for processing. Semantics currently rather
mysterious 8(
-receive_room() - Can be called by the driver layer at any time when
- the ldisc is opened. The ldisc must be able to
- handle the reported amount of data at that instant.
- Synchronization between active receive_buf and
- receive_room calls is down to the driver not the
- ldisc. Must not sleep.
-
write_wakeup() - May be called at any point between open and close.
The TTY_DO_WRITE_WAKEUP flag indicates if a call
is needed but always races versus calls. Thus the