From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756091AbXGQOdR (ORCPT ); Tue, 17 Jul 2007 10:33:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752377AbXGQOdF (ORCPT ); Tue, 17 Jul 2007 10:33:05 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:48478 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752144AbXGQOdC (ORCPT ); Tue, 17 Jul 2007 10:33:02 -0400 From: "Rafael J. Wysocki" To: Alan Stern Subject: Re: Hibernation considerations Date: Tue, 17 Jul 2007 16:40:38 +0200 User-Agent: KMail/1.9.5 Cc: david@lang.hm, LKML , Andrew Morton , "Eric W. Biederman" , "Huang, Ying" , Jeremy Maitin-Shepard , Kyle Moffett , Nigel Cunningham , Pavel Machek , pm list , Al Boldi References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707171640.39955.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, 17 July 2007 16:15, Alan Stern wrote: > On Mon, 16 Jul 2007 david@lang.hm wrote: > > > > I agree, it would be good to have a non-ACPI-specific hibernation mode, > > > something which would look to ACPI like a normal shutdown. But I'm not > > > so sure this is possible. > > > > why would it not be possible? > > > I can't think of anything much more frustrating then thinking that I > > suspended a system and then discovering that becouse the battery went dead > > (a complete power loss) that the system wouldn't boot up properly. to me > > this would be a fairly common condition (when I'm mobile I use the machine > > until I am out of battery, then stop and it may be a long time (days) > > before I can charge the thing up again) this would not be a reliable > > suspend as far as I'm concerned. > > > > for suspend-to-ram you have to worry about ACPI states and what you are > > doing with them, for suspend-to-disk you can ignore them and completely > > power the system off instead. > > If the only problem with doing this would be lack of wakeup support > then I'm all for it. There must be a lot of people who would like > their computers to hibernate with power drain as close to 0 as possible > and who don't care about remote wakeup. In fact they might even prefer > not to have wakeup support, so the computer doesn't resume at > unexpected times. I'm afraid of one thing, though. If we create a framework without ACPI (well, ACPI needs to be enabled in the kernel anyway for other reasons, like the ability to suspend to RAM) and then it turns out that we have to add some ACPI hooks to it, that might be difficult to do cleanly. Thus, it seems reasonable to think of the ACPI handling in advance. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth