cpufreq: Notify governors when cpus are hot-[un]plugged

Because cpufreq core and governors worry only about the online cpus, if a cpu is
hot [un]plugged, we must notify governors about it, otherwise be ready to expect
something unexpected.

We already have notifiers in the form of CPUFREQ_GOV_START/CPUFREQ_GOV_STOP, we
just need to call them now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index de9951766dd8..a0a33bdb4533 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -751,11 +751,16 @@ static int cpufreq_add_dev_policy(unsigned int cpu,
                                 return -EBUSY;
                         }
 
+                        __cpufreq_governor(managed_policy, CPUFREQ_GOV_STOP);
+
                         spin_lock_irqsave(&cpufreq_driver_lock, flags);
                         cpumask_copy(managed_policy->cpus, policy->cpus);
                         per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
                         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
+                        __cpufreq_governor(managed_policy, CPUFREQ_GOV_START);
+                        __cpufreq_governor(managed_policy, CPUFREQ_GOV_LIMITS);
+
                         pr_debug("CPU already managed, adding link\n");
                         ret = sysfs_create_link(&dev->kobj,
                                                 &managed_policy->kobj,
@@ -1066,8 +1071,13 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif
          */
         if (unlikely(cpu != data->cpu)) {
                 pr_debug("removing link\n");
+                __cpufreq_governor(data, CPUFREQ_GOV_STOP);
                 cpumask_clear_cpu(cpu, data->cpus);
                 spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+                __cpufreq_governor(data, CPUFREQ_GOV_START);
+                __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
+
                 kobj = &dev->kobj;
                 cpufreq_cpu_put(data);
                 unlock_policy_rwsem_write(cpu);