drm/i915: Move CRTC updating in atomic_commit into it's own hook

Since we have to write ddb allocations at the same time as we do other
plane updates, we're going to need to be able to control the order in
which we execute modesets on each pipe. The easiest way to do this is to
just factor this section of intel_atomic_commit_tail()
(intel_atomic_commit() for stable branches) into it's own function, and
add an appropriate display function hook for it.

Based off of Matt Rope's suggestions

Changes since v1:
 - Drop pipe_config->base.active check in intel_update_crtcs() since we
   check that before calling the function
Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
[omitting CC for stable, since this patch will need to be changed for
such backports first]
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lyude <cpaul@redhat.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471961565-28540-1-git-send-email-cpaul@redhat.com

drivers/gpu/drm/i915/i915_drv.h

@@ -514,6 +514,8 @@ struct drm_i915_display_funcs {
 			    struct drm_atomic_state *old_state);
 	void (*crtc_disable)(struct intel_crtc_state *old_crtc_state,
 			     struct drm_atomic_state *old_state);
+	void (*update_crtcs)(struct drm_atomic_state *state,
+			     unsigned int *crtc_vblank_mask);
 	void (*audio_codec_enable)(struct drm_connector *connector,
 				   struct intel_encoder *encoder,
 				   const struct drm_display_mode *adjusted_mode);

drivers/gpu/drm/i915/intel_display.c

@@ -14173,6 +14173,52 @@ static bool needs_vblank_wait(struct intel_crtc_state *crtc_state)
 	return false;
 }
 
+static void intel_update_crtc(struct drm_crtc *crtc,
+			      struct drm_atomic_state *state,
+			      struct drm_crtc_state *old_crtc_state,
+			      unsigned int *crtc_vblank_mask)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct intel_crtc_state *pipe_config = to_intel_crtc_state(crtc->state);
+	bool modeset = needs_modeset(crtc->state);
+
+	if (modeset) {
+		update_scanline_offset(intel_crtc);
+		dev_priv->display.crtc_enable(pipe_config, state);
+	} else {
+		intel_pre_plane_update(to_intel_crtc_state(old_crtc_state));
+	}
+
+	if (drm_atomic_get_existing_plane_state(state, crtc->primary)) {
+		intel_fbc_enable(
+		    intel_crtc, pipe_config,
+		    to_intel_plane_state(crtc->primary->state));
+	}
+
+	drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
+
+	if (needs_vblank_wait(pipe_config))
+		*crtc_vblank_mask |= drm_crtc_mask(crtc);
+}
+
+static void intel_update_crtcs(struct drm_atomic_state *state,
+			       unsigned int *crtc_vblank_mask)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	int i;
+
+	for_each_crtc_in_state(state, crtc, old_crtc_state, i) {
+		if (!crtc->state->active)
+			continue;
+
+		intel_update_crtc(crtc, state, old_crtc_state,
+				  crtc_vblank_mask);
+	}
+}
+
 static void intel_atomic_commit_tail(struct drm_atomic_state *state)
 {
 	struct drm_device *dev = state->dev;
@@ -14271,17 +14317,9 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
 		intel_modeset_verify_disabled(dev);
 	}
 
-	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
+	/* Complete the events for pipes that have now been disabled */
 	for_each_crtc_in_state(state, crtc, old_crtc_state, i) {
-		struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 		bool modeset = needs_modeset(crtc->state);
-		struct intel_crtc_state *pipe_config =
-			to_intel_crtc_state(crtc->state);
-
-		if (modeset && crtc->state->active) {
-			update_scanline_offset(to_intel_crtc(crtc));
-			dev_priv->display.crtc_enable(pipe_config, state);
-		}
 
 		/* Complete events for now disable pipes here. */
 		if (modeset && !crtc->state->active && crtc->state->event) {
@@ -14291,21 +14329,11 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
 
 			crtc->state->event = NULL;
 		}
-
-		if (!modeset)
-			intel_pre_plane_update(to_intel_crtc_state(old_crtc_state));
-
-		if (crtc->state->active &&
-		    drm_atomic_get_existing_plane_state(state, crtc->primary))
-			intel_fbc_enable(intel_crtc, pipe_config, to_intel_plane_state(crtc->primary->state));
-
-		if (crtc->state->active)
-			drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
-
-		if (pipe_config->base.active && needs_vblank_wait(pipe_config))
-			crtc_vblank_mask |= 1 << i;
 	}
 
+	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
+	dev_priv->display.update_crtcs(state, &crtc_vblank_mask);
+
 	/* FIXME: We should call drm_atomic_helper_commit_hw_done() here
 	 * already, but still need the state for the delayed optimization. To
 	 * fix this:
@@ -15823,6 +15851,8 @@ void intel_init_display_hooks(struct drm_i915_private *dev_priv)
 		dev_priv->display.crtc_disable = i9xx_crtc_disable;
 	}
 
+	dev_priv->display.update_crtcs = intel_update_crtcs;
+
 	/* Returns the core display clock speed */
 	if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv))
 		dev_priv->display.get_display_clock_speed =