From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754269AbaGUJxf (ORCPT ); Mon, 21 Jul 2014 05:53:35 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:42550 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752714AbaGUJxd (ORCPT ); Mon, 21 Jul 2014 05:53:33 -0400 Message-ID: <53CCE31C.90300@linaro.org> Date: Mon, 21 Jul 2014 11:53:32 +0200 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Krzysztof Kozlowski , Russell King , Kukjin Kim , "Rafael J. Wysocki" , Sachin Kamat , Tushar Behera , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org CC: Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz , Tomasz Figa Subject: Re: [PATCH 1/3] cpuidle: exynos: Allow to use the driver without AFTR References: <1405931771-24100-1-git-send-email-k.kozlowski@samsung.com> In-Reply-To: <1405931771-24100-1-git-send-email-k.kozlowski@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/21/2014 10:36 AM, Krzysztof Kozlowski wrote: > Allow the driver to be used when AFTR enter function is not provided > (device platform data is NULL). > > This actually does not give any special energy-saving benefits but > allows to track the idle time of each core. Additionally it is a safe > way to validate supplied platform data. > > Signed-off-by: Krzysztof Kozlowski I think we already talk about this in the mailing list several times. It does not make sense to enable the cpuidle driver for WFI just for the sake of tracking via sysfs some idle timings. Using the cpuidle driver means using the underlying cpuidle infrastructure with all the stats computation in the governor. If there is a *real* need of a WFI cpuidle driver, then a generic WFI cpuidle driver could be implemented to supersede this one. It took a while to cleanup this driver and remove all the hacks around this AFTR state... :) > --- > drivers/cpuidle/cpuidle-exynos.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/cpuidle/cpuidle-exynos.c b/drivers/cpuidle/cpuidle-exynos.c > index 7c0151263828..5325a394be7e 100644 > --- a/drivers/cpuidle/cpuidle-exynos.c > +++ b/drivers/cpuidle/cpuidle-exynos.c > @@ -77,7 +77,10 @@ static int exynos_cpuidle_probe(struct platform_device *pdev) > { > int ret; > > + /* If NULL enter only WFI */ > exynos_enter_aftr = (void *)(pdev->dev.platform_data); > + if (!exynos_enter_aftr) > + exynos_idle_driver.state_count = 1; > > ret = cpuidle_register(&exynos_idle_driver, NULL); > if (ret) { > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog