From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: Bug Report - [Acer Aspire V5-122P] Unable to adjust screen brightness Date: Fri, 23 May 2014 09:34:47 +0800 Message-ID: <537EA5B7.9050509@intel.com> References: <537BFF89.9010806@intel.com> <537C9DC5.5040408@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com ([192.55.52.93]:59429 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750990AbaEWBfV (ORCPT ); Thu, 22 May 2014 21:35:21 -0400 In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Lewis Toohey Cc: linux-acpi@vger.kernel.org, Hans de Goede On 05/21/2014 09:02 PM, Lewis Toohey wrote: > Hi Aaron > > I followed your instructions and can report some limited success. I > have two interfaces listed in /sys/class/backlight namely: > acpi_video0 radeon_bl0 > > max_brightness for acpi_video0 is 11. Echo-ing new values to > brightness appears to have no effect. > > max_brightness for radeon_bl0 is 255. Echo-ing new values to > brightness does adjust the screen brightness as you would expect. > > Results are the same on both battery and powered. > > I hope that is useful. I think Hans' patchset should solve your problem, can you please give it a try? You will need to pass the video.use_native_backlight=1 to kernel cmdline when testing, thanks. [PATCH resend 0/4] Make video.use_native_backlight=1 work properly with nouveau http://www.spinics.net/lists/dri-devel/msg59941.html -Aaron