drm/i915/display/icl: In port sync mode disable slaves first then master

In the transcoder port sync mode, the slave transcoders mask their vblanks
until master transcoder's vblank so while disabling them, make
sure slaves are disabled first and then the masters.

v5:
* Dont pass dev priv to get_slave_crtc (Ville)
v4:
* Obtain slave state from master (Maarten)
v3:
* Rebase
v2:
* Use the intel_old_crtc_state_disables() helper

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191018172725.1338-6-manasi.d.navare@intel.com

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

@@ -14130,6 +14130,37 @@ static void intel_old_crtc_state_disables(struct intel_atomic_state *state,
 						     new_crtc_state);
 }
 
+static void intel_trans_port_sync_modeset_disables(struct intel_atomic_state *state,
+						   struct intel_crtc *crtc,
+						   struct intel_crtc_state *old_crtc_state,
+						   struct intel_crtc_state *new_crtc_state)
+{
+	struct intel_crtc *slave_crtc = intel_get_slave_crtc(new_crtc_state);
+	struct intel_crtc_state *new_slave_crtc_state =
+		intel_atomic_get_new_crtc_state(state, slave_crtc);
+	struct intel_crtc_state *old_slave_crtc_state =
+		intel_atomic_get_old_crtc_state(state, slave_crtc);
+
+	WARN_ON(!slave_crtc || !new_slave_crtc_state ||
+		!old_slave_crtc_state);
+
+	/* Disable Slave first */
+	intel_pre_plane_update(old_slave_crtc_state, new_slave_crtc_state);
+	if (old_slave_crtc_state->base.active)
+		intel_old_crtc_state_disables(state,
+					      old_slave_crtc_state,
+					      new_slave_crtc_state,
+					      slave_crtc);
+
+	/* Disable Master */
+	intel_pre_plane_update(old_crtc_state, new_crtc_state);
+	if (old_crtc_state->base.active)
+		intel_old_crtc_state_disables(state,
+					      old_crtc_state,
+					      new_crtc_state,
+					      crtc);
+}
+
 static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 {
 	struct intel_crtc_state *new_crtc_state, *old_crtc_state;
@@ -14148,6 +14179,20 @@ static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 		if (!needs_modeset(new_crtc_state))
 			continue;
 
+		/* In case of Transcoder port Sync master slave CRTCs can be
+		 * assigned in any order and we need to make sure that
+		 * slave CRTCs are disabled first and then master CRTC since
+		 * Slave vblanks are masked till Master Vblanks.
+		 */
+		if (is_trans_port_sync_mode(new_crtc_state)) {
+			if (is_trans_port_sync_master(new_crtc_state))
+				intel_trans_port_sync_modeset_disables(state,
+								       crtc,
+								       old_crtc_state,
+								       new_crtc_state);
+			else
+				continue;
+		} else {
 			intel_pre_plane_update(old_crtc_state, new_crtc_state);
 
 			if (old_crtc_state->base.active)
@@ -14156,6 +14201,7 @@ static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 							      new_crtc_state,
 							      crtc);
 		}
+	}
 }
 
 static void intel_commit_modeset_enables(struct intel_atomic_state *state)