From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756201AbZBBCGX (ORCPT ); Sun, 1 Feb 2009 21:06:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752969AbZBBCGO (ORCPT ); Sun, 1 Feb 2009 21:06:14 -0500 Received: from mail.crca.org.au ([67.207.131.56]:41471 "EHLO crca.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752907AbZBBCGN (ORCPT ); Sun, 1 Feb 2009 21:06:13 -0500 X-Bogosity: Ham, spamicity=0.000000 Subject: Re: [linux-pm] [PATCH 2/3] PCI PM: Let the core be more careful with respect to drivers using new framework From: Nigel Cunningham To: "Rafael J. Wysocki" Cc: Jesse Barnes , Linux PCI , pm list , Linus Torvalds , LKML In-Reply-To: <200902012233.17790.rjw@sisk.pl> References: <200902012229.27517.rjw@sisk.pl> <200902012233.17790.rjw@sisk.pl> Content-Type: text/plain Organization: Christian Reformed Churches of Australia Date: Mon, 02 Feb 2009 13:06:40 +1100 Message-Id: <1233540400.21871.7.camel@nigel-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rafael. Just a couple of typos in the comment: On Sun, 2009-02-01 at 22:33 +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Currently, the PM core always attempts to manage devices with drivers > that use the new PM framework. In particular, it attempts to disable > the devices (which is unnecessary), to save their state (which may be > undesirable if the driver has done that already) and to put them into > low power states (again, this may be undesirable if the driver has > already put the device into a low power state). That need not be > the right thing to do, so make the core be more careful in this > respect. > > Generally, there are the following categories of devices to consider: > * bridge devices without drivers > * non-bridge devices without drivers > * bridge devices with drivers > * non-bridge devices with drivers > and each of them should be handled differently. > > For bridge devices without drivers the PCI PM core will save their > state on suspend and restore it (early) during resume, after putting > them into D0 if necessary. It will not attepmt to do anything else s/attepmt/attempt/ > to these devices. > > For non-bridge devices without drivers the PCI PM core will disable > them and save their state on suspend. During resume, it will put > them into D0, if necessary, restore their state (early) and reenable > them. > > For bridge devices without drivers the PCI PM core will only save s/without/with/ > their state on suspend if the driver hasn't done that already. > Still, the core will restore their state (early) during resume, > after putting them into D0, if necessary. > > For non-bridge devices with drivers the PCI PM core will only save > their state on suspend if the driver hasn't done that already. Also, > if the state of the device hasn't been saved by the driver, the core > will attempt to put the device into a low power state. During > resume the core will restore the state of the device (early), after > putting it into D0, if necessary. > > For all devices the core will disable wake-up during resume. > > Signed-off-by: Rafael J. Wysocki I'm not pretending to understand the gory details of the code itself, and so don't want you to add a Reviewed-by or such like for me, thanks. Regards, Nigel