Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762985AbXEQGTE (ORCPT ); Thu, 17 May 2007 02:19:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755695AbXEQGSz (ORCPT ); Thu, 17 May 2007 02:18:55 -0400 Received: from mx1.redhat.com ([66.187.233.31]:43866 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754287AbXEQGSz (ORCPT ); Thu, 17 May 2007 02:18:55 -0400 Date: Thu, 17 May 2007 02:18:04 -0400 From: Dave Jones To: "H. Peter Anvin" Cc: Linus Torvalds , Christian , linux-kernel@vger.kernel.org Subject: Re: 2.6.22-rc1 does not boot on VIA C3_2 cause of X86_CMPXCHG64 Message-ID: <20070517061804.GM30166@redhat.com> Mail-Followup-To: Dave Jones , "H. Peter Anvin" , Linus Torvalds , Christian , linux-kernel@vger.kernel.org References: <464B9D2C.7040704@cv-sv.de> <464BAF07.9020003@cv-sv.de> <464BC67F.7080707@zytor.com> <464BDF58.2090907@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <464BDF58.2090907@zytor.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1448 Lines: 36 On Wed, May 16, 2007 at 09:51:36PM -0700, H. Peter Anvin wrote: > Linus Torvalds wrote: > > > > On Wed, 16 May 2007, H. Peter Anvin wrote: > >> It gets turned on by the code in arch/i386/kernel/cpu. It's just that > >> the new code that Andi added runs during setup, i.e. in real mode, so > >> *way* earlier than that. > > > > Ahh. Do we really need it that early? > > The reason to do it early is so that we can still get a message out if > the CPU doesn't have the necessary features. This is generic code and > not specific to CX8. > > Since I'm rewriting the setup code in C, I have added code to enable > features on VIA and Transmeta CPUs (there was already code in there to > enable features on AMD; Intel isn't known to hide any features other > than PAE on 400 MHz FSB Pentium-M.) > > I think the early feature detection makes good sense. It's a heckuva > lot nicer to get a message on your screen saying that you can't boot > this kernel on this CPU than a crash, or an early_printk which may never > actually get to you. agreed, though we'll still need something for .22 (I'm assuming your rework isn't intended for .22) Dave -- http://www.codemonkey.org.uk - 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/