From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Meyer Subject: Re: 2.6.38-rc2: acpi backlight control missing Date: Fri, 28 Jan 2011 22:12:05 +0100 Message-ID: <1296249125.2006.7.camel@localhost.localdomain> References: <1295693349.2120.3.camel@localhost.localdomain> <201101222043.07703.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201101222043.07703.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" , rui.zhang@intel.com, len.brown@intel.com Cc: Linux Kernel Mailing List , ACPI Devel Mailing List List-Id: linux-acpi@vger.kernel.org Am Samstag, den 22.01.2011, 20:43 +0100 schrieb Rafael J. Wysocki: > On Saturday, January 22, 2011, Thomas Meyer wrote: > > with 2.6.38-rc2 the acpi backlight is gone: > > > > any ideas? > > Not really, but Matthew may have some (CCed). Okay, found the problem. This commit broke my backlight: commit 677bd810eedce61edf15452491781ff046b92edc Author: Zhang Rui Date: Mon Dec 6 15:04:21 2010 +0800 ACPI video: remove output switching control This is because in function "acpi_is_video_device()" (drivers/acpi/video_detect.c) the backlight device is only checked when some video capabilities were found, but by removing the check for the VIDEO_OUTPUT_SWITCHING (that seems to be the only video capability on my system) the check for the backlight device isn't done anymore. by reverting above commit, the backlight is back again. kind regards thomas