Date: Thu, 09 Jan 2014 08:19:55 +0100
From: Lukasz Majewski <l.majewski@samsung.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>, Zhang Rui <rui.zhang@intel.com>,
        Eduardo Valentin <eduardo.valentin@ti.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
        "cpufreq@vger.kernel.org" <cpufreq@vger.kernel.org>,
        Linux PM list <linux-pm@vger.kernel.org>,
        Jonghwa Lee <jonghwa3.lee@samsung.com>,
        Lukasz Majewski <l.majewski@majess.pl>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Myungjoo Ham <myungjoo.ham@samsung.com>, durgadoss.r@intel.com,
        linux-samsung-soc@vger.kernel.org, rjw@sisk.pl
Subject: Re: [PATCH v12 0/7] cpufreq:boost: CPU Boost mode support
Message-id: <20140109081955.6324e08e@amdc2363>
In-reply-to: <9268964.f27SUq68sj@vostro.rjw.lan>
References: <1370502472-7249-1-git-send-email-l.majewski@samsung.com>
 <1387549495-809-1-git-send-email-l.majewski@samsung.com>
 <20140107075824.59a1ed3c@amdc2363> <9268964.f27SUq68sj@vostro.rjw.lan>
Organization: SPRC Poland
MIME-version: 1.0
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

Hi Rafael, Zhang,

> 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?

I'd really appreciate Ack from Rui on this patch series.

However, after Rui's comments on v9, I've completely removed the BOOST
code from thermal core.

Since the v10, I've only adjusted default data for Exynos SoC. This
approach has been finally accepted by Eduardo (who is responsible for
this part of the thermal subsystem) on the v12.


> 
> Rafael
> 

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/