Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755547AbZFYAAU (ORCPT ); Wed, 24 Jun 2009 20:00:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752283AbZFYAAI (ORCPT ); Wed, 24 Jun 2009 20:00:08 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:57596 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752095AbZFYAAH (ORCPT ); Wed, 24 Jun 2009 20:00:07 -0400 Date: Wed, 24 Jun 2009 17:00:05 -0700 From: Gary Hade To: Linus Torvalds Cc: Yinghai Lu , Ingo Molnar , Jesse Barnes , Gary Hade , Matthew Wilcox , Larry Finger , Andrew Morton , linux-pci@vger.kernel.org, "linux-kernel@vger.kernel.org" , Jaswinder Singh Rajput Subject: Re: [PATCH] x86/pci: don't use crs for root if we only have one root bus Message-ID: <20090625000005.GD12934@us.ibm.com> References: <20090624122433.GA24781@elte.hu> <20090624145119.GA12664@elte.hu> <4A429EBB.5010209@kernel.org> <4A42AFAC.6000300@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1533 Lines: 42 On Wed, Jun 24, 2009 at 04:09:36PM -0700, Linus Torvalds wrote: > > Should we not just revert 9e9f46c44e487af0a82eb61b624553e2f7118f5b? > > The thing says: > > "At this point, it seems to solve more problems than it causes, so let's > try using it by default. It's an easy revert if it ends up causing > trouble." > > and it clearly does _not_ solve more problems than it causes, and the > whole message in that commit implies we should revert it. > > I'm happy to apply various patches to fix it up, but regardless, I thinkwe > should revert that commit as bogus. We can try making it the default again > next round, when maybe it will be true that it doesn't cause issues. > > What did it even ever help with? In our case it is needed on some of our systems for PCI hotplug to avoid MCKs due to a device under one root bus getting a resource during hotplug that can only be used by devices under a different root bus. If the user does not intend to use PCI hotplug, the function isn't needed (i.e. 'pci=use_crs' can be omitted) because resources are properly directed to the installed cards via BIOS pre-assignment. 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 -- 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/