From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [linux-pm] Re: [PATCH 2/2] Introduce CONFIG_SUSPEND (updated) Date: Tue, 31 Jul 2007 12:01:07 +0200 Message-ID: <200707311201.09384.rjw@sisk.pl> References: <200707251238.50218.lenb@kernel.org> <200707311115.29057.rjw@sisk.pl> <200707311116.39857.oliver@neukum.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from ogre.sisk.pl ([217.79.144.158]:57014 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752717AbXGaJwe (ORCPT ); Tue, 31 Jul 2007 05:52:34 -0400 In-Reply-To: <200707311116.39857.oliver@neukum.org> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Oliver Neukum Cc: linux-pm@lists.linux-foundation.org, Len Brown , david@lang.hm, Nigel Cunningham , linux-kernel@vger.kernel.org, Adrian Bunk , linux-acpi@vger.kernel.org, Stefan Richter , Pavel Machek , Andrew Morton , Linus Torvalds On Tuesday, 31 July 2007 11:16, Oliver Neukum wrote: > Am Dienstag 31 Juli 2007 schrieb Rafael J. Wysocki: > > > Well, the people on linux-pm seem to agree that the .suspend() and .resume() > > callbacks are not suitable for runtime power management, so having them > > built without SUSPEND or HIBERNATION wouldn't be very useful. ;-) > > These are what USB runtime power management uses. To be precise, I think the rule should be that if some code is needed for anything else than suspend/hibernation, it should be under plain CONFIG_PM. Still, if something is only needed for suspend/hibernation, it should go under CONFIG_PM_SLEEP or CONFIG_SUSPEND/HIBERNATION, depending on what it's needed for. Now, AFAICS, for the majority of drivers .suspend() and .resume() are only needed for suspend/hibernation and really should be used for suspending only (some other callbacks are needed for hibernation). > How many code paths for power management do you want to introduce? At least one more, for hibernation. That also depends on what approach to the runtime power management is widely accepted. For now, USB is in the vanguard. :-) Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth