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authorViresh Kumar <viresh.kumar@linaro.org>2013-04-22 00:48:03 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-04-22 00:48:03 +0200
commit820c6ca293e99ae225dc9dd7e0e689c444b08f92 (patch)
treebb4baa6b7e3d27f7495d248ba3e0235470751ac2 /drivers/cpufreq/cpufreq.c
parent70eb0855b2f8fcf61f9f47626b9fa70e7b45ab06 (diff)
downloadblackbird-op-linux-820c6ca293e99ae225dc9dd7e0e689c444b08f92.tar.gz
blackbird-op-linux-820c6ca293e99ae225dc9dd7e0e689c444b08f92.zip
cpufreq: Don't call __cpufreq_governor() for drivers without target()
Some cpufreq drivers implement their own governor and so don't need us to call generic governors interface via __cpufreq_governor(). Few recent commits haven't obeyed this law well and we saw some regressions. This patch is an attempt to fix the above issue. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com> Tested-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
-rw-r--r--drivers/cpufreq/cpufreq.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 3564947ea7ac..a6f65954b0ab 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -858,13 +858,18 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling,
struct device *dev)
{
struct cpufreq_policy *policy;
- int ret = 0;
+ int ret = 0, has_target = 0;
unsigned long flags;
policy = cpufreq_cpu_get(sibling);
WARN_ON(!policy);
- __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
+ rcu_read_lock();
+ has_target = !!rcu_dereference(cpufreq_driver)->target;
+ rcu_read_unlock();
+
+ if (has_target)
+ __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
lock_policy_rwsem_write(sibling);
@@ -877,8 +882,10 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling,
unlock_policy_rwsem_write(sibling);
- __cpufreq_governor(policy, CPUFREQ_GOV_START);
- __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
+ if (has_target) {
+ __cpufreq_governor(policy, CPUFREQ_GOV_START);
+ __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
+ }
ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
if (ret) {
@@ -1146,7 +1153,8 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif
/* If cpu is last user of policy, free policy */
if (cpus == 1) {
- __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
+ if (has_target)
+ __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
lock_policy_rwsem_read(cpu);
kobj = &data->kobj;
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