drm/i915: Mask the vblank interrupt on bdw by default

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

drivers/gpu/drm/i915/i915_irq.c

@@ -2917,15 +2917,15 @@ static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
 static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 {
 	struct drm_device *dev = dev_priv->dev;
-	uint32_t de_pipe_enables = GEN8_PIPE_FLIP_DONE |
-				   GEN8_PIPE_VBLANK |
+	uint32_t de_pipe_masked = GEN8_PIPE_FLIP_DONE |
 		GEN8_PIPE_CDCLK_CRC_DONE |
 		GEN8_PIPE_FIFO_UNDERRUN |
 		GEN8_DE_PIPE_IRQ_FAULT_ERRORS;
+	uint32_t de_pipe_enables = de_pipe_masked | GEN8_PIPE_VBLANK;
 	int pipe;
-	dev_priv->de_irq_mask[PIPE_A] = ~de_pipe_enables;
-	dev_priv->de_irq_mask[PIPE_B] = ~de_pipe_enables;
-	dev_priv->de_irq_mask[PIPE_C] = ~de_pipe_enables;
+	dev_priv->de_irq_mask[PIPE_A] = ~de_pipe_masked;
+	dev_priv->de_irq_mask[PIPE_B] = ~de_pipe_masked;
+	dev_priv->de_irq_mask[PIPE_C] = ~de_pipe_masked;
 
 	for_each_pipe(pipe) {
 		u32 tmp = I915_READ(GEN8_DE_PIPE_IIR(pipe));