diff options
author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-09-12 11:04:11 (GMT) |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-09-12 11:04:11 (GMT) |
commit | f1728fd1599112239ed5cebc7be9810264db6792 (patch) | |
tree | de36bb207a71db98c7170b57c557017e340831b7 /drivers/cpufreq | |
parent | 0df03a30c333d67ee9b4c37f32d423624f48fe05 (diff) | |
parent | 44871c9c7f7963f8869dd8bc9620221c9e9db153 (diff) | |
download | linux-f1728fd1599112239ed5cebc7be9810264db6792.tar.xz |
Merge branch 'pm-cpufreq'
* pm-cpufreq:
cpufreq: Acquire the lock in cpufreq_policy_restore() for reading
cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu
cpufreq: Restructure if/else block to avoid unintended behavior
cpufreq: Fix crash in cpufreq-stats during suspend/resume
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r-- | drivers/cpufreq/cpufreq.c | 49 |
1 files changed, 32 insertions, 17 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 5a64f66..43c24aa 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -906,11 +906,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) struct cpufreq_policy *policy; unsigned long flags; - write_lock_irqsave(&cpufreq_driver_lock, flags); + read_lock_irqsave(&cpufreq_driver_lock, flags); policy = per_cpu(cpufreq_cpu_data_fallback, cpu); - write_unlock_irqrestore(&cpufreq_driver_lock, flags); + read_unlock_irqrestore(&cpufreq_driver_lock, flags); return policy; } @@ -947,6 +947,21 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) kfree(policy); } +static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) +{ + if (cpu == policy->cpu) + return; + + policy->last_cpu = policy->cpu; + policy->cpu = cpu; + +#ifdef CONFIG_CPU_FREQ_TABLE + cpufreq_frequency_table_update_policy_cpu(policy); +#endif + blocking_notifier_call_chain(&cpufreq_policy_notifier_list, + CPUFREQ_UPDATE_POLICY_CPU, policy); +} + static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, bool frozen) { @@ -1000,7 +1015,18 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, if (!policy) goto nomem_out; - policy->cpu = cpu; + + /* + * In the resume path, since we restore a saved policy, the assignment + * to policy->cpu is like an update of the existing policy, rather than + * the creation of a brand new one. So we need to perform this update + * by invoking update_policy_cpu(). + */ + if (frozen && cpu != policy->cpu) + update_policy_cpu(policy, cpu); + else + policy->cpu = cpu; + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; cpumask_copy(policy->cpus, cpumask_of(cpu)); @@ -1092,18 +1118,6 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) return __cpufreq_add_dev(dev, sif, false); } -static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) -{ - policy->last_cpu = policy->cpu; - policy->cpu = cpu; - -#ifdef CONFIG_CPU_FREQ_TABLE - cpufreq_frequency_table_update_policy_cpu(policy); -#endif - blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_UPDATE_POLICY_CPU, policy); -} - static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, unsigned int old_cpu, bool frozen) { @@ -1182,8 +1196,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, cpumask_clear_cpu(cpu, policy->cpus); unlock_policy_rwsem_write(cpu); - if (cpu != policy->cpu && !frozen) { - sysfs_remove_link(&dev->kobj, "cpufreq"); + if (cpu != policy->cpu) { + if (!frozen) + sysfs_remove_link(&dev->kobj, "cpufreq"); } else if (cpus > 1) { new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen); |