commit 2a92d5bca1999b69c78f3c3e97b5484985b094b9
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Jul 8 10:40:29 2014 +0100

    drm/i915: Disable RCS flips on Ivybridge
    
    We currently see random GPU hangs when using RCS flips with multiple
    pipes on Ivybridge. Now that we have mmio flips, we can fairly cheaply
    fallback to using CPU driven flips instead.
    
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77104
    Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8043e4b..8728c88 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9658,6 +9658,8 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 
 	if (IS_VALLEYVIEW(dev)) {
 		ring = &dev_priv->ring[BCS];
+	} else if (IS_IVYBRIDGE(dev)) {
+		ring = &dev_priv->ring[BCS];
 	} else if (INTEL_INFO(dev)->gen >= 7) {
 		ring = obj->ring;
 		if (ring == NULL || ring->id != RCS)