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>
---
drivers/gpu/drm/i915/intel_display.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4871ba0..f851db7 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6184,7 +6184,7 @@ void intel_crtc_load_lut(struct drm_crtc *crtc)
int i;
/* The clocks have to be on to load the palette. */
- if (!crtc->enabled)
+ if (!crtc->enabled || !intel_crtc->active)
return;
/* use legacy palette for Ironlake */
--
1.7.7.6