diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index bc6da10..7a0e5c4 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -144,6 +144,8 @@
 /*
  * NOTE: mutex_trylock() follows the spin_trylock() convention,
  *       not the down_trylock() convention!
+ *
+ * Returns 1 if the mutex has been acquired successfully, and 0 on contention.
  */
 extern int mutex_trylock(struct mutex *lock);
 extern void mutex_unlock(struct mutex *lock);