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From: josephl@nvidia.com (Joseph Lo)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V4 3/7] ARM: tegra30: cpuidle: add powered-down state for secondary CPUs
Date: Thu, 1 Nov 2012 09:51:19 +0800	[thread overview]
Message-ID: <1351734679.3231.64.camel@jlo-ubuntu-64.nvidia.com> (raw)
In-Reply-To: <CAMbhsRRT60oyecsZqjf196Y=Cog209TwfMCPJ9nyLG+fwu7mqg@mail.gmail.com>

On Thu, 2012-11-01 at 05:19 +0800, Colin Cross wrote:
> On Wed, Oct 31, 2012 at 2:41 AM, Joseph Lo <josephl@nvidia.com> wrote:
> > This supports power-gated idle on secondary CPUs for Tegra30. The
> > secondary CPUs can go into powered-down state independently. When
> > CPU goes into this state, it saves it's contexts and puts itself
> > to flow controlled WFI state. After that, it will been power gated.
> >
> > Be aware of that, you may see the legacy power state "LP2" in the
> > code which is exactly the same meaning of "CPU power down".
> 
> On Tegra20, LP2 included powering off the GIC.  Is that still the case
> for Tegra30 individual secondary cpu power gating?  If so, how do IPIs
> to an idle cpu wake it up?

Hi Colin,

Thanks for your review.
For Tegra30, the LP2 of secondary CPU didn't power gate GIC. Only when 4
cores in LP2, the power of cpu cluster will be shut off that include
GIC. For the LP2 of individual secondary CPU, it can be woke up by IPI.

Thanks,
Joseph

  reply	other threads:[~2012-11-01  1:51 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-31  9:41 [PATCH V4 0/7] ARM: tegra30: cpuidle: add a powered-down state Joseph Lo
2012-10-31  9:41 ` [PATCH V4 1/7] ARM: tegra: cpuidle: separate cpuidle driver for different chips Joseph Lo
2012-10-31  9:41 ` [PATCH V4 2/7] ARM: tegra: cpuidle: add CPU resume function Joseph Lo
2012-10-31  9:41 ` [PATCH V4 3/7] ARM: tegra30: cpuidle: add powered-down state for secondary CPUs Joseph Lo
2012-10-31 21:19   ` Colin Cross
2012-11-01  1:51     ` Joseph Lo [this message]
2012-10-31  9:41 ` [PATCH V4 4/7] ARM: tegra30: common: enable csite clock Joseph Lo
2012-10-31  9:41 ` [PATCH V4 5/7] ARM: tegra30: clocks: add CPU low-power function into tegra_cpu_car_ops Joseph Lo
2012-10-31  9:41 ` [PATCH V4 6/7] ARM: tegra30: flowctrl: add cpu_suspend_exter/exit function Joseph Lo
2012-10-31  9:41 ` [PATCH V4 7/7] ARM: tegra30: cpuidle: add powered-down state for CPU0 Joseph Lo
2012-10-31 20:24 ` [PATCH V4 0/7] ARM: tegra30: cpuidle: add a powered-down state Stephen Warren

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