[PATCH 5/5] drm/i915: track sprite coverage and disable primary plane if possible

[Jesse Barnes]

To save power when the sprite is full screen, we can disable the primary
plane on the same pipe.  Track the sprite status and enable/disable the
primary opportunistically.

Signed-off-by: Jesse Barnes
---
 drivers/gpu/drm/i915/intel_drv.h    |    1 +
 drivers/gpu/drm/i915/intel_sprite.c |   19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index b0081d2..ff553a6 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -180,6 +180,7 @@ struct intel_plane {
 	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,
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 1adeda8..e65498d 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -395,9 +395,23 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 
 	start = obj->gtt_offset;
 
+	/*
+	 * Be sure to re-enable the primary before the sprite is no longer
+	 * covering it fully.
+	 */
+	if (!disable_primary && intel_plane->primary_disabled) {
+		//dev_priv->display.enable_primary(dev, crtc);
+		intel_plane->primary_disabled = false;
+	}
+
 	intel_plane->update_plane(plane, fb, start, crtc_x, crtc_y,
 				  crtc_w, crtc_h, x, y, src_w, src_h);
 
+	if (disable_primary) {
+		//dev_priv->display.disable_primary(dev, crtc);
+		intel_plane->primary_disabled = true;
+	}
+
 	/* Unpin old obj after new one is active to avoid ugliness */
 	if (old_obj) {
 		/*
@@ -427,6 +441,11 @@ intel_disable_plane(struct drm_plane *plane)
 
 	mutex_lock(&dev->struct_mutex);
 
+	if (intel_plane->primary_disabled) {
+		//dev_priv->display.enable_primary(dev, crtc);
+		intel_plane->primary_disabled = false;
+	}
+
 	intel_plane->disable_plane(plane);
 
 	if (!intel_plane->obj)
-- 
1.7.4.1