status=tty_register_ldisc(N_R3964, NULL); 
status=tty_unregister_ldisc(N_R3964); 
static void __exit r3964_exit(void){   int status;      TRACE_M ("cleanup_module()");   status=tty_register_ldisc(N_R3964, NULL);      if(status!=0)   {      printk(KERN_ERR "r3964: error unregistering linediscipline: %d\n", status);   }   else   {      TRACE_L("linediscipline successfully unregistered");   }   }
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/64ccd715d3cf498318b14b646ce5f97e7ab15bb5/n_r3964.c/clean/drivers/char/n_r3964.c