--- zzzz-none-000/linux-3.10.107/drivers/tty/serial/kgdboc.c	2017-06-27 09:49:32.000000000 +0000
+++ vr9-7490-729/linux-3.10.107/drivers/tty/serial/kgdboc.c	2021-11-10 11:53:55.000000000 +0000
@@ -179,8 +179,10 @@
 		goto do_register;
 
 	p = tty_find_polling_driver(cptr, &tty_line);
-	if (!p)
+	if (!p) {
+		printk(KERN_ERR "kgdboc: no valid polling driver\n");
 		goto noconfig;
+	}
 
 	cons = console_drivers;
 	while (cons) {
@@ -198,8 +200,10 @@
 
 do_register:
 	err = kgdb_register_io_module(&kgdboc_io_ops);
-	if (err)
+	if (err) {
+		printk(KERN_ERR "kgdboc: register io failed\n");
 		goto noconfig;
+	}
 
 	err = kgdb_register_nmi_console();
 	if (err)