From owner-freebsd-stable Mon Apr 16 14:25: 1 2001 Delivered-To: freebsd-stable@freebsd.org Received: from resnet.uoregon.edu (resnet.uoregon.edu [128.223.122.47]) by hub.freebsd.org (Postfix) with ESMTP id 6531837B449 for ; Mon, 16 Apr 2001 14:24:56 -0700 (PDT) (envelope-from dwhite@resnet.uoregon.edu) Received: from localhost (dwhite@localhost) by resnet.uoregon.edu (8.10.1/8.10.1) with ESMTP id f3GLO7t82853; Mon, 16 Apr 2001 14:24:07 -0700 (PDT) Date: Mon, 16 Apr 2001 14:24:07 -0700 (PDT) From: Doug White To: Matthias Andree Cc: Subject: Re: FreeBSD 4.x refuses to use DMA on WDC31200F? In-Reply-To: Message-ID: X-All-Your-Base: are belong to us MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 14 Apr 2001, Matthias Andree wrote: > Hi, > > I recently noticed that FreeBSD 4.x (4.0-RELEASE, 4.2-RELEASE, > 4.2-STABLE, currently 4.3-RC) refuses to use DMA to transfer data > to/from my Western Digital Caviar AC31200F. This drive is able to do > DMA1 or PIO3, for a reason I cannot see and that is neither mentioned in > ata(4) or in syslog, even sysctl -w hd.atamodes=dma,---,---,---, does > not change FreeBSD's mind. Try booting -v and see if the system is intentionally demoting your controller. Not all controllers that claim DMA support actually work with it. Also note there are 2 "DMA" modes ... UltraDMA ("UDMA") and "WDMA". > The drive is attached to a VIA VT82C586B (Apollo MVP3) on a Tyan Trinity > 100AT (S1590). There's code to activate the 586B in src/sys/dev/ata/ata-dma.c, at least. But then again I was talking to someone the other day having problems with that chipset... Doug White | FreeBSD: The Power to Serve dwhite@resnet.uoregon.edu | www.FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message