From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760454AbYE0WyT (ORCPT ); Tue, 27 May 2008 18:54:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757531AbYE0WyK (ORCPT ); Tue, 27 May 2008 18:54:10 -0400 Received: from mga02.intel.com ([134.134.136.20]:2910 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757711AbYE0WyI (ORCPT ); Tue, 27 May 2008 18:54:08 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.27,550,1204531200"; d="scan'208";a="285503819" Date: Tue, 27 May 2008 15:45:07 -0700 From: Kristen Carlson Accardi To: Jesse Barnes Cc: Kenji Kaneshige , Andrew Morton , Ingo Molnar , linux-kernel@vger.kernel.org, Thomas Gleixner , "Rafael J. Wysocki" , drzeus-list@drzeus.cx Subject: Re: [patch, -git] pcie hotplug bootup crash fix Message-ID: <20080527154507.76c61d40@appleyard> In-Reply-To: <200805260920.15912.jbarnes@virtuousgeek.org> References: <20080524165828.GA29993@elte.hu> <20080526015232.5faac5bb.akpm@linux-foundation.org> <483A9050.5000206@jp.fujitsu.com> <200805260920.15912.jbarnes@virtuousgeek.org> Reply-To: kristen.c.accardi@intel.com X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.5; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 26 May 2008 09:20:15 -0700 Jesse Barnes wrote: > On Monday, May 26, 2008 3:26 am Kenji Kaneshige wrote: > > Andrew Morton wrote: > > > On Mon, 26 May 2008 10:47:09 +0200 Ingo Molnar wrote: > > >> * Kenji Kaneshige wrote: > > >>> I updated Ingo's patch. If it's ok, I'll send it to Jess Barnes with > > >>> some other patches for the other pciehp regression problems. > > >> > > >> looks good to me, thanks Kenji. > > > > > > It's a bit sad to add a large workaround like this. I'm surprised > > > that fixing it properly is considered unviable for 2.6.26. Normally > > > these fixes are pretty simple - just request the IRQ a bit later? > > > > Although I have not considered how to implement proper fix deeply, > > I don't think it's so simple. For example, current pciehp is doing > > like this: > > > > (1) some initialization > > (2) request_irq() > > (3) issue command > > (4) initialize slot data structure > > > > Maybe we want to do (2) after (4) to fix the problem. But if we > > simply move (2) after (4), we cannot detect the command completion > > event at (3) and it will cause command timeout. > > > > It's just an example, and there might be other things like this. > > This example might be fixed simply, but all my worry is that fixing > > this quickly might cause another regressions. This is why I think > > Ingo's approach is better in a short term. > > > > And another reason is I'm very nervous because I already caused > > many problems in pciehp since 2.6.26-rcX... :( > > But you also fixed the problems, which is even more important! :) I'm ok with > the workaround for 2.6.26 as long as we can get a more proper fix into > 2.6.27. > > Any thoughts, Kristen? > > Thanks, > Jesse > I'm in favor of the workaround for now.