Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751465AbWJEXgc (ORCPT ); Thu, 5 Oct 2006 19:36:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751467AbWJEXgc (ORCPT ); Thu, 5 Oct 2006 19:36:32 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:38537 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1751465AbWJEXgb (ORCPT ); Thu, 5 Oct 2006 19:36:31 -0400 Message-ID: <452596F9.3010107@garzik.org> Date: Thu, 05 Oct 2006 19:36:25 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.7 (X11/20060913) MIME-Version: 1.0 To: Linus Torvalds CC: Andi Kleen , discuss@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [discuss] Re: Please pull x86-64 bug fixes References: <200610051910.25418.ak@suse.de> <452564B9.4010209@garzik.org> <200610060052.46538.ak@suse.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.3 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1863 Lines: 47 Linus Torvalds wrote: > If we had the > > void __iomem *cfg = mmiocfg_remap(dev); > > interface, we could (fairly easily) blacklist known-bad motherboards if we > needed to, and also, it would allow drivers to check whether mmiocfg is > available. It's possible that some drivers might want it if it exists, but > it wouldn't necessarily be somethign that they _require_, so they could > gracefully handle the case of getting a NULL config space handle back. > > For example, for some devices, maybe they'd lose some error handling > capability, but they'd still be able to work otherwise. Ugh. Large PCI config space is going to be the norm real soon. That will just nasty up drivers. > We _can_ do the same thing with checking the error return value from > "pci_read_config_xxxx()", and use the "use different access method if the > index is >= 256", but I have to say, that just makes my gag reflex > trigger. Having the same function just silently do two different things > depending on the offset just sounds like a recipe for disaster. Agreed. > I dunno. I'm not likely to care _that_ deeply about this all, but I do > think that machines that hang on device discovery is just about the worst > possible thing, so I'd much rather have ten machines that can't use their > very rare devices without some explicit kernel command line than have even > _one_ machine that just hangs because MMIOCFG is buggered. > > (And we should probably have the "pci=mmiocfg" kernel command line entry > that forces MMIOCFG regardless of any e820 issues, even for normal > accesses). Agreed. Jeff - 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/