From 56e69b35155ea6b699c6dba228aae5521fa8d4a2 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Tue, 2 Jul 2013 16:36:28 +0530 Subject: 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 --- drivers/cpufreq/cpufreq.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers') 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) { 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 @@ -295,7 +296,7 @@ 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, -- cgit v1.2.3