From: Daniel Lezcano <daniel.lezcano@linaro.org>
Date: Wed, 12 Jun 2013 13:08:55 +0000 (+0200)
Subject: cpuidle: Check if device is already registered
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=c878a52d3c7cabab5b24460825c24eafd8be7058;p=deliverable%2Flinux.git

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 5b63185da59b..d75040ddd2b3 100644
--- 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;