diff --git a/drivers/staging/unisys/visorutil/charqueue.c b/drivers/staging/unisys/visorutil/charqueue.c
index 1ce7003c3a903040f696a62a7e05c154ed7ce6fb..ac7acb7c5b7955eb63c1c7403eebb314f2fc5cb9 100644
--- a/drivers/staging/unisys/visorutil/charqueue.c
+++ b/drivers/staging/unisys/visorutil/charqueue.c
@@ -28,7 +28,7 @@
 struct charqueue {
 	int alloc_size;
 	int nslots;
-	spinlock_t lock;
+	spinlock_t lock; /* read/write lock for this structure */
 	int head, tail;
 	unsigned char buf[0];
 };