diff --git a/include/driver_mem.h b/include/driver_mem.h
index 3a1b9e9..975a4c1 100644
--- a/include/driver_mem.h
+++ b/include/driver_mem.h
@@ -8,5 +8,6 @@
 extern int driver_mem_init(void);
 extern void *driver_mem_alloc(long amount);
 extern int driver_mem_free(void *addr);
+extern void driver_mem_release(void);
 
 #endif /* _DRIVER_MEM_H_ */
diff --git a/sys/driver_mem.c b/sys/driver_mem.c
index 0750e14..e996a9f 100644
--- a/sys/driver_mem.c
+++ b/sys/driver_mem.c
@@ -336,7 +336,7 @@ int driver_mem_init(void)
 	return(0);
 }
 
-void driver_mem_stop(void)
+void driver_mem_release(void)
 {
 	if (init_count-- == 0)
 	{
diff --git a/sys/exceptions.S b/sys/exceptions.S
index 4ac892d..58e34ae 100644
--- a/sys/exceptions.S
+++ b/sys/exceptions.S
@@ -819,13 +819,9 @@ handler_psc3:
 
 		lea	MCF_PSC0_PSCTB_8BIT,a0		// ++ vr
 		mchar	move.l,'\P,'\I,'C,' ,(a0)
-		// move.l	#'PIC ',(a0)
 		mchar	move.l,'I,'N,'T,'\ ,(a0)
-		// move.l	#'INT ',(a0)
 		mchar	move.l,'R,'T,'C,'!,(a0)
-		// move.l	#'RTC!',(a0)
 		mchar 	move.l,0x0d,0x0a,0,0,(a0)
-		//move.l	#0x0d0a,(a0)
 
 		lea		0xffff8961,a0
 		lea		MCF_PSC3_PSCTB_8BIT,a3
diff --git a/usb/usb.c b/usb/usb.c
index bcda079..4f750af 100644
--- a/usb/usb.c
+++ b/usb/usb.c
@@ -234,7 +234,7 @@ int usb_stop(void)
 			}
 		}
 		bus_index = 0;
-		driver_mem_stop();
+		driver_mem_release();	/* release all driver mem */
 	}
 	return res;
 }