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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	cpufreq <cpufreq@vger.kernel.org>, pm <linux-pm@vger.kernel.org>
Subject: [patch 15/16] cpufreq: intel-pstate: Use del_timer_sync in intel_pstate_cpu_exit()
Date: Sun, 23 Mar 2014 15:09:32 -0000	[thread overview]
Message-ID: <20140323150754.272874059@linutronix.de> (raw)
In-Reply-To: 20140323150557.288925975@linutronix.de

[-- Attachment #1: cpufreq-intel-pstate-use-del_timer_sync.patch --]
[-- Type: text/plain, Size: 1153 bytes --]

We are about to free the data structure. Make sure no timer callback
is running. I might be paranoid, but the ->exit callback can be
invoked from so many places, that it is not entirely clear whether
del_timer is always called on the cpu on which it is enqueued.

While looking through the call sites I noticed, that
cpufreq_init_policy() can fail and invoke cpufreq_driver->exit() but
it does not return the failure and the callsite happily proceeds.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: cpufreq <cpufreq@vger.kernel.org>
Cc: pm <linux-pm@vger.kernel.org>
---

 drivers/cpufreq/intel_pstate.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: tip/drivers/cpufreq/intel_pstate.c
===================================================================
--- tip.orig/drivers/cpufreq/intel_pstate.c
+++ tip/drivers/cpufreq/intel_pstate.c
@@ -777,7 +777,7 @@ static int intel_pstate_cpu_exit(struct
 {
 	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;


       reply	other threads:[~2014-03-23 15:09 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20140323150557.288925975@linutronix.de>
2014-03-23 15:09 ` Thomas Gleixner [this message]
2014-03-24  1:56   ` [patch 15/16] cpufreq: intel-pstate: Use del_timer_sync in intel_pstate_cpu_exit() Rafael J. Wysocki
2014-03-24 14:18     ` Dirk Brandewie
2014-03-24  4:45   ` Viresh Kumar

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