Subject: Re: Serial Port Strangeness.
To: Perry E. Metzger <perry@piermont.com>
From: Bill Studenmund <skippy@macro.stanford.edu>
List: current-users
Date: 09/09/1997 12:47:19
On Tue, 9 Sep 1997, Perry E. Metzger wrote:
>
> Dave Burgess writes:
> > I asked this on the port-i386 list, and got a couple of answers - one of
> > which makes me wonder it this might not be a problem across the
> > platforms.
> >
> > I'm working on mgetty with the 1.2G tar 'non-release' from last month.
> > Whenever I use the TIOCMGET ioctl on the /dev/tty0* ports, I get an
> > [ENOTTY] error. The rest of the TIO ioctls I tried all work (some of
> > them only sort of, but they don't error out).
>
> As a wild guess, do you have COMPAT_43 in your kernel config?
The answer's far simpler. TIOCM* support disapeared with one of the serial
port upgrades. Quoting /sys/dev/isa/com.c sup'd last week,
comioctl(dev, cmd, data, flag, p)
dev_t dev;
u_long cmd;
caddr_t data;
int flag;
struct proc *p;
{
....
switch (cmd) {
....
case TIOCMSET:
case TIOCMBIS:
case TIOCMBIC:
case TIOCMGET:
default:
return (ENOTTY);
}
....
return (0);
}
They used to be there, as I used them as a model for adding such support
to the z8530tty driver.
Sounds like a good candidate for a PR.
Take care,
Bill