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cpufreq: Clear policy->cpus bits in __cpufreq_remove_dev_finish()

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This broke after a recent change "cedb70a cpufreq: Split __cpufreq_remove_dev()
into two parts" from Srivatsa.

Consider a scenario where we have two CPUs in a policy (0 & 1) and we are
removing CPU 1. On the call to __cpufreq_remove_dev_prepare() we have cleared 1
from policy->cpus and now on a call to __cpufreq_remove_dev_finish() we read
cpumask_weight of policy->cpus, which will come as 1 and this code will behave
as if we are removing the last CPU from policy :)

Fix it by clearing the CPU mask in __cpufreq_remove_dev_finish() instead of
__cpufreq_remove_dev_prepare().

Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2013-09-12 17:06:33 +05:30 committed by Rafael J. Wysocki
parent 272b98c645
commit 9c8f1ee40b
1 changed files with 8 additions and 8 deletions
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16
drivers/cpufreq/cpufreq.c
View file

@ -1125,7 +1125,7 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
int ret; int ret;
/* first sibling now owns the new sysfs dir */ /* first sibling now owns the new sysfs dir */
cpu_dev = get_cpu_device(cpumask_first(policy->cpus)); cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu));
/* Don't touch sysfs files during light-weight tear-down */ /* Don't touch sysfs files during light-weight tear-down */
if (frozen) if (frozen)
@ -1189,12 +1189,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
policy->governor->name, CPUFREQ_NAME_LEN); policy->governor->name, CPUFREQ_NAME_LEN);
#endif #endif
WARN_ON(lock_policy_rwsem_write(cpu)); lock_policy_rwsem_read(cpu);
cpus = cpumask_weight(policy->cpus); cpus = cpumask_weight(policy->cpus);
unlock_policy_rwsem_read(cpu);
if (cpus > 1)
cpumask_clear_cpu(cpu, policy->cpus);
unlock_policy_rwsem_write(cpu);
if (cpu != policy->cpu) { if (cpu != policy->cpu) {
if (!frozen) if (!frozen)
@ -1237,9 +1234,12 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
return -EINVAL; return -EINVAL;
} }
lock_policy_rwsem_read(cpu); WARN_ON(lock_policy_rwsem_write(cpu));
cpus = cpumask_weight(policy->cpus); cpus = cpumask_weight(policy->cpus);
unlock_policy_rwsem_read(cpu);
if (cpus > 1)
cpumask_clear_cpu(cpu, policy->cpus);
unlock_policy_rwsem_write(cpu);
/* If cpu is last user of policy, free policy */ /* If cpu is last user of policy, free policy */
if (cpus == 1) { if (cpus == 1) {