From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763047AbYEIQF5 (ORCPT ); Fri, 9 May 2008 12:05:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755268AbYEIQFs (ORCPT ); Fri, 9 May 2008 12:05:48 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:45129 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755216AbYEIQFr (ORCPT ); Fri, 9 May 2008 12:05:47 -0400 Date: Fri, 9 May 2008 09:05:16 -0700 From: Gary Hade To: Jesse Barnes Cc: Linus Torvalds , Dave Airlie , kernel list , Gary Hade , Ingo Molnar , Thomas Gleixner Subject: Re: regression fixed by using pci=rom Message-ID: <20080509160516.GA6255@us.ibm.com> References: <21d7e9970805081654h6de38d58q5ad3b6d3520b45f1@mail.gmail.com> <200805081717.54102.jbarnes@virtuousgeek.org> <200805082329.39987.jbarnes@virtuousgeek.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200805082329.39987.jbarnes@virtuousgeek.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 08, 2008 at 11:29:39PM -0700, Jesse Barnes wrote: > On Thursday, May 08, 2008 6:46 pm Linus Torvalds wrote: > > On Thu, 8 May 2008, Jesse Barnes wrote: > > > Hm, yeah in many cases we definitely *do* want to try to get the > > > expansion ROM space allocated. But maybe it should be a lower priority > > > than other BARs... Gary? > > > > The thing is, a lot of these things have been done this way because not > > doing them that way breaks. > > > > We want to allocate expansion ROM space - even if we don't enable it - > > because not doing so will screw up bus sizing etc, and can make it > > impossible to allocate later. > > > > In general, changing PCI allocation strategy is really _really_ dangerous, > > even when it is "right", because it tends to expose a lot of issues where > > something worked just because it was perhaps indirectly causing a layout > > that worked. > > Yeah, that was my first impression too, but the patch went upstream awhile ago > and I didn't see any background except for the changelog. > > If anything, we should have a pci=norom option instead, so that big systems > that don't need the ROMs can use their address space more efficiently. This is actually the solution I was going to suggest. I will work on it. 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