| From | "Rafael J. Wysocki" <> | Date | Tue, 6 Sep 2016 23:27:46 +0200 | Subject | Re: [PATCH 12/21] cpufreq: Convert to hotplug state machine |
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On Tue, Sep 6, 2016 at 7:04 PM, Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote: > Install the callbacks via the state machine. > > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Cc: linux-pm@vger.kernel.org > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > drivers/cpufreq/cpufreq.c | 38 ++++++++++++-------------------------- > 1 file changed, 12 insertions(+), 26 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 3dd4884c6f9e..e0bc632a259e 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -1358,7 +1358,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) > return add_cpu_dev_symlink(policy, cpu); > } > > -static void cpufreq_offline(unsigned int cpu) > +static int cpufreq_offline(unsigned int cpu) > { > struct cpufreq_policy *policy; > int ret; > @@ -1368,7 +1368,7 @@ static void cpufreq_offline(unsigned int cpu) > policy = cpufreq_cpu_get_raw(cpu); > if (!policy) { > pr_debug("%s: No cpu_data found\n", __func__); > - return; > + return 0; > } > > down_write(&policy->rwsem); > @@ -1417,6 +1417,7 @@ static void cpufreq_offline(unsigned int cpu) > > unlock: > up_write(&policy->rwsem); > + return 0; > } > > /** > @@ -2332,28 +2333,6 @@ int cpufreq_update_policy(unsigned int cpu) > } > EXPORT_SYMBOL(cpufreq_update_policy); > > -static int cpufreq_cpu_callback(struct notifier_block *nfb, > - unsigned long action, void *hcpu) > -{ > - unsigned int cpu = (unsigned long)hcpu; > - > - switch (action & ~CPU_TASKS_FROZEN) { > - case CPU_ONLINE: > - case CPU_DOWN_FAILED: > - cpufreq_online(cpu); > - break; > - > - case CPU_DOWN_PREPARE: > - cpufreq_offline(cpu); > - break; > - } > - return NOTIFY_OK; > -} > - > -static struct notifier_block __refdata cpufreq_cpu_notifier = { > - .notifier_call = cpufreq_cpu_callback, > -}; > - > /********************************************************************* > * BOOST * > *********************************************************************/ > @@ -2455,6 +2434,7 @@ EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); > /********************************************************************* > * REGISTER / UNREGISTER CPUFREQ DRIVER * > *********************************************************************/ > +static enum cpuhp_state hp_online; > > /** > * cpufreq_register_driver - register a CPU Frequency driver > @@ -2517,7 +2497,13 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data) > goto err_if_unreg; > } > > - register_hotcpu_notifier(&cpufreq_cpu_notifier); > + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "cpufreq:online", > + cpufreq_online, > + cpufreq_offline); > + if (ret < 0) > + goto err_if_unreg; > + hp_online = ret;
hp_online is enum cpuhp_state (and we pass it to cpuhp_remove_state_nocalls(() later on), but cpuhp_setup_state_nocalls() returns an int (and that should be 0 if it is not an error code AFAICS), so is this actually correct?
Thanks, Rafael
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