From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marco Chiappero Subject: Re: Commit 7751ab8e600f26e10c2ba12a92d48a4852a51da8 Date: Wed, 13 Apr 2011 18:50:34 +0200 Message-ID: <4DA5D45A.9070901@absence.it> References: <4D9B4094.4010609@absence.it> <20110412152009.GA32032@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from aa013-1msr.fastwebnet.it ([62.101.93.133]:39368 "EHLO aa013-1msr.fastwebnet.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756155Ab1DMQui (ORCPT ); Wed, 13 Apr 2011 12:50:38 -0400 In-Reply-To: <20110412152009.GA32032@srcf.ucam.org> Sender: platform-driver-x86-owner@vger.kernel.org List-ID: To: Matthew Garrett Cc: platform-driver-x86@vger.kernel.org, Javier Achirica , Mattia Dongili Il 12/04/2011 17:20, Matthew Garrett ha scritto: > Hmm. How low is useful? There's no real problem with shifting everything > by an offset. I agree. The DSDT of any ALS equipped Vaio provides us 9 backlight levels (that are LCD/model specific), so the first and the last ones define our useful operating range, which is always different from 0-255 (eg. 13-255 for the Vaio S, 52-255 for the Vaio F, 7-182 for the Vaio Z, 7-213 for the Vaio TT and so on). However the code to retrieve and use those lower and upper bounds is still lacking upstream (I, Javier Achirica and many other people are testing a heavily modified sony-laptop.c written by us which includes lots of features that we might include soon, but there is no patchset yet). Moreover it is questionable whether to expose this "wire-range"/fine grain backlight device, which is intended to be used for an ambient light based regulation (that requires smooth transitions and sometimes minimal changes), while for normal backlight operations the 9 levels already mentioned should suffice. Regards, Marco Chiappero