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Date: Sat, 1 Jun 1996 04:47:21 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199605311847.EAA15960@godzilla.zeta.org.au>
To: hackers@FreeBSD.org, marc@bowtie.nl
Subject: Re: Problems with serial port
Sender: owner-hackers@FreeBSD.org
X-Loop: FreeBSD.org
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>I'm having a problem with sendfax (from mgetty 0.99) hanging in a 
>ttywait (used ps auxl). This seems to happen to me after the machine
>has been up for a longer period (19 days in this case, it also
>happened a while back. The machine had been up for a similar period).

Hangs in ttywait are normally caused by using crtscts and the external
device keeping CTS low.  This sometimes causes processes to hang in
exit() where you can't kill them.

The wait time can be limited to 60 seconds using
`comcontrol dev/ttydX drainwait 60'.

Use `pstat -t' to get more information on what the tty is waiting for.

Bruce