discipline even with the same data or your computer again will be eaten by
demons.
-In order to remove a line discipline call tty_register_ldisc passing NULL.
+In order to remove a line discipline call tty_unregister_ldisc().
In ancient times this always worked. In modern times the function will
return -EBUSY if the ldisc is currently in use. Since the ldisc referencing
code manages the module counts this should not usually be a concern.
ldisc must be careful about setting order and to
handle unexpected calls. Must not sleep.
+ The driver is forbidden from calling this directly
+ from the ->write call from the ldisc as the ldisc
+ is permitted to call the driver write method from
+ this function. In such a situation defer it.
+
Locking