Subject: Re: tty_lock problems with zs (was: sparc64 -current kernel fails to boot)
To: Chris Ross <>
From: Andrew Doran <>
List: current-users
Date: 12/22/2007 19:48:02
On Sat, Dec 22, 2007 at 12:39:45AM -0500, Chris Ross wrote:

>   So, I looked into this a little more.  There are mutex_spin_enter()
> and mutex_spin_exit() calls in sys/kern/tty.c in both nullmodem() and
> ttymodem().  Either or both of those will cause the same:
> Mutex error: mutex_vector_enter: locking against myself
>   crash if the calls are only removed from zstty_softint().  I
> experimented with taking those out as well, despite presuming that
> was the "wrong thing to do," and the machine comes up to multi-user,
> but crashes with an unlocked mutex as soon as I try to log in.
>   The following change to sys/dev/ic/z8530tty.c causes the machine
> to come up multi-user, and I can ssh in and do things.  But, I was
> just guessing at something to try, and would want someone who knows
> much more about the recent vmlocking branch merges to give an
> opinion.  Andrew?

I made similar changes so it should be OK now. It would be nice to simplify
the tty driver interface but that would take a lot of time.