From 307072cd20110c0b8ae15edde4dba49fbd1923aa Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rjw@sisk.pl>
Date: Sun, 29 Apr 2012 22:54:47 +0200
Subject: [PATCH] --- yaml --- r: 305824 b: refs/heads/master c:
 23e0fc5ae64925e0ff1b6221b83dff1b217545df h: refs/heads/master v: v3

---
 [refs]                         |  2 +-
 trunk/drivers/base/power/qos.c | 19 ++++++++++++-------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index ec334c552871..0eedc9308613 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 76e267d822f2913893ad210ba431607aa8e2af94
+refs/heads/master: 23e0fc5ae64925e0ff1b6221b83dff1b217545df
diff --git a/trunk/drivers/base/power/qos.c b/trunk/drivers/base/power/qos.c
index 71855570922d..fd849a2c4fa8 100644
--- a/trunk/drivers/base/power/qos.c
+++ b/trunk/drivers/base/power/qos.c
@@ -352,21 +352,26 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
  *
  * Will register the notifier into a notification chain that gets called
  * upon changes to the target value for the device.
+ *
+ * If the device's constraints object doesn't exist when this routine is called,
+ * it will be created (or error code will be returned if that fails).
  */
 int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
 {
-	int retval = 0;
+	int ret = 0;
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	/* Silently return if the constraints object is not present. */
-	if (dev->power.constraints)
-		retval = blocking_notifier_chain_register(
-				dev->power.constraints->notifiers,
-				notifier);
+	if (!dev->power.constraints)
+		ret = dev->power.power_state.event != PM_EVENT_INVALID ?
+			dev_pm_qos_constraints_allocate(dev) : -ENODEV;
+
+	if (!ret)
+		ret = blocking_notifier_chain_register(
+				dev->power.constraints->notifiers, notifier);
 
 	mutex_unlock(&dev_pm_qos_mtx);
-	return retval;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);