ppbus_remove_handler
error = ppbus_remove_handler(ppbus, lp_intr);
ppbus_remove_handler(ppbus, lp_intr);
return bus->ppbus_remove_handler(device_parent(dev), func);
int ppbus_remove_handler(device_t, void (*)(void *));
ppbus->ppbus_remove_handler = sc_link->parport_remove_handler;
PARPORT_REMOVE_HANDLER_T ppbus_remove_handler;
ppbus_remove_handler(ppbus, ppsintr);