cpuidle: Check if device is already registered

Make __cpuidle_register_device() check whether or not the device has
been registered already and return -EBUSY immediately if that's the
case.

[rjw: Changelog]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 5b63185da59b7d40045e7370bdb7fff162c8700d..d75040ddd2b3ba8e317dfc76f5367faa62340b8f 100644 (file)
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -400,13 +400,16 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
  */
 int cpuidle_register_device(struct cpuidle_device *dev)
 {
-       int ret;
+       int ret = -EBUSY;
 
        if (!dev)
                return -EINVAL;
 
        mutex_lock(&cpuidle_lock);
 
+       if (dev->registered)
+               goto out_unlock;
+
        ret = __cpuidle_device_init(dev);
        if (ret)
                goto out_unlock;