From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tomasz Figa <tomasz.figa@gmail.com>
Subject: Re: [PATCH 2/4] ARM: exynos: Ensure PM domains are powered at initialization
Date: Wed, 01 Oct 2014 13:23:46 +0200
Message-ID: <542BE442.9040505@gmail.com>
References: <1412081033-8136-1-git-send-email-ulf.hansson@linaro.org>	<1412081033-8136-3-git-send-email-ulf.hansson@linaro.org> <7hiok5x8k1.fsf@deeprootsystems.com>
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To: Kevin Hilman <khilman@kernel.org>, Ulf Hansson <ulf.hansson@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>, Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>, linux-pm@vger.kernel.org, Geert Uytterhoeven <geert+renesas@glider.be>, Philipp Zabel <philipp.zabel@gmail.com>, Russell King <linux@arm.linux.org.uk>, Mark Brown <broonie@kernel.org>, Wolfram Sang <wsa@the-dreams.de>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, Jack Dai <jack.dai@rock-chips.com>, Jinkun Hong <jinkun.hong@rock-chips.com>, "linux-samsung-soc@vger.kernel.org" <linux-samsung-soc@vger.kernel.org>
List-Id: linux-pm@vger.kernel.org

On 30.09.2014 20:33, Kevin Hilman wrote:
> Ulf Hansson <ulf.hansson@linaro.org> writes:
> 
>> At ->probe() it's common practice for drivers/subsystems to bring their
>> devices to full power and without depending on CONFIG_PM_RUNTIME.
>>
>> We could also expect that drivers/subsystems requires their device's
>> corresponding PM domains to be powered, to successfully complete a
>> ->probe() sequence.
>>
>> Align to the behavior above, by ensuring all PM domains are powered
>> prior initialization of a generic PM domain.
>>
>> Do note, since the generic PM domain will try to power off unused PM
>> domains at late_init, there are no increased power consumption over
>> time.
> 
> IMO "no increased power consumption" is a bit misleading because
> boot-time power consumption may have a major increase when all power
> domains are powered on.  Sure, they will eventually (hopefully) be
> turned off in after late_initcall, but there will still be an impact.
> 
> I guess the Samsung folks should comment here on whether that is
> significant.

Unfortunately this series has not been posted to linux-samsung-soc
mailing list and I'm a formerly-Samsung folk now, so it hasn't really
reached there.

Best regards,
Tomasz