[PATCH 3.12 22/98] intel_pstate: Use del_timer_sync in intel_pstate_cpu_stop

From: Jiri Slaby
Date: Mon Apr 11 2016 - 09:50:28 EST


From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit c2294a2f7853e6450361d078b65407bdaa6d1d11 upstream.

Ensure that no timer callback is running since we are about to free
the timer structure. We cannot guarantee that the call back is called
on the CPU where the timer is running.

Reported-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 132a9139c19f..a8056af80999 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -635,7 +635,7 @@ static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
{
int cpu = policy->cpu;

- del_timer(&all_cpu_data[cpu]->timer);
+ del_timer_sync(&all_cpu_data[cpu]->timer);
kfree(all_cpu_data[cpu]);
all_cpu_data[cpu] = NULL;
return 0;
--
2.8.1