drm/i915/fbdev: Perform async fbdev initialisation much later

Setting up fbdev requires everything ready and registered (in particular
the connectors). In the forthcoming patches, we defer registration of the KMS
objects and unless we defer setting off fbdev, it may run before they are
registered and oops.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466497015-8509-1-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_dma.c

@@ -525,18 +525,6 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	/* Only enable hotplug handling once the fbdev is fully set up. */
 	intel_hpd_init(dev_priv);
 
-	/*
-	 * Some ports require correctly set-up hpd registers for detection to
-	 * work properly (leading to ghost connected connector status), e.g. VGA
-	 * on gm45.  Hence we can only set up the initial fbdev config after hpd
-	 * irqs are fully enabled. Now we should scan for the initial config
-	 * only once hotplug handling is enabled, but due to screwed-up locking
-	 * around kms/fbdev init we can't protect the fdbev initial config
-	 * scanning against hotplug events. Hence do this first and ignore the
-	 * tiny window where we will loose hotplug notifactions.
-	 */
-	intel_fbdev_initial_config_async(dev);
-
 	drm_kms_helper_poll_init(dev);
 
 	return 0;
@@ -1421,6 +1409,15 @@ static void i915_driver_register(struct drm_i915_private *dev_priv)
 		intel_gpu_ips_init(dev_priv);
 
 	i915_audio_component_init(dev_priv);
+
+	/*
+	 * Some ports require correctly set-up hpd registers for detection to
+	 * work properly (leading to ghost connected connector status), e.g. VGA
+	 * on gm45.  Hence we can only set up the initial fbdev config after hpd
+	 * irqs are fully enabled. We do it last so that the async config
+	 * cannot run before the connectors are registered.
+	 */
+	intel_fbdev_initial_config_async(dev);
 }
 
 /**