Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261532AbUJ0CCn (ORCPT ); Tue, 26 Oct 2004 22:02:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261561AbUJ0CCn (ORCPT ); Tue, 26 Oct 2004 22:02:43 -0400 Received: from fmr12.intel.com ([134.134.136.15]:60035 "EHLO orsfmr001.jf.intel.com") by vger.kernel.org with ESMTP id S261532AbUJ0CCk (ORCPT ); Tue, 26 Oct 2004 22:02:40 -0400 Subject: Re: [ACPI] [Proposal]Another way to save/restore PCI config space for suspend/resume From: Li Shaohua To: Hiroshi 2 Itoh Cc: ACPI-DEV , greg@kroah.com, Len Brown , lkml , Pavel Machek In-Reply-To: References: Content-Type: text/plain Message-Id: <1098842129.12477.2.camel@sli10-desk.sh.intel.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Wed, 27 Oct 2004 09:55:30 +0800 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1687 Lines: 41 On Wed, 2004-10-27 at 09:32, Hiroshi 2 Itoh wrote: > > > Hi, > > acpi-devel-admin@lists.sourceforge.net wrote on 2004/10/26 13:50:57: > > > Hi, > > We suffer from PCI config space issue for a long time, which causes many > > system can't correctly resume. Current Linux mechanism isn't sufficient. > > Here is a another idea: > > Record all PCI writes in Linux kernel, and redo all the write after > > resume in order. The idea assumes Firmware will restore all PCI config > > space to the boot time state, which is true at least for IA32. > > > > I think a basic problem of current Linux device model is that there is no > effective message path from sibling devices to their root device. > Although the message direction from a root device to sibling devices is > natural from the viewpoint of device enumeration, the direction from > sibling devices to a root device is required for effective arbitration for > device configuration and power management. > > The Windows driver model uses the direction from sibling drivers to a root > bus driver mainly, i.e. sibling drivers are layered on a root bus driver. > While we need a kind of callback mechanism from PCI (sibling) devices to > PCI bus (root) device instead because their normal call interface is from a > root device to sibling devices. Hiro-san, I don't really understand why this is related with suspend/resume. Could you please explain it more clearly? Thanks, Shaohua - 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/