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| author | Viresh Kumar <viresh.kumar@linaro.org> | 2013-09-12 15:36:33 +0400 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-09-18 02:01:27 +0400 |
| commit | 9c8f1ee40b6368e6b2775c9c9f816e2a5dca3c07 (patch) | |
| tree | 40ecbfa5c590cb9b04f13ec9f62ac6a209233834 /drivers/cpufreq | |
| parent | 272b98c6455f00884f0350f775c5342358ebb73f (diff) | |
| download | linux-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.c | 16 |
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) { |