lkml.org 
[lkml]   [2013]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5/5] cpufreq: use correct values of cpus in __cpufreq_remove_dev_finish()
Date
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 cpu mask in __cpufreq_remove_dev_finish() instead of
__cpufreq_remove_dev_prepare().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/cpufreq.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 0e11fcb..b556d46 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1175,12 +1175,9 @@ 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)
@@ -1222,9 +1219,12 @@ 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) {
--
1.7.12.rc2.18.g61b472e


\
 
 \ /
  Last update: 2013-09-12 07:41    [W:0.214 / U:0.364 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site