From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753328AbZEULzY (ORCPT ); Thu, 21 May 2009 07:55:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752866AbZEULzN (ORCPT ); Thu, 21 May 2009 07:55:13 -0400 Received: from mailservice.tudelft.nl ([130.161.131.5]:6013 "EHLO mailservice.tudelft.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752484AbZEULzM (ORCPT ); Thu, 21 May 2009 07:55:12 -0400 X-Spam-Flag: NO X-Spam-Score: -12.589 Message-ID: <4A15411F.3050704@tremplin-utc.net> Date: Thu, 21 May 2009 13:55:11 +0200 From: =?windows-1252?Q?=C9ric_Piel?= User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.21) Gecko/20090319 Mandriva/2.0.0.21-1mdv2009.1 (2009.1) Thunderbird/2.0.0.21 Mnenhy/0.7.5.0 MIME-Version: 1.0 To: Pavel Machek Cc: Andrew Morton , LKML Subject: Re: [PATCH 2/4] lis3: remove automatic shutdown of the device References: <4A151E9F.1080405@tremplin-utc.net> <4A151F52.3050908@tremplin-utc.net> <20090521113618.GF2637@elf.ucw.cz> In-Reply-To: <20090521113618.GF2637@elf.ucw.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Op 21-05-09 13:36, Pavel Machek schreef: > Hi! > >> After measurement on my laptop, it seems that turning off the device >> does not bring any energy saving (within 0.1W precision). So let's keep >> the device always on. It simplifies the code, and it avoids the problem >> of reading a wrong value sometimes just after turning the device on. > > Well, 0.1W is still quite much for cellphone etc... but as we do not > have any such small users in the tree, I guess this can go in... > Yes. BTW, what I meant is that the power consumption on my laptop can be read with 0.1W precision. Turning on and off the device showed 0.0W variations. The device should using even much less than 0.1W. According to the documentation, it's about 2.2mW when on and 3µW when off. Eric