Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759538Ab0HDXlL (ORCPT ); Wed, 4 Aug 2010 19:41:11 -0400 Received: from mail.lang.hm ([64.81.33.126]:46912 "EHLO bifrost.lang.hm" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759508Ab0HDXlH (ORCPT ); Wed, 4 Aug 2010 19:41:07 -0400 Date: Wed, 4 Aug 2010 16:39:58 -0700 (PDT) From: david@lang.hm X-X-Sender: dlang@asgard.lang.hm To: "Rafael J. Wysocki" cc: =?ISO-8859-15?Q?Arve_Hj=F8nnev=E5g?= , "Paul E. McKenney" , Arjan van de Ven , "Ted Ts'o" , linux-pm@lists.linux-foundation.org, linux-kernel , mjg59@srcf.ucam.org, pavel@ucw.cz, florian@mickler.org, stern@rowland.harvard.edu, swetland@google.com, peterz@infradead.org, tglx@linutronix.de, alan@lxorguk.ukuu.org.uk Subject: Re: Attempted summary of suspend-blockers LKML thread In-Reply-To: <201008050126.20812.rjw@sisk.pl> Message-ID: References: <20100801210548.23f77ff6@infradead.org> <201008042231.51901.rjw@sisk.pl> <201008050126.20812.rjw@sisk.pl> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1908 Lines: 43 On Thu, 5 Aug 2010, Rafael J. Wysocki wrote: > On Thursday, August 05, 2010, david@lang.hm wrote: >> On Wed, 4 Aug 2010, Rafael J. Wysocki wrote: >> >>> Subject: Re: Attempted summary of suspend-blockers LKML thread >>> >>> On Wednesday, August 04, 2010, david@lang.hm wrote: >>>> On Wed, 4 Aug 2010, Rafael J. Wysocki wrote: >>>>> In the suspend case, when you have frozen all applications, you can >>>>> sequentially disable all interrupts except for a few selected ("wakeup") ones >>>>> in a safe way. By disabling them, you ensure that the CPU will only be >>>>> "revived" by a limited set of events and that allows the system to stay >>>>> low-power for extended time intervals. >>>> >>>> the benifit of this will depend on what wakeups you are able to avoid by >>>> putting the hardware to sleep. Depending on the hardware, this may be not >>>> matter that much. >>> >>> That's correct, but evidently it does make a difference with the hardware >>> Android commonly runs on. >> >> Ok, but is there a way to put some of this to sleep without involving a >> full suspend? > > Technically, maybe, but we have no generic infrastructure in the kernel for that. > There may be SoC-specific implementations, but nothing general enough. well, I know that we have specific cases of this (drive spin-down, cpu speed, display backlight for a few examples), is it worth trying to define a generic way to do this sort of thing? or should it be left as a per-device thing (with per-device knobs to control it) I thought I had seen discussion on how to define such a generic power management interface, and I thought the results had been acceptable. David Lang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/