From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Milgram Subject: Screen extremely dim on Dell Latitude D630 after upgrading to Linux kernel-3.14 Date: Thu, 22 May 2014 16:17:49 -0400 Message-ID: <537E5B6D.1030408@redhat.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1948843307==" Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTP id 92B576ECE9 for ; Thu, 22 May 2014 13:17:55 -0700 (PDT) Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s4MKHtj3016302 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 22 May 2014 16:17:55 -0400 Received: from delos.home (vpn-230-119.phx2.redhat.com [10.3.230.119]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s4MKHsWv005917 for ; Thu, 22 May 2014 16:17:54 -0400 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org This is a multi-part message in MIME format. --===============1948843307== Content-Type: multipart/alternative; boundary="------------090601030405000602030309" This is a multi-part message in MIME format. --------------090601030405000602030309 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit After upgrading to linux Kernel-3.14, the screen on my Dell Latitude D630 was nearly unreadably dim. When I Boot the 3.13 kernel, my screen is bright. I opened a Bug here: https://bugzilla.redhat.com/show_bug.cgi?id=1094066 and others have chimed in that they have the same problem. I bisected the kernel, and found the following commit is responsible for this problem: b35684b8fa94e04f55fd38bf672b737741d2f9e2 is the first bad commit commit b35684b8fa94e04f55fd38bf672b737741d2f9e2 Author: Jani Nikula > Date: Thu Nov 14 12:13:41 2013 +0200 drm/i915: do full backlight setup at enable time We should now have all the information we need to do a full initialization of the backlight registers. v2: Keep QUIRK_NO_PCH_PWM_ENABLE for now (Imre). Signed-off-by: Jani Nikula > Reviewed-by: Imre Deak > Signed-off-by: Daniel Vetter > :040000 040000 0aae5515ca62ff1bfd2e1c2769e30c58b016ffeb 01c2f8cd145f8cf29730908d52e7e89b787a059e M drivers I can find my way around the kernel, but haven't hit this area before. Any help is appreciated. Marc Milgram --------------090601030405000602030309 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit After upgrading to linux Kernel-3.14, the screen on my Dell Latitude D630 was nearly unreadably dim. When I Boot the 3.13 kernel, my screen is bright.

I opened a Bug here: https://bugzilla.redhat.com/show_bug.cgi?id=1094066 and others have chimed in that they have the same problem.

I bisected the kernel, and found the following commit is responsible for this problem:

b35684b8fa94e04f55fd38bf672b737741d2f9e2 is the first bad commit
commit b35684b8fa94e04f55fd38bf672b737741d2f9e2
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Thu Nov 14 12:13:41 2013 +0200

    drm/i915: do full backlight setup at enable time
    
    We should now have all the information we need to do a full
    initialization of the backlight registers.
    
    v2: Keep QUIRK_NO_PCH_PWM_ENABLE for now (Imre).
    
    Signed-off-by: Jani Nikula <jani.nikula@intel.com>
    Reviewed-by: Imre Deak <imre.deak@intel.com>
    Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

:040000 040000 0aae5515ca62ff1bfd2e1c2769e30c58b016ffeb 01c2f8cd145f8cf29730908d52e7e89b787a059e M	drivers

I can find my way around the kernel, but haven't hit this area before.

Any help is appreciated.

Marc Milgram

--------------090601030405000602030309-- --===============1948843307== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx --===============1948843307==--