Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754146AbYANQCm (ORCPT ); Mon, 14 Jan 2008 11:02:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751341AbYANQCd (ORCPT ); Mon, 14 Jan 2008 11:02:33 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:42348 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751333AbYANQCd (ORCPT ); Mon, 14 Jan 2008 11:02:33 -0500 Date: Mon, 14 Jan 2008 08:01:50 -0800 From: Arjan van de Ven To: tcamuso@redhat.com Cc: Alan Cox , Ivan Kokshaysky , Greg KH , Matthew Wilcox , Linus Torvalds , Greg KH , linux-kernel@vger.kernel.org, Jeff Garzik , linux-pci@atrey.karlin.mff.cuni.cz, Benjamin Herrenschmidt , Martin Mares , Loic Prylli , Prarit Bhargava , "Chumbalkar, Nagananda" , "Schoeller, Patrick (Linux - Houston, TX)" , Bhavana Nagendra Subject: Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in Message-ID: <20080114080150.23ace331@laptopd505.fenrus.org> In-Reply-To: <478B7E62.9070700@redhat.com> References: <20080111213803.GS18741@parisc-linux.org> <20080111235856.GA16079@jurassic.park.msu.ru> <20080112002638.GA18710@kroah.com> <20080112144030.GA19279@jurassic.park.msu.ru> <20080112094557.71f5382a@laptopd505.fenrus.org> <20080112214911.GA20102@jurassic.park.msu.ru> <20080112150120.05f93768@laptopd505.fenrus.org> <47895767.3090503@redhat.com> <20080112164006.6f6f7bc2@laptopd505.fenrus.org> <47896B3B.2000108@redhat.com> <20080112204248.29abb1dd@laptopd505.fenrus.org> <478A075F.7010503@redhat.com> <20080113090311.0a9a1db5@laptopd505.fenrus.org> <478A8268.6020107@redhat.com> <20080114005434.48340f84@lxorguk.ukuu.org.uk> <20080113173331.617ac935@laptopd505.fenrus.org> <478AD713.8060204@redhat.com> <20080113210501.4584e4d2@laptopd505.fenrus.o! rg> <478B5D0D.7060808@redhat.com> <20080114064614.22081ff3@laptopd505.fenrus.org> <478B7E62.9070700@redhat.com> Organization: Intel X-Mailer: Claws Mail 3.2.0 (GTK+ 2.12.3; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1713 Lines: 44 On Mon, 14 Jan 2008 10:23:14 -0500 Tony Camuso wrote: > Arjan van de Ven wrote: > > On Mon, 14 Jan 2008 08:01:01 -0500 > > Tony Camuso wrote: > >> > >> If we're going to differentiate MMCONFIG from > >> some other access mechanism, it only needs to be done at the > >> Northbridge level. Devices are electrically ignorant of the > >> protocol used between CPU and Northbridge to get the Northbridge > >> to assert config cycles on the bus. > > > > Again this is about having systems that don't need extended config > > space not use it. At all. The only way to do that is have the > > drivers say they need it, and not use it otherwise. It has NOTHING > > to do with how things are wired up. It's pure a kernel level policy > > decision about whether to use extended config space AT ALL. > > > > The problem with compelling device drivers to determine the PCI > config mechanism is that it must be forced upon arches that > have no PCI configuration quirks or don't even use the same > PCI config mechanisms as x86. it's not pci_enable_mmconf(), it's pci_enable_extended_config_space... it's independent of the mechanism! > > I don't think that's a good policy. > > Better to confine arch-specific quirks to the arch-specific code > whenever possible. > -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/