diff options
| author | Daniel Lezcano <daniel.lezcano@linaro.org> | 2012-10-31 16:44:46 +0000 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2012-11-15 00:34:22 +0100 |
| commit | 41682032715c2c969357c81391a442a24dd1c2c2 (patch) | |
| tree | 8ffc83dc3ba0a4feea15da36c7f2da604be06513 /drivers/cpuidle | |
| parent | 42f67f2acab2b7179c0d1ab234869e391448dfa6 (diff) | |
| download | kernel-common-41682032715c2c969357c81391a442a24dd1c2c2.tar.gz kernel-common-41682032715c2c969357c81391a442a24dd1c2c2.tar.bz2 kernel-common-41682032715c2c969357c81391a442a24dd1c2c2.zip | |
cpuidle: move driver checking within the lock section
The code is racy and the check with cpuidle_curr_driver should be
done under the lock.
I don't find a path in the different drivers where that could happen
because the arch specific drivers are written in such way it is not
possible to register a driver while it is unregistered, except maybe
in a very improbable case when "intel_idle" and "processor_idle" are
competing. One could unregister a driver, while the other one is
registering.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/driver.c | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 39ba8e181e96..3e5907569233 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -85,17 +85,9 @@ EXPORT_SYMBOL_GPL(cpuidle_get_driver); */ void cpuidle_unregister_driver(struct cpuidle_driver *drv) { - if (drv != cpuidle_curr_driver) { - WARN(1, "invalid cpuidle_unregister_driver(%s)\n", - drv->name); - return; - } - spin_lock(&cpuidle_driver_lock); - - if (!WARN_ON(drv->refcnt > 0)) + if (drv == cpuidle_curr_driver && !WARN_ON(drv->refcnt > 0)) cpuidle_curr_driver = NULL; - spin_unlock(&cpuidle_driver_lock); } EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); |