diff -pNaru5 perle-serial-3.9.2.orig-0004/pserial/perle-serial.c perle-serial-3.9.2/pserial/perle-serial.c
--- perle-serial-3.9.2.orig-0004/pserial/perle-serial.c	2021-09-14 11:26:40.756869474 -0400
+++ perle-serial-3.9.2/pserial/perle-serial.c	2021-09-14 11:26:52.547298877 -0400
@@ -5201,26 +5201,23 @@ void ps_unregister_serial(int line)
 }
 
 static void __exit ps_fini(void) 
 {
 //	unsigned long flags;
-	int e1;
 	int i;
 	struct ps_async_struct *info;
 
 	printk(KERN_INFO "Unloading %s: version %s\n", serial_name, serial_version);
 #ifdef USE_PS_TIMER
 	del_timer_sync(&serial_timer);
 #endif
     
 #if LINUX_VERSION_CODE <  KERNEL_VERSION(2,5,0)
 	remove_bh( PERLE_SERIAL_BH );
-	if ((e1 = tty_unregister_driver(&serial_driver)))
-		printk("serial: failed to unregister Perle's serial driver (%d)\n", e1);
+	tty_unregister_driver(&serial_driver);
 #else
-	if ((e1 = tty_unregister_driver(serial_driver)))
-		printk("serial: failed to unregister Perle's serial driver (%d)\n", e1);
+	tty_unregister_driver(serial_driver);
 	put_tty_driver(serial_driver);
 #endif
 	for (i = 0; i < NR_PORTS; i++) {
 		if ((info = ps_table[i].info)) {
 //			if (info->state->XRflatreg) // This code causes oops. Remove for now plus all other Sleep calls.