Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755187AbXL1Fif (ORCPT ); Fri, 28 Dec 2007 00:38:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751540AbXL1Fi0 (ORCPT ); Fri, 28 Dec 2007 00:38:26 -0500 Received: from smtp2.linux-foundation.org ([207.189.120.14]:38072 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751056AbXL1Fi0 (ORCPT ); Fri, 28 Dec 2007 00:38:26 -0500 Date: Thu, 27 Dec 2007 21:37:49 -0800 (PST) From: Linus Torvalds To: Benjamin Herrenschmidt cc: Loic Prylli , Robert Hancock , Jeff Garzik , Arjan van de Ven , Linux Kernel Mailing List , gregkh@suse.de, linux-pci , Martin Mares , Matthew Wilcox , Kai Ruhnau Subject: Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in In-Reply-To: <1198819790.7209.27.camel@pasglop> Message-ID: References: <4773EBB4.2020805@shaw.ca> <477414C9.3040906@myri.com> <1198819790.7209.27.camel@pasglop> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1077 Lines: 26 On Fri, 28 Dec 2007, Benjamin Herrenschmidt wrote: > > I have embedded boards where proper CRS operations is critical since the > kernel brings the PCIe link up itself, and thus is likely to hit devices > still in the middle of CRS. .. but that's perfectly fine. A PCI-E bridge will certainly retry it in hardware (or it isn't a PCI-E bridge!). The CRS bit in question is purely the *software*visible* bit - ie whether the OS gets told about the delay or not. As long as the OS then just retries the same device, enabling CRS SV is pointless. So I'm going to disable that thing. If there is some _other_ PCI-E bridge that is simply buggy, and cannot handle the hw retry itself or is just otherwise dodgy, we can have a white-list for cases where it really needs to be done, but the current code is just bogus. Linus -- 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/