cpufreq: stats: do cpufreq_cpu_put() corresponding to cpufreq_cpu_get()

In cpufreq_stats_free_sysfs() we aren't balancing calls to
cpufreq_cpu_get() with cpufreq_cpu_put(). This will never let us have
ref count to policy->kobj as zero.

We will get a hang if somehow cpufreq_driver_unregister() is called.
And that can happen when we compile our driver as module and
insmod/rmmod it.

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

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 2fd779eb1ed1..bfd6273fd873 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -180,15 +180,19 @@ static void cpufreq_stats_free_sysfs(unsigned int cpu)
 {
         struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 
-        if (!cpufreq_frequency_get_table(cpu))
+        if (!policy)
                 return;
 
-        if (policy && !policy_is_shared(policy)) {
+        if (!cpufreq_frequency_get_table(cpu))
+                goto put_ref;
+
+        if (!policy_is_shared(policy)) {
                 pr_debug("%s: Free sysfs stat\n", __func__);
                 sysfs_remove_group(&policy->kobj, &stats_attr_group);
         }
-        if (policy)
-                cpufreq_cpu_put(policy);
+
+put_ref:
+        cpufreq_cpu_put(policy);
 }
 
 static int cpufreq_stats_create_table(struct cpufreq_policy *policy,