diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 6e2377e6c1d6013d01457b452952cc038be0e07b..851d44fa5457e017287bdeb02bb7b497a97d57d9 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -203,11 +203,17 @@ struct lock_list {
 	struct lock_list		*parent;
 };
 
-/*
- * We record lock dependency chains, so that we can cache them:
+/**
+ * struct lock_chain - lock dependency chain record
+ *
+ * @irq_context: the same as irq_context in held_lock below
+ * @depth:       the number of held locks in this chain
+ * @base:        the index in chain_hlocks for this chain
+ * @entry:       the collided lock chains in lock_chain hash list
+ * @chain_key:   the hash key of this lock_chain
  */
 struct lock_chain {
-	/* see BUILD_BUG_ON()s in lookup_chain_cache() */
+	/* see BUILD_BUG_ON()s in add_chain_cache() */
 	unsigned int			irq_context :  2,
 					depth       :  6,
 					base	    : 24;