From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764610AbXGUTtG (ORCPT ); Sat, 21 Jul 2007 15:49:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752738AbXGUTsy (ORCPT ); Sat, 21 Jul 2007 15:48:54 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:60582 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753324AbXGUTsx (ORCPT ); Sat, 21 Jul 2007 15:48:53 -0400 Date: Sat, 21 Jul 2007 21:49:06 +0200 From: Pavel Machek To: david@lang.hm Cc: Jeremy Maitin-Shepard , "Rafael J. Wysocki" , Alan Stern , LKML , Andrew Morton , "Eric W. Biederman" , "Huang, Ying" , Kyle Moffett , Nigel Cunningham , pm list , Al Boldi Subject: Re: Hibernation considerations Message-ID: <20070721194906.GC3701@elf.ucw.cz> References: <200707171802.30903.rjw@sisk.pl> <200707172150.44417.rjw@sisk.pl> <20070721102520.GE1902@elf.ucw.cz> <87ps2lojlc.fsf@jbms.ath.cx> <20070721175639.GA3701@elf.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > >>>So it will be break at least battery status and "AC plugged in" > >>>status, because those are handled by ACPI and we do not know how to > >>>control them by hand. > >> > >>It seems that it should be possible to initialize ACPI as if the system > >>just booted up normally. Then battery status and such should be > >>correct, since they are correct after normal initialization. > >> > >>It should be possible to make hibernate look just like a reboot to all > >>of the devices, including ACPI stuff. > > > >Patch to make that work with swsusp/shutdown method would be indeed > >welcome. It does not work today. > > is this a problem in the restore path? > > with the kexec approach (and ignoring suspend to ram and disk for the > moment) the system will actually get shutdown completely after the image > is written. on resume it gets cold booted. at this point the ACPI stuff > should have no problem > > now if the ACPI drivers are storing something in ram about the battery > status and AC power status, but don't re-check after the resume, it >seems That seems to be the problem. They store something in ram, and we don't tell them that we resumed. That's why platform mode is important, and way to go on ACPI systems. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html