From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH v5 0/5] ARM: EXYNOS: cpuidle: fix AFTR mode on boards with secure firmware enabled Date: Tue, 05 Aug 2014 17:07:36 +0200 Message-ID: <53E0F338.8080006@linaro.org> References: <1407245666-20016-1-git-send-email-b.zolnierkie@samsung.com> <53E0E420.8060207@linaro.org> <53E0E98F.5020706@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-wi0-f182.google.com ([209.85.212.182]:63658 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751235AbaHEPHm (ORCPT ); Tue, 5 Aug 2014 11:07:42 -0400 Received: by mail-wi0-f182.google.com with SMTP id d1so1534382wiv.15 for ; Tue, 05 Aug 2014 08:07:40 -0700 (PDT) In-Reply-To: <53E0E98F.5020706@samsung.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Kukjin Kim Cc: linux-samsung-soc@vger.kernel.org, linux-pm@vger.kernel.org, Sachin Kamat , Viresh Kumar , Tomasz Figa , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Kyungmin Park , linaro-kernel@lists.linaro.org, linux-arm-kernel@lists.infradead.org On 08/05/2014 04:26 PM, Krzysztof Kozlowski wrote: > On 05.08.2014 16:03, Daniel Lezcano wrote: >> On 08/05/2014 03:34 PM, Bartlomiej Zolnierkiewicz wrote: >>> Hi, >>> >>> This patch series adds support for AFTR idle mode on boards with >>> secure firmware enabled and allows EXYNOS cpuidle driver usage on >>> Exynos4x12 SoCs. >>> >>> It has been tested on Trats2 board (using Exynos4412 SoC with secur= e >>> firmware enabled) on which AFTR mode reduces power consumption by ~= 12% >>> when EXYNOS cpuidle driver is enabled (in both cases the default >>> exynos_defconfig config is used and CPU1-3 are offlined). >> >> As a sidenote: >> >> On my odroid-U2: >> * 4 cpus online -> 130 mA >> * 3 cpus online -> 164 mA >> * 2 cpus online -> 160 mA >> * 1 cpu online -> 157 mA >> >> So were are consuming more when there are unplugged cpu ... any idea= s ? > > On which tree are you testing? Current next has ARMCLK down feature > enabled. ARMCLK down may stop working after hotunplugging CPU: > http://www.spinics.net/lists/arm-kernel/msg352890.html > > That was observed especially on Exynos4212 where ARMCLK down stops > working permanently. On Trats2 (Exynos4412) the clock down stopped on= ly > a for short period after disabling CPU. Hi Krzysztof, I tested the patches you mentioned above on top of this patchset. You are right this is directly related to the ARMCLK but the behavior=20 may be not as you expect I think. When I boot: 4 cpus online =3D> 131 mA Then I unplug one by one the cpus: 3 cpus online =3D> 127 mA 2 cpus online =3D> 123 mA 1 cpu online =3D> 120 mA This is consistent. But now, I online the cpus: 2 cpus online =3D> 162 mA 3 cpus online =3D> 165 mA 4 cpus online =3D> 131 mA -- side note -- Please note, I did not disable the cpuidle neither the AFTR state and=20 the kernel did not hang but I don't see the noticeable power saving we=20 should be observing when there is one cpu remaining entering the AFTR=20 state (cpuidle stats show we enter AFTR). So there is definitively=20 something wrong with this state. --=20 Linaro.org =E2=94=82 Open source software fo= r ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog