Date:	Thu, 16 Jan 2014 16:51:20 +0100
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Lukasz Majewski <l.majewski@...sung.com>
Cc:	Zhang Rui <rui.zhang@...el.com>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	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>,
	Myungjoo Ham <myungjoo.ham@...sung.com>, durgadoss.r@...el.com,
	linux-samsung-soc@...r.kernel.org
Subject: Re: [PATCH v12 0/7] cpufreq:boost: CPU Boost mode support

On Thursday, January 16, 2014 10:40:08 AM Lukasz Majewski wrote:
> Hi Rafael,
> 
> > On Wed, 2014-01-08 at 01:35 +0100, Rafael J. Wysocki wrote:
> > > On Tuesday, January 07, 2014 07:58:24 AM Lukasz Majewski wrote:
> > > > Hi Rafael,
> > > 
> > > Hi,
> > > 
> > > > > This patch series introduces support for CPU overclocking
> > > > > technique called Boost.
> > > > > 
> > > > > It is a follow up of a LAB governor proposal. Boost is a LAB
> > > > > component:
> > > > > http://thread.gmane.org/gmane.linux.kernel/1484746/match=cpufreq
> > > > > 
> > > > > Boost unifies hardware based solution (e.g. Intel Nehalem) with
> > > > > software oriented one (like the one done at Exynos).
> > > > > For this reason cpufreq/freq_table code has been reorganized to
> > > > > include common code.
> > > > > 
> > > > > Important design decisions:
> > > > > - Boost related code is compiled-in unconditionally to cpufreq
> > > > > core and disabled by default. The cpufreq_driver is
> > > > > responsibile for setting boost_supported flag and providing
> > > > > set_boost callback(if HW support is needed). For software
> > > > > managed boost, special Kconfig flag - CONFIG_CPU_FREQ_BOOST_SW
> > > > > has been defined. It will be selected only when a target
> > > > > platform has thermal framework properly configured.
> > > > > 
> > > > > - struct cpufreq_driver has been extended with boost related
> > > > > fields: -- boost_supported - when driver supports boosting
> > > > >         -- boost_enabled - boost state
> > > > >         -- set_boost - callback to function, which is necessary
> > > > > to enable/disable boost
> > > > > 
> > > > > - Boost sysfs attribute (/sys/devices/system/cpu/cpufreq/boost)
> > > > > is visible _only_ when cpufreq driver supports Boost.
> > > > > 
> > > > > - No special spin_lock for Boost was created. The one from
> > > > > cpufreq core was reused.
> > > > > 
> > > > > - The Boost code doesn't rely on any policy. When boost state is
> > > > > changed, then the policy list is iterated and proper
> > > > > adjustements are done.
> > > > > 
> > > > > - To improve safety level, the thermal framework is also
> > > > > extended to disable software boosting, when thermal trip point
> > > > > is reached. After cooling down the boost can be enabled again.
> > > > > This emulates behaviour similar to HW managed boost (like x86)
> > > > > 
> > > > > Tested at HW:
> > > > >        Exynos 4412 3.13-rc4 Linux
> > > > >        Intel Core i7-3770 3.13-rc4 Linux
> > > > > 
> > > > > Above patches were posted on top of kernel_pm/bleeding-edge
> > > > > (SHA1: bd0f3a5d9dce48a917ce1f1047534d79c725149)
> > > > > 
> > > > > Lukasz Majewski (7):
> > > > >   cpufreq: Add boost frequency support in core
> > > > >   cpufreq:acpi:x86: Adjust the acpi-cpufreq.c code to work with
> > > > > common boost solution
> > > > >   cpufreq:boost:Kconfig: Provide support for software managed
> > > > > BOOST cpufreq:exynos:Extend Exynos cpufreq driver to support
> > > > > boost framework
> > > > >   Documentation:cpufreq:boost: Update BOOST documentation
> > > > >   cpufreq:exynos4x12: Change L0 driver data to
> > > > > CPUFREQ_BOOST_FREQ thermal:exynos:boost: Automatic
> > > > > enable/disable of BOOST feature (at Exynos4412)
> > > > > 
> > > > >  Documentation/cpu-freq/boost.txt          |   26 +++----
> > > > >  drivers/cpufreq/Kconfig                   |    4 +
> > > > >  drivers/cpufreq/Kconfig.arm               |   15 ++++
> > > > >  drivers/cpufreq/acpi-cpufreq.c            |   86
> > > > > +++++++-------------- drivers/cpufreq/cpufreq.c
> > > > > | 118 ++++++++++++++++++++++++++++-
> > > > > drivers/cpufreq/exynos-cpufreq.c          |    3 +
> > > > > drivers/cpufreq/exynos4x12-cpufreq.c      |    2 +-
> > > > > drivers/cpufreq/freq_table.c              |   56 ++++++++++++--
> > > > > drivers/thermal/samsung/exynos_tmu_data.c |   12 +--
> > > > > include/linux/cpufreq.h                   |   24 ++++++ 10 files
> > > > > changed, 261 insertions(+), 85 deletions(-)
> > > > > 
> > > > 
> > > > A gentle ping about BOOST patches.
> > > > 
> > > > Its been already acked by Viresh and Eduardo.
> > > > 
> > > > It applies on kernel_pm/bleeding_edge SHA1:
> > > > 4836deb72c5e2a9af0cb2129c1149783a26d99ab
> > > 
> > > It looks like Rui is still looking into this.
> > > 
> > > Rui, are you fine with this series?
> > > 
> > Yes, I'm okay with the thermal related parts of this patch set.
> > 
> 
> Rafael, gentle reminder about BOOST patches ... :-)

I'm about to take them for 3.14.

Thanks!

[PS: Please don't use the rjw@...k.pl address, that domain is gone.]

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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