From aed3f09db39596e539f90b11a5016aea4d8442e1 Mon Sep 17 00:00:00 2001
From: Alban Browaeys <prahal@yahoo.com>
Date: Fri, 24 Feb 2012 17:12:45 +0000
Subject: [PATCH] drm/i915: Prevent a machine hang by checking crtc->active
 before loading lut

Before loading the lut (gamma), check the active state of intel_crtc,
otherwise at least on gen2 hang ensue.

This is reproducible in Xorg via:
  xset dpms force off
then
  xgamma -rgamma 2.0 # freeze.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44505
Signed-off-by: Alban Browaeys <prahal@yahoo.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: stable@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
Reading git-format-patch failed