Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271104AbTG1UzN (ORCPT ); Mon, 28 Jul 2003 16:55:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271094AbTG1UxA (ORCPT ); Mon, 28 Jul 2003 16:53:00 -0400 Received: from webmail.hamiltonfunding.la ([12.162.17.40]:14213 "EHLO umhlanga.STRATNET.NET") by vger.kernel.org with ESMTP id S271038AbTG1UwY (ORCPT ); Mon, 28 Jul 2003 16:52:24 -0400 To: "Kathy Frazier" Cc: Subject: Re: DMA not supported with Intel ICH4 I/O controller? References: X-Message-Flag: Warning: May contain useful information X-Priority: 1 X-MSMail-Priority: High From: Roland Dreier Date: 28 Jul 2003 13:52:20 -0700 In-Reply-To: Message-ID: <52brvegyrf.fsf@topspin.com> User-Agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.4 (Common Lisp) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 28 Jul 2003 20:52:20.0291 (UTC) FILETIME=[2331C130:01C3554A] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1636 Lines: 28 Kathy> It's a proprietary board that we use to allow the PC to Kathy> send blocks of data to some industrial equipment. We Kathy> developed the hardware and Linux driver in-house. This Kathy> same board works (under Linux) on a MoBo using the Intel Kathy> 815E chipset (Pentium III) with an IHC2 I/O Controller Hub. Kathy> This is the system I did _all_ my stress testing in. The Kathy> plan was to ship our product with these ASUS P4PE MoBos Kathy> (using Intel 845PE and ICH4 controller) and were Kathy> un-pleasantly surprise when it didn't work. It sounds like your board is acting as a PCI bus master. This is completely different from DMA for the IDE controller. External PCI bus masters should be supported by any version of Linux that works on the motherboard at all. However there are of course many differences between an 815E and an 845PE motherboard, and between the ICH2 and ICH4. You may have borderline PCI compliance or signal integrity issues that only cause problems on the P4PE motherboard. The BIOS on the P4PE may be setting your device up differently from the 815E motherboard. Your device might be confusing the BIOS on the P4PE so that the IRQ routing information (eg in ACPI tables) is screwed up. And so on. However, I have not heard of any generic problems with external PCI bus masters and the ICH4. Best, Roland - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/