From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 10 Mar 2003 17:26:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 10 Mar 2003 17:26:46 -0500 Received: from adsl-67-113-154-34.dsl.sntc01.pacbell.net ([67.113.154.34]:28155 "EHLO postbox.aslab.com") by vger.kernel.org with ESMTP id ; Mon, 10 Mar 2003 17:26:44 -0500 Message-ID: <3E6D150E.40105@aslab.com> Date: Mon, 10 Mar 2003 14:43:26 -0800 From: Michael Madore User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20020830 X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Video kernel modules can't enable write-combining Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, I am experiencing a problem with AGP graphic cards on a SuperMicro X5DAL-G motherboard with RAM >= 4 GB. I am seeing the problem with both an Nvidia as well as an ATI card, so I'm thinking that it is not the drivers. Also, when the system is populated with 2GB of RAM, both cards work fine. Here are the diagnostic messages from the Nvidia driver: Mar 10 14:20:04 asl193 kernel: 1: nvidia: loading NVIDIA Linux x86 nvidia.o Kernel Module 1.0-4191 Mon Dec 9 11:49:01 PST 2002 Mar 10 14:21:33 asl193 kernel: mtrr: type mismatch for e4000000,4000000 old: uncachable new: write-combining Mar 10 14:21:33 asl193 kernel: 1: nvidia: cannot write-combine 0xe4000000, 64M The performance of the video after X starts is extremely poor, and the contents of /proc/driver/nvidia/agp/status indicate that AGP is not enable. I have tried 2.4.19 and 2.4.21pre5 (with PAE enabled) with the same results. The contents of /proc/mtrr are: reg00: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1 reg01: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1 reg02: base=0x100000000 (4096MB), size= 512MB: write-back, count=1 reg03: base=0xdff80000 (3583MB), size= 512KB: uncachable, count=1 The contents of /proc/meminfo are: total: used: free: shared: buffers: cached: Mem: 4233945088 221356032 4012589056 0 17256448 160219136 Swap: 4293586944 0 4293586944 MemTotal: 4134712 kB MemFree: 3918544 kB MemShared: 0 kB Buffers: 16852 kB Cached: 156464 kB SwapCached: 0 kB Active: 75996 kB Inactive: 102752 kB HighTotal: 3276260 kB HighFree: 3111608 kB LowTotal: 858452 kB LowFree: 806936 kB SwapTotal: 4192956 kB SwapFree: 4192956 kB BigFree: 0 kB If I install Windows XP on the same machine, the graphics performance is fine. Interestingly, Windows only reports < 3.5GB of available memory. Is it the case that this machine has only 3.5GB of usable memory? If so, how do I configure the kernel to avoid putting the AGP aperture in the uncacheable region? I tried passing mem=3400M at boot time. /proc/meminfo reported the reduced memory, but the problem persists. In any case, that would not work in a machine with 6GB. Thanks for any advice Mike Madore