drm/i915: Move DPINVGTT setup to vlv_display_irq_reset()

DPINVGTT lives inside the disp2d power well so we can't frob it unless
we know the power well is active. Let's this stuff into
vlv_display_irq_reset() which is only called at the right times so that
we don't get unclaimed register access errors.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94164
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460382992-28728-10-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>

drivers/gpu/drm/i915/i915_irq.c

@@ -3289,6 +3289,11 @@ static void vlv_display_irq_reset(struct drm_i915_private *dev_priv)
 {
 	enum pipe pipe;
 
+	if (IS_CHERRYVIEW(dev_priv))
+		I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK_CHV);
+	else
+		I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK);
+
 	i915_hotplug_interrupt_update_locked(dev_priv, 0xffffffff, 0);
 	I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
 
@@ -3352,8 +3357,6 @@ static void valleyview_irq_preinstall(struct drm_device *dev)
 
 	gen5_gt_irq_reset(dev);
 
-	I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK);
-
 	spin_lock_irq(&dev_priv->irq_lock);
 	if (dev_priv->display_irqs_enabled)
 		vlv_display_irq_reset(dev_priv);
@@ -3430,8 +3433,6 @@ static void cherryview_irq_preinstall(struct drm_device *dev)
 
 	GEN5_IRQ_RESET(GEN8_PCU_);
 
-	I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK_CHV);
-
 	spin_lock_irq(&dev_priv->irq_lock);
 	if (dev_priv->display_irqs_enabled)
 		vlv_display_irq_reset(dev_priv);
@@ -3717,12 +3718,6 @@ static int valleyview_irq_postinstall(struct drm_device *dev)
 
 	gen5_gt_irq_postinstall(dev);
 
-	/* ack & enable invalid PTE error interrupts */
-#if 0 /* FIXME: add support to irq handler for checking these bits */
-	I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK);
-	I915_WRITE(DPINVGTT, DPINVGTT_EN_MASK);
-#endif
-
 	spin_lock_irq(&dev_priv->irq_lock);
 	if (dev_priv->display_irqs_enabled)
 		vlv_display_irq_postinstall(dev_priv);