From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: selective wakeups Date: Tue, 3 Feb 2015 13:14:37 +0100 Message-ID: <20150203121437.GA26492@amd> References: <54D09AC7.5080503@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:33513 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750746AbbBCMOk (ORCPT ); Tue, 3 Feb 2015 07:14:40 -0500 Content-Disposition: inline In-Reply-To: <54D09AC7.5080503@collabora.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Tomeu Vizoso Cc: linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Derek Basehore , Javier Martinez Canillas Hi! > I'm looking at how to support wakeup sources that resume a subset of the > suspended devices. The goal is for the machine to be able to wakeup the > CPU but not the display or sound card when the wakeup source isn't > user-initiated, such as RTC or a network card (we can call it automatic > resume). > > http://www.chromium.org/chromium-os/packages/power_manager/suspend-and-resume#TOC-Dark-Resume > My first idea is for userspace to be able to configure via sysfs which > devices aren't going to be resumed when a given wakeup source fires. > We'll also need a way to resume the display and sound card if there's > user interaction when the system has resumed automatically. Well.. the web page describes quite different use case. Anyway... right solution would be not to resume devices that were runtime-suspended, no? With that, additional sysfs tweaks should not be needed? For the "periodically wakeup from S3 to prevent battery draining".. Some machines (Sharp Zaurus) already do similar tricks directly from kernel, and you may want to do the same. Battery completely draining when in S3 is quite bad situation, and preventing it even without userspace support would be good. Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html