From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759320AbYDAXBB (ORCPT ); Tue, 1 Apr 2008 19:01:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753227AbYDAXAv (ORCPT ); Tue, 1 Apr 2008 19:00:51 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:49036 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752285AbYDAXAu (ORCPT ); Tue, 1 Apr 2008 19:00:50 -0400 From: "Rafael J. Wysocki" To: Nigel Cunningham Subject: Re: [RFC][PATCH] PM: Introduce new top level suspend and hibernation callbacks (rev. 6) Date: Wed, 2 Apr 2008 01:00:13 +0200 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: pm list , ACPI Devel Maling List , Alan Stern , Greg KH , Len Brown , LKML , Alexey Starikovskiy , David Brownell , Pavel Machek , Benjamin Herrenschmidt , Oliver Neukum References: <200803292317.50218.rjw@sisk.pl> <200804012357.30529.rjw@sisk.pl> <1207089138.23143.117.camel@nigel-laptop> In-Reply-To: <1207089138.23143.117.camel@nigel-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200804020100.14962.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, 2 of April 2008, Nigel Cunningham wrote: > Hi. > > On Tue, 2008-04-01 at 23:57 +0200, Rafael J. Wysocki wrote: > > On Tuesday, 1 of April 2008, Nigel Cunningham wrote: > > > Hi Rafael etc. > > > > > > On Tue, 2008-04-01 at 22:12 +0200, Rafael J. Wysocki wrote: [--snip--] > > > > > > > > > + * However, drivers may NOT assume anything about the availability of the > > > > > > + * user space at that time and it is not correct to request firmware from > > > > > > + * within @prepare() (it's too late to do that). > > > > > > > > > > That doesn't sound good. It would be good to be able to get drivers to > > > > > request firmware early in the process. > > > > > > > > That will be possible when we drop the freezer. > > > > > > Yeah, but right now, it seems to me to be a bogus limitation for drivers > > > to have no way of automatically loading firmware when you're about to > > > hibernate. (Of course I've since been reminded of the notifier chain - > > > that should probably be mentioned here as the way of achieving this). > > > > This is a tricky stuff, though, because the notifier is used for disabling the > > user mode helpers too ... > > Hmm. Yet another notifier? Well, perhaps it's better to disable user mode helpers directly from freeze_processes(). Still, let's do one thing at a time. :-) > > > By the way, I'm going to go on record now as saying I think dropping the > > > freezer is a silly idea. I'm therefore currently considering including > > > the freezer in TuxOnice from the time it gets dropped from mainline. I > > > know that will only make it less likely that TuxOnIce gets merged, but > > > I've given up caring about that anyway - caring about merging is > > > pointless when the people who decide if it gets merged don't care. > > > > Well, I'm just not sure if dropping the freezer entirely will actually work, > > but we won't know that if we don't try. > > > > There's been a lot of pressure on going into this direction recently and > > in principle it seems to be doable at least for suspend. Hibernation is > > another issue, but IMO it's better to focus on suspend first. > > For suspend, I agree with dropping its use. For hibernation... I'm not sure and that's why I added the comment about the availability of the user space during ->prepare(). Besides, for now, the freezer is necessary anyway, even for suspend. Thanks, Rafael