Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934280AbYCDXVB (ORCPT ); Tue, 4 Mar 2008 18:21:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934900AbYCDXPy (ORCPT ); Tue, 4 Mar 2008 18:15:54 -0500 Received: from mx2.suse.de ([195.135.220.15]:42596 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934894AbYCDXPu (ORCPT ); Tue, 4 Mar 2008 18:15:50 -0500 Date: Tue, 4 Mar 2008 15:15:25 -0800 From: Greg KH To: Alex Chiang , Matthew Wilcox , Gary Hade , kaneshige.kenji@jp.fujitsu.com, warthog19@eaglescrag.net, kristen.c.accardi@intel.com, rick.jones2@hp.com, linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, linux-acpi@vger.kernel.org Subject: Re: [PATCH 4/4] ACPI PCI slot detection driver Message-ID: <20080304231525.GA25125@suse.de> References: <20080229002341.GA21420@ldl.fc.hp.com> <20080229002938.GE21420@ldl.fc.hp.com> <20080301052542.GD19353@suse.de> <20080301144307.GD24386@parisc-linux.org> <20080304054927.GA15566@suse.de> <20080304225830.GC3694@ldl.fc.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080304225830.GC3694@ldl.fc.hp.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3020 Lines: 73 On Tue, Mar 04, 2008 at 03:58:30PM -0700, Alex Chiang wrote: > * Greg KH : > > On Sat, Mar 01, 2008 at 07:43:07AM -0700, Matthew Wilcox wrote: > > > On Fri, Feb 29, 2008 at 09:25:42PM -0800, Greg KH wrote: > > > > What is the guarantee that the names of these slots are correct > > No guarantee there. We report whatever firmware tells us. > > > > > and do not happen to be the same as the hotpluggable ones? > > Stronger guarantee here, since both pci_slot and hp driver > will be getting the name of the slot from the same place. > > > > That would be a bug -- and yes, bugs happen, and we have to deal with > > > them. > > > > My main concern is that BIOS vendors will not fix these bugs, as no > > other OS cares/does this kind of thing today. The ammount of bad > > information out there might be quite large, and I think this was > > confirmed by some initial testing of IBM systems, right? > > We saw problems on Fujitsu machines, where they return an error > code when the _SUN method is called on a slot that exists in the > namespace but isn't actually present. > > After discussing with Kenji-san about specs, we came to the > agreement that he was ok with this behavior because he had the > option to not load pci_slot on his machines. > > I agree that there might be lots of buggy firmwares out there, > but we won't know for certain until we get some exposure. And I > think the upside is worth it. > > Kristen suggested the linux-next tree. That sounds viable to > me... > > > > > Why show this information on machines that can not do > > > > anything with these slots at all? Will that not just > > > > confuse people? > > > > > > Only for people who think that /sys/bus/pci/slots/ is for > > > hotpluggable slots only. There is plenty of useful > > > information available for slots that aren't hotpluggable (eg > > > bus address, speed, width, error status). > > > > Can the userspace tools that are using the existing directories > > thinking that only hotplug slots are there, handle > > "non-hotplug" slots showing up in this location? > > Of course we shouldn't break userspace, no one wants that. But > nothing about that name (/sys/bus/pci/slots/) implies "hotplug > only", and we have no idea how big the problem might be. But that is what the current code does, so I know a lot of userspace programs assume that all slots there are valid hotplug slots. I know I sure don't want to go fix up a lot of horrible Java closed-source code in IBM's huge system management toolkits :( > Again, I'm thinking more exposure in linux-next might be a > reasonable way for us to figure out how bad (or good) the > situation might really be out there. Ok, care to resend them with the requested updates? thanks, greg k-h -- 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/