diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c
index 7481fbb947d3..a2a598ad6e6d 100644
--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -10,6 +10,7 @@
 #include <linux/cpu_pm.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
+#include <linux/rcupdate.h>
 #include <linux/spinlock.h>
 #include <linux/syscore_ops.h>
 
@@ -76,7 +77,8 @@ EXPORT_SYMBOL_GPL(cpu_pm_register_notifier);
  *
  * Remove a driver from the CPU PM notifier list.
  *
- * This function has the same return conditions as raw_notifier_chain_unregister.
+ * This function may sleep, and has the same return conditions as
+ * raw_notifier_chain_unregister.
  */
 int cpu_pm_unregister_notifier(struct notifier_block *nb)
 {
@@ -86,6 +88,11 @@ int cpu_pm_unregister_notifier(struct notifier_block *nb)
 	raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags);
 	ret = raw_notifier_chain_unregister(&cpu_pm_notifier.chain, nb);
 	raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags);
+
+	/* Wait for the rcu_read_lock() walkers in cpu_pm_notify(). */
+	if (!ret)
+		synchronize_rcu();
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier);