RE: Linux-2.4.20 modem control

From: Ed Vance (EdV@macrolink.com)
Date: Mon Mar 17 2003 - 19:34:25 EST


On Mon, Mar 17, 2003 at 4:34 PM, Richard B. Johnson wrote:
>
> On Mon, 17 Mar 2003, Ed Vance wrote:
> [SNIPPED...]
>
> > >
> > Hi Richard,
> >
> > What you are doing looks just fine.
> >
> > As long as HUPCL is set when the close happens, DTR will
> > drop. There are delays that are enforced in both open and
> > close when a second process is blocked opening a closing
> > port. Of course, that would not be your case, because the
> > open does not occur until the closing process terminates.
> > In a quick look, I didn't see an enforced close-to-open
> > delay for your case. Maybe I missed something. I am
> > looking at 2.4.18 Red Hat -3. I didn't notice a patch to
> > serial.c in the 2.4.19 or 2.4.20 changelog that would
> > affect this. There are some weird calculations that
> > appear to scale the close_delay field value based on HZ.
> >
> > Which was the last "working" kernel rev that you used?
> >
> > Did you switch to a faster CPU?
> >
> > Are you using any "low latency" patches?
> >
> > Did the HZ value change between the last rev that worked
> > and 2.4.20?
> >
> > What HZ value are you running with?
> >
> > Cheers,
> > Ed
>
> I'm now using 2.4.20. The previous version was 2.2.18 (yikes)!
> I just transferred my old hard disks (SCSI) to a new system and
> everything worked fine, so I decided to upgrade to a later more
> stable kernel. I use this system to be my own internet provider
> and I am, in fact, logged in running a ppp link from home over
> the modem at this time. I had to modify `agetty` to make it
> work with the new kernel and a faster CPU (1.2 GHz, 330 MHz
> front-side bus, Tyan Thunder-II).
>
> The agetty code is attached. It hangs up before it sleeps for
> a new connection because when the previous process terminates,
> init instantly starts a new instance, the modem never hangs up
> even though, possibly the DTR was lowered for that instant.
>
> Cheers,
> Dick Johnson
> Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips).
> Why is the government concerned about the lunatic fringe?
> Think about it.
>
Hi,

Yep. 2.2.18 was a good one.
I'll look at it.

Cheers,
Ed

----------------------------------------------------------------
Ed Vance edv (at) macrolink (dot) com
Macrolink, Inc. 1500 N. Kellogg Dr Anaheim, CA 92807
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