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path: root/drivers/cpufreq/cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
-rw-r--r--drivers/cpufreq/cpufreq.c34
1 files changed, 28 insertions, 6 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2ce3de5e84af..5e626b12b97e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -763,6 +763,8 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
init_completion(&policy->kobj_unregister);
INIT_WORK(&policy->update, handle_update);
+ /* Set governor before ->init, so that driver could check it */
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
/* call driver. From then on the cpufreq must be able
* to accept all calls to ->verify and ->setpolicy for this CPU
*/
@@ -1109,12 +1111,7 @@ unsigned int cpufreq_quick_get(unsigned int cpu)
unsigned int ret_freq = 0;
if (policy) {
- if (unlikely(lock_policy_rwsem_read(cpu)))
- return ret_freq;
-
ret_freq = policy->cur;
-
- unlock_policy_rwsem_read(cpu);
cpufreq_cpu_put(policy);
}
@@ -1483,6 +1480,31 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
{
int ret;
+ /* Only must be defined when default governor is known to have latency
+ restrictions, like e.g. conservative or ondemand.
+ That this is the case is already ensured in Kconfig
+ */
+#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
+ struct cpufreq_governor *gov = &cpufreq_gov_performance;
+#else
+ struct cpufreq_governor *gov = NULL;
+#endif
+
+ if (policy->governor->max_transition_latency &&
+ policy->cpuinfo.transition_latency >
+ policy->governor->max_transition_latency) {
+ if (!gov)
+ return -EINVAL;
+ else {
+ printk(KERN_WARNING "%s governor failed, too long"
+ " transition latency of HW, fallback"
+ " to %s governor\n",
+ policy->governor->name,
+ gov->name);
+ policy->governor = gov;
+ }
+ }
+
if (!try_module_get(policy->governor->owner))
return -EINVAL;
@@ -1703,7 +1725,7 @@ int cpufreq_update_policy(unsigned int cpu)
}
EXPORT_SYMBOL(cpufreq_update_policy);
-static int cpufreq_cpu_callback(struct notifier_block *nfb,
+static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;