[comp.unix.i386] serial ports under 2.0.x

ryding@trwrb.UUCP (Mark Ryding) (09/27/89)

Hello,
	I'm running version 2.0.2 on a NEC Powermate SX.  I am having
quite a bit of difficulty getting the serial ports to behave themselves.
Even though I've specified the baud rate in inittab (both by editing 
and using sysadm) the only speed I ever get is 300.  Additionally, if I
try to enable the port(s) for use by terminals, I get the message:

	INIT: command respawning too rapidly: check for possible errors
	id: 00 "/etc/getty /dev/tty00 300H"

I can get the ports to go at speeds greater than that by using

	(stty 4800 0<&1; cat /etc/passwd) > /dev/tty00

but the port won't hold the baud rate, it immediately drops back to 300 baud
when the above command finishes.  Is anybody else experiencing this?

Thanks in advance,
Mark Ryding

{USENET   ...!trwrb!ryding | Internet  mryding@oz.bmd.trw.com}

lisbon@vpnet.UUCP (Gerry Swetsky) (10/02/89)

Sounds as if you're experiencing an interrupt conflict on your serial
port.  Similiar thing happened at vpnet.  Check /etc/conf/cf.d/asy.  If
another device is using either interrupt three or four there is a way
to open only ONE of the two serial ports and thus free up the interrupt
in conflict.

I'd write more, but I gotta get to work.  Mail me for more info.

T.Casey@ucl-cs.UUCP (10/15/89)

From: T.Casey@uk.ac.ucl.cs

Yes, I had a similar problem trying to drive a sony  LVR-6000 through
the comm port. I tried to change tty00 at boot time to 9600 baud and got
the same error message.

Finally I took the easy way out and opened tty00, set arg.c_cflag to B9600
and used the ioctl system call with TCSETA. It works fine as long as the file
is open, but of course reverts back to 300 baud on exit, which for my purposes
is okay . 

But, I would like a cleaner solution and also be able to set parameters 
for the c_cflag, c_oflag, & c_lflag for comms ports at boottime.

Can anyone point me to information about this. The manuals are not clear on
how this can be done.

Thanks in advance.

Tom