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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.c61
1 files changed, 47 insertions, 14 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 3aa7a7a..abda660 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -331,16 +331,15 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
* function. It is called twice on all CPU frequency changes that have
* external effects.
*/
-void cpufreq_notify_transition(struct cpufreq_policy *policy,
+static void cpufreq_notify_transition(struct cpufreq_policy *policy,
struct cpufreq_freqs *freqs, unsigned int state)
{
for_each_cpu(freqs->cpu, policy->cpus)
__cpufreq_notify_transition(policy, freqs, state);
}
-EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
/* Do post notifications when there are chances that transition has failed */
-void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
+static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
struct cpufreq_freqs *freqs, int transition_failed)
{
cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
@@ -351,7 +350,41 @@ void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
}
-EXPORT_SYMBOL_GPL(cpufreq_notify_post_transition);
+
+void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
+ struct cpufreq_freqs *freqs)
+{
+wait:
+ wait_event(policy->transition_wait, !policy->transition_ongoing);
+
+ spin_lock(&policy->transition_lock);
+
+ if (unlikely(policy->transition_ongoing)) {
+ spin_unlock(&policy->transition_lock);
+ goto wait;
+ }
+
+ policy->transition_ongoing = true;
+
+ spin_unlock(&policy->transition_lock);
+
+ cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
+}
+EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
+
+void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
+ struct cpufreq_freqs *freqs, int transition_failed)
+{
+ if (unlikely(WARN_ON(!policy->transition_ongoing)))
+ return;
+
+ cpufreq_notify_post_transition(policy, freqs, transition_failed);
+
+ policy->transition_ongoing = false;
+
+ wake_up(&policy->transition_wait);
+}
+EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
/*********************************************************************
@@ -985,6 +1018,8 @@ static struct cpufreq_policy *cpufreq_policy_alloc(void)
INIT_LIST_HEAD(&policy->policy_list);
init_rwsem(&policy->rwsem);
+ spin_lock_init(&policy->transition_lock);
+ init_waitqueue_head(&policy->transition_wait);
return policy;
@@ -1470,8 +1505,8 @@ static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq,
policy = per_cpu(cpufreq_cpu_data, cpu);
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
- cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
- cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+ cpufreq_freq_transition_begin(policy, &freqs);
+ cpufreq_freq_transition_end(policy, &freqs, 0);
}
/**
@@ -1652,14 +1687,13 @@ void cpufreq_resume(void)
cpufreq_suspended = false;
list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
- if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
+ if (cpufreq_driver->resume && cpufreq_driver->resume(policy))
+ pr_err("%s: Failed to resume driver: %p\n", __func__,
+ policy);
+ else if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
|| __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))
pr_err("%s: Failed to start governor for policy: %p\n",
__func__, policy);
- else if (cpufreq_driver->resume
- && cpufreq_driver->resume(policy))
- pr_err("%s: Failed to resume driver: %p\n", __func__,
- policy);
/*
* schedule call cpufreq_update_policy() for boot CPU, i.e. last
@@ -1832,8 +1866,7 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
__func__, policy->cpu, freqs.old, freqs.new);
- cpufreq_notify_transition(policy, &freqs,
- CPUFREQ_PRECHANGE);
+ cpufreq_freq_transition_begin(policy, &freqs);
}
retval = cpufreq_driver->target_index(policy, index);
@@ -1842,7 +1875,7 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
__func__, retval);
if (notify)
- cpufreq_notify_post_transition(policy, &freqs, retval);
+ cpufreq_freq_transition_end(policy, &freqs, retval);
}
out:
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