diff --git a/[refs] b/[refs]
index fca66ee8c5fd..2917d9a1e101 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b65b5b59f98aa317df399318b0b2770f50732d3c
+refs/heads/master: 6ac12dfe9c2027cd3c5ed603f11d1bb4f04906fe
diff --git a/trunk/drivers/rtc/class.c b/trunk/drivers/rtc/class.c
index 5396beec30d0..1cb61a761cb2 100644
--- a/trunk/drivers/rtc/class.c
+++ b/trunk/drivers/rtc/class.c
@@ -94,7 +94,9 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev,
 	kfree(rtc);
 
 exit_idr:
+	mutex_lock(&idr_lock);
 	idr_remove(&rtc_idr, id);
+	mutex_unlock(&idr_lock);
 
 exit:
 	dev_err(dev, "rtc core: unable to register %s, err = %d\n",