Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756938AbaJ2Uu1 (ORCPT ); Wed, 29 Oct 2014 16:50:27 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:55193 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752359AbaJ2UuY (ORCPT ); Wed, 29 Oct 2014 16:50:24 -0400 From: "Rafael J. Wysocki" To: Kevin Hilman , Daniel Lezcano Cc: Preeti Murthy , Nicolas Pitre , "linux-pm@vger.kernel.org" , LKML , Peter Zijlstra , Lists linaro-kernel , patches@linaro.org, Preeti U Murthy Subject: Re: [PATCH V2 3/5] cpuidle: idle: menu: Don't reflect when a state selection failed Date: Wed, 29 Oct 2014 22:11 +0100 Message-ID: <1509380.Ri3TuW8Kom@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <7h8ujybyuk.fsf@deeprootsystems.com> References: <1414054881-17713-1-git-send-email-daniel.lezcano@linaro.org> <544FE032.5050900@linaro.org> <7h8ujybyuk.fsf@deeprootsystems.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit 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 Wednesday, October 29, 2014 09:54:43 AM Kevin Hilman wrote: > Daniel Lezcano writes: > > > On 10/28/2014 08:01 AM, Preeti Murthy wrote: > >> On Thu, Oct 23, 2014 at 2:31 PM, Daniel Lezcano > >> wrote: > >>> In the current code, the check to reflect or not the outcoming state is done > >>> against the idle state which has been chosen and its value. > >>> > >>> Instead of doing a check in each of the reflect functions, just don't call reflect > >>> if something went wrong in the idle path. > >>> > >>> Signed-off-by: Daniel Lezcano > >>> Acked-by: Nicolas Pitre > >>> --- > >>> drivers/cpuidle/governors/ladder.c | 3 +-- > >>> drivers/cpuidle/governors/menu.c | 4 +--- > >>> kernel/sched/idle.c | 3 ++- > >>> 3 files changed, 4 insertions(+), 6 deletions(-) > >>> > >>> diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c > >>> index fb396d6..c0b36a8 100644 > >>> --- a/drivers/cpuidle/governors/ladder.c > >>> +++ b/drivers/cpuidle/governors/ladder.c > >>> @@ -165,8 +165,7 @@ static int ladder_enable_device(struct cpuidle_driver *drv, > >>> static void ladder_reflect(struct cpuidle_device *dev, int index) > >>> { > >>> struct ladder_device *ldev = &__get_cpu_var(ladder_devices); > >>> - if (index > 0) > >>> - ldev->last_state_idx = index; > >>> + ldev->last_state_idx = index; > >>> } > >>> > >>> static struct cpuidle_governor ladder_governor = { > >>> diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c > >>> index a17515f..3907301 100644 > >>> --- a/drivers/cpuidle/governors/menu.c > >>> +++ b/drivers/cpuidle/governors/menu.c > >>> @@ -365,9 +365,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, > >>> static void menu_reflect(struct cpuidle_device *dev, int index) > >>> { > >>> struct menu_device *data = &__get_cpu_var(menu_devices); > >>> - data->last_state_idx = index; > >>> - if (index >= 0) > >>> - data->needs_update = 1; > >>> + data->needs_update = 1; > >> > >> Why is the last_state_idx not getting updated ? > > > > Oups, right. This is missing. > > > > Thanks for pointing this out. > > > > By the way, I don't think a back end driver is changing the selected > > state currently and I am not sure this is desirable since we want to > > trust the state we are going (as a best effort). > > FYI, the OMAP3 backend driver can does not always obey the selected > state, and will return a different state than the one requested. The ACPI driver can do that as well. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/