Subject: Re: More on the hung PPP
To: None <current-users@NetBSD.ORG>
From: Gerald C. Simmons <darykon!>
List: current-users
Date: 05/02/1995 07:44:19
On Thu, 27 Apr, 1995 -- Randy Terbush wrote:

>NetBSD-current i386
>Connected to ISP via 28.8 USR interfaced 115200 baud
>Hayes ESP with 1K FIFOs

I have a couple data points I'd like for someone to reality check for me. I
have also been trying to get a Hayes ESP board to work in my 486 system
running NetBSD-1.0, after having given up on the 16550 serial ports, I've run
into difficulty getting NetBSD to talk to the ESP and during my investigations
have found a few interesting things.

I got hold of an RS232 Analyzing tool which lets me look at all RS232 control
lines. My thinking was that I was having some kind of hardware handshaking
problem. First, I looked at a 16450 port. Here's what I found:

	* When NetBSD-1.0 boots, the /dev/tty00 port has RTS low and
          DTR low. This seems cool. If I have nothing plugged into the
	  port and try "tip tty00" I get "line down." This also seems okay,
	  it looked for DSR and didn't see it.

	* Put a Supra 28.8 Modem on line. Did "tip tty00." DTR went hi as well
	  as RTS. Good. Could talk to the Modem as well.

	* Tried strapping CTS low (signal back from modem should tell PC to
          stop sending.) This was totally ignored by either com.c or tip. Not
	  so good.

	* "~."'d out of tip, DTR came low. Removed Modem. Went back into "tip
          tty00." Did not get "line down," just went back in like all was
          peachy! Is com.c or tip only checking DSR once?

My initial conclusions: Looks like perhaps hardware handshaking isn't really
supported with com.c. Is it supposed to be? I've been working my issue of my
Supra 28.8 Modem not working reliably with NetBSD-1.0. Everyone I've talked to
have steered me to a flow control problem. I was told to shut off all software
flow control for UUCP. All that's left is hardware. Am I on the right track.

Could everyone's problem's with hanging PPP be releated to com.c?

Gerry Simmons

BTW, to recap on my issue with the Supra 28.8. I have the following harware:

	Intel 486/DX2-66		NEC 3X CD-ROM SCSI
	16M RAM				Archive 150MB Tape SCSI
	2 WD5420 500M IDE Drives
	Adaptec 1542 Controller

I have a CHEAP Logicode Internal 14.4 Modem ($50.) This works great with SLIP
and UUCP. I've been trying to get a Supra 28.8 Modem working with the system
also. I have straight through RS232 cables (Now confirmed with the tester.)
The Supra has bad UUCP packet problems galore with either 16450 or 16550 serial
ports, in fact, after too many bad packets using the 16550 port, My system
hangs! Coyote Ugly! All this lead me to persue a Hayes ESP board, which I have
not gotten NetBSD-1.0 to talk to at all (w/tip.) When I try, it locks my
system up. I'm now forced to crawl into the Kernel Debugger to see what's
going on. I'm assuming it's com.c, but I could be wrong!