On 2016-11-28 10:45:20 [+0530], Viresh Kumar wrote:
> > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> > index 297e9128fe9f..2c29cbaca7b5 100644
> > --- a/drivers/cpufreq/acpi-cpufreq.c
> > +++ b/drivers/cpufreq/acpi-cpufreq.c
> > @@ -922,37 +909,47 @@ static struct cpufreq_driver acpi_cpufreq_driver = {
> > .attr = acpi_cpufreq_attr,
> > };
> >
> > +static enum cpuhp_state acpi_cpufreq_online;
> > +
> > static void __init acpi_cpufreq_boost_init(void)
> > {
> > - if (boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)) {
> > - msrs = msrs_alloc();
> > + int ret;
> >
> > - if (!msrs)
> > - return;
> > + if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)))
> > + return;
> >
> > - acpi_cpufreq_driver.set_boost = set_boost;
> > - acpi_cpufreq_driver.boost_enabled = boost_state(0);
> > + msrs = msrs_alloc();
> >
> > - cpu_notifier_register_begin();
> > + if (!msrs)
> > + return;
> >
> > - /* Force all MSRs to the same value */
> > - boost_set_msrs(acpi_cpufreq_driver.boost_enabled,
> > - cpu_online_mask);
>
> Why isn't this required anymore ?
Later there is cpuhp_setup_state() which invokes the online callback
(cpufreq_boost_online) which is doing this.
> > + acpi_cpufreq_driver.set_boost = set_boost;
> > + acpi_cpufreq_driver.boost_enabled = boost_state(0);
> >
> > - __register_cpu_notifier(&boost_nb);
> > -
> > - cpu_notifier_register_done();
> > + /*
> > + * This calls the online callback on all online cpu and forces all
> > + * MSRs to the same value.
> > + */
> > + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpufreq/acpi:online",
> > + cpufreq_boost_online, cpufreq_boost_down_prep);
> > + if (ret < 0) {
> > + pr_err("acpi_cpufreq: failed to register hotplug callbacks\n");
> > + msrs_free(msrs);
>
> If 'msrs = NULL' is required to be done in the _exit() routine, then it should
> be done here as well. Right?
It is not required in the exit path, it is just needed here. It is gone
in the following patch anyway but I will post a fixed version.
> > + return;
> > }
> > + acpi_cpufreq_online = ret;
> > }
> >
> > static void acpi_cpufreq_boost_exit(void)
> > {
> > - if (msrs) {
> > - unregister_cpu_notifier(&boost_nb);
> > + if (!msrs)
> > + return;
> >
> > - msrs_free(msrs);
> > - msrs = NULL;
> > - }
> > + if (acpi_cpufreq_online >= 0)
> > + cpuhp_remove_state_nocalls(acpi_cpufreq_online);
> > +
> > + msrs_free(msrs);
> > + msrs = NULL;
> > }
> >
> > static int __init acpi_cpufreq_init(void)
> > --
> > 2.10.2
Sebastian
