drm/i915: Disable crtcs gracefully before GPU reset on gen3/4

The GPU reset also resets the display on gen3/4. The g33 docs say we
should disable all planes before flipping the reset switch. Just
disable all the crtcs instead. That seems a nicer thing to do anyway.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 56664e63e10f..910df02840d6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2803,6 +2803,9 @@ static void intel_update_primary_planes(struct drm_device *dev)
 
 void intel_prepare_reset(struct drm_device *dev)
 {
+        struct drm_i915_private *dev_priv = to_i915(dev);
+        struct intel_crtc *crtc;
+
         /* no reset support for gen2 */
         if (IS_GEN2(dev))
                 return;
@@ -2812,6 +2815,15 @@ void intel_prepare_reset(struct drm_device *dev)
                 return;
 
         drm_modeset_lock_all(dev);
+
+        /*
+         * Disabling the crtcs gracefully seems nicer. Also the
+         * g33 docs say we should at least disable all the planes.
+         */
+        for_each_intel_crtc(dev, crtc) {
+                if (crtc->active)
+                        dev_priv->display.crtc_disable(&crtc->base);
+        }
 }
 
 void intel_finish_reset(struct drm_device *dev)