37 Locking  section in Low Level Serial API
41 necessary locking using port->lock.  There are some exceptions (which
55 locking.
77 	Locking: none.
98 	Locking: port->lock taken.
119 	Locking: port->lock taken.
133 	Locking: port->lock taken.
142 	Locking: port->lock taken.
154 	Locking: serialized with .unthrottle() and termios modification by the
164 	Locking: serialized with .throttle() and termios modification by the
176 	Locking: none.
184 	Locking: port->lock taken.
197 	Locking: port->lock taken.
209 	Locking: caller holds tty_port->mutex
218 	Locking: port_sem taken.
233 	Locking: port_sem taken.
244 	Locking: port->lock taken.
307 	Locking: caller holds tty_port->mutex
316 	Locking: caller holds tty_port->mutex
329 	Locking: none.
338 	Locking: none.
346 	Locking: none.
355 	Locking: none.
371 	Locking: none.
379 	Locking: none.
387 	Locking: none.
396 	Locking: tty_mutex and tty_port->mutex taken.
404 	Locking: none.
415 	Locking: none.
428 	Locking: caller is expected to take port->lock
444 	Locking: caller dependent.
455 	Locking: caller dependent.
463 	Locking: n/a
471 	Locking: port->lock should be held.
482 	Locking: none
491 	Locking: none