Subject: Re: 230400 on com.c?
To: Herb Peyerl <>
From: Frank van der Linden <>
List: current-users
Date: 05/02/2002 15:46:01
On Thu, May 02, 2002 at 07:21:34AM -0600, Herb Peyerl wrote:
> I have a piece of hardware that seems to be insisting I speak to it at
> 230400.  I'm being annoyed by the vendor who claims that it just works
> under 'linux' if you do some stupid setserial thing.  It appears there's
> some hack under linux to set the 16550 at 230400.  In our com.c, the
> comspeed() function won't let it go to 230400 since the percentage of
> error is too high...
> Anyway, do we have any way to do 230400 with a 16550 under NetBSD or
> is it just a lose?

You can only really use a speed > 115200 if the serial chip is clocked
with a frequency high enough to deal with it. If you have a 16x50 with
a higher clock, you can change COM_FREQ in sys/dev/ic/comreg.h to
match it. There's currently no way to change that at runtime.

The hardware must actually allow it though. You can't make a 16550
with a crystal at 1.8432 Mhz do 230400.

- Frank

Frank van der Linden                 
Quality NetBSD CDs, Support & Service.