From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [linux-pm] Runtime PM discussion notes Date: Sat, 9 Jul 2011 05:06:22 +0100 Message-ID: <20110709040622.GH26900@sirena.org.uk> References: <201106232234.21930.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cassiel.sirena.org.uk ([80.68.93.111]:48471 "EHLO cassiel.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750702Ab1GIEGg (ORCPT ); Sat, 9 Jul 2011 00:06:36 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Paul Walmsley Cc: Arve Hj?nnev?g , "Rafael J. Wysocki" , Alan Stern , linux-pm@lists.linux-foundation.org, linux-omap@vger.kernel.org, Magnus Damm , Kevin Hilman On Tue, Jun 28, 2011 at 01:47:47PM -0600, Paul Walmsley wrote: > On Fri, 24 Jun 2011, Arve Hj?nnev?g wrote: > > On Fri, Jun 24, 2011 at 12:53 PM, Paul Walmsley wrote: > > > "On the hardware that shipped we enter the same power state from idle > > > and suspend, so the only power savings we get from suspend that we > > > don't get in idle is from not respecting the scheduler and timers." > > This is no longer the case. Both the Nexus-S and Xoom enter lower > > power states from suspend than idle. > Just out of curiosity, is that due to some kind of hardware limitation on > those platforms, or is it because the software infrastructure for dynamic > deep idle hasn't been fully implemented in that subarchitecture code? At least the Nexus S doesn't implmeent any of the deep idle infrastructure. However, I'd expect that you can achieve some power saving from entering system suspend as if *everything* is off then the PMIC can be suspended which can enable additional power savings. Unless I'm missing something that'd be hard to hit with cpuidle only stuff.