From 70a59fde6e69d1d8579f84bf4555bfffb3ce452d Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 20 Jun 2019 08:35:50 +0530 Subject: cpufreq: Avoid calling cpufreq_verify_current_freq() from handle_update() On some occasions cpufreq_verify_current_freq() schedules a work whose callback is handle_update(), which further calls cpufreq_update_policy() which may end up calling cpufreq_verify_current_freq() again. On the other hand, when cpufreq_update_policy() is called from handle_update(), the pointer to the cpufreq policy is already available, but cpufreq_cpu_acquire() is still called to get it in cpufreq_update_policy(), which should be avoided as well. To fix these issues, create a new helper, refresh_frequency_limits(), and make both handle_update() call it cpufreq_update_policy(). Signed-off-by: Viresh Kumar [ rjw: Rename reeval_frequency_limits() as refresh_frequency_limits() ] [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index cba9c9e1bd0f..ceb57af15ca0 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1115,13 +1115,25 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp return ret; } +static void refresh_frequency_limits(struct cpufreq_policy *policy) +{ + struct cpufreq_policy new_policy = *policy; + + pr_debug("updating policy for CPU %u\n", policy->cpu); + + new_policy.min = policy->user_policy.min; + new_policy.max = policy->user_policy.max; + + cpufreq_set_policy(policy, &new_policy); +} + static void handle_update(struct work_struct *work) { struct cpufreq_policy *policy = container_of(work, struct cpufreq_policy, update); - unsigned int cpu = policy->cpu; - pr_debug("handle_update for cpu %u called\n", cpu); - cpufreq_update_policy(cpu); + + pr_debug("handle_update for cpu %u called\n", policy->cpu); + refresh_frequency_limits(policy); } static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) @@ -2376,7 +2388,6 @@ int cpufreq_set_policy(struct cpufreq_policy *policy, void cpufreq_update_policy(unsigned int cpu) { struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); - struct cpufreq_policy new_policy; if (!policy) return; @@ -2389,12 +2400,7 @@ void cpufreq_update_policy(unsigned int cpu) (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false)))) goto unlock; - pr_debug("updating policy for CPU %u\n", cpu); - memcpy(&new_policy, policy, sizeof(*policy)); - new_policy.min = policy->user_policy.min; - new_policy.max = policy->user_policy.max; - - cpufreq_set_policy(policy, &new_policy); + refresh_frequency_limits(policy); unlock: cpufreq_cpu_release(policy); -- cgit v1.2.3