From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH 3/3] acpi-video: change acpi-video brightness_switch_enabled default to 0 Date: Tue, 06 May 2014 14:46:17 +0200 Message-ID: <5368D999.9080700@redhat.com> References: <1399282690-5381-1-git-send-email-hdegoede@redhat.com> <1399282690-5381-3-git-send-email-hdegoede@redhat.com> <53684260.1050806@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:5428 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757646AbaEFMq3 (ORCPT ); Tue, 6 May 2014 08:46:29 -0400 In-Reply-To: <53684260.1050806@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Aaron Lu , Zhang Rui , "Rafael J. Wysocki" , Len Brown Cc: edm , Balint Szigeti , AnAkkk , lou.cardone@gmail.com, linux-acpi@vger.kernel.org Hi, On 05/06/2014 04:01 AM, Aaron Lu wrote: > On 05/05/2014 05:38 PM, Hans de Goede wrote: >> acpi-video is unique in that it not only generates brightness up/down >> keypresses, but also (sometimes) actively changes the brightness itself. >> >> This presents an inconsistent kernel interface to userspace, basically there >> are 2 different scenarios, depending on the laptop model: >> >> 1) On some laptops a brightness up/down keypress means: show a brightness osd >> with the current brightness, iow it is a brightness has changed notification. >> >> 2) Where as on (a lot of) other laptops it means a brightness up/down key was >> pressed, deal with it. >> >> Most of the desktop environments interpret any press as in scenario 2, and >> change the brightness up / down as a response to the key events, causing it >> to be changed twice, once by acpi-video and once by the DE. >> >> With the new default for video.use_native_backlight we will be moving even >> more laptops over to behaving as in scenario 2. Making the remaining laptops >> even more of a weird exception. Also note that it is hard to detect scenario >> 1 properly in userspace, and AFAIK none of the DE-s deals with it. >> >> Therefor this commit changes the default of brightness_switch_enabled to 0 >> making its behavior consistent with all the other backlight drivers. >> >> Signed-off-by: Hans de Goede > > Reviewed-by: Aaron Lu > > Note that the Documentation/kernel-parameters.txt has to be modified > accordingly to change the default value for video.brightness_switch_enabled > to 0. Good one, I'll send a v2 with this fixed. Regards, Hans