From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752321Ab0JVVuq (ORCPT ); Fri, 22 Oct 2010 17:50:46 -0400 Received: from g6t0186.atlanta.hp.com ([15.193.32.63]:3921 "EHLO g6t0186.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952Ab0JVVuo (ORCPT ); Fri, 22 Oct 2010 17:50:44 -0400 From: Bjorn Helgaas To: Ram Pai Subject: Re: [RFC v2 PATCH 1/1] PCI: override BIOS/firmware resource allocation Date: Fri, 22 Oct 2010 15:49:21 -0600 User-Agent: KMail/1.13.2 (Linux/2.6.32-25-generic; KDE/4.4.2; x86_64; ; ) Cc: Jesse Barnes , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clemens@ladisch.de, Yinghai Lu , Linus Torvalds References: <20101006225834.GE2945@ram-laptop> <201010221155.19123.bjorn.helgaas@hp.com> <20101022185937.GF24820@ram-laptop> In-Reply-To: <20101022185937.GF24820@ram-laptop> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201010221549.22124.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, October 22, 2010 12:59:37 pm Ram Pai wrote: > On Fri, Oct 22, 2010 at 11:55:18AM -0600, Bjorn Helgaas wrote: > > If we assign resources to bridges with no devices behind them while > > starving bridges that DO have devices behind them, I think that's a bug. > > It'd be great if you could isolate and fix that before we complicate > > things by throwing Yinghai's patch into the mix. > > Yes. I sent out a patch an hour back with a fix for that. Yeah, I saw that right after I hit "send" :-) > > I think it'd interesting to have a debug parameter like "pci=assign-all" > > that meant "ignore all BIOS PCI config and start from scratch." I'm > > sure we'd trip over lots of issues and it would be easier to resolve them > > before trying to make things fancier. > > The patch that I had sent 3-weeks back had that feature. It can be triggered > by pci=override=always. > > However, your arguement earlier was that it would make no difference because > no one will enable that parameter by default. This means hardly anyone will > report any bugs. I just meant as a development tool, maybe not even upstream, as a way to exercise the Linux allocation code. I don't have much confidence in it yet. We certainly don't want Linux to ignore the BIOS config in general; we should just use it unless we can tell it's broken. > Gating "Yinghai's patch or any other approach" on fixing all the bugs in the > pci subsystem, implicitly means 'go away' ;). I hope you dont mean that. Oh, no. > I propose to bring Yinghai's patch, for that will enable us to expose bugs and > at the same time it will enable SRIOV on *all* the platforms that don't have it. Yes, we should consider Yinghai's patch again after all the known issues with it are fixed. I just don't know whether we're there yet. Bjorn