From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kukjin Kim Subject: RE: [PATCH v5] arm64: dts: exynos7: add support for cpuidle core power down Date: Thu, 27 Nov 2014 16:21:19 +0900 Message-ID: <08b101d00a12$bd15dc80$37419580$@kernel.org> References: <1415683897-983-1-git-send-email-k.chander@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mailout1.samsung.com ([203.254.224.24]:26335 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbaK0HVW (ORCPT ); Thu, 27 Nov 2014 02:21:22 -0500 In-reply-to: <1415683897-983-1-git-send-email-k.chander@samsung.com> Content-language: ko Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: 'Chander Kashyap' , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, daniel.lezcano@linaro.org, lorenzo.pieralisi@arm.com, catalin.marinas@arm.com, mark.rutland@arm.com, rjw@rjwysocki.net Chander Kashyap wrote: > > Exynos7 supports multiple idle states. Core power down is one such > idle state, where cores can be powered off independently. > > This patch adds support for core power down idle state. > > Entry latency for core power down idle state is calculated as follows: > 1. Time difference is measured between cpuidle entry and exit. > 2. WFI is skipped for measuring the time. > 3. Select the worst case time in a set of 100000 cpuidle transactions, > with varying load. > > Exit latency and min residency values are supplied as per HW team. > > Signed-off-by: Chander Kashyap > Acked-by: Lorenzo Pieralisi Lorenzo, thanks for your ack. Will apply. - Kukjin > --- > This patch has following dependencies: > - [PATCH v5 0/8] arch: arm64: Enable support for Samsung Exynos7 SoC > www.spinics.net/lists/arm-kernel/msg375961.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. > Changes in v4: > - Corrected the commit message. > - Corrected the entry latency value. > Changes in v5: > - Commit message modified > > 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 d7a37c3..891eef4 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"; > reg = <0x0>; > enable-method = "psci"; > + cpu-idle-states = <&CPU_SLEEP>; > }; > > cpu@1 { > @@ -44,6 +45,7 @@ > compatible = "arm,cortex-a57", "arm,armv8"; > reg = <0x1>; > enable-method = "psci"; > + cpu-idle-states = <&CPU_SLEEP>; > }; > > cpu@2 { > @@ -51,6 +53,7 @@ > compatible = "arm,cortex-a57", "arm,armv8"; > reg = <0x2>; > enable-method = "psci"; > + cpu-idle-states = <&CPU_SLEEP>; > }; > > cpu@3 { > @@ -58,6 +61,20 @@ > compatible = "arm,cortex-a57", "arm,armv8"; > reg = <0x3>; > enable-method = "psci"; > + 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 = <34>; > + exit-latency-us = <150>; > + min-residency-us = <2100>; > + }; > }; > }; > > -- > 1.9.1