From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759397AbaKANlR (ORCPT ); Sat, 1 Nov 2014 09:41:17 -0400 Received: from fep12.mx.upcmail.net ([62.179.121.32]:40809 "EHLO fep12.mx.upcmail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758036AbaKANlQ (ORCPT ); Sat, 1 Nov 2014 09:41:16 -0400 X-SourceIP: 2001:470:25:65c::2 X-Authenticated-Sender: odi.ch@hispeed.ch Message-ID: <5454E2F3.2060404@odi.ch> Date: Sat, 01 Nov 2014 14:41:07 +0100 From: =?UTF-8?B?T3J0d2luIEdsw7xjaw==?= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: "linux-kernel@vger.kernel.org" , Jani Nikula Subject: [drm] 3.18 regression: backlight dark after resume Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Since 3.18-rc1 backlight is dark after resume from suspend. This is on a Samsung laptop with i5 IvyBridge 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) I have bisected this problem to the following commit: 73580fb764c4213d305c0d36bd8f856ae631eb42 is the first bad commit commit 73580fb764c4213d305c0d36bd8f856ae631eb42 Author: Jani Nikula Date: Tue Aug 12 17:11:41 2014 +0300 drm/i915/dp: make backlight bl_power control power sequencer backlight This lets the userspace switch off the backlight using the backlight class sysfs bl_power file. The switch is done using the power sequencer; the backlight PWM, and everything else, remains enabled. The display backlight won't draw power, but for maximum power savings the encoder needs to be switched off. Signed-off-by: Jani Nikula Reviewed_by: Clinton Taylor Tested_by: Clinton Taylor Signed-off-by: Daniel Vetter Thanks, Ortwin