diff -uNr 2420_start/arch/i386/kdb/kdba_io.c 2420_kdb/arch/i386/kdb/kdba_io.c
--- 2420_start/arch/i386/kdb/kdba_io.c	2003-04-30 12:13:15.000000000 -0700
+++ 2420_kdb/arch/i386/kdb/kdba_io.c	2003-09-03 17:09:35.000000000 -0700
@@ -86,7 +86,7 @@
 	extern u_short  plain_map[], shift_map[], ctrl_map[];
 
 	/* Is USB initialized ? */
-	if(!kdb_usb_infos.poll_func)
+	if(!kdb_usb_infos.poll_func || !kdb_usb_infos.urb)
     		return -1;
 
 	/* Transfer char if they are present */