Merge branch 'pm-cpufreq'
* pm-cpufreq:
cpufreq: Acquire the lock in cpufreq_policy_restore() for reading
cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu
cpufreq: Restructure if/else block to avoid unintended behavior
cpufreq: Fix crash in cpufreq-stats during suspend/resume
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 5a64f66..43c24aa 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -906,11 +906,11 @@
struct cpufreq_policy *policy;
unsigned long flags;
- write_lock_irqsave(&cpufreq_driver_lock, flags);
+ read_lock_irqsave(&cpufreq_driver_lock, flags);
policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ read_unlock_irqrestore(&cpufreq_driver_lock, flags);
return policy;
}
@@ -947,6 +947,21 @@
kfree(policy);
}
+static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
+{
+ if (cpu == policy->cpu)
+ return;
+
+ policy->last_cpu = policy->cpu;
+ policy->cpu = cpu;
+
+#ifdef CONFIG_CPU_FREQ_TABLE
+ cpufreq_frequency_table_update_policy_cpu(policy);
+#endif
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_UPDATE_POLICY_CPU, policy);
+}
+
static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
bool frozen)
{
@@ -1000,7 +1015,18 @@
if (!policy)
goto nomem_out;
- policy->cpu = cpu;
+
+ /*
+ * In the resume path, since we restore a saved policy, the assignment
+ * to policy->cpu is like an update of the existing policy, rather than
+ * the creation of a brand new one. So we need to perform this update
+ * by invoking update_policy_cpu().
+ */
+ if (frozen && cpu != policy->cpu)
+ update_policy_cpu(policy, cpu);
+ else
+ policy->cpu = cpu;
+
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
cpumask_copy(policy->cpus, cpumask_of(cpu));
@@ -1092,18 +1118,6 @@
return __cpufreq_add_dev(dev, sif, false);
}
-static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
-{
- policy->last_cpu = policy->cpu;
- policy->cpu = cpu;
-
-#ifdef CONFIG_CPU_FREQ_TABLE
- cpufreq_frequency_table_update_policy_cpu(policy);
-#endif
- blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
- CPUFREQ_UPDATE_POLICY_CPU, policy);
-}
-
static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
unsigned int old_cpu, bool frozen)
{
@@ -1182,8 +1196,9 @@
cpumask_clear_cpu(cpu, policy->cpus);
unlock_policy_rwsem_write(cpu);
- if (cpu != policy->cpu && !frozen) {
- sysfs_remove_link(&dev->kobj, "cpufreq");
+ if (cpu != policy->cpu) {
+ if (!frozen)
+ sysfs_remove_link(&dev->kobj, "cpufreq");
} else if (cpus > 1) {
new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen);
