Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932338AbaGUMwC (ORCPT ); Mon, 21 Jul 2014 08:52:02 -0400 Received: from mail-wi0-f169.google.com ([209.85.212.169]:63476 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932188AbaGUMwA (ORCPT ); Mon, 21 Jul 2014 08:52:00 -0400 MIME-Version: 1.0 In-Reply-To: <1405694193-29643-1-git-send-email-k.kozlowski@samsung.com> References: <1405694193-29643-1-git-send-email-k.kozlowski@samsung.com> Date: Mon, 21 Jul 2014 13:51:59 +0100 Message-ID: Subject: Re: [PATCH v2 1/2] clk: samsung: exynos4: Enable ARMCLK down feature From: Daniel Drake To: Krzysztof Kozlowski Cc: Tomasz Figa , Mike Turquette , Kukjin Kim , linux-samsung-soc , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 18, 2014 at 3:36 PM, Krzysztof Kozlowski wrote: > Enable ARMCLK down feature on all Exynos4 SoCs. The frequency of > ARMCLK will be reduced upon entering idle mode (WFI or WFE). > > The feature behaves like very fast cpufreq ondemand governor. In idle > mode this reduces energy consumption on full frequency chosen by > cpufreq governor by approximately: > - Trats2: 6.5% (153 mA -> 143 mA) > - Trats: 33.0% (180 mA -> 120 mA) > - Gear1: 27.0% (180 mA -> 130 mA) > > The patch uses simillar settings as Exynos5250 (clk-exynos5250.c), > except it disables clock up feature and on Exynos4412 ARMCLK down is > enabled for all 4 cores. > > Tested on Trats board (Exynos4210), Trats2 board (Exynos4412) and > Samsung Gear 1 (Exynos4212). > > Signed-off-by: Krzysztof Kozlowski Tested on ODROID-U2, seems to be working. I don't have a way of measuring the power usage, but the system seems as stable as before. Tested-by: Daniel Drake -- 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/