From a8d7c3bc2396aff14f9e920677072cb55b016040 Mon Sep 17 00:00:00 2001 From: Elias Oltmanns Date: Mon, 22 Oct 2007 09:50:13 +0200 Subject: [CPUFREQ] Make cpufreq_conservative handle out-of-sync events properly Make cpufreq_conservative handle out-of-sync events properly Currently, the cpufreq_conservative governor doesn't get notified when the actual frequency the cpu is running at differs from what cpufreq thought it was. As a result the cpu may stay at the maximum frequency after a s2ram / resume cycle even though the system is idle. Signed-off-by: Elias Oltmanns Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_conservative.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index 4bd33ce8a6f..57d02e990af 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -116,6 +116,27 @@ static inline unsigned int get_cpu_idle_time(unsigned int cpu) return ret; } +/* keep track of frequency transitions */ +static int +dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, + void *data) +{ + struct cpufreq_freqs *freq = data; + struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, + freq->cpu); + + if (!this_dbs_info->enable) + return 0; + + this_dbs_info->requested_freq = freq->new; + + return 0; +} + +static struct notifier_block dbs_cpufreq_notifier_block = { + .notifier_call = dbs_cpufreq_notifier +}; + /************************** sysfs interface ************************/ static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) { @@ -511,6 +532,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, dbs_tuners_ins.sampling_rate = def_sampling_rate; dbs_timer_init(); + cpufreq_register_notifier( + &dbs_cpufreq_notifier_block, + CPUFREQ_TRANSITION_NOTIFIER); } mutex_unlock(&dbs_mutex); @@ -525,9 +549,13 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, * Stop the timerschedule work, when this governor * is used for first time */ - if (dbs_enable == 0) + if (dbs_enable == 0) { dbs_timer_exit(); - + cpufreq_unregister_notifier( + &dbs_cpufreq_notifier_block, + CPUFREQ_TRANSITION_NOTIFIER); + } + mutex_unlock(&dbs_mutex); break; -- cgit v1.2.3-18-g5258