diff options
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 37 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 10 |
2 files changed, 47 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index d8d6bc9d1815..d57806a85def 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -353,6 +353,41 @@ void cpufreq_notify_post_transition(struct cpufreq_policy *policy, } 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); + /********************************************************************* * SYSFS INTERFACE * @@ -985,6 +1020,8 @@ 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; diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 2d2e62c8666a..e33760268a86 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -16,6 +16,7 @@ #include <linux/completion.h> #include <linux/kobject.h> #include <linux/notifier.h> +#include <linux/spinlock.h> #include <linux/sysfs.h> /********************************************************************* @@ -104,6 +105,11 @@ struct cpufreq_policy { * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); */ struct rw_semaphore rwsem; + + /* Synchronization for frequency transitions */ + bool transition_ongoing; /* Tracks transition status */ + spinlock_t transition_lock; + wait_queue_head_t transition_wait; }; /* Only for ACPI */ @@ -337,6 +343,10 @@ void cpufreq_notify_transition(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs, unsigned int state); void cpufreq_notify_post_transition(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs, int transition_failed); +void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs); +void cpufreq_freq_transition_end(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs, int transition_failed); #else /* CONFIG_CPU_FREQ */ static inline int cpufreq_register_notifier(struct notifier_block *nb, |