Commit 7c30ed ("cpufreq: make sure frequency transitions are serialized") interacts poorly with systems that have a single core freqency for all cores. On such systems we have a single policy for all cores with several CPUs. When we do a frequency transition the governor calls the pre and post change notifiers which causes cpufreq_notify_transition() per CPU. Since the policy is the same for all of them all CPUs after the first and the warnings added are generated by checking a per-policy flag the warnings will be triggered for all cores after the first.
Fix this by allowing notifier to be called for n times. Where n is the number of cpus in policy->cpus.
Reported-and-Tested-by: Mark Brown broonie@linaro.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- Hi Rafael,
This is a fix for 3.11.
drivers/cpufreq/cpufreq.c | 7 ++++--- include/linux/cpufreq.h | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index b557503..b7bda8d 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -312,11 +312,12 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy, switch (state) {
case CPUFREQ_PRECHANGE: - if (WARN(policy->transition_ongoing, + if (WARN(policy->transition_ongoing == + cpumask_weight(policy->cpus), "In middle of another frequency transition\n")) return;
- policy->transition_ongoing = true; + policy->transition_ongoing++;
/* detect if the driver reported a value as "old frequency" * which is not equal to what the cpufreq core thinks is @@ -341,7 +342,7 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy, "No frequency transition in progress\n")) return;
- policy->transition_ongoing = false; + policy->transition_ongoing--;
adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 4d7390b..90d5a15 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -119,7 +119,7 @@ struct cpufreq_policy {
struct kobject kobj; struct completion kobj_unregister; - bool transition_ongoing; /* Tracks transition status */ + int transition_ongoing; /* Tracks transition status */ };
#define CPUFREQ_ADJUST (0)