From owner-freebsd-alpha@FreeBSD.ORG  Wed Apr 16 11:58:57 2003
Return-Path: <owner-freebsd-alpha@FreeBSD.ORG>
Delivered-To: freebsd-alpha@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 11FB837B401
	for <freebsd-alpha@freebsd.org>; Wed, 16 Apr 2003 11:58:57 -0700 (PDT)
Received: from trillian.santala.org (ip212-226-173-33.adsl.kpnqwest.fi
	[212.226.173.33])
	by mx1.FreeBSD.org (Postfix) with SMTP id E9EBE43FA3
	for <freebsd-alpha@freebsd.org>;
	Wed, 16 Apr 2003 11:58:55 -0700 (PDT)	(envelope-from jake@iki.fi)
Received: (qmail 47123 invoked by uid 11053); 16 Apr 2003 18:58:54 -0000
Received: from localhost (sendmail-bs@127.0.0.1)
  by localhost with SMTP; 16 Apr 2003 18:58:54 -0000
Date: Wed, 16 Apr 2003 21:58:54 +0300 (EEST)
From: Jarkko Santala <jake@iki.fi>
X-X-Sender: jake@trillian.santala.org
To: Andrew Gallatin <gallatin@cs.duke.edu>
In-Reply-To: <16029.36001.229632.79139@grasshopper.cs.duke.edu>
Message-ID: <20030416215733.R316@trillian.santala.org>
References: <Pine.OSF.4.33.0304151146380.1028-100000@poptart.bithose.com>
	<16029.20850.720877.563791@grasshopper.cs.duke.edu>
	<16029.36001.229632.79139@grasshopper.cs.duke.edu>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: freebsd-alpha@freebsd.org
Subject: Re: problem with UDMA mode on XP1000
X-BeenThere: freebsd-alpha@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Porting FreeBSD to the Alpha <freebsd-alpha.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-alpha>,
	<mailto:freebsd-alpha-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-alpha>
List-Post: <mailto:freebsd-alpha@freebsd.org>
List-Help: <mailto:freebsd-alpha-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-alpha>,
	<mailto:freebsd-alpha-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 16 Apr 2003 18:58:57 -0000

On Wed, 16 Apr 2003, Andrew Gallatin wrote:

>
> Jarkko Santala writes:
>  > I suppose no checking explains the performance. ;) But good to know
>  > anyway. Any reason why it gets enabled by default if its not safe?
>
> The ata code just enables the highest available mode by default.
>
> I'm no expert, but I don't think PIO is safe either.  I think it just
> stresses things so much less than DMA that its assumed to be safe. Drew

How about adding all this into the alpha Hardware Notes?

	-jake

-- 
Jarkko Santala <jake@iki.fi>            http://www.iki.fi/~jake/
System Administrator                    2001:670:83:f08::/64