Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761715AbXEWAyX (ORCPT ); Tue, 22 May 2007 20:54:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757739AbXEWAyQ (ORCPT ); Tue, 22 May 2007 20:54:16 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:2377 "EHLO pd3mo2so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756335AbXEWAyP (ORCPT ); Tue, 22 May 2007 20:54:15 -0400 Date: Tue, 22 May 2007 18:53:53 -0600 From: Robert Hancock Subject: Re: [RFC PATCH] PCI MMCONFIG: add validation against ACPI motherboard resources In-reply-to: <200705221738.09571.jbarnes@virtuousgeek.org> To: Jesse Barnes Cc: Olivier Galibert , linux-kernel , Andi Kleen , Chuck Ebbert , Len Brown Message-id: <465390A1.1020307@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: <4635510D.4060103@shaw.ca> <200705211322.18937.jbarnes@virtuousgeek.org> <46538B67.3080007@shaw.ca> <200705221738.09571.jbarnes@virtuousgeek.org> User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1933 Lines: 39 Jesse Barnes wrote: > On Tuesday, May 22, 2007, Robert Hancock wrote: >> Eww. I don't see where we disable the decode at all while we probe the >> BARs on the device. That seems like a bad thing, especially with the way >> we probe 64-bit BARs (do the low 32 bits first and then the high 32 >> bits). This means the base address effectively gets set to 0xfffffff0 >> momentarily, which might cause some issues. > > I'm a bit shocked that things work as well as they do without the > disabling... > >> I'd try adding some code inside pci_setup_device (drivers/pci/probe.c) >> to disable PCI_COMMAND_IO and PCI_COMMAND_MEMORY on the device when >> probing devices with the standard header type and then restoring the >> previous command bits afterwards, and see what effect that has. It'll be >> interesting if it does, since obviously it seems to work as it is with >> non-MMCONFIG access methods. Maybe the base address being set like that >> interferes with MMCONFIG access itself somehow? > > I tried that, and it seems to get past probing the graphics device at > least, but it hangs a bit later. It could be that the enable/disable I > added wasn't correct though, I didn't check to see which one I should > disable in the command word, which may be a problem (just disabled them > both every probe). I'll try again with more precise enable/disable > semantics. It'd be interesting to see at what access it ran into trouble next, at least if it's consistent. Could be that some device doesn't like having the decode disabled.. -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/ - 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/