From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH v2] arm: exynos: Support cluster power off on exynos5420/5800 Date: Thu, 19 Jun 2014 13:34:49 -0700 Message-ID: <7hy4wsvdsm.fsf@paris.lan> References: <1403104722-14848-1-git-send-email-a.kesavan@samsung.com> <1403181617-19743-1-git-send-email-a.kesavan@samsung.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-pb0-f50.google.com ([209.85.160.50]:39876 "EHLO mail-pb0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756433AbaFSUev (ORCPT ); Thu, 19 Jun 2014 16:34:51 -0400 Received: by mail-pb0-f50.google.com with SMTP id rp16so2285923pbb.37 for ; Thu, 19 Jun 2014 13:34:51 -0700 (PDT) In-Reply-To: <1403181617-19743-1-git-send-email-a.kesavan@samsung.com> (Abhilash Kesavan's message of "Thu, 19 Jun 2014 18:10:17 +0530") Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Abhilash Kesavan Cc: linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, kgene.kim@samsung.com, nicolas.pitre@linaro.org, kesavan.abhilash@gmail.com, abrestic@chromium.org Abhilash Kesavan writes: > Turning off a cluster when all 4 cores of the cluster are powered off > saves power significantly. Powering off the A15 L2 alone gives around > 100mW in savings. Add support for powering off the A15/A7 clusters on > exynos5420/5800. > > The patch enables specific register bits which ensure that: > - cluster L2 will be turned on before the first man is powered up. > - last man will be turned off before the cluster L2 is turned off. > - core is powered down before powering it up. > > Remove the exynos_cluster_power_control function completely as we can > rely on the above mentioned bits rather than polling the cluster power > status register. > > Signed-off-by: Abhilash Kesavan > Acked-by: Nicolas Pitre > --- > Change in v2: > Added a macro for the COMMON_OPTION register and used it in the MCPM > back-end. > > The patch is based on Linux-next 20140619. It has been tested on an > exynos5420-based chromebook using the "/dev/bL_switcher" interface as > well as the script provided by Nicolas Pitre and Dave Martin [1]. > > Patch depends on: > [v2] ARM: EXYNOS: mcpm: Don't rely on firmware's secondary_cpu_start > > [1] http://www.spinics.net/lists/linux-samsung-soc/msg31257.html Tested on exynos5800/Chromebook2 along with the dependency patch and using the script from Dave and Nico. Tested-by: Kevin Hilman Kevin From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@linaro.org (Kevin Hilman) Date: Thu, 19 Jun 2014 13:34:49 -0700 Subject: [PATCH v2] arm: exynos: Support cluster power off on exynos5420/5800 In-Reply-To: <1403181617-19743-1-git-send-email-a.kesavan@samsung.com> (Abhilash Kesavan's message of "Thu, 19 Jun 2014 18:10:17 +0530") References: <1403104722-14848-1-git-send-email-a.kesavan@samsung.com> <1403181617-19743-1-git-send-email-a.kesavan@samsung.com> Message-ID: <7hy4wsvdsm.fsf@paris.lan> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Abhilash Kesavan writes: > Turning off a cluster when all 4 cores of the cluster are powered off > saves power significantly. Powering off the A15 L2 alone gives around > 100mW in savings. Add support for powering off the A15/A7 clusters on > exynos5420/5800. > > The patch enables specific register bits which ensure that: > - cluster L2 will be turned on before the first man is powered up. > - last man will be turned off before the cluster L2 is turned off. > - core is powered down before powering it up. > > Remove the exynos_cluster_power_control function completely as we can > rely on the above mentioned bits rather than polling the cluster power > status register. > > Signed-off-by: Abhilash Kesavan > Acked-by: Nicolas Pitre > --- > Change in v2: > Added a macro for the COMMON_OPTION register and used it in the MCPM > back-end. > > The patch is based on Linux-next 20140619. It has been tested on an > exynos5420-based chromebook using the "/dev/bL_switcher" interface as > well as the script provided by Nicolas Pitre and Dave Martin [1]. > > Patch depends on: > [v2] ARM: EXYNOS: mcpm: Don't rely on firmware's secondary_cpu_start > > [1] http://www.spinics.net/lists/linux-samsung-soc/msg31257.html Tested on exynos5800/Chromebook2 along with the dependency patch and using the script from Dave and Nico. Tested-by: Kevin Hilman Kevin