From owner-freebsd-stable Sat Apr 14 2:31: 8 2001 Delivered-To: freebsd-stable@freebsd.org Received: from emma1.emma.line.org (p3EE3CC9E.dip.t-dialin.net [62.227.204.158]) by hub.freebsd.org (Postfix) with ESMTP id E96DA37B50D for ; Sat, 14 Apr 2001 02:31:05 -0700 (PDT) (envelope-from ma@dt.e-technik.uni-dortmund.de) Received: by emma1.emma.line.org (Postfix, from userid 500) id 26C0CA2001; Sat, 14 Apr 2001 11:30:59 +0200 (CEST) To: freebsd-stable@freebsd.org Subject: FreeBSD 4.x refuses to use DMA on WDC31200F? From: Matthias Andree Date: 14 Apr 2001 11:30:59 +0200 Message-ID: Lines: 25 User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.7 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG 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. A WDCAC420400D is used in DMA mode (UDMA/33). My system is boots and mounts /, /usr and /var from a SCSI disk attached to a Tekram DC-390 (AMD PCscsiII/53C974). That very same drive can be successfully used in DMA mode with NetBSD 1.5 (same machine) and Linux 2.2.19 (same board type/chipset), I've never seen corruption on that drive with DMA. The drive is attached to a VIA VT82C586B (Apollo MVP3) on a Tyan Trinity 100AT (S1590). What causes FreeBSD's refusal to use DMA? Can I fix that? Can somebody else fix that? -- Matthias Andree To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message