Messages in this thread | | | Date | Mon, 17 Mar 2003 19:33:50 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | RE: Linux-2.4.20 modem control |
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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. [unhandled content-type:application/octet-stream] | |