Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753621AbZLHK2J (ORCPT ); Tue, 8 Dec 2009 05:28:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753265AbZLHK2J (ORCPT ); Tue, 8 Dec 2009 05:28:09 -0500 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:54713 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753227AbZLHK2I (ORCPT ); Tue, 8 Dec 2009 05:28:08 -0500 Date: Tue, 8 Dec 2009 10:28:12 +0000 From: Mark Brown To: Brian Swetland Cc: Rebecca Schultz Zavin , Mike Lockwood , Linus Walleij , cbou@mail.ru, dwmw2@infradead.org, LKML , linux-embedded@vger.kernel.org Subject: Re: [POWER] battery calibration parameters from sysfs Message-ID: <20091208102812.GC28378@rakim.wolfsonmicro.main> References: <20091204104930.GA28625@sirena.org.uk> <20091207114825.GA26965@rakim.wolfsonmicro.main> <20091207165628.GA24981@rakim.wolfsonmicro.main> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Cookie: Check your local listings. User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1608 Lines: 28 On Mon, Dec 07, 2009 at 09:27:20PM -0800, Brian Swetland wrote: > On Mon, Dec 7, 2009 at 8:56 AM, Mark Brown > > I don't think the existing Android devices are much of an issue here, > > it's not as though end users have the ability modify the firmware on > > them (modulo the fairly small number of ADP devices). ?This is an issue > > for people producing new devices who are already going to be doing some > > development to get the kernel up and running on their hardware. > My preference, from an Android point of view, would be to make sure we > have some reasonable userspace abstraction and provide a default > implementation that will do the right thing with an intelligent > battery driver (our usual design for inhouse work). Then alternative > implementations can be plugged in, should that not be sufficient. It proably makes sense to have some of the performance tracking in there by default - while there are some systems out there which are able to do high quality battery tracking there's several previous generations of monitoring technology out there which have substantial accuracy issues (especially in the face of removable battery packs) but which will report information to userspace. This makes it unwise to rely to totally on the information you're getting from the kernel - the smartness of a smart battery driver can vary greatly. -- 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/