From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uli Luckas Subject: Re: [RFC][PATCH 00/11] Android PM extensions Date: Mon, 2 Feb 2009 17:24:29 +0100 Message-ID: <200902021724.30172.u.luckas@road.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: linux-pm@lists.linux-foundation.org Cc: Brian Swetland , Nigel Cunningham List-Id: linux-pm@vger.kernel.org On Monday, 2. February 2009, Alan Stern wrote: > On Mon, 2 Feb 2009, Uli Luckas wrote: > > On Sunday, 1. February 2009, Alan Stern wrote: > > > Early-suspend seems to be a completely different matter. =A0In fact it > > > isn't a suspend state at all, as far as I understand it. =A0It's more > > > like what you get simply by doing a runtime suspend on some collection > > > of devices. =A0I don't see that the kernel needs to treat it as a spe= cial > > > state, and in might be possible to have a user program manage the who= le > > > thing -- provided the drivers in question implement runtime power > > > management (as USB has done). > > > > > > Alan Stern > > > > Except you always want early-suspend and auto-suspend at the same time. > > The idea is, if all display of system states is off (early-suspend), we > > can enable or disable the cpu at will (auto-suspend) because nobody will > > notice. > > Why should the kernel have to get involved? Why can't userspace manage > both early-suspend and auto-suspend? > > That is, consider the following: Userspace initiates an early-suspend > by using a runtime PM interface to turn off the screen and some other > devices. After a short time, if they are still off, then userspace can > initiate an auto-suspend by writing "auto-mem" to /sys/power/state. > > All the kernel would need to know is the difference between > auto-suspend and normal suspend: one respects wakelocks and the other > doesn't. > Actually i don't know. Arve? Things would get a lot less complex if we could leave the early suspend stu= ff = out of the kernel. Uli -- = ------- ROAD ...the handyPC Company - - - ) ) ) Uli Luckas Head of Software Development ROAD GmbH Bennigsenstr. 14 | 12159 Berlin | Germany fon: +49 (30) 230069 - 62 | fax: +49 (30) 230069 - 69 url: www.road.de Amtsgericht Charlottenburg: HRB 96688 B Managing director: Hans-Peter Constien