diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 34ad999b8300962ea1e513757c2254ab532876d6..df3751323511c1fe8b4ffbfab9c1eacbf8f7b128 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3321,6 +3321,9 @@ static void vlv_display_irq_postinstall(struct drm_i915_private *dev_priv)
 		I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
 	if (IS_CHERRYVIEW(dev_priv))
 		enable_mask |= I915_DISPLAY_PIPE_C_EVENT_INTERRUPT;
+
+	WARN_ON(dev_priv->irq_mask != ~0);
+
 	dev_priv->irq_mask = ~enable_mask;
 
 	GEN5_IRQ_INIT(VLV_, dev_priv->irq_mask, enable_mask);