From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH 1/2] video: always update the brightness when poking "brightness" Date: Wed, 31 Dec 2008 03:24:12 +0000 Message-ID: <20081231032412.GA25598@srcf.ucam.org> References: <1230088058.562.219.camel@rzhang-dt> <1230633250.5328.8.camel@dax.rpnet.com> <1230687781.562.249.camel@rzhang-dt> <20081231020146.GA24861@srcf.ucam.org> <1230692328.562.289.camel@rzhang-dt> <1230693119.562.300.camel@rzhang-dt> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:37977 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752327AbYLaDYR (ORCPT ); Tue, 30 Dec 2008 22:24:17 -0500 Content-Disposition: inline In-Reply-To: <1230693119.562.300.camel@rzhang-dt> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Zhang Rui Cc: Richard Purdie , linux-acpi , Len Brown On Wed, Dec 31, 2008 at 11:11:59AM +0800, Zhang Rui wrote: > On Wed, 2008-12-31 at 10:58 +0800, Zhang Rui wrote: > > always update pros.brightness no matter the backlight is changed > > via procfs, hotkeys or sysfs. > by the way, with this patch applied, we really don't need > "actual_brightness" any more, at least for ACPI backlight class I/F. > is there any chance that "actual_brightness" returns a different value > from "brightness"? Depending on _DOS, AC events can switch the backlight value without sending a notification. I don't /think/ it's worth worrying about that case, but it's still worth keeping the two attributes so that there's a consistent interface for userspace. -- Matthew Garrett | mjg59@srcf.ucam.org