From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263717AbTJCLll (ORCPT ); Fri, 3 Oct 2003 07:41:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263718AbTJCLll (ORCPT ); Fri, 3 Oct 2003 07:41:41 -0400 Received: from VIA-PPPD24017.vianetworks.es ([213.236.24.17]:37098 "EHLO servidor.eurogaran.com") by vger.kernel.org with ESMTP id S263717AbTJCLlj (ORCPT ); Fri, 3 Oct 2003 07:41:39 -0400 Date: Fri, 3 Oct 2003 13:41:36 +0200 To: linux-kernel@vger.kernel.org Subject: PROBLEM: If Linux is to be run with CPU cache disabled then this is no bug (but please tell me if so). Message-ID: <20031003114136.GA11539@eurogaran.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.28i From: =?iso-8859-1?Q?Juanjo_Garc=EDa_Carr=E9?= Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -Foreword: I am not complaining; just hoping to help in developing a better kernel. -Symptom: When accelerating graphics, the machine freezes completely (no response to emergency sys req keys or net access). As a consequence, NOTHING GETS LOGGED (sorry). -How to reproduce: 1) Use the following hardware: Radeon 9200 AGP graphics card. CPU PentiumII Deschutes (Tried the same card on an Athlon machine -all the rest being equal- and the problem did not happen). baseplate Tyan (This means Intel 440BX and Intel AGP bus 2x ) 2) Enable in BIOS the CPU internal cache to "Write Back" mode. (Either "Write Thru" or "Disabled" will eliminate the problem, at the expense of an extremely low performance). 3) Use ANY Linux-2.6.0-test kernel, or ANY linux-2.4 kernel, (in which case you will need an updated version for the radeon module). 4) Use XFree86 4.3.0 or over (for radeon acceleration support). 5) In the XF86Config-4 file, specify the chipset of a Radeon 9100 or another radeon for which acceleration is already supported (I know this is not the culprit factor, since -as I said before- it works on an Athlon machine). 6) In the XF86Config-4 file, make sure the option ForcePCIMode is off (when it is enabled, everything works fine, safe for halving performance). _ALL_ the other options are indifferent in order to reproduce the problem, (even the option to use the XFree GPL radeon driver or the propietary FireGL drivers from Ati). 7) Make sure the agpgart module (and the intel_agp module for 2.6 kernels) are loaded before launching XFree. 8) Launch X. Everything seems to work; glxinfo says Yes as to direct rendering. Now launch an OpenGL application, like glxgears: It runs for some instants, then becomes blocked, as the rest of the system. Please reply with Cc to juanjo@eurogaran.com because I am not suscribed to any kernel mailing list. Thank you.