From owner-freebsd-stable  Mon Jun 17 08:17:00 1996
Return-Path: owner-stable
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.5/8.7.3) id IAA24272
          for stable-outgoing; Mon, 17 Jun 1996 08:17:00 -0700 (PDT)
Received: from freefall.freebsd.org (localhost.cdrom.com [127.0.0.1])
          by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id IAA24260;
          Mon, 17 Jun 1996 08:16:57 -0700 (PDT)
Message-Id: <199606171516.IAA24260@freefall.freebsd.org>
To: rich@rich.isdn.bcm.tmc.edu
cc: jdw@wwwi.com, freebsd-stable@freebsd.org
Subject: Re: Trap 12/supervisor read, page not present 
In-reply-to: Your message of "Mon, 17 Jun 1996 10:07:33 CDT."
             <199606171507.KAA00642@richc.isdn.bcm.tmc.edu> 
Date: Mon, 17 Jun 1996 08:16:57 -0700
From: "Justin T. Gibbs" <gibbs@freefall.freebsd.org>
Sender: owner-stable@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

>ncrcontrol -u 0 -t 0 -s tags=0
>
>It eliminated kernel panics that would occur beginning
>with the messages:

>sd0(ncr0:0:0): COMMAND FAILED (4 28) @f0ab1800
>
>This indicates that the queue is full on the Atlas.  I
>don't know why this happens but once I disabled tags
>the problems went away.  It's not obvious to me now how
>do that with the ahc driver, but it might be worth
>trying.  Rich

The aic7xxx driver will automatically retry a command returned
with a Queue Full status, but I doubt that's his problem.  You
have to actively enable tagged queueing for the aic7xxx driver
through a kernel config option that wasn't in his posted config
file.
--
Justin T. Gibbs
===========================================
  FreeBSD: Turning PCs into workstations
===========================================