v6 5/8] cpufreq:boost:Kconfig: Provide support for software managed BOOST

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Message-id: <20130812122614.0d4d31a3@amdc308.digital.local>
Date:	Mon, 12 Aug 2013 12:26:14 +0200
From:	Lukasz Majewski <l.majewski@...sung.com>
To:	Viresh Kumar <viresh.kumar@...aro.org>
Cc:	"Rafael J. Wysocki" <rjw@...k.pl>, Zhang Rui <rui.zhang@...el.com>,
	Eduardo Valentin <eduardo.valentin@...com>,
	"cpufreq@...r.kernel.org" <cpufreq@...r.kernel.org>,
	Linux PM list <linux-pm@...r.kernel.org>,
	Jonghwa Lee <jonghwa3.lee@...sung.com>,
	Lukasz Majewski <l.majewski@...ess.pl>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Kukjin Kim <kgene.kim@...sung.com>, durgadoss.r@...el.com
Subject: Re: [PATCH v6 5/8] cpufreq:boost:Kconfig: Provide support for software
 managed BOOST

On Mon, 29 Jul 2013 12:28:02 +0530 Viresh Kumar viresh.kumar@...aro.org
wrote,
> On 26 July 2013 16:51, Lukasz Majewski <l.majewski@...sung.com> wrote:
> > On Fri, 26 Jul 2013 15:54:56 +0530 Viresh Kumar wrote,
> >> On 25 July 2013 22:03, Lukasz Majewski <l.majewski@...sung.com>
> >> wrote:
> 
> >> > +config CPU_FREQ_BOOST_SW
> >> > +       bool
> >>
> >> Invisible is fine but this must be disabled by default and must
> >> depend on thermal, rather than moving dependency on platform's
> >> config.
> >
> > The CPU_FREQ_BOOST_SW [1] is a generic flag (invisible).
> >
> > I will add "default n" to it.
> 
> Leave it.. We don't need it now.. that's how these kind of config
> options are defined as they are disabled by default.

Ok. Please see below proposition.

> 
> > Depending only on [3], results at situation where SW BOOST can be
> > enabled at x86 or ARM target with only generic THERMAL support
> > (which doesn't protect from overheating).
> 
> I had a similar concern.. Currently also we aren't stopping anybody to
> enable boost. By selecting thermal from CPU_FREQ_BOOST_SW, atleast
> we are communicating this very well to developers that they need
> something else as well. And currently we only have thermal as a source
> for telling when to block boost but it can be something else too..
> 
> I never said, don't use EXYNOS_THERMAL, its good to have a
> dependency on it in the Exynos specific config for boost, but I wanted
> normal sw boost also to depend on thermal..

1. at ./drivers/cpufreq/Kconfig:

+config CPU_FREQ_BOOST_SW
+	bool
+	depends on THERMAL

2. at ./drivers/cpufreq/Kconfig.arm:

+config ARM_EXYNOS_CPU_FREQ_BOOST_SW
+	bool "EXYNOS Frequency Overclocking - Software"
+	depends on ARM_EXYNOS_CPUFREQ
+	select CPU_FREQ_BOOST_SW
+	select EXYNOS_THERMAL
+	default n
+	help
+	  This driver supports software managed overclocking (BOOST).
+	  It allows usage of special frequencies for Samsung Exynos
+	  processors if thermal conditions are appropriate.
+
+	  It reguires, for safe operation, thermal framework with
  properly
+	  defined trip points.
+
+	  If in doubt, say N.
+

Shall I split this patch to two (1. and 2.) or leave it as a single one?

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
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