From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756215AbYEISym (ORCPT ); Fri, 9 May 2008 14:54:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752739AbYEISyc (ORCPT ); Fri, 9 May 2008 14:54:32 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:37168 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752675AbYEISyb (ORCPT ); Fri, 9 May 2008 14:54:31 -0400 Date: Fri, 9 May 2008 11:54:26 -0700 From: Gary Hade To: Linus Torvalds Cc: Gary Hade , Ingo Molnar , Jesse Barnes , Dave Airlie , kernel list , Thomas Gleixner Subject: Re: regression fixed by using pci=rom Message-ID: <20080509185425.GC6255@us.ibm.com> References: <21d7e9970805081654h6de38d58q5ad3b6d3520b45f1@mail.gmail.com> <200805081717.54102.jbarnes@virtuousgeek.org> <20080509064402.GA15754@elte.hu> <20080509164551.GB6255@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 09, 2008 at 10:26:47AM -0700, Linus Torvalds wrote: > > > On Fri, 9 May 2008, Gary Hade wrote: > > > > Ingo, Would you (or others listening to this discussion) know > > exactly what Windows does with respect to BIOS unassigned > > expansion ROMs? > > Nobody really seems to know what windows does for *any* resources. And it > probably depends on windows version too, and on detailed chipset issues > (ie does Windows do the same thing as Linux wrt transparent bridges that > still have bus translation resources set up?). > > So the "try to do what Windows does" is something we strive for in > particular cases, but it's not an absolute thing, and probably can never > even be that in theory. It's more a guideline, especially when we don't > know which particular choice is better and both seem otherwise equally > good. > > But "doesn't work" always trumps "that's what windows does". Because even > if something works under Windows, sometimes Linux drivers simply then act > differently (ie they may use PIO vs MMIO, or in the case of graphics they > may need ROMs for re-POST'ing while a windows driver is written by the > chipset vendor and DTRT without even looking at the BIOS tables) Yea, this is probably a good explanation of why Windows does run, presumably without PCI resource allocation issues, on those same systems where we have struggling with the expansion ROM resource allocation failures from Linux. Thanks. Gary -- Gary Hade System x Enablement IBM Linux Technology Center 503-578-4503 IBM T/L: 775-4503 garyhade@us.ibm.com http://www.ibm.com/linux/ltc