From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759334AbXGNOnX (ORCPT ); Sat, 14 Jul 2007 10:43:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752989AbXGNOnQ (ORCPT ); Sat, 14 Jul 2007 10:43:16 -0400 Received: from khc.piap.pl ([195.187.100.11]:43980 "EHLO khc.piap.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752234AbXGNOnP (ORCPT ); Sat, 14 Jul 2007 10:43:15 -0400 To: William Montgomery Cc: linux-kernel@vger.kernel.org Subject: Re: e100 PCI bridge problem References: <4697B85B.4040902@opinicus.com> From: Krzysztof Halasa Date: Sat, 14 Jul 2007 16:43:13 +0200 In-Reply-To: <4697B85B.4040902@opinicus.com> (William Montgomery's message of "Fri, 13 Jul 2007 13:37:31 -0400") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org William Montgomery writes: > In an earlier post to the list I described a hard lockup condition > that occurs on linux kernels 2.4.22, 2.6.13, and 2.6.17 when using > a 4 port 10/100 fast ethernet card. The lockup is easily repeatable > and occurs on 2 out of 3 computers. > > Further testing has revealed that the lockup can be prevented on all > computers by making sure the card is installed on the primary PCI bus. > If the card is installed in a slot on the secondary PCI bus (behind a > PCI to PCI bridge) the lockup occurs. Does the machine #3 have a PCI slot connected to a "secondary" bus? Have you tried with any other machine with a secondary bus? > Are there any PCI tuning registers that I can tweak to get around > this problem? Any changes I could make to the e100 driver to fix this? Could be a hardware/BIOS problem on machines #1 and #2. Could be a Linux bug as well, though similar configurations are known to work fine. I don't think it has anything to do with IRQs. Perhaps it doesn't like a bridge (on the card) behind a bridge (on the motherboard). I would test with another multiport card such as old DLink DFE-570TX (using a DEC 21150 bridge and four 21143 Ethernet chips). I'd probably use some PCI analyzer or, at least, I'd check the bus state with a multimeter. -- Krzysztof Halasa