*BSD News Article 23159


Return to BSD News archive

Newsgroups: comp.os.386bsd.questions
Path: sserve!newshost.anu.edu.au!munnari.oz.au!constellation!osuunx.ucc.okstate.edu!moe.ksu.ksu.edu!crcnis1.unl.edu!wupost!howland.reston.ans.net!europa.eng.gtefsd.com!uunet!noc.near.net!das-news.harvard.edu!honeydew.srv.cs.cmu.edu!bronco.ece.cmu.edu!fs7.ece.cmu.edu!crabapple.srv.cs.cmu.edu!cline
From: cline+@cs.cmu.edu (Kenneth Cline)
Subject: FreeBSD sio driver bug
Message-ID: <CFuIIC.70w.1@cs.cmu.edu>
Sender: news@cs.cmu.edu (Usenet News System)
Nntp-Posting-Host: snow.fox.cs.cmu.edu
Organization: School of Computer Science, Carnegie Mellon
Date: Tue, 2 Nov 1993 03:46:59 GMT
Lines: 28

I just installed FreeBSD-1.0 (epsilon) binaries and kernel sources on
top of my 386BSD filesystem, and then ran MAKEDEV to create /dev/tty01
which is connected to my modem.

Unfortunately, I was unable to connect to my modem.  More specifically,
the following code hangs until interrupted:

    fopen("/dev/tty01","rw");

A little kernel tracing led me to conclude that sioopen is sitting in a
loop waiting for the modem to turn the carrier on.(!)  Of course, the
modem isn't about to turn the carrier on until a connection is made!

Eliminating the while look in sioopen (in file /sys/i386/isa/sio.c)
just before label "out" fixed the problem.  (I am typing this article
using my fixed driver and modem at this very moment)

Anyway, I was just wondering what's up with this code?  Is this an
honest bug, or am I missing something?  Also, what are all the
"#ifdef COM_BIDIR"'s (which I believe are not enabled)?  Should I
go ahead and leave the loop in sioopen disabled?

Thanks,

Ken

PS.  Please respond by email (or mail me a copy) - our news handling
is in transition, and articles seem to get lost occasionally.