From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Pandruvada Subject: Re: [PATCH] cpufreq: use last policy after online Date: Wed, 02 Dec 2015 14:05:27 -0800 Message-ID: <1449093927.3240.37.camel@spandruv-desk3.jf.intel.com> References: <1449017534-6127-1-git-send-email-srinivas.pandruvada@linux.intel.com> <3188790.ma3TNFyjuZ@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com ([192.55.52.88]:15448 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751775AbbLBWG2 (ORCPT ); Wed, 2 Dec 2015 17:06:28 -0500 In-Reply-To: <3188790.ma3TNFyjuZ@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: rafael.j.wysocki@intel.com, viresh.kumar@linaro.org, linux-pm@vger.kernel.org On Wed, 2015-12-02 at 03:05 +0100, Rafael J. Wysocki wrote: > On Tuesday, December 01, 2015 04:52:14 PM Srinivas Pandruvada wrote: > > For cpufreq drivers which use setpolicy interface, after offline->online > > the policy is set to default. This can be reproduced by setting the > > default policy of intel_pstate or longrun to ondemand and then change to > > "performance". After offline and online, the setpolicy will be called with > > the policy=ondemand. > > For drivers using governors this condition is handled by storing > > last_governor, during offline and restoring during online. The same should > > be done for drivers using setpolicy interface. Storing last_policy during > > offline and restoring during online. > > > > Signed-off-by: Srinivas Pandruvada > > I guess this is urgent, right? I don't think. I tried couple of old kernels, same issue. Thanks, Srinivas > > Is it a regression fix or has it just never worked? > > > --- > > drivers/cpufreq/cpufreq.c | 14 ++++++++++---- > > include/linux/cpufreq.h | 1 + > > 2 files changed, 11 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > index a83c995..8412ce5 100644 > > --- a/drivers/cpufreq/cpufreq.c > > +++ b/drivers/cpufreq/cpufreq.c > > @@ -976,10 +976,14 @@ static int cpufreq_init_policy(struct cpufreq_policy *policy) > > > > new_policy.governor = gov; > > > > - /* Use the default policy if its valid. */ > > - if (cpufreq_driver->setpolicy) > > - cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); > > - > > + /* Use the default policy if there is no last_policy. */ > > + if (cpufreq_driver->setpolicy) { > > + if (policy->last_policy) > > + new_policy.policy = policy->last_policy; > > + else > > + cpufreq_parse_governor(gov->name, &new_policy.policy, > > + NULL); > > + } > > /* set default policy */ > > return cpufreq_set_policy(policy, &new_policy); > > } > > @@ -1330,6 +1334,8 @@ static void cpufreq_offline_prepare(unsigned int cpu) > > if (has_target()) > > strncpy(policy->last_governor, policy->governor->name, > > CPUFREQ_NAME_LEN); > > + else > > + policy->last_policy = policy->policy; > > } else if (cpu == policy->cpu) { > > /* Nominate new CPU */ > > policy->cpu = cpumask_any(policy->cpus); > > diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h > > index ef4c5b1..177c768 100644 > > --- a/include/linux/cpufreq.h > > +++ b/include/linux/cpufreq.h > > @@ -77,6 +77,7 @@ struct cpufreq_policy { > > unsigned int suspend_freq; /* freq to set during suspend */ > > > > unsigned int policy; /* see above */ > > + unsigned int last_policy; /* policy before unplug */ > > struct cpufreq_governor *governor; /* see below */ > > void *governor_data; > > bool governor_enabled; /* governor start/stop flag */ > > > > Thanks, > Rafael >