drm/i915: restore QUIRK_NO_PCH_PWM_ENABLE

This reverts the bisected regressing

commit bc0bb9fd1c
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Thu Nov 14 12:14:29 2013 +0200

    drm/i915: remove QUIRK_NO_PCH_PWM_ENABLE

restoring QUIRK_NO_PCH_PWM_ENABLE for a couple of Dell XPS models which
broke in 3.14.

There is no such revert upstream. We have root caused and fixed the
issue upstream, without the quirk, with:

commit 39fbc9c8f6
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Apr 9 11:22:06 2014 +0300

    drm/i915: check VBT for supported backlight type

and

commit c675949ec5
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Apr 9 11:31:37 2014 +0300

    drm/i915: do not setup backlight if not available according to VBT

While the commits are within the stable rules otherwise, and fix more
machines than just the regressed Dell XPS models, we feel backporting
them to stable may be too risky. The revert is limited to the broken
machines, and the impact should be effectively the same as what the
upstream commits do more generally.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76276
Reported-by: Romain Francoise <romain@orebokech.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Tested-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Romain Francoise <romain@orebokech.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jani Nikula 2014-04-28 13:10:07 +03:00 • committed by Greg Kroah-Hartman
commit e4b2de2daa
3 changed files with 21 additions and 0 deletions