From owner-freebsd-questions  Sun Feb  9 15:39:32 1997
Return-Path: <owner-questions>
Received: (from root@localhost)
          by freefall.freebsd.org (8.8.5/8.8.5) id PAA19282
          for questions-outgoing; Sun, 9 Feb 1997 15:39:32 -0800 (PST)
Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127])
          by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id PAA19274
          for <questions@freebsd.org>; Sun, 9 Feb 1997 15:39:28 -0800 (PST)
Received: (from root@localhost) by dyson.iquest.net (8.8.4/8.6.9) id SAA00183; Sun, 9 Feb 1997 18:38:06 -0500 (EST)
From: "John S. Dyson" <toor@dyson.iquest.net>
Message-Id: <199702092338.SAA00183@dyson.iquest.net>
Subject: Re: Intel 82371SB IDE interface
To: thompson@tgsoft.com (mark thompson)
Date: Sun, 9 Feb 1997 18:38:06 -0500 (EST)
Cc: questions@freebsd.org
In-Reply-To: <199702092146.NAA04516@squirrel.tgsoft.com> from "mark thompson" at Feb 9, 97 01:46:52 pm
Reply-To: dyson@freebsd.org
X-Mailer: ELM [version 2.4 PL24 ME8]
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: owner-questions@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

> 
> I have noticed that in 2.2 there is a driver for the 83271SB:
> (sys/pci/wd82371.c) that includes itself iff NPCI > 0. 
> 
> So what is going on here? wd82371 creates a piix device that appears to
> be a DMA controller. Does the wdc driver magically use this? I simply
> fail to see where that is happening.
> 
Good, because it isn't in the code :-).  I have hacked a little on it,
but with little success.  I mostly suggest that you make sure that your
bios is "tuned-up" to the speed that the drive can support, and FreeBSD
will use the PIO mode that the bios sets.

Someday, someone will add the DMA support.  PIO is really slow on P6
machines as I have heard.

John