Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754758AbXL1Fak (ORCPT ); Fri, 28 Dec 2007 00:30:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751056AbXL1Fad (ORCPT ); Fri, 28 Dec 2007 00:30:33 -0500 Received: from gate.crashing.org ([63.228.1.57]:55096 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751049AbXL1Fac (ORCPT ); Fri, 28 Dec 2007 00:30:32 -0500 Subject: Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Linus Torvalds 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 In-Reply-To: References: <4773EBB4.2020805@shaw.ca> <477414C9.3040906@myri.com> Content-Type: text/plain Date: Fri, 28 Dec 2007 16:29:50 +1100 Message-Id: <1198819790.7209.27.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: 1175 Lines: 28 On Thu, 2007-12-27 at 13:37 -0800, Linus Torvalds wrote: > The code doesn't actually do what CRS is supposed to help with (ie go > on > to probe another device and then come back to the slow one later), so > right now it's pretty much useless *anyway*. It's not totally useless... Instead of not seeing the device that hasn't fully initialized yet at all, we end up waiting a bit and then seeing it. Going to probe somebody else is a nice optimization we could do with multithread PCI probe but doesn't remove the need for CRS. 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. Note that I'm -very- surprised however that your BIOS hands control out of the kernel with devices still issuing CRS... Unless those devices may do it after boot but that's dodgy and will break many other things. 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/