From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH 3/7] cpufreq: Introduce ->usable() callback for cpufreq drivers Date: Thu, 27 Nov 2014 01:25:25 +0100 Message-ID: <5490890.8GRTWn2e7b@vostro.rjw.lan> References: <95b84bb8af3d4d9667a79db520cfa37d9444d75b.1416980448.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from v094114.home.net.pl ([79.96.170.134]:56470 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752089AbaK0AEK (ORCPT ); Wed, 26 Nov 2014 19:04:10 -0500 In-Reply-To: <95b84bb8af3d4d9667a79db520cfa37d9444d75b.1416980448.git.viresh.kumar@linaro.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: edubezval@gmail.com, linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, l.majewski@samsung.com On Wednesday, November 26, 2014 11:22:58 AM Viresh Kumar wrote: > Currently there is no callback for cpufreq drivers which is called once the > policy is ready to be used. There are some requirements where such a callback is > required. > > One of them is registering a cooling device with the help of > of_cpufreq_cooling_register(). This routine tries to get 'struct cpufreq_policy' > for CPUs which isn't yet initialed at the time ->init() is called and so we face > issues while registering the cooling device. > > Because we can't register cooling device from ->init(), we need a callback that > is called after the policy is ready to be used and hence we introduce ->usable() > callback. > > Signed-off-by: Viresh Kumar > --- > drivers/cpufreq/cpufreq.c | 5 +++++ > include/linux/cpufreq.h | 4 ++++ > 2 files changed, 9 insertions(+) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index de2c3e1..4fb95b9 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -1285,8 +1285,13 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) > up_write(&policy->rwsem); > > kobject_uevent(&policy->kobj, KOBJ_ADD); > + > up_read(&cpufreq_rwsem); > > + /* Callback for handling stuff after policy is ready */ > + if (cpufreq_driver->usable) > + cpufreq_driver->usable(policy); > + > pr_debug("initialization complete\n"); > > return 0; > diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h > index db3c130..4795c0b 100644 > --- a/include/linux/cpufreq.h > +++ b/include/linux/cpufreq.h > @@ -267,6 +267,10 @@ struct cpufreq_driver { > void (*stop_cpu)(struct cpufreq_policy *policy); > int (*suspend)(struct cpufreq_policy *policy); > int (*resume)(struct cpufreq_policy *policy); > + > + /* Will be called after the driver is fully initialized */ > + void (*usable)(struct cpufreq_policy *policy); What about void (*ready)(struct cpufreq_policy *policy); > + > struct freq_attr **attr; > > /* platform specific boost support code */ > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.