drm/i915: set pm._irqs_disabled at IRQ init time

Before we've installed the handler, we can set this and avoid confusing
init code that then thinks IRQs are enabled and spews complaints
everywhere.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 6774f88..6cdaecf 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -4669,6 +4669,9 @@
 
 	pm_qos_add_request(&dev_priv->pm_qos, PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE);
 
+	/* Haven't installed the IRQ handler yet */
+	dev_priv->pm._irqs_disabled = true;
+
 	if (IS_GEN2(dev)) {
 		dev->max_vblank_count = 0;
 		dev->driver->get_vblank_counter = i8xx_get_vblank_counter;