On Wed, Nov 05, 2014 at 10:15:36AM +0000, Chander Kashyap wrote: > Exynos7 has core power down state where cores can be powered off independently. > This patch adds support for this state. > > Entry latency for the core power down is calculated as follows: > 1. Time difference is measured between cpuidle entry and exit. > 2. WFI is skipped measuring the time. > 3. The time is averaged out for 100000 cpuidle transactions with varying load. - entry-latency-us Usage: Required "Definition: u32 value representing worst case latency in microseconds required to enter the idle state. ..." Is that an average value in your opinion ? I am being pedantic, I know, but we define bindings to be followed, not interpreted. Thanks, Lorenzo > Exit latency and target residency are supplied as per HW team > > Signed-off-by: Chander Kashyap <k.chander@xxxxxxxxxxx> > --- > This patch has following dependencies: > - [PATCH v5 0/8] arch: arm64: Enable support for Samsung Exynos7 SoC > http://www.spinics.net/lists/linux-samsung-soc/msg37047.html > Changes in v2: > - Moved the cpu-idle-state property after reg property > - removed the status property. > > Changes in v3: > - Added the Entry latency calculation in commit message. > > arch/arm64/boot/dts/exynos/exynos7.dtsi | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/arch/arm64/boot/dts/exynos/exynos7.dtsi b/arch/arm64/boot/dts/exynos/exynos7.dtsi > index 50ae936..444dde1 100644 > --- a/arch/arm64/boot/dts/exynos/exynos7.dtsi > +++ b/arch/arm64/boot/dts/exynos/exynos7.dtsi > @@ -37,6 +37,7 @@ > compatible = "arm,cortex-a57", "arm,armv8"; > enable-method = "psci"; > reg = <0x0>; > + cpu-idle-states = <&CPU_SLEEP>; > }; > > cpu@1 { > @@ -44,6 +45,7 @@ > compatible = "arm,cortex-a57", "arm,armv8"; > enable-method = "psci"; > reg = <0x1>; > + cpu-idle-states = <&CPU_SLEEP>; > }; > > cpu@2 { > @@ -51,6 +53,7 @@ > compatible = "arm,cortex-a57", "arm,armv8"; > enable-method = "psci"; > reg = <0x2>; > + cpu-idle-states = <&CPU_SLEEP>; > }; > > cpu@3 { > @@ -58,6 +61,20 @@ > compatible = "arm,cortex-a57", "arm,armv8"; > enable-method = "psci"; > reg = <0x3>; > + cpu-idle-states = <&CPU_SLEEP>; > + }; > + > + idle-states { > + entry-method = "arm,psci"; > + > + CPU_SLEEP: cpu-sleep { > + compatible = "arm,idle-state"; > + local-timer-stop; > + arm,psci-suspend-param = <0x0010000>; > + entry-latency-us = <20>; > + exit-latency-us = <150>; > + min-residency-us = <2100>; > + }; > }; > }; > > -- > 1.7.9.5 > > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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