From owner-freebsd-embedded@FreeBSD.ORG  Wed Aug 27 00:29:16 2008
Return-Path: <owner-freebsd-embedded@FreeBSD.ORG>
Delivered-To: freebsd-embedded@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id E1EE6106564A
	for <freebsd-embedded@freebsd.org>;
	Wed, 27 Aug 2008 00:29:16 +0000 (UTC)
	(envelope-from marauder@pi.avalonnetworks.us)
Received: from pi.avalonnetworks.us (pi.avalonnetworks.us [76.164.27.10])
	by mx1.freebsd.org (Postfix) with ESMTP id A6AAD8FC08
	for <freebsd-embedded@freebsd.org>;
	Wed, 27 Aug 2008 00:29:16 +0000 (UTC)
	(envelope-from marauder@pi.avalonnetworks.us)
Received: from Project_Infinity-MTA by pi.avalonnetworks.us
	with Novell_GroupWise; Tue, 26 Aug 2008 18:08:35 -0600
Message-Id: <48B4461C.5689.0089.0@pi.avalonnetworks.us>
X-Mailer: Novell GroupWise Internet Agent 7.0 
Date: Tue, 26 Aug 2008 18:08:09 -0600
From: "Marauder" <marauder@pi.avalonnetworks.us>
To: <freebsd-embedded@freebsd.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
Subject: DMA to ATA drive failure
X-BeenThere: freebsd-embedded@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Dedicated and Embedded Systems <freebsd-embedded.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-embedded>, 
	<mailto:freebsd-embedded-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-embedded>
List-Post: <mailto:freebsd-embedded@freebsd.org>
List-Help: <mailto:freebsd-embedded-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-embedded>, 
	<mailto:freebsd-embedded-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 27 Aug 2008 00:29:17 -0000

Hi,

I have a system that needs to directly access the local storage device in =
are machine (In this case it is a ATA hard disk). To do that we are use =
code similar to this

storageFD =3D open("/dev/ad4", O_RDWR);
if (write(storageFD, configBlock, 512) =3D=3D -1) {
   cout << "Error" << endl;
}

We currently make sure we are writing to the disk in full sector sizes =
(512 in this case) and im sure we have the disk open for write.

But for some reason on some machines that we do this on we get the =
following error displayed from the kernel. "Aligned DMA transfer attempted.=
 ad4: Setting up DMA failed" We have tried adding "SET hw.ata.ata_dma=3D0" =
in are loader.rc file with no luck.

Any help would be greatly appreciated
Thanx
M