ttydev_cdevsw has no d_purge

[Ed Schouten]

Hi Hans,

2012/8/9 Hans Petter Selasky <hselasky at c2i.net>:
> 1) Use unrhdr. Suggested by ed.

Thanks!

> 2) Implement tty_set_softc() and use that when dereffing ucom unit numbers.

We're getting there. Now that I think of it, if we want to go in this
direction, we might as well do the following:

- Simply call tty_alloc() -- not tty_alloc_mutex(). I'd rather get rid
of this functionality altogether, if possible.
- Use the TTY mutex to lock down the state of the ucom driver, e.g.
#define ucom_lock(sc) tty_lock(sc->sc_mtx).

Any thoughts?

-- 
Ed Schouten <ed at 80386.nl>