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authorViresh Kumar <viresh.kumar@linaro.org>2015-05-12 12:22:51 +0530
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-05-15 02:46:45 +0200
commit18bf3a124ef87fe43045cbf13dff7ea7e3a94aa3 (patch)
treeca480f2d5808574d85711b1be1872cf3a7ba01f7 /drivers/cpufreq
parent4573237b01221881702fbe6655f3ae5135be1c18 (diff)
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cpufreq: Mark policy->governor = NULL for inactive policies
Later commits would change the way policies are managed today. Policies wouldn't be freed on cpu hotplug (currently they aren't freed on suspend), and while the CPU is offline, the sysfs cpufreq files would still be present. Because we don't mark policy->governor as NULL, it still contains pointer of the last used governor. And if the governor is removed, while all the CPUs of a policy are hotplugged out, this pointer wouldn't be valid anymore. And if we try to read the 'scaling_governor', etc. from sysfs, it will result in kernel OOPs. To prevent this, mark policy->governor as NULL for all inactive policies while the governor is removed from kernel. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 16275ba6428e..c08de5e985c7 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1083,7 +1083,6 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
if (likely(policy)) {
/* Policy should be inactive here */
WARN_ON(!policy_is_inactive(policy));
- policy->governor = NULL;
}
return policy;
@@ -2145,8 +2144,10 @@ void cpufreq_unregister_governor(struct cpufreq_governor *governor)
/* clear last_governor for all inactive policies */
read_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_inactive_policy(policy) {
- if (!strcmp(policy->last_governor, governor->name))
+ if (!strcmp(policy->last_governor, governor->name)) {
+ policy->governor = NULL;
strcpy(policy->last_governor, "\0");
+ }
}
read_unlock_irqrestore(&cpufreq_driver_lock, flags);