Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 12 Mar 2001 07:28:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 12 Mar 2001 07:27:41 -0500 Received: from mumm.ibr.cs.tu-bs.de ([134.169.34.190]:46798 "EHLO mumm.ibr.cs.tu-bs.de") by vger.kernel.org with ESMTP id ; Mon, 12 Mar 2001 07:27:35 -0500 Date: Mon, 12 Mar 2001 13:26:51 +0100 Message-Id: <200103121226.NAA09602@kelts.ibr.cs.tu-bs.de> From: Joerg Diederich To: linux-kernel@vger.kernel.org Subject: Problem with mtrr and Cyrix 6x86MX: no mtrr for... Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! I switched to Linux 2.4 recently and ran into the following problem: When starting XFree 4.0.2, I get error messages like 'no mtrr for 0xe0000000,0x400000' (or sth similar, I am not currently at the machine with the Cyrix). Digging deeper, I found the following, non XFree-related problem: When I do 'echo "base=0xe0000000 size=0x400000 type=write-combining" > /proc/mtrr' as said in linux/Documentation/mtrr.txt in order to enable mtrr's for my graphics board, a 'cat /proc/mtrr' tells me, that the size is 8MB. If I do 'echo "base=0xe0000000 size=0x200000 type=write-combining" > /proc/mtrr' the behaviour becomes even stranger: When I do it the first time, again the size is 8MB (according to /proc/mtrr). When I delete the entry again (with 'echo delete...'), and repeat the above 'echo "base...', then the size is 4MB and there are no error messages when I start Xfree (which increases the 'count' in /proc/mtrr to 2). Probably it might be of interest, that the '8MB size' entry in /proc/mtrr is always in reg=6, whereas the 4MB size entry is in reg=2. My question is now, if this behavior is correct (since I do not know at all, what the mtrr stuff does except for that it speeds up my system. That's why I want to use it :-) or if it is an already known bug. If it is an unknown bug, I can give more information if someone tells me which one (exact /proc/mtrr output, /proc/cpuinfo etc, I didn't want to attach all the stuff in case this issue is known already) I am using the 2.4.2 kernel from SuSe, but I think this is not related to the SuSe-kernel... (However, I can check it with vanilla 2.4.2 or any patched version). Regards, /J"org - 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/