Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754703AbaFBNKY (ORCPT ); Mon, 2 Jun 2014 09:10:24 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:44944 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754327AbaFBNKW (ORCPT ); Mon, 2 Jun 2014 09:10:22 -0400 Message-ID: <538C77AD.1000801@gmail.com> Date: Mon, 02 Jun 2014 15:10:05 +0200 From: Tomasz Figa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Bartlomiej Zolnierkiewicz , Kukjin Kim CC: Daniel Lezcano , Tomasz Figa , Sachin Kamat , Viresh Kumar , "Rafael J. Wysocki" , Kyungmin Park , linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org Subject: Re: [PATCH v2 6/7] ARM: EXYNOS: PM: fix register setup on EXYNOS4x12 for AFTR mode code References: <1401712543-14281-1-git-send-email-b.zolnierkie@samsung.com> <1401712543-14281-7-git-send-email-b.zolnierkie@samsung.com> In-Reply-To: <1401712543-14281-7-git-send-email-b.zolnierkie@samsung.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 02.06.2014 14:35, Bartlomiej Zolnierkiewicz wrote: > Add S5P_CENTRAL_SEQ_OPTION register setup for EXYNOS4x12 to AFTR > mode code. Without this setup AFTR mode doesn't show any benefit > over WFI one. When this setup is applied AFTR mode reduces power > consumption by ~12% (as measured on Trats2 board). > > This change is a preparation for adding secure firmware support to > EXYNOS cpuidle driver. > > Signed-off-by: Bartlomiej Zolnierkiewicz > Acked-by: Kyungmin Park > --- > arch/arm/mach-exynos/pm.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c > index aeff99e..0fb9a5a 100644 > --- a/arch/arm/mach-exynos/pm.c > +++ b/arch/arm/mach-exynos/pm.c > @@ -456,6 +456,10 @@ static int exynos_cpu_pm_notifier(struct notifier_block *self, > case CPU_PM_ENTER: > if (cpu == 0) { > exynos_pm_central_suspend(); > + if (soc_is_exynos4212() || soc_is_exynos4412()) > + __raw_writel(S5P_USE_STANDBY_WFI0 | > + S5P_USE_STANDBY_WFE0, > + S5P_CENTRAL_SEQ_OPTION); I wonder whether this isn't required on any Exynos SoC in general, as this mask decides which STANDBY_WFI/WFE signals are considered before entering the lower power state. Also you should check the behavior with Krzysztof's patch adding support for delayed reset assertion, which should cause WFI/WFE signals of CPUs powered down to be kept asserted. Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/