Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757573AbXLSALi (ORCPT ); Tue, 18 Dec 2007 19:11:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753047AbXLSALa (ORCPT ); Tue, 18 Dec 2007 19:11:30 -0500 Received: from idcmail-mo1so.shaw.ca ([24.71.223.10]:31165 "EHLO pd2mo3so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752826AbXLSAL3 (ORCPT ); Tue, 18 Dec 2007 19:11:29 -0500 Date: Tue, 18 Dec 2007 18:11:03 -0600 From: Robert Hancock Subject: Re: PCI resource problems caused by improper address rounding In-reply-to: To: Linus Torvalds Cc: Richard Henderson , Chuck Ebbert , linux-kernel , Ivan Kokshaysky , Daniel Ritz , Greg KH , Keith Packard , Bjorn Helgaas Message-id: <47686197.6080807@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-15; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1462 Lines: 41 Linus Torvalds wrote: > > On Tue, 18 Dec 2007, Richard Henderson wrote: >> I've added dmesg, /proc/iomem, and lspci -v output to that bug. >> >> Basically, we have >> >> c0000000-cfffffff : free >> ddf00000-dfefffff : PCI Bus #04 >> e0000000-efffffff : pnp 00:0b >> f0000000-fedfffff : less than 256MB > > Gaah. > > That really is very unlucky. That 256M only goes at one point in the low > 4GB, but the thing is, it fits perfectly well above it, and dammit, that > resource is explicitly a 64-bit resource or a really good reason. > > However, I wonder about that > > e0000000-efffffff : pnp 00:0b > > thing. I actually suspect that that whole allocation is literally *meant* > for that 256MB graphics aperture, but the kernel explicitly avoids it > because it's listed in the PnP tables. That is probably the MMCONFIG aperture, in that case any attempt to map the graphics BAR there will have disastrous results. (This BIOS has an MCFG table, though it looks like this Fedora kernel has MMCONFIG disabled, so we can't tell what it actually contains.) -- 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/