drm/i915: Move dbuf slice update to proper place

Current DBuf slices update wasn't done in proper
place, especially its "post" part, which should
disable those only once vblank had passed and
all other changes are committed.

v2: Fix to use dev_priv and intel_atomic_state
    instead of skl_ddb_values
    (to be nuked in Villes patch)

v3: Renamed "enabled_slices" to "enabled_dbuf_slices_num"
    (Matt Roper)

v4: - Rebase against drm-tip.
    - Move post_update closer to optimize_watermarks,
      to prevent unneeded noise from underrun reporting
      (Ville Syrjälä)
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200202230630.8975-3-stanislav.lisovskiy@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -15445,13 +15445,33 @@ static void intel_update_trans_port_sync_crtcs(struct intel_crtc *crtc,
 				       state);
 }
 
+static void icl_dbuf_slice_pre_update(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	u8 hw_enabled_slices = dev_priv->enabled_dbuf_slices_num;
+	u8 required_slices = state->enabled_dbuf_slices_num;
+
+	/* If 2nd DBuf slice required, enable it here */
+	if (INTEL_GEN(dev_priv) >= 11 && required_slices > hw_enabled_slices)
+		icl_dbuf_slices_update(dev_priv, required_slices);
+}
+
+static void icl_dbuf_slice_post_update(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	u8 hw_enabled_slices = dev_priv->enabled_dbuf_slices_num;
+	u8 required_slices = state->enabled_dbuf_slices_num;
+
+	/* If 2nd DBuf slice is no more required disable it */
+	if (INTEL_GEN(dev_priv) >= 11 && required_slices < hw_enabled_slices)
+		icl_dbuf_slices_update(dev_priv, required_slices);
+}
+
 static void skl_commit_modeset_enables(struct intel_atomic_state *state)
 {
 	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
 	struct intel_crtc *crtc;
 	struct intel_crtc_state *old_crtc_state, *new_crtc_state;
-	u8 hw_enabled_slices = dev_priv->enabled_dbuf_slices_num;
-	u8 required_slices = state->enabled_dbuf_slices_num;
 	struct skl_ddb_entry entries[I915_MAX_PIPES] = {};
 	const u8 num_pipes = INTEL_NUM_PIPES(dev_priv);
 	u8 update_pipes = 0, modeset_pipes = 0;
@@ -15472,10 +15492,6 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
 		}
 	}
 
-	/* If 2nd DBuf slice required, enable it here */
-	if (INTEL_GEN(dev_priv) >= 11 && required_slices > hw_enabled_slices)
-		icl_dbuf_slices_update(dev_priv, required_slices);
-
 	/*
 	 * Whenever the number of active pipes changes, we need to make sure we
 	 * update the pipes in the right order so that their ddb allocations
@@ -15577,9 +15593,6 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
 
 	WARN_ON(modeset_pipes);
 
-	/* If 2nd DBuf slice is no more required disable it */
-	if (INTEL_GEN(dev_priv) >= 11 && required_slices < hw_enabled_slices)
-		icl_dbuf_slices_update(dev_priv, required_slices);
 }
 
 static void intel_atomic_helper_free_state(struct drm_i915_private *dev_priv)
@@ -15706,6 +15719,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	if (state->modeset)
 		intel_encoders_update_prepare(state);
 
+	/* Enable all new slices, we might need */
+	icl_dbuf_slice_pre_update(state);
+
 	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
 	dev_priv->display.commit_modeset_enables(state);
 
@@ -15759,6 +15775,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 			dev_priv->display.optimize_watermarks(state, crtc);
 	}
 
+	/* Disable all slices, we don't need */
+	icl_dbuf_slice_post_update(state);
+
 	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 		intel_post_plane_update(state, crtc);