diff options
authorViresh Kumar <>2013-07-02 16:36:28 +0530
committerMarek Szyprowski <>2014-04-01 13:07:34 +0200
commit56e69b35155ea6b699c6dba228aae5521fa8d4a2 (patch)
parentf561427a7dbfd94e20b69e062d4b1c0ffc93d996 (diff)
cpufreq: Fix serialization of frequency transitions
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. Change-Id: I5712dde7f992644f9c3ddc8313151f80bea0d877 Reported-and-tested-by: Mark Brown <> Signed-off-by: Viresh Kumar <> Signed-off-by: Rafael J. Wysocki <>
2 files changed, 5 insertions, 4 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 00050b057cb..398882939cb 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -266,11 +266,12 @@ void __cpufreq_notify_transition(struct cpufreq_policy *policy,
switch (state) {
- if (WARN(policy->transition_ongoing,
+ if (WARN(policy->transition_ongoing ==
+ cpumask_weight(policy->cpus),
"In middle of another frequency transition\n"))
- 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
@@ -295,7 +296,7 @@ void __cpufreq_notify_transition(struct cpufreq_policy *policy,
"No frequency transition in progress\n"))
- 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 e3da73bbcf0..bd1ad374076 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -121,7 +121,7 @@ struct cpufreq_policy {
struct list_head policy_list;
struct kobject kobj;
struct completion kobj_unregister;
- bool transition_ongoing; /* Tracks transition status */
+ int transition_ongoing; /* Tracks transition status */
#define CPUFREQ_ADJUST (0)