Subject: Re: Terrible serial overruns
To: NetBSD/pmax List <port-pmax@NetBSD.ORG>
From: Michael L. Hitch <>
List: port-pmax
Date: 02/18/1998 11:28:26
On Feb 17, 11:37pm, Trevor Schroeder wrote:
> I recently installed NetBSD 1.3 and have PPP running.  However, I keep getting
> a number of silo overflows (hundreds or even thousands at a time) on scc0,0.
> I've got a Hayes Accura 33.6 and I've set my serial rate to 28800, 33600
> (which didn't work), 38400, and 57600.  I've tried it with hardware flow
> control and without.  I've used 250, 296, and 1500 for my MTU.  Nothing seems
> to help.  Every few seconds the line will just han while it straightens out
> the problem.

  [A later message indicates this is on a 5000/25 - so I'm not suprised it
gets copious quantities of silo overflows.]

  I'm not sure the serial driver even supports hardware flow control.

> Someboody please tell me there is a fix for this.  I would occassionally get

  Yes, there is a fix:  rewrite the pmax handling of spl/interrupt levels,
and rewrite the serial driver :-)

  Other than that, there's not much you can do.


Michael L. Hitch
Computer Consultant
Information Technology Center
Montana State University	Bozeman, MT	USA