> From: matthew green <mrg@eterna.com.au>
> Date: Sat, 01 Nov 1997 16:58:02 +1100

>    I fixed the race condition that was causing this earlier this year
>    in the previous version of the zs driver.  I fear that change was
>    not ported to the current driver.

Right.  It was intentionally handled differently, though that
(different) handling has a minor bug which is easily corrected
by either the patch der-Mouse just sent or my follow-up.

> sigh.
> 
> i believe we should backout the new zs driver for NetBSD/sparc 1.3,
> as it has so far shown at least two cases of lossage (hangs when
> DCD asserted, and crtscts being set, and this new panic).  the new
> driver was not heavily tested before being commited (did anyone
> besides gordon test it, even?), and while it is in use in several
> other ports, it is very very new to the sparc.

You could do that, but then you would also revert to:
 H/W flow control that does not really work (ring overruns)
 Keyboard with no toggles, no arrows, etc.

Take your pick.