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    SubjectRE: Linux-2.4.20 modem control
    On Mon, 17 Mar 2003, Ed Vance wrote:

    > >
    > 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.

    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.
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