From owner-freebsd-hackers@FreeBSD.ORG  Wed Aug 13 22:43:04 2003
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id DF7E537B401
	for <freebsd-hackers@FreeBSD.ORG>;
	Wed, 13 Aug 2003 22:43:04 -0700 (PDT)
Received: from spider.deepcore.dk
	(cpe.atm2-0-56339.0x50c6aa0a.abnxx2.customer.tele.dk [80.198.170.10])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 16F2D43F75
	for <freebsd-hackers@FreeBSD.ORG>;
	Wed, 13 Aug 2003 22:43:01 -0700 (PDT)
	(envelope-from sos@spider.deepcore.dk)
Received: (from sos@localhost)
	by spider.deepcore.dk (8.12.9/8.12.9) id h7E5gxFL034186;
	Thu, 14 Aug 2003 07:42:59 +0200 (CEST)
	(envelope-from sos)
From: Soeren Schmidt <sos@spider.deepcore.dk>
Message-Id: <200308140542.h7E5gxFL034186@spider.deepcore.dk>
In-Reply-To: <20030814092542.G10062@news1.macomnet.ru>
To: Maxim Konovalov <maxim@macomnet.ru>
Date: Thu, 14 Aug 2003 07:42:59 +0200 (CEST)
X-Mailer: ELM [version 2.4ME+ PL98b (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=ISO-8859-1
cc: freebsd-hackers@FreeBSD.ORG
cc: Alexander Serkov <serkov@ukrpost.net>
Subject: Re: Why is ATAPI DMA disabled by default ?
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 14 Aug 2003 05:43:05 -0000

It seems Maxim Konovalov wrote:
> 
> > I use 5.1-current and have found that by default FreeBSD disables ATAPI's
> > support for DMA transfers and thus uses CPU hungry PIO modes.
> > It even makes sysctl used to change this read-only.
> > I had changed the default value of atapi_dma to 1 in dev/ata/atapi-all.c to 1
> > and it worked fine for me.
> 
> Hint: put hw.ata.atapi_dma="1" in /boot/loader.conf.

Or just use atacontrol to change the mode once the system is running...

-Søren