From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Purdie Subject: Re: [PATCH 2/2] video: mark "actual_brightness" deprecated Date: Tue, 30 Dec 2008 10:37:17 +0000 Message-ID: <1230633437.5328.13.camel@dax.rpnet.com> References: <1230088061.562.220.camel@rzhang-dt> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from 93-97-173-237.zone5.bethere.co.uk ([93.97.173.237]:64108 "EHLO tim.rpsys.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751729AbYL3LGH (ORCPT ); Tue, 30 Dec 2008 06:06:07 -0500 In-Reply-To: <1230088061.562.220.camel@rzhang-dt> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Zhang Rui Cc: linux-acpi , Len Brown On Wed, 2008-12-24 at 11:07 +0800, Zhang Rui wrote: > /sys/class/backlight/.../brightness returns a cached value, > which confuses a lot of users. > > Make the "brightness" reflect the actual backlight levels, > and mark /sys/class/backlight/.../brightness as depreacated > in this patch. This isn't an acceptable approach I'm afraid. We have some hardware which needs limiting of the backlight brightness in cases of low battery for example. "brightness" is the user requested value, "actual_brightness" is the one that is actually active. This also makes it clear when things like console blanking are active since the actual value is 0 but brightness preserves the user requested value. Cheers, Richard -- Richard Purdie Intel Open Source Technology Centre