Date: Mon, 16 Apr 2001 14:24:07 -0700 (PDT) From: Doug White <dwhite@resnet.uoregon.edu> To: Matthias Andree <ma@dt.e-technik.uni-dortmund.de> Cc: <freebsd-stable@FreeBSD.ORG> Subject: Re: FreeBSD 4.x refuses to use DMA on WDC31200F? Message-ID: <Pine.BSF.4.33.0104161421520.81871-100000@resnet.uoregon.edu> In-Reply-To: <m3ae5jakvg.fsf@emma1.emma.line.org>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.33.0104161421520.81871-100000>