From owner-freebsd-small@FreeBSD.ORG Thu Jul 21 14:08:56 2005 Return-Path: X-Original-To: freebsd-small@freebsd.org Delivered-To: freebsd-small@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6E39A16A41F for ; Thu, 21 Jul 2005 14:08:56 +0000 (GMT) (envelope-from imp@bsdimp.com) Received: from harmony.village.org (vc4-2-0-87.dsl.netrack.net [199.45.160.85]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5C12A43D83 for ; Thu, 21 Jul 2005 14:08:48 +0000 (GMT) (envelope-from imp@bsdimp.com) Received: from localhost (localhost.village.org [127.0.0.1]) by harmony.village.org (8.13.3/8.13.3) with ESMTP id j6LE5lgV085138; Thu, 21 Jul 2005 08:05:47 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Thu, 21 Jul 2005 08:06:36 -0600 (MDT) Message-Id: <20050721.080636.01051330.imp@bsdimp.com> To: NKoch@demig.de From: "M. Warner Losh" In-Reply-To: <000201c58dd4$5e114360$4801a8c0@ws-ew-3.W2KDEMIG> References: <20050721.020703.41710119.imp@bsdimp.com> <000201c58dd4$5e114360$4801a8c0@ws-ew-3.W2KDEMIG> X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-small@freebsd.org, non_secure@yahoo.com Subject: Re: DMA disable for sandisk CF cards ? X-BeenThere: freebsd-small@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Dedicated and Embedded Systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Jul 2005 14:08:56 -0000 In message: <000201c58dd4$5e114360$4801a8c0@ws-ew-3.W2KDEMIG> "Norbert Koch" writes: : > > May be, I miss the point. Why do you want to disable : > > dma on the cf card, when you can instruct FreeBSD : > > to just not use dma (atacontrol(8)) ? : > : > Because newer CF cards, like the SanDisk, negotiate DMA with the : > controller. However, most of the IDE <-> CF Adapters aren't properly : > wired for this, as they only implement CF 1.5 and not CF 2.0. So, : > when FreeBSD goes to access the device, you get all kinds of timeout : > errors. If you are lucky, ata will failback to PIO mode. Most of the : > time it has bitten me, I've not been lucky :-(. : > : > hw.ata.ata_dma=0 is the magic. You can set it at the boot loader : > prompt, or you can add it to /boot/loader.conf. atacontrol is way too : > late, since this disabling must be done prior to geom's scan for root : > (or the moral equivalent in 4.x). : : Ok, I understand. But you can't do that selectively on a per-device basis, : can you? There may be something you can do with atacontrol after boot. I've never needed it. Warner