diff --git a/drivers/base/class.c b/drivers/base/class.c
index 839d27c..5667c2f 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -198,6 +198,7 @@
  * class_create - create a struct class structure
  * @owner: pointer to the module that is to "own" this struct class
  * @name: pointer to a string for the name of this class.
+ * @key: the lock_class_key for this class; used by mutex lock debugging
  *
  * This is used to create a struct class pointer that can then be used
  * in calls to device_create().
diff --git a/kernel/mutex.c b/kernel/mutex.c
index bcdc9ac..12c779d 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -34,6 +34,7 @@
 /***
  * mutex_init - initialize the mutex
  * @lock: the mutex to be initialized
+ * @key: the lock_class_key for the class; used by mutex lock debugging
  *
  * Initialize the mutex to unlocked state.
  *