From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH V5 5/5] arm64: dts: imx8mm: Enable cpu-idle driver Date: Thu, 15 Aug 2019 18:12:50 +0200 Message-ID: <34c03d76-ae61-63b4-153f-3f9911cc962e@linaro.org> References: <20190710063056.35689-1-Anson.Huang@nxp.com> <20190710063056.35689-5-Anson.Huang@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190710063056.35689-5-Anson.Huang@nxp.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Anson.Huang@nxp.com, catalin.marinas@arm.com, will@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tglx@linutronix.de, leonard.crestez@nxp.com, aisheng.dong@nxp.com, daniel.baluta@nxp.com, ping.bai@nxp.com, l.stach@pengutronix.de, abel.vesa@nxp.com, andrew.smirnov@gmail.com, ccaione@baylibre.com, angus@akkea.ca, agx@sigxcpu.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi Anson, sorry for the late review, I've been pretty busy. If Shawn is ok, I can pick the patches 1-4 in my tree and then this one after you fix the comments below. On 10/07/2019 08:30, Anson.Huang@nxp.com wrote: [ ... ] > + idle-states { > + entry-method = "psci"; > + > + cpu_sleep_wait: cpu-sleep-wait { Is that a retention state or a powerdown? It is preferable to change the name to the idle state naming convention given in the PSCI documentation [1] page 16-17 > + compatible = "arm,idle-state"; > + arm,psci-suspend-param = <0x0010033>; > + local-timer-stop; > + entry-latency-us = <1000>; > + exit-latency-us = <700>; > + min-residency-us = <2700>; > + wakeup-latency-us = <1500>; It is pointless to specify the entry + exit *and* the wakeup-latency [2]. Thanks -- Daniel [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0022d/Power_State_Coordination_Interface_PDD_v1_1_DEN0022D.pdf [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/cpuidle/dt_idle_states.c#n41 -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog