drm/i915/ivb: Move WaCxSRDisabledForSpriteScaling w/a to atomic check

Determine whether we need to apply this workaround at atomic check time
and just set a flag that will be used by the main watermark update
routine.

Moving this workaround into the atomic framework reduces
ilk_update_sprite_wm() to just a standard watermark update, so drop it
completely and just ensure that ilk_update_wm() is called whenever a
sprite plane is updated in a way that would affect watermarks.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 3aca66d..b8c3e22 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3730,6 +3730,18 @@
 
 	WARN_ON(cstate->base.active != intel_crtc->active);
 
+	/*
+	 * IVB workaround: must disable low power watermarks for at least
+	 * one frame before enabling scaling.  LP watermarks can be re-enabled
+	 * when scaling is disabled.
+	 *
+	 * WaCxSRDisabledForSpriteScaling:ivb
+	 */
+	if (cstate->disable_lp_wm) {
+		ilk_disable_lp_wm(dev);
+		intel_wait_for_vblank(dev, intel_crtc->pipe);
+	}
+
 	intel_compute_pipe_wm(cstate, &pipe_wm);
 
 	if (!memcmp(&intel_crtc->wm.active, &pipe_wm, sizeof(pipe_wm)))
@@ -3761,28 +3773,6 @@
 	ilk_write_wm_values(dev_priv, &results);
 }
 
-static void
-ilk_update_sprite_wm(struct drm_plane *plane,
-		     struct drm_crtc *crtc,
-		     uint32_t sprite_width, uint32_t sprite_height,
-		     int pixel_size, bool enabled, bool scaled)
-{
-	struct drm_device *dev = plane->dev;
-	struct intel_plane *intel_plane = to_intel_plane(plane);
-
-	/*
-	 * IVB workaround: must disable low power watermarks for at least
-	 * one frame before enabling scaling.  LP watermarks can be re-enabled
-	 * when scaling is disabled.
-	 *
-	 * WaCxSRDisabledForSpriteScaling:ivb
-	 */
-	if (IS_IVYBRIDGE(dev) && scaled && ilk_disable_lp_wm(dev))
-		intel_wait_for_vblank(dev, intel_plane->pipe);
-
-	ilk_update_wm(crtc);
-}
-
 static void skl_pipe_wm_active_state(uint32_t val,
 				     struct skl_pipe_wm *active,
 				     bool is_transwm,
@@ -7108,7 +7098,6 @@
 		    (!IS_GEN5(dev) && dev_priv->wm.pri_latency[0] &&
 		     dev_priv->wm.spr_latency[0] && dev_priv->wm.cur_latency[0])) {
 			dev_priv->display.update_wm = ilk_update_wm;
-			dev_priv->display.update_sprite_wm = ilk_update_sprite_wm;
 		} else {
 			DRM_DEBUG_KMS("Failed to read display plane latency. "
 				      "Disable CxSR\n");