disp: msm: dp: fix mst slot allocation on disable

When a display is disabled, the mst slot payloads get updated in the
topology manager and also the start_slot for the remaining payloads
get adjusted, if necessary to start from 1. But the copy of these
values in dp_mst_drm context are getting readjusted properly. But
since the local context is used to update the slot configuration in
the dp controller, it is possible for the slot configuration in the
source and sink to mismatch causing blank output.

This change introduces a 2 pass solution while updating timeslots to
make sure the values in the bridge context reflect the values in
the topology manager.

Change-Id: Ia6f66e8d5ffcde3f25b1b2649733a547a06de995
Signed-off-by: Rajkumar Subbiah <[email protected]>

msm/dp/dp_mst_drm.c

@@ -487,38 +487,54 @@ static void _dp_mst_update_timeslots(struct dp_mst_private *mst,
 {
 	int i;
 	struct dp_mst_bridge *dp_bridge;
-	int pbn, start_slot, num_slots;
 #if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
 	struct drm_dp_mst_topology_state *mst_state;
 	struct drm_dp_mst_atomic_payload *payload;
+	int prev_start = 0;
+	int prev_slots = 0;
 
 	mst_state = to_drm_dp_mst_topology_state(mst->mst_mgr.base.state);
 	payload = drm_atomic_get_mst_payload_state(mst_state, port);
 
-	mst_state->start_slot = 1;
-	mst->mst_fw_cbs->update_payload_part1(&mst->mst_mgr, mst_state, payload);
-	pbn = 0;
-	start_slot = 1;
-	num_slots = 0;
-
 	for (i = 0; i < MAX_DP_MST_DRM_BRIDGES; i++) {
 		dp_bridge = &mst->mst_bridge[i];
 		if (mst_bridge == dp_bridge) {
-			dp_bridge->pbn = payload->pbn;
-			dp_bridge->start_slot = payload->vc_start_slot;
-			dp_bridge->num_slots = payload->time_slots;
-			dp_bridge->vcpi = payload->vcpi;
+			/*
+			 * When a payload was removed make sure to move any payloads after it
+			 * to the left so all payloads are aligned to the left.
+			 */
+			if (payload->vc_start_slot < 0) {
+				// cache the payload
+				prev_start = dp_bridge->start_slot;
+				prev_slots = dp_bridge->num_slots;
+				dp_bridge->pbn = 0;
+				dp_bridge->start_slot = 1;
+				dp_bridge->num_slots = 0;
+				dp_bridge->vcpi = 0;
+			} else { //add payload
+				dp_bridge->pbn = payload->pbn;
+				dp_bridge->start_slot = payload->vc_start_slot;
+				dp_bridge->num_slots = payload->time_slots;
+				dp_bridge->vcpi = payload->vcpi;
+			}
+		} else if ((payload->vc_start_slot < 0) && (dp_bridge->start_slot > prev_start)) {
+			dp_bridge->start_slot -= prev_slots;
 		}
+	}
 
+	// Now commit all the updated payloads
+	for (i = 0; i < MAX_DP_MST_DRM_BRIDGES; i++) {
+		dp_bridge = &mst->mst_bridge[i];
 		mst->dp_display->set_stream_info(mst->dp_display, dp_bridge->dp_panel,
 				dp_bridge->id, dp_bridge->start_slot, dp_bridge->num_slots,
 				dp_bridge->pbn, dp_bridge->vcpi);
-
 		DP_INFO("conn:%d vcpi:%d start_slot:%d num_slots:%d, pbn:%d\n",
 			DP_MST_CONN_ID(dp_bridge), dp_bridge->vcpi, dp_bridge->start_slot,
 			dp_bridge->num_slots, dp_bridge->pbn);
 	}
 #else
+	int pbn, start_slot, num_slots;
+
 	mst->mst_fw_cbs->update_payload_part1(&mst->mst_mgr);
 
 	for (i = 0; i < MAX_DP_MST_DRM_BRIDGES; i++) {
@@ -579,6 +595,10 @@ static void _dp_mst_bridge_pre_enable_part1(struct dp_mst_bridge *dp_bridge)
 		to_sde_connector(dp_bridge->connector);
 	struct dp_mst_private *mst = dp_display->dp_mst_prv_info;
 	struct drm_dp_mst_port *port = c_conn->mst_port;
+#if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
+	struct drm_dp_mst_topology_state *mst_state;
+	struct drm_dp_mst_atomic_payload *payload;
+#endif
 	bool ret;
 	int pbn, slots;
 
@@ -601,7 +621,13 @@ static void _dp_mst_bridge_pre_enable_part1(struct dp_mst_bridge *dp_bridge)
 	DP_INFO("conn:%d pbn:%d, slots:%d\n", DP_MST_CONN_ID(dp_bridge), pbn, slots);
 
 	ret = false;
-#if (KERNEL_VERSION(6, 1, 0) > LINUX_VERSION_CODE)
+#if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
+	mst_state = to_drm_dp_mst_topology_state(mst->mst_mgr.base.state);
+	payload = drm_atomic_get_mst_payload_state(mst_state, port);
+
+	drm_dp_mst_update_slots(mst_state, DP_CAP_ANSI_8B10B);
+	mst->mst_fw_cbs->update_payload_part1(&mst->mst_mgr, mst_state, payload);	
+#else
 	ret = mst->mst_fw_cbs->allocate_vcpi(&mst->mst_mgr, port, pbn, slots);
 	if (!ret) {
 		DP_ERR("mst: failed to allocate vcpi. bridge:%d\n", dp_bridge->id);
@@ -609,8 +635,8 @@ static void _dp_mst_bridge_pre_enable_part1(struct dp_mst_bridge *dp_bridge)
 	}
 
 	dp_bridge->vcpi = port->vcpi.vcpi;
-#endif
 	dp_bridge->pbn = pbn;
+#endif
 	_dp_mst_update_timeslots(mst, dp_bridge, port);
 }
 
@@ -672,8 +698,9 @@ static void _dp_mst_bridge_pre_disable_part1(struct dp_mst_bridge *dp_bridge)
 	mst->mst_fw_cbs->reset_vcpi_slots(&mst->mst_mgr, mst_state, payload);
 #else
 	mst->mst_fw_cbs->reset_vcpi_slots(&mst->mst_mgr, port);
-	_dp_mst_update_timeslots(mst, dp_bridge, port);
 #endif
+	pr_info("rsdbg: calling update after remove\n");
+	_dp_mst_update_timeslots(mst, dp_bridge, port);
 
 	DP_MST_DEBUG("mst bridge [%d] _pre disable part-1 complete\n",
 			dp_bridge->id);
@@ -705,9 +732,9 @@ static void _dp_mst_bridge_pre_disable_part2(struct dp_mst_bridge *dp_bridge)
 
 	port->vcpi.vcpi = dp_bridge->vcpi;
 	mst->mst_fw_cbs->deallocate_vcpi(&mst->mst_mgr, port);
-#endif
 	dp_bridge->vcpi = 0;
 	dp_bridge->pbn = 0;
+#endif
 
 	DP_MST_DEBUG("mst bridge [%d] _pre disable part-2 complete\n",
 			dp_bridge->id);