On Wednesday, July 08, 2015 11:23:58 AM Viresh Kumar wrote: > When all CPUs of a policy are hot-unplugged, we EXIT the governor but > don't mark policy->governor as NULL. This was done in order to keep last > used governor's information intact in sysfs, while the CPUs are offline. > > We also missed marking policy->governor as NULL while restoring the > policy. Because of that, we call __cpufreq_governor(CPUFREQ_GOV_LIMITS)
How exactly does that happen? > for an uninitialized policy. Which eventually returns -EBUSY. > > Fix this by setting policy->governor to NULL while restoring the policy. > > Reported-by: Pi-Cheng Chen <pi-cheng.c...@linaro.org> > Reported-by: "Jon Medhurst (Tixy)" <t...@linaro.org> > Fixes: 18bf3a124ef8 ("cpufreq: Mark policy->governor = NULL for inactive > policies") > Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org> > --- > For 4.2-rc > > drivers/cpufreq/cpufreq.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index b612411655f9..2c22e3902e72 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -1132,6 +1132,7 @@ static struct cpufreq_policy > *cpufreq_policy_restore(unsigned int cpu) > > down_write(&policy->rwsem); > policy->cpu = cpu; > + policy->governor = NULL; > up_write(&policy->rwsem); > } > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/