drm/i915: Switch off FBC when disabling the primary plane when obscured

As we switch on/off the primary plane if it is completely obscured by an
overlapping video sprite, we also nee to make sure that we update the
FBC configuration at the same time.

v2: Not all crtcs are intel_crtcs, as spotted by Daniel.
v3: Boot testing rules.

References: https://bugs.freedesktop.org/show_bug.cgi?id=50238
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 1a1fdb0..5290e9d 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -169,6 +169,7 @@
 	u8 lut_r[256], lut_g[256], lut_b[256];
 	int dpms_mode;
 	bool active; /* is the crtc on? independent of the dpms mode */
+	bool primary_disabled; /* is the crtc obscured by a plane? */
 	bool busy; /* is scanout buffer being updated frequently? */
 	struct timer_list idle_timer;
 	bool lowfreq_avail;
@@ -191,7 +192,6 @@
 	struct drm_plane base;
 	enum pipe pipe;
 	struct drm_i915_gem_object *obj;
-	bool primary_disabled;
 	int max_downscale;
 	u32 lut_r[1024], lut_g[1024], lut_b[1024];
 	void (*update_plane)(struct drm_plane *plane,