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authorViresh Kumar <viresh.kumar@linaro.org>2013-09-12 15:36:33 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-09-18 02:01:27 +0400
commit9c8f1ee40b6368e6b2775c9c9f816e2a5dca3c07 (patch)
tree40ecbfa5c590cb9b04f13ec9f62ac6a209233834 /drivers/cpufreq
parent272b98c6455f00884f0350f775c5342358ebb73f (diff)
downloadlinux-9c8f1ee40b6368e6b2775c9c9f816e2a5dca3c07.tar.xz
cpufreq: Clear policy->cpus bits in __cpufreq_remove_dev_finish()
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>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 43c24aa756f6..dbfe219667d3 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1125,7 +1125,7 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
int ret;
/* 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 */
if (frozen)
@@ -1189,12 +1189,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
policy->governor->name, CPUFREQ_NAME_LEN);
#endif
- WARN_ON(lock_policy_rwsem_write(cpu));
+ lock_policy_rwsem_read(cpu);
cpus = cpumask_weight(policy->cpus);
-
- if (cpus > 1)
- cpumask_clear_cpu(cpu, policy->cpus);
- unlock_policy_rwsem_write(cpu);
+ unlock_policy_rwsem_read(cpu);
if (cpu != policy->cpu) {
if (!frozen)
@@ -1237,9 +1234,12 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
return -EINVAL;
}
- lock_policy_rwsem_read(cpu);
+ WARN_ON(lock_policy_rwsem_write(cpu));
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 (cpus == 1) {