Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934324AbXLMXKU (ORCPT ); Thu, 13 Dec 2007 18:10:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764163AbXLMXKH (ORCPT ); Thu, 13 Dec 2007 18:10:07 -0500 Received: from gate.crashing.org ([63.228.1.57]:33041 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762708AbXLMXKF (ORCPT ); Thu, 13 Dec 2007 18:10:05 -0500 Subject: Re: Possible issue with dangling PCI BARs From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Ivan Kokshaysky Cc: Jesse Barnes , Alan Cox , Robert Hancock , linux-pci@atrey.karlin.mff.cuni.cz, Linux Kernel list , Linus Torvalds In-Reply-To: <20071214001239.B21652@jurassic.park.msu.ru> References: <1197544621.15741.132.camel@pasglop> <1197544820.15741.137.camel@pasglop> <200712131204.18227.jesse.barnes@intel.com> <1197579066.15741.167.camel@pasglop> <20071214001239.B21652@jurassic.park.msu.ru> Content-Type: text/plain Date: Fri, 14 Dec 2007 10:09:28 +1100 Message-Id: <1197587368.15741.187.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1210 Lines: 33 On Fri, 2007-12-14 at 00:12 +0300, Ivan Kokshaysky wrote: > On Fri, Dec 14, 2007 at 07:51:06AM +1100, Benjamin Herrenschmidt wrote: > > If the device is behind a P2P bridge and the BIOS has set the windows of > > that bridge so tightly that there is no room to allocate the MMIO BAR, > > then a full disable/full enable would fail on a device that would > > otherwise work using only PIO. > > It won't be a problem with separate io/mmio enable. > > > However, I'd be curious to see that happening in practice :-) > > > > But I think it's fair enough to do an IO only / MEM only approach. I've > > seen cases where IO is just not useable because of other constraints and > > so I expect the MEM-only case to be more common, especially on non-x86. > > Everybody wants MEM if it's available - it's just faster :-) > So I guess a common case will be .../... Right, I'm going to cook up some patch as time permit, maybe not before next week tho. Cheers, Ben. -- 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/