From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932376AbZHVJ2w (ORCPT ); Sat, 22 Aug 2009 05:28:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754821AbZHVJ2v (ORCPT ); Sat, 22 Aug 2009 05:28:51 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:43631 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753721AbZHVJ2u (ORCPT ); Sat, 22 Aug 2009 05:28:50 -0400 Date: Sat, 22 Aug 2009 11:28:45 +0200 From: Pavel Machek To: Mark Brown Cc: Felipe Balbi , Liam Girdwood , Mike Rapoport , linux-kernel@vger.kernel.org Subject: Re: Smart Battery System Design (was: Re: Question about userspace-consumer) Message-ID: <20090822092845.GE11448@elf.ucw.cz> References: <20090810215800.GB4528@sirena.org.uk> <20090811054438.GA7176@gandalf> <20090811094020.GA6762@rakim.wolfsonmicro.main> <1249986616.5807.28.camel@odin> <20090811204914.GB13969@gandalf> <20090811223645.GA4691@sirena.org.uk> <20090814163201.GB1626@ucw.cz> <20090815164324.GA4252@sirena.org.uk> <20090815223434.GB27637@elf.ucw.cz> <20090816091858.GB12567@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090816091858.GB12567@sirena.org.uk> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > Ok, well... anyway many machines _want_ fastcharge while suspended, > > and putting charging into userland would break them (or make that > > fairly difficult). > > Are you sure that's a real need? Disabling user interaction I can see > but forcing the system into sleep doesn't seem to be any particular > benefit - devices like this tend to be designed to appear to be always > on and clearly when fast charging there's no need to save power > > which is At least zaurus sl-3000c is designed like a notebook -- inactive in s2ram. It is quite old design. Charging while suspended is preffered, because it allows faster charge. The machine eats non-trivial power while active, charger is only 1A, and there's not enough current left for a charge with machine active. > the main motiviation for going into suspend. Also bear in mind that a > soft SBS system requires constant activity from the CPU for basic > management of the charge cycle so suspend isn't going to be a real > option anyway, you'd be suspending for seconds at a time. Well, if the code is to be useful for something else than SBS... (And suspending for seconds at a time is okay on zaurus type machines). Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html