Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751948AbaKCKeZ (ORCPT ); Mon, 3 Nov 2014 05:34:25 -0500 Received: from mga14.intel.com ([192.55.52.115]:55158 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751547AbaKCKeY convert rfc822-to-8bit (ORCPT ); Mon, 3 Nov 2014 05:34:24 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,307,1413270000"; d="scan'208";a="615933691" From: Jani Nikula To: Ortwin =?utf-8?Q?Gl=C3=BCck?= , "linux-kernel\@vger.kernel.org" , "intel-gfx\@lists.freedesktop.org" Subject: Re: [drm] 3.18 regression: backlight dark after resume In-Reply-To: <5454E2F3.2060404@odi.ch> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <5454E2F3.2060404@odi.ch> User-Agent: Notmuch/0.18.2+151~g6d88668 (http://notmuchmail.org) Emacs/24.3.1 (x86_64-pc-linux-gnu) Date: Mon, 03 Nov 2014 12:34:15 +0200 Message-ID: <87wq7ch8t4.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 01 Nov 2014, Ortwin Glück wrote: > 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 See https://bugs.freedesktop.org/show_bug.cgi?id=80773 (please ignore comments up to #10 or so). Please attach dmesg with drm.debug=14 module parameter set, from boot to suspend/resume and the problem, running the debug patch from comment #18. Preferrably please attach the dmesg on the bug to keep everything in one place. Thanks, Jani. -- Jani Nikula, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/