From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754693Ab2BQTht (ORCPT ); Fri, 17 Feb 2012 14:37:49 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:49470 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754563Ab2BQThr (ORCPT ); Fri, 17 Feb 2012 14:37:47 -0500 Date: Fri, 17 Feb 2012 19:37:42 +0000 From: Matthew Garrett To: Pavel Machek Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, lenb@kernel.org Subject: Re: [PATCH 1/3] ACPI: Provide config option to disable BIOS brightness changes on power events Message-ID: <20120217193742.GA11132@srcf.ucam.org> References: <1328282293-16551-1-git-send-email-mjg@redhat.com> <20120217192704.GB2707@elf.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120217192704.GB2707@elf.ucw.cz> User-Agent: Mutt/1.5.20 (2009-06-14) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@cavan.codon.org.uk X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 17, 2012 at 08:27:04PM +0100, Pavel Machek wrote: > Hi! > > > The default ACPI behaviour is to instruct the BIOS to automatically change > > brightness on power events. This may be undesirable for distributions who > > manage brightness in userspace. Provide a config option that disables this > > behaviour and leaves brightness control up to the OS. > > Should this be configured during runtime? > > Like... when userspace power management starts, it disables this? This is ACPI-specific. It's not emulated by any of the other backlight drivers. There's no terribly easy way to have generic userspace handle it. -- Matthew Garrett | mjg59@srcf.ucam.org