Linux 1.3.59 / 66 locks solid on modem hangup

Oliver Jowett (oliver@sa-search.massey.ac.nz)
Wed, 21 Feb 1996 16:40:26 +1300 (NZDT)

I've just run into a nasty problem that's present in at least
1.3.59-mark1, 1.3.59-mark6, and 1.3.66. I run a Linux box as a PPP server
(it also runs ftp,http,etc) with 2 modems on a standard serial card.
Intermittently, when one of the modems hangs up, the box will lock solid:
no VT switching, no ping response, no reboot, no messages to syslog.
Using the software watchdog doesn't help. It only seems to happen when the
modem hangs up on its own (e.g. with a noisy line); I haven't had a lockup
when the modem hangs up in response to a dropped DTR.

I haven't been able to track this one down at all. 1.2.13-elf seems to run
fine. I'm running a fairly vanilla Slackware 3.0, mgetty+sendfax 0.98,
diald 0.12/pppd 2.2.0e.

Any suggestions?

-- Oliver