Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-11 15:49:56 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge branch 'pm-cpufreq'

Browse Source 
* 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
This commit is contained in:
Rafael J. Wysocki 2013-09-12 13:04:11 +02:00
commit f1728fd159
1 changed files with 32 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
drivers/cpufreq/cpufreq.c
View File

@ -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);