From mboxrd@z Thu Jan  1 00:00:00 1970
From: Viresh Kumar <viresh.kumar@linaro.org>
Subject: Re: [PATCH v3 1/3] cpufreq: Add boost frequency support in core
Date: Thu, 20 Jun 2013 10:35:26 +0530
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To: Lukasz Majewski <l.majewski@samsung.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>, "cpufreq@vger.kernel.org" <cpufreq@vger.kernel.org>, Linux PM list <linux-pm@vger.kernel.org>, Vincent Guittot <vincent.guittot@linaro.org>, Jonghwa Lee <jonghwa3.lee@samsung.com>, Myungjoo Ham <myungjoo.ham@samsung.com>, linux-kernel <linux-kernel@vger.kernel.org>, Lukasz Majewski <l.majewski@majess.pl>, Andre Przywara <andre.przywara@linaro.org>, Daniel Lezcano <daniel.lezcano@linaro.org>, Kukjin Kim <kgene.kim@samsung.com>, Amit Daniel Kachhap <amit.daniel@samsung.com>
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On 18 June 2013 19:14, Lukasz Majewski <l.majewski@samsung.com> wrote:
> On Tue, 18 Jun 2013 15:26:16 +0200, Rafael J. Wysocki wrote:
>> On Tuesday, June 18, 2013 12:12:13 PM Viresh Kumar wrote:
>> > On 17 June 2013 19:21, Lukasz Majewski <l.majewski@samsung.com>

>> Well, that's why on x86 turbo is controlled by hardware that takes
>> care of keeping things within the chip's thermal limits.
>
> And this is the reason why I don't want to overly change acpi-cpufreq.c
> code. :-)

We need to keep both hardware/software boost features at the same place
in core, they may behave differently though. That's why I wanted you
to do that.

> I think that thermal subsystem shall be the second option to disable SW
> boosting.
>
> The main control shall be done inside the cpufreq core. The idea to
> disable boost when more than one core is active is rational.

But then, it might not be enough. A single core can make your SoC
very hot.