ttymon fails to drop DTR?

ttymon fails to drop DTR?

Post by Adam Donnis » Sat, 13 Mar 1993 11:08:46

I have ESIX SVR4.0.3a with all the patches for that release.  I have a
Specialix SI with 12 ports (a 4 port and an 8 port expansion).  I have a
V32 modem (Interlink Fasbit II).  AND I have a problem.

Most of the time the system works well, it dials out, connects, uucps,
drops DTR, the line drops, all is well.

BUT after about 3 days of working fine, ttymon fails to drop DTR.  THis
results in the modem holding the line open indefinately.  If I do :
stty 0 < /dev/term/[offending line]
DTR drops and the modem drops the phone line O.K.  I can also get back
control by stopping the ttymon port monitor (not the service, the
monitor) and restarting it.  Just disabling, and re-enabling the service
does no good.

The service is configured as :

19200NP Hangup, Connect on Carrier, Timeout 30, Wait Read on 1.

Does anyone know what is going on here?

P.S. The system is a 386/33 with 380MB ESDI and 8MB RAM.


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1. DCD Drops, then DTR Drops, Want to Increase Delay (SLIP)

I'm having an occasional problem on my SLIP connection that causes DCD
(incoming) to drop out momentarily.

When this happens, Linux drops DTR in response, and the connection
gets broken.  Generally it happens only once in several hours, though
sometimes it will happen several times in a row over a space of an
hour before it will settle down.

What I would like to do is increase the delay between the time Linux
detects lost DCD and the time it drops DTR ... would like to increase
it to around a second or so.

If someone could direct me to the portion of the code that monitors
DCD and drops DTR, I can take care of the rest.  But I've looked all
through /usr/src/linux/ ..... (I forget the rest of the path to
serial.c), grepped on things like DCD and DTR in as much of the rest
of the source as I can find, and don't see where it's happening.

Linux version is 0.99.15, Slackware 1.1.2, using agetty in inittab to
open up the serial ports (for some reason I was not able to get getty
or getty_ps to do what I needed, probably just a config or RTFM
problem, but in any case agetty works fine).

Any assistance or pointers gratefully accepted.

 . . . . . ep

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