From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH] implement pm_ops.valid for everybody Date: Sat, 24 Mar 2007 01:01:47 +0100 Message-ID: <20070324000147.GC14427@elf.ucw.cz> References: <200703221344.l2MDi2Q9007989@olwen.urbana.css.mot.com> <200703231443.19536.rjw@sisk.pl> <200703231057.16539.david-b@pacbell.net> <200703232139.38721.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <200703232139.38721.rjw@sisk.pl> 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: "Rafael J. Wysocki" Cc: alexey.y.starikovskiy@intel.com, dirk.behme@de.bosch.com, linux-pm@lists.linux-foundation.org, johannes@sipsolutions.net, nico@cam.org, ben@simtec.co.uk, g.liakhovetski@gmx.de List-Id: linux-pm@vger.kernel.org Hi! (I do not want to get into this flamewar). > > That's a false choice, when you "mean" anything more than > > fairly broad behavioral expectations: STR saves more power > > than "standby", and transitions to/from STR take more > > time than to/from "standby". > = > So be it. > = > Assume that the user does 'echo standby > /sys/power/state'. I think he = can > expect that in such a case we'll freeze tasks and put devices into low-po= wer > states and when he wakes up the system (BTW, I think the method of waking > up can be treated as a differentiating factor) he should be able to conti= nue > from where he stopped after a little time. Fine. > = > Now, we have to make that happen. After we have frozen tasks, we need to > call something like device_suspend(some_argument) where the argument shou= ld > tell drivers what to do. Say we use something like PMSG_STANDBY and now We would add another field to that struct, distingushing "mem" and "standby". And meaning for the drivers would be "try to save a lot of power, but keep the latency low" for standby, vs. "save as much power as possible" for mem. Pavel -- = (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html