From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752104AbcDJDQv (ORCPT ); Sat, 9 Apr 2016 23:16:51 -0400 Received: from mail-pf0-f180.google.com ([209.85.192.180]:35400 "EHLO mail-pf0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750837AbcDJDQu (ORCPT ); Sat, 9 Apr 2016 23:16:50 -0400 Date: Sun, 10 Apr 2016 08:46:46 +0530 From: Viresh Kumar To: "Rafael J. Wysocki" Cc: Linux PM list , Linux Kernel Mailing List , Srinivas Pandruvada Subject: Re: [PATCH] cpufreq: Skip all governor-related actions for cpufreq_suspended set Message-ID: <20160410031646.GI9674@vireshk-i7> References: <2044559.GVlD7a2JcO@vostro.rjw.lan> <20160408054513.GF9674@vireshk-i7> <1865551.sGARmvFdEr@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1865551.sGARmvFdEr@vostro.rjw.lan> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08-04-16, 23:54, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > Subject: [PATCH] cpufreq: Skip all governor-related actions for cpufreq_suspended set > > Since governor operations are generally skipped if cpufreq_suspended > is set, do nothing at all in cpufreq_start_governor() in that case. > > That function is called in the cpufreq_online() path, and may also > be called from cpufreq_offline() in some cases, which are invoked > by the nonboot CPUs disabing/enabling code during system suspend > to RAM and resume. That happens when all devices have been > suspended, so if the cpufreq driver relies on things like I2C to > get the current frequency, it may not be ready to do that then. > > The change here prevents problems from happening for this reason. > > Fixes: 3bbf8fe3ae08 (cpufreq: Always update current frequency before startig governor) > Signed-off-by: Rafael J. Wysocki > Acked-by: Viresh Kumar > --- > drivers/cpufreq/cpufreq.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > Index: linux-pm/drivers/cpufreq/cpufreq.c > =================================================================== > --- linux-pm.orig/drivers/cpufreq/cpufreq.c > +++ linux-pm/drivers/cpufreq/cpufreq.c > @@ -2053,6 +2053,9 @@ static int cpufreq_start_governor(struct > { > int ret; > > + if (cpufreq_suspended) > + return 0; > + > if (cpufreq_driver->get && !cpufreq_driver->setpolicy) > cpufreq_update_current_freq(policy); Since we no longer have the same check in cpufreq_exit_governor(), what about moving it to cpufreq_update_current_freq() instead? That's all we are trying to protect here anyway, as cpufreq_governor() is already protected. -- viresh