diff --git a/apps/blemesh/src/main.c b/apps/blemesh/src/main.c
index 65270554b..56d0476f8 100644
--- a/apps/blemesh/src/main.c
+++ b/apps/blemesh/src/main.c
@@ -144,11 +144,12 @@ static struct bt_mesh_model_pub gen_onoff_pub;
 static uint8_t gen_on_off_state;
 static int16_t gen_level_state;
 
-static void gen_onoff_status(struct bt_mesh_model *model,
+static int gen_onoff_status(struct bt_mesh_model *model,
                              struct bt_mesh_msg_ctx *ctx)
 {
     struct os_mbuf *msg = NET_BUF_SIMPLE(3);
     uint8_t *status;
+    int rc;
 
     console_printf("#mesh-onoff STATUS\n");
 
@@ -156,23 +157,25 @@ static void gen_onoff_status(struct bt_mesh_model *model,
     status = net_buf_simple_add(msg, 1);
     *status = gen_on_off_state;
 
-    if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+    rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+    if (rc) {
         console_printf("#mesh-onoff STATUS: send status failed\n");
     }
 
     os_mbuf_free_chain(msg);
+    return rc;
 }
 
-static void gen_onoff_get(struct bt_mesh_model *model,
+static int gen_onoff_get(struct bt_mesh_model *model,
               struct bt_mesh_msg_ctx *ctx,
               struct os_mbuf *buf)
 {
     console_printf("#mesh-onoff GET\n");
 
-    gen_onoff_status(model, ctx);
+    return gen_onoff_status(model, ctx);
 }
 
-static void gen_onoff_set(struct bt_mesh_model *model,
+static int gen_onoff_set(struct bt_mesh_model *model,
               struct bt_mesh_msg_ctx *ctx,
               struct os_mbuf *buf)
 {
@@ -181,10 +184,10 @@ static void gen_onoff_set(struct bt_mesh_model *model,
     gen_on_off_state = buf->om_data[0];
     hal_gpio_write(LED_2, !gen_on_off_state);
 
-    gen_onoff_status(model, ctx);
+    return gen_onoff_status(model, ctx);
 }
 
-static void gen_onoff_set_unack(struct bt_mesh_model *model,
+static int gen_onoff_set_unack(struct bt_mesh_model *model,
                 struct bt_mesh_msg_ctx *ctx,
                 struct os_mbuf *buf)
 {
@@ -192,6 +195,7 @@ static void gen_onoff_set_unack(struct bt_mesh_model *model,
 
     gen_on_off_state = buf->om_data[0];
     hal_gpio_write(LED_2, !gen_on_off_state);
+    return 0;
 }
 
 static const struct bt_mesh_model_op gen_onoff_op[] = {
@@ -201,48 +205,56 @@ static const struct bt_mesh_model_op gen_onoff_op[] = {
     BT_MESH_MODEL_OP_END,
 };
 
-static void gen_level_status(struct bt_mesh_model *model,
+static int gen_level_status(struct bt_mesh_model *model,
                              struct bt_mesh_msg_ctx *ctx)
 {
     struct os_mbuf *msg = NET_BUF_SIMPLE(4);
+    int rc;
 
     console_printf("#mesh-level STATUS\n");
 
     bt_mesh_model_msg_init(msg, BT_MESH_MODEL_OP_2(0x82, 0x08));
     net_buf_simple_add_le16(msg, gen_level_state);
 
-    if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+    rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+    if (rc) {
         console_printf("#mesh-level STATUS: send status failed\n");
     }
 
     os_mbuf_free_chain(msg);
+    return rc;
 }
 
-static void gen_level_get(struct bt_mesh_model *model,
+static int gen_level_get(struct bt_mesh_model *model,
               struct bt_mesh_msg_ctx *ctx,
               struct os_mbuf *buf)
 {
     console_printf("#mesh-level GET\n");
 
-    gen_level_status(model, ctx);
+    return gen_level_status(model, ctx);
 }
 
-static void gen_level_set(struct bt_mesh_model *model,
+static int gen_level_set(struct bt_mesh_model *model,
               struct bt_mesh_msg_ctx *ctx,
               struct os_mbuf *buf)
 {
     int16_t level;
+    int rc;
 
     level = (int16_t) net_buf_simple_pull_le16(buf);
     console_printf("#mesh-level SET: level=%d\n", level);
 
-    gen_level_status(model, ctx);
+    rc = gen_level_status(model, ctx);
+    if (rc) {
+        return rc;
+    }
 
     gen_level_state = level;
     console_printf("#mesh-level: level=%d\n", gen_level_state);
+    return 0;
 }
 
-static void gen_level_set_unack(struct bt_mesh_model *model,
+static int gen_level_set_unack(struct bt_mesh_model *model,
                 struct bt_mesh_msg_ctx *ctx,
                 struct os_mbuf *buf)
 {
@@ -253,9 +265,10 @@ static void gen_level_set_unack(struct bt_mesh_model *model,
 
     gen_level_state = level;
     console_printf("#mesh-level: level=%d\n", gen_level_state);
+    return 0;
 }
 
-static void gen_delta_set(struct bt_mesh_model *model,
+static int gen_delta_set(struct bt_mesh_model *model,
               struct bt_mesh_msg_ctx *ctx,
               struct os_mbuf *buf)
 {
@@ -268,9 +281,10 @@ static void gen_delta_set(struct bt_mesh_model *model,
 
     gen_level_state += delta_level;
     console_printf("#mesh-level: level=%d\n", gen_level_state);
+    return 0;
 }
 
-static void gen_delta_set_unack(struct bt_mesh_model *model,
+static int gen_delta_set_unack(struct bt_mesh_model *model,
                 struct bt_mesh_msg_ctx *ctx,
                 struct os_mbuf *buf)
 {
@@ -281,18 +295,21 @@ static void gen_delta_set_unack(struct bt_mesh_model *model,
 
     gen_level_state += delta_level;
     console_printf("#mesh-level: level=%d\n", gen_level_state);
+    return 0;
 }
 
-static void gen_move_set(struct bt_mesh_model *model,
+static int gen_move_set(struct bt_mesh_model *model,
              struct bt_mesh_msg_ctx *ctx,
              struct os_mbuf *buf)
 {
+    return 0;
 }
 
-static void gen_move_set_unack(struct bt_mesh_model *model,
+static int gen_move_set_unack(struct bt_mesh_model *model,
                    struct bt_mesh_msg_ctx *ctx,
                    struct os_mbuf *buf)
 {
+    return 0;
 }
 
 static const struct bt_mesh_model_op gen_level_op[] = {
@@ -317,11 +334,12 @@ static struct bt_mesh_model root_models[] = {
 
 static struct bt_mesh_model_pub vnd_model_pub;
 
-static void vnd_model_recv(struct bt_mesh_model *model,
+static int vnd_model_recv(struct bt_mesh_model *model,
                            struct bt_mesh_msg_ctx *ctx,
                            struct os_mbuf *buf)
 {
     struct os_mbuf *msg = NET_BUF_SIMPLE(3);
+    int rc;
 
     console_printf("#vendor-model-recv\n");
 
@@ -331,11 +349,13 @@ static void vnd_model_recv(struct bt_mesh_model *model,
     bt_mesh_model_msg_init(msg, BT_MESH_MODEL_OP_3(0x01, CID_VENDOR));
     os_mbuf_append(msg, buf->om_data, buf->om_len);
 
+    rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
     if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
         console_printf("#vendor-model-recv: send rsp failed\n");
     }
 
     os_mbuf_free_chain(msg);
+    return rc;
 }
 
 static const struct bt_mesh_model_op vnd_model_op[] = {
diff --git a/apps/blemesh_models_example_1/src/main.c b/apps/blemesh_models_example_1/src/main.c
index 736d4d32b..80a69c705 100644
--- a/apps/blemesh_models_example_1/src/main.c
+++ b/apps/blemesh_models_example_1/src/main.c
@@ -68,19 +68,19 @@
 #define BT_MESH_MODEL_OP_GEN_ONOFF_SET_UNACK	BT_MESH_MODEL_OP_2(0x82, 0x03)
 #define BT_MESH_MODEL_OP_GEN_ONOFF_STATUS	BT_MESH_MODEL_OP_2(0x82, 0x04)
 
-static void gen_onoff_set(struct bt_mesh_model *model,
+static int gen_onoff_set(struct bt_mesh_model *model,
                           struct bt_mesh_msg_ctx *ctx,
                           struct os_mbuf *buf);
 
-static void gen_onoff_set_unack(struct bt_mesh_model *model,
+static int gen_onoff_set_unack(struct bt_mesh_model *model,
                                 struct bt_mesh_msg_ctx *ctx,
                                 struct os_mbuf *buf);
 
-static void gen_onoff_get(struct bt_mesh_model *model,
+static int gen_onoff_get(struct bt_mesh_model *model,
                           struct bt_mesh_msg_ctx *ctx,
                           struct os_mbuf *buf);
 
-static void gen_onoff_status(struct bt_mesh_model *model,
+static int gen_onoff_status(struct bt_mesh_model *model,
                              struct bt_mesh_msg_ctx *ctx,
                              struct os_mbuf *buf);
 
@@ -318,26 +318,29 @@ static uint16_t primary_net_idx;
  *
  */
 
-static void gen_onoff_get(struct bt_mesh_model *model,
+static int gen_onoff_get(struct bt_mesh_model *model,
                           struct bt_mesh_msg_ctx *ctx,
                           struct os_mbuf *buf)
 {
     struct os_mbuf *msg = NET_BUF_SIMPLE(2 + 1 + 4);
     struct onoff_state *state = model->user_data;
+    int rc;
 
     BT_INFO("addr 0x%04x onoff 0x%02x",
                 bt_mesh_model_elem(model)->addr, state->current);
     bt_mesh_model_msg_init(msg, BT_MESH_MODEL_OP_GEN_ONOFF_STATUS);
     net_buf_simple_add_u8(msg, state->current);
 
-    if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+    rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+    if (rc) {
         BT_ERR("Unable to send On Off Status response");
     }
 
     os_mbuf_free_chain(msg);
+    return rc;
 }
 
-static void gen_onoff_set_unack(struct bt_mesh_model *model,
+static int gen_onoff_set_unack(struct bt_mesh_model *model,
                                 struct bt_mesh_msg_ctx *ctx,
                                 struct os_mbuf *buf)
 {
@@ -372,23 +375,34 @@ static void gen_onoff_set_unack(struct bt_mesh_model *model,
                                BT_MESH_MODEL_OP_GEN_ONOFF_STATUS);
         net_buf_simple_add_u8(msg, state->current);
         err = bt_mesh_model_publish(model);
-        if (err) {
+        if (err != 0) {
             BT_ERR("bt_mesh_model_publish err %d", err);
+            return err;
         }
     }
+    return 0;
 }
 
-static void gen_onoff_set(struct bt_mesh_model *model,
+static int gen_onoff_set(struct bt_mesh_model *model,
                           struct bt_mesh_msg_ctx *ctx,
                           struct os_mbuf *buf)
 {
     BT_INFO("");
+    int rc;
 
-    gen_onoff_set_unack(model, ctx, buf);
-    gen_onoff_get(model, ctx, buf);
+    rc = gen_onoff_set_unack(model, ctx, buf);
+    if (rc != 0) {
+        return rc;
+    }
+
+    rc = gen_onoff_get(model, ctx, buf);
+    if (rc != 0) {
+        return rc;
+    }
+    return 0;
 }
 
-static void gen_onoff_status(struct bt_mesh_model *model,
+static int gen_onoff_status(struct bt_mesh_model *model,
                              struct bt_mesh_msg_ctx *ctx,
                              struct os_mbuf *buf)
 {
@@ -398,6 +412,7 @@ static void gen_onoff_status(struct bt_mesh_model *model,
 
     BT_INFO("Node 0x%04x OnOff status from 0x%04x with state 0x%02x",
                 bt_mesh_model_elem(model)->addr, ctx->addr, state);
+    return 0;
 }
 
 static int output_number(bt_mesh_output_action_t action, uint32_t number)
diff --git a/apps/blemesh_models_example_2/src/device_composition.c b/apps/blemesh_models_example_2/src/device_composition.c
index 5dfeaf8ed..40ede5012 100644
--- a/apps/blemesh_models_example_2/src/device_composition.c
+++ b/apps/blemesh_models_example_2/src/device_composition.c
@@ -147,7 +147,7 @@ static struct bt_mesh_elem elements[];
 /* message handlers (Start) */
 
 /* Generic OnOff Server message handlers */
-static void gen_onoff_get(struct bt_mesh_model *model,
+static int gen_onoff_get(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
@@ -168,16 +168,17 @@ static void gen_onoff_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-void gen_onoff_publish(struct bt_mesh_model *model)
+int gen_onoff_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct generic_onoff_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_OP_GEN_ONOFF_STATUS);
@@ -193,21 +194,23 @@ void gen_onoff_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void gen_onoff_set_unack(struct bt_mesh_model *model,
+static int gen_onoff_set_unack(struct bt_mesh_model *model,
 				struct bt_mesh_msg_ctx *ctx,
 				struct os_mbuf *buf)
 {
 	uint8_t tid, onoff, tt, delay;
 	int64_t now;
+	int err;
 	struct generic_onoff_state *state = model->user_data;
 
 	onoff = net_buf_simple_pull_u8(buf);
 	tid = net_buf_simple_pull_u8(buf);
 
 	if (onoff > STATE_ON) {
-		return;
+		return 0;
 	}
 
 	now = k_uptime_get();
@@ -215,7 +218,7 @@ static void gen_onoff_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -226,13 +229,13 @@ static void gen_onoff_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -247,8 +250,7 @@ static void gen_onoff_set_unack(struct bt_mesh_model *model,
 	if (state->target_onoff != state->onoff) {
 		onoff_tt_values(state, tt, delay);
 	} else {
-		gen_onoff_publish(model);
-		return;
+        return gen_onoff_publish(model);
 	}
 
 	/* For Instantaneous Transition */
@@ -257,23 +259,28 @@ static void gen_onoff_set_unack(struct bt_mesh_model *model,
 	}
 
 	state->transition->just_started = true;
-	gen_onoff_publish(model);
+	err = gen_onoff_publish(model);
 	onoff_handler(state);
+	if (err) {
+        return err;
+	}
+    return 0;
 }
 
-static void gen_onoff_set(struct bt_mesh_model *model,
+static int gen_onoff_set(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
 	uint8_t tid, onoff, tt, delay;
 	int64_t now;
+	int rc;
 	struct generic_onoff_state *state = model->user_data;
 
 	onoff = net_buf_simple_pull_u8(buf);
 	tid = net_buf_simple_pull_u8(buf);
 
 	if (onoff > STATE_ON) {
-		return;
+		return 0;
 	}
 
 	now = k_uptime_get();
@@ -281,8 +288,8 @@ static void gen_onoff_set(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		gen_onoff_get(model, ctx, buf);
-		return;
+		rc = gen_onoff_get(model, ctx, buf);
+		return rc;
 	}
 
 	switch (buf->om_len) {
@@ -293,13 +300,13 @@ static void gen_onoff_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -315,8 +322,8 @@ static void gen_onoff_set(struct bt_mesh_model *model,
 		onoff_tt_values(state, tt, delay);
 	} else {
 		gen_onoff_get(model, ctx, buf);
-		gen_onoff_publish(model);
-		return;
+		rc = gen_onoff_publish(model);
+		return rc;
 	}
 
 	/* For Instantaneous Transition */
@@ -326,12 +333,13 @@ static void gen_onoff_set(struct bt_mesh_model *model,
 
 	state->transition->just_started = true;
 	gen_onoff_get(model, ctx, buf);
-	gen_onoff_publish(model);
+	rc = gen_onoff_publish(model);
 	onoff_handler(state);
+    return rc;
 }
 
 /* Generic OnOff Client message handlers */
-static void gen_onoff_status(struct bt_mesh_model *model,
+static int gen_onoff_status(struct bt_mesh_model *model,
 			     struct bt_mesh_msg_ctx *ctx,
 			     struct os_mbuf *buf)
 {
@@ -342,10 +350,11 @@ static void gen_onoff_status(struct bt_mesh_model *model,
 		printk("Target OnOff = %02x\n", net_buf_simple_pull_u8(buf));
 		printk("Remaining Time = %02x\n", net_buf_simple_pull_u8(buf));
 	}
+    return 0;
 }
 
 /* Generic Level Server message handlers */
-static void gen_level_get(struct bt_mesh_model *model,
+static int gen_level_get(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
@@ -366,16 +375,17 @@ static void gen_level_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-void gen_level_publish(struct bt_mesh_model *model)
+int gen_level_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct generic_level_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_OP_GEN_LEVEL_STATUS);
@@ -391,9 +401,10 @@ void gen_level_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void gen_level_set_unack(struct bt_mesh_model *model,
+static int gen_level_set_unack(struct bt_mesh_model *model,
 				struct bt_mesh_msg_ctx *ctx,
 				struct os_mbuf *buf)
 {
@@ -410,7 +421,7 @@ static void gen_level_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -421,13 +432,13 @@ static void gen_level_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -443,7 +454,7 @@ static void gen_level_set_unack(struct bt_mesh_model *model,
 		level_tt_values(state, tt, delay);
 	} else {
 		gen_level_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -463,9 +474,10 @@ static void gen_level_set_unack(struct bt_mesh_model *model,
 		transition_type = LEVEL_TEMP_TT;
 		level_temp_handler(state);
 	}
+    return 0;
 }
 
-static void gen_level_set(struct bt_mesh_model *model,
+static int gen_level_set(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
@@ -483,7 +495,7 @@ static void gen_level_set(struct bt_mesh_model *model,
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
 		gen_level_get(model, ctx, buf);
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -494,13 +506,13 @@ static void gen_level_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -517,7 +529,7 @@ static void gen_level_set(struct bt_mesh_model *model,
 	} else {
 		gen_level_get(model, ctx, buf);
 		gen_level_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -538,9 +550,10 @@ static void gen_level_set(struct bt_mesh_model *model,
 		transition_type = LEVEL_TEMP_TT;
 		level_temp_handler(state);
 	}
+    return 0;
 }
 
-static void gen_delta_set_unack(struct bt_mesh_model *model,
+static int gen_delta_set_unack(struct bt_mesh_model *model,
 				struct bt_mesh_msg_ctx *ctx,
 				struct os_mbuf *buf)
 {
@@ -559,7 +572,7 @@ static void gen_delta_set_unack(struct bt_mesh_model *model,
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
 
 		if (state->last_delta == delta) {
-			return;
+			return 0;
 		}
 		tmp32 = state->last_level + delta;
 
@@ -576,13 +589,13 @@ static void gen_delta_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -605,8 +618,7 @@ static void gen_delta_set_unack(struct bt_mesh_model *model,
 	if (state->target_level != state->level) {
 		level_tt_values(state, tt, delay);
 	} else {
-		gen_level_publish(model);
-		return;
+        return gen_level_publish(model);
 	}
 
 	/* For Instantaneous Transition */
@@ -627,9 +639,10 @@ static void gen_delta_set_unack(struct bt_mesh_model *model,
 		transition_type = LEVEL_TEMP_TT_DELTA;
 		level_temp_handler(state);
 	}
+    return 0;
 }
 
-static void gen_delta_set(struct bt_mesh_model *model,
+static int gen_delta_set(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
@@ -649,7 +662,7 @@ static void gen_delta_set(struct bt_mesh_model *model,
 
 		if (state->last_delta == delta) {
 			gen_level_get(model, ctx, buf);
-			return;
+			return 0;
 		}
 		tmp32 = state->last_level + delta;
 
@@ -666,13 +679,13 @@ static void gen_delta_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -697,7 +710,7 @@ static void gen_delta_set(struct bt_mesh_model *model,
 	} else {
 		gen_level_get(model, ctx, buf);
 		gen_level_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -718,14 +731,16 @@ static void gen_delta_set(struct bt_mesh_model *model,
 		transition_type = LEVEL_TEMP_TT_DELTA;
 		level_temp_handler(state);
 	}
+    return 0;
 }
 
-static void gen_level_move_get(struct bt_mesh_model *model,
+static int gen_level_move_get(struct bt_mesh_model *model,
 			       struct bt_mesh_msg_ctx *ctx,
 			       struct os_mbuf *buf)
 {
 	struct os_mbuf *msg = NET_BUF_SIMPLE(2 + 5 + 4);
 	struct generic_level_state *state = model->user_data;
+	int rc;
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_OP_GEN_LEVEL_STATUS);
 	net_buf_simple_add_le16(msg, state->level);
@@ -740,21 +755,23 @@ static void gen_level_move_get(struct bt_mesh_model *model,
 		net_buf_simple_add_u8(msg, UNKNOWN_VALUE);
 	}
 
-	if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+	rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+	if (rc) {
 		printk("Unable to send GEN_LEVEL_SRV Status response\n");
 	}
 
 	os_mbuf_free_chain(msg);
+    return rc;
 }
 
-static void gen_level_move_publish(struct bt_mesh_model *model)
+static int gen_level_move_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct generic_level_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_OP_GEN_LEVEL_STATUS);
@@ -774,9 +791,10 @@ static void gen_level_move_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void gen_move_set_unack(struct bt_mesh_model *model,
+static int gen_move_set_unack(struct bt_mesh_model *model,
 			       struct bt_mesh_msg_ctx *ctx,
 			       struct os_mbuf *buf)
 {
@@ -785,6 +803,7 @@ static void gen_move_set_unack(struct bt_mesh_model *model,
 	int32_t tmp32;
 	int64_t now;
 	struct generic_level_state *state = model->user_data;
+	int rc;
 
 	delta = (int16_t) net_buf_simple_pull_le16(buf);
 	tid = net_buf_simple_pull_u8(buf);
@@ -794,7 +813,7 @@ static void gen_move_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -805,13 +824,13 @@ static void gen_move_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -835,16 +854,16 @@ static void gen_move_set_unack(struct bt_mesh_model *model,
 	if (state->target_level != state->level) {
 		level_tt_values(state, tt, delay);
 	} else {
-		gen_level_move_publish(model);
-		return;
+		rc = gen_level_move_publish(model);
+		return rc;
 	}
 
 	if (state->transition->counter == 0) {
-		return;
+		return 0;
 	}
 
 	state->transition->just_started = true;
-	gen_level_move_publish(model);
+	rc = gen_level_move_publish(model);
 
 	if (bt_mesh_model_elem(model)->addr == elements[0].addr) {
 		/* Root element */
@@ -855,9 +874,10 @@ static void gen_move_set_unack(struct bt_mesh_model *model,
 		transition_type = LEVEL_TEMP_TT_MOVE;
 		level_temp_handler(state);
 	}
+    return rc;
 }
 
-static void gen_move_set(struct bt_mesh_model *model,
+static int gen_move_set(struct bt_mesh_model *model,
 			 struct bt_mesh_msg_ctx *ctx,
 			 struct os_mbuf *buf)
 {
@@ -866,6 +886,7 @@ static void gen_move_set(struct bt_mesh_model *model,
 	int32_t tmp32;
 	int64_t now;
 	struct generic_level_state *state = model->user_data;
+	int rc;
 
 	delta = (int16_t) net_buf_simple_pull_le16(buf);
 	tid = net_buf_simple_pull_u8(buf);
@@ -875,8 +896,8 @@ static void gen_move_set(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		gen_level_move_get(model, ctx, buf);
-		return;
+		rc = gen_level_move_get(model, ctx, buf);
+		return rc;
 	}
 
 	switch (buf->om_len) {
@@ -887,13 +908,13 @@ static void gen_move_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -918,17 +939,17 @@ static void gen_move_set(struct bt_mesh_model *model,
 		level_tt_values(state, tt, delay);
 	} else {
 		gen_level_move_get(model, ctx, buf);
-		gen_level_move_publish(model);
-		return;
+		rc = gen_level_move_publish(model);
+		return rc;
 	}
 
 	if (state->transition->counter == 0) {
-		return;
+		return 0;
 	}
 
 	state->transition->just_started = true;
 	gen_level_move_get(model, ctx, buf);
-	gen_level_move_publish(model);
+	rc = gen_level_move_publish(model);
 
 	if (bt_mesh_model_elem(model)->addr == elements[0].addr) {
 		/* Root element */
@@ -939,10 +960,11 @@ static void gen_move_set(struct bt_mesh_model *model,
 		transition_type = LEVEL_TEMP_TT_MOVE;
 		level_temp_handler(state);
 	}
+    return rc;
 }
 
 /* Generic Level Client message handlers */
-static void gen_level_status(struct bt_mesh_model *model,
+static int gen_level_status(struct bt_mesh_model *model,
 			     struct bt_mesh_msg_ctx *ctx,
 			     struct os_mbuf *buf)
 {
@@ -953,10 +975,11 @@ static void gen_level_status(struct bt_mesh_model *model,
 		printk("Target Level = %04x\n", net_buf_simple_pull_le16(buf));
 		printk("Remaining Time = %02x\n", net_buf_simple_pull_u8(buf));
 	}
+    return 0;
 }
 
 /* Generic Default Transition Time Server message handlers */
-static void gen_def_trans_time_get(struct bt_mesh_model *model,
+static int gen_def_trans_time_get(struct bt_mesh_model *model,
 				   struct bt_mesh_msg_ctx *ctx,
 				   struct os_mbuf *buf)
 {
@@ -971,16 +994,17 @@ static void gen_def_trans_time_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-static void gen_def_trans_time_publish(struct bt_mesh_model *model)
+static int gen_def_trans_time_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct gen_def_trans_time_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_GEN_DEF_TRANS_TIME_STATUS);
@@ -990,6 +1014,7 @@ static void gen_def_trans_time_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
 static bool gen_def_trans_time_setunack(struct bt_mesh_model *model,
@@ -1017,71 +1042,78 @@ static bool gen_def_trans_time_setunack(struct bt_mesh_model *model,
 	return true;
 }
 
-static void gen_def_trans_time_set_unack(struct bt_mesh_model *model,
+static int gen_def_trans_time_set_unack(struct bt_mesh_model *model,
 					 struct bt_mesh_msg_ctx *ctx,
 					 struct os_mbuf *buf)
 {
 	if (gen_def_trans_time_setunack(model, ctx, buf) == true) {
-		gen_def_trans_time_publish(model);
+        return gen_def_trans_time_publish(model);
 	}
+    return 0;
 }
 
-static void gen_def_trans_time_set(struct bt_mesh_model *model,
+static int gen_def_trans_time_set(struct bt_mesh_model *model,
 				   struct bt_mesh_msg_ctx *ctx,
 				   struct os_mbuf *buf)
 {
 	if (gen_def_trans_time_setunack(model, ctx, buf) == true) {
 		gen_def_trans_time_get(model, ctx, buf);
-		gen_def_trans_time_publish(model);
+        return gen_def_trans_time_publish(model);
 	}
+    return 0;
 }
 
 /* Generic Default Transition Time Client message handlers */
-static void gen_def_trans_time_status(struct bt_mesh_model *model,
+static int gen_def_trans_time_status(struct bt_mesh_model *model,
 				      struct bt_mesh_msg_ctx *ctx,
 				      struct os_mbuf *buf)
 {
 	printk("Acknownledgement from GEN_DEF_TT_SRV\n");
 	printk("Transition Time = %02x\n", net_buf_simple_pull_u8(buf));
+    return 0;
 }
 
 /* Generic Power OnOff Server message handlers */
-static void gen_onpowerup_get(struct bt_mesh_model *model,
+static int gen_onpowerup_get(struct bt_mesh_model *model,
 			      struct bt_mesh_msg_ctx *ctx,
 			      struct os_mbuf *buf)
 {
 	struct os_mbuf *msg = NET_BUF_SIMPLE(2 + 1 + 4);
 	struct generic_onpowerup_state *state = model->user_data;
+	int rc;
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_GEN_ONPOWERUP_STATUS);
 	net_buf_simple_add_u8(msg, state->onpowerup);
 
-	if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+	rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+	if (rc) {
 		printk("Unable to send GEN_POWER_ONOFF_SRV Status response\n");
 	}
 
 	os_mbuf_free_chain(msg);
+    return rc;
 }
 
 /* Generic Power OnOff Client message handlers */
-static void gen_onpowerup_status(struct bt_mesh_model *model,
+static int gen_onpowerup_status(struct bt_mesh_model *model,
 				 struct bt_mesh_msg_ctx *ctx,
 				 struct os_mbuf *buf)
 {
 	printk("Acknownledgement from GEN_POWER_ONOFF_SRV\n");
 	printk("OnPowerUp = %02x\n", net_buf_simple_pull_u8(buf));
+    return 0;
 }
 
 /* Generic Power OnOff Setup Server message handlers */
 
-static void gen_onpowerup_publish(struct bt_mesh_model *model)
+static int gen_onpowerup_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct generic_onpowerup_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_GEN_ONPOWERUP_STATUS);
@@ -1091,6 +1123,7 @@ static void gen_onpowerup_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
 static bool gen_onpowerup_setunack(struct bt_mesh_model *model,
@@ -1117,32 +1150,35 @@ static bool gen_onpowerup_setunack(struct bt_mesh_model *model,
 	return true;
 }
 
-static void gen_onpowerup_set_unack(struct bt_mesh_model *model,
+static int gen_onpowerup_set_unack(struct bt_mesh_model *model,
 				    struct bt_mesh_msg_ctx *ctx,
 				    struct os_mbuf *buf)
 {
 	if (gen_onpowerup_setunack(model, ctx, buf) == true) {
-		gen_onpowerup_publish(model);
+        return gen_onpowerup_publish(model);
 	}
+	return 0;
 }
 
-static void gen_onpowerup_set(struct bt_mesh_model *model,
+static int gen_onpowerup_set(struct bt_mesh_model *model,
 			      struct bt_mesh_msg_ctx *ctx,
 			      struct os_mbuf *buf)
 {
 	if (gen_onpowerup_setunack(model, ctx, buf) == true) {
 		gen_onpowerup_get(model, ctx, buf);
-		gen_onpowerup_publish(model);
+        return gen_onpowerup_publish(model);
 	}
+    return 0;
 }
 
 /* Vendor Model message handlers*/
-static void vnd_get(struct bt_mesh_model *model,
+static int vnd_get(struct bt_mesh_model *model,
 		    struct bt_mesh_msg_ctx *ctx,
 		    struct os_mbuf *buf)
 {
 	struct os_mbuf *msg = NET_BUF_SIMPLE(3 + 6 + 4);
 	struct vendor_state *state = model->user_data;
+    int err;
 
 	/* This is dummy response for demo purpose */
 	state->response = 0xA578FEB3;
@@ -1151,14 +1187,16 @@ static void vnd_get(struct bt_mesh_model *model,
 	net_buf_simple_add_le16(msg, state->current);
 	net_buf_simple_add_le32(msg, state->response);
 
-	if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+	err = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+	if (err) {
 		printk("Unable to send VENDOR Status response\n");
 	}
 
 	os_mbuf_free_chain(msg);
+    return err;
 }
 
-static void vnd_set_unack(struct bt_mesh_model *model,
+static int vnd_set_unack(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
@@ -1175,7 +1213,7 @@ static void vnd_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	state->last_tid = tid;
@@ -1193,27 +1231,37 @@ static void vnd_set_unack(struct bt_mesh_model *model,
 		/* LED2 Off */
 		hal_gpio_write(led_device[1], 1);
 	}
+    return 0;
 }
 
-static void vnd_set(struct bt_mesh_model *model,
+static int vnd_set(struct bt_mesh_model *model,
 		    struct bt_mesh_msg_ctx *ctx,
 		    struct os_mbuf *buf)
 {
-	vnd_set_unack(model, ctx, buf);
-	vnd_get(model, ctx, buf);
+    int rc;
+	rc = vnd_set_unack(model, ctx, buf);
+	if (rc) {
+        return rc;
+	}
+	rc = vnd_get(model, ctx, buf);
+	if (rc) {
+	    return rc;
+	}
+    return 0;
 }
 
-static void vnd_status(struct bt_mesh_model *model,
+static int vnd_status(struct bt_mesh_model *model,
 		       struct bt_mesh_msg_ctx *ctx,
 		       struct os_mbuf *buf)
 {
 	printk("Acknownledgement from Vendor\n");
 	printk("cmd = %04x\n", net_buf_simple_pull_le16(buf));
 	printk("response = %08lx\n", net_buf_simple_pull_le32(buf));
+    return 0;
 }
 
 /* Light Lightness Server message handlers */
-static void light_lightness_get(struct bt_mesh_model *model,
+static int light_lightness_get(struct bt_mesh_model *model,
 				struct bt_mesh_msg_ctx *ctx,
 				struct os_mbuf *buf)
 {
@@ -1234,16 +1282,17 @@ static void light_lightness_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-void light_lightness_publish(struct bt_mesh_model *model)
+int light_lightness_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_lightness_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_LIGHT_LIGHTNESS_STATUS);
@@ -1259,9 +1308,10 @@ void light_lightness_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void light_lightness_set_unack(struct bt_mesh_model *model,
+static int light_lightness_set_unack(struct bt_mesh_model *model,
 				      struct bt_mesh_msg_ctx *ctx,
 				      struct os_mbuf *buf)
 {
@@ -1278,7 +1328,7 @@ static void light_lightness_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -1289,13 +1339,13 @@ static void light_lightness_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -1318,7 +1368,7 @@ static void light_lightness_set_unack(struct bt_mesh_model *model,
 		light_lightness_actual_tt_values(state, tt, delay);
 	} else {
 		light_lightness_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -1329,9 +1379,10 @@ static void light_lightness_set_unack(struct bt_mesh_model *model,
 	state->transition->just_started = true;
 	light_lightness_publish(model);
 	light_lightness_actual_handler(state);
+    return 0;
 }
 
-static void light_lightness_set(struct bt_mesh_model *model,
+static int light_lightness_set(struct bt_mesh_model *model,
 				struct bt_mesh_msg_ctx *ctx,
 				struct os_mbuf *buf)
 {
@@ -1339,6 +1390,7 @@ static void light_lightness_set(struct bt_mesh_model *model,
 	uint16_t actual;
 	int64_t now;
 	struct light_lightness_state *state = model->user_data;
+	int rc;
 
 	actual = net_buf_simple_pull_le16(buf);
 	tid = net_buf_simple_pull_u8(buf);
@@ -1348,8 +1400,7 @@ static void light_lightness_set(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		light_lightness_get(model, ctx, buf);
-		return;
+	    return light_lightness_get(model, ctx, buf);
 	}
 
 	switch (buf->om_len) {
@@ -1360,13 +1411,13 @@ static void light_lightness_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -1388,9 +1439,9 @@ static void light_lightness_set(struct bt_mesh_model *model,
 	if (state->target_actual != state->actual) {
 		light_lightness_actual_tt_values(state, tt, delay);
 	} else {
-		light_lightness_get(model, ctx, buf);
+		rc = light_lightness_get(model, ctx, buf);
 		light_lightness_publish(model);
-		return;
+		return rc;
 	}
 
 	/* For Instantaneous Transition */
@@ -1402,9 +1453,10 @@ static void light_lightness_set(struct bt_mesh_model *model,
 	light_lightness_get(model, ctx, buf);
 	light_lightness_publish(model);
 	light_lightness_actual_handler(state);
+    return 0;
 }
 
-static void light_lightness_linear_get(struct bt_mesh_model *model,
+static int light_lightness_linear_get(struct bt_mesh_model *model,
 				       struct bt_mesh_msg_ctx *ctx,
 				       struct os_mbuf *buf)
 {
@@ -1426,16 +1478,17 @@ static void light_lightness_linear_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-void light_lightness_linear_publish(struct bt_mesh_model *model)
+int light_lightness_linear_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_lightness_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg,
@@ -1452,9 +1505,10 @@ void light_lightness_linear_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void light_lightness_linear_set_unack(struct bt_mesh_model *model,
+static int light_lightness_linear_set_unack(struct bt_mesh_model *model,
 					     struct bt_mesh_msg_ctx *ctx,
 					     struct os_mbuf *buf)
 {
@@ -1471,7 +1525,7 @@ static void light_lightness_linear_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -1482,13 +1536,13 @@ static void light_lightness_linear_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -1504,7 +1558,7 @@ static void light_lightness_linear_set_unack(struct bt_mesh_model *model,
 		light_lightness_linear_tt_values(state, tt, delay);
 	} else {
 		light_lightness_linear_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -1515,9 +1569,10 @@ static void light_lightness_linear_set_unack(struct bt_mesh_model *model,
 	state->transition->just_started = true;
 	light_lightness_linear_publish(model);
 	light_lightness_linear_handler(state);
+    return 0;
 }
 
-static void light_lightness_linear_set(struct bt_mesh_model *model,
+static int light_lightness_linear_set(struct bt_mesh_model *model,
 				       struct bt_mesh_msg_ctx *ctx,
 				       struct os_mbuf *buf)
 {
@@ -1525,6 +1580,7 @@ static void light_lightness_linear_set(struct bt_mesh_model *model,
 	uint16_t linear;
 	int64_t now;
 	struct light_lightness_state *state = model->user_data;
+	int rc;
 
 	linear = net_buf_simple_pull_le16(buf);
 	tid = net_buf_simple_pull_u8(buf);
@@ -1534,8 +1590,7 @@ static void light_lightness_linear_set(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		light_lightness_linear_get(model, ctx, buf);
-		return;
+	    return light_lightness_linear_get(model, ctx, buf);
 	}
 
 	switch (buf->om_len) {
@@ -1546,13 +1601,13 @@ static void light_lightness_linear_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -1567,9 +1622,9 @@ static void light_lightness_linear_set(struct bt_mesh_model *model,
 	if (state->target_linear != state->linear) {
 		light_lightness_linear_tt_values(state, tt, delay);
 	} else {
-		light_lightness_linear_get(model, ctx, buf);
+		rc = light_lightness_linear_get(model, ctx, buf);
 		light_lightness_linear_publish(model);
-		return;
+		return rc;
 	}
 
 	/* For Instantaneous Transition */
@@ -1581,9 +1636,10 @@ static void light_lightness_linear_set(struct bt_mesh_model *model,
 	light_lightness_linear_get(model, ctx, buf);
 	light_lightness_linear_publish(model);
 	light_lightness_linear_handler(state);
+    return 0;
 }
 
-static void light_lightness_last_get(struct bt_mesh_model *model,
+static int light_lightness_last_get(struct bt_mesh_model *model,
 				     struct bt_mesh_msg_ctx *ctx,
 				     struct os_mbuf *buf)
 {
@@ -1598,9 +1654,10 @@ static void light_lightness_last_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-static void light_lightness_default_get(struct bt_mesh_model *model,
+static int light_lightness_default_get(struct bt_mesh_model *model,
 					struct bt_mesh_msg_ctx *ctx,
 					struct os_mbuf *buf)
 {
@@ -1616,9 +1673,10 @@ static void light_lightness_default_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-static void light_lightness_range_get(struct bt_mesh_model *model,
+static int light_lightness_range_get(struct bt_mesh_model *model,
 				      struct bt_mesh_msg_ctx *ctx,
 				      struct os_mbuf *buf)
 {
@@ -1637,18 +1695,19 @@ static void light_lightness_range_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
 /* Light Lightness Setup Server message handlers */
 
-static void light_lightness_default_publish(struct bt_mesh_model *model)
+static int light_lightness_default_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_lightness_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg,
@@ -1659,9 +1718,10 @@ static void light_lightness_default_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void light_lightness_default_set_unack(struct bt_mesh_model *model,
+static int light_lightness_default_set_unack(struct bt_mesh_model *model,
 					      struct bt_mesh_msg_ctx *ctx,
 					      struct os_mbuf *buf)
 {
@@ -1679,26 +1739,37 @@ static void light_lightness_default_set_unack(struct bt_mesh_model *model,
 		save_on_flash(LIGHTNESS_TEMP_DEF_STATE);
 	}
 
-	light_lightness_default_publish(model);
+    return light_lightness_default_publish(model);
 }
 
-static void light_lightness_default_set(struct bt_mesh_model *model,
+static int light_lightness_default_set(struct bt_mesh_model *model,
 					struct bt_mesh_msg_ctx *ctx,
 					struct os_mbuf *buf)
 {
-	light_lightness_default_set_unack(model, ctx, buf);
-	light_lightness_default_get(model, ctx, buf);
-	light_lightness_default_publish(model);
+    int rc;
+	rc = light_lightness_default_set_unack(model, ctx, buf);
+	if (rc) {
+	    return rc;
+	}
+	rc = light_lightness_default_get(model, ctx, buf);
+	if (rc) {
+	    return rc;
+	}
+	rc = light_lightness_default_publish(model);
+	if (rc) {
+	    return rc;
+	}
+    return 0;
 }
 
-static void light_lightness_range_publish(struct bt_mesh_model *model)
+static int light_lightness_range_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_lightness_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_LIGHT_LIGHTNESS_RANGE_STATUS);
@@ -1710,6 +1781,7 @@ static void light_lightness_range_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
 static bool light_lightness_range_setunack(struct bt_mesh_model *model,
@@ -1748,27 +1820,36 @@ static bool light_lightness_range_setunack(struct bt_mesh_model *model,
 	return true;
 }
 
-static void light_lightness_range_set_unack(struct bt_mesh_model *model,
+static int light_lightness_range_set_unack(struct bt_mesh_model *model,
 					    struct bt_mesh_msg_ctx *ctx,
 					    struct os_mbuf *buf)
 {
 	if (light_lightness_range_setunack(model, ctx, buf) == true) {
-		light_lightness_range_publish(model);
+        return light_lightness_range_publish(model);
 	}
+    return 0;
 }
 
-static void light_lightness_range_set(struct bt_mesh_model *model,
+static int light_lightness_range_set(struct bt_mesh_model *model,
 				      struct bt_mesh_msg_ctx *ctx,
 				      struct os_mbuf *buf)
 {
+    int rc;
 	if (light_lightness_range_setunack(model, ctx, buf) == true) {
-		light_lightness_range_get(model, ctx, buf);
-		light_lightness_range_publish(model);
+		rc = light_lightness_range_get(model, ctx, buf);
+		if (rc) {
+		    return rc;
+		}
+		rc = light_lightness_range_publish(model);
+		if (rc) {
+		    return rc;
+		}
 	}
+    return 0;
 }
 
 /* Light Lightness Client message handlers */
-static void light_lightness_status(struct bt_mesh_model *model,
+static int light_lightness_status(struct bt_mesh_model *model,
 				   struct bt_mesh_msg_ctx *ctx,
 				   struct os_mbuf *buf)
 {
@@ -1780,9 +1861,10 @@ static void light_lightness_status(struct bt_mesh_model *model,
 		       net_buf_simple_pull_le16(buf));
 		printk("Remaining Time = %02x\n", net_buf_simple_pull_u8(buf));
 	}
+    return 0;
 }
 
-static void light_lightness_linear_status(struct bt_mesh_model *model,
+static int light_lightness_linear_status(struct bt_mesh_model *model,
 					  struct bt_mesh_msg_ctx *ctx,
 					  struct os_mbuf *buf)
 {
@@ -1794,25 +1876,28 @@ static void light_lightness_linear_status(struct bt_mesh_model *model,
 		       net_buf_simple_pull_le16(buf));
 		printk("Remaining Time = %02x\n", net_buf_simple_pull_u8(buf));
 	}
+    return 0;
 }
 
-static void light_lightness_last_status(struct bt_mesh_model *model,
+static int light_lightness_last_status(struct bt_mesh_model *model,
 					struct bt_mesh_msg_ctx *ctx,
 					struct os_mbuf *buf)
 {
 	printk("Acknownledgement from LIGHT_LIGHTNESS_SRV (Last)\n");
 	printk("Lightness = %04x\n", net_buf_simple_pull_le16(buf));
+    return 0;
 }
 
-static void light_lightness_default_status(struct bt_mesh_model *model,
+static int light_lightness_default_status(struct bt_mesh_model *model,
 					   struct bt_mesh_msg_ctx *ctx,
 					   struct os_mbuf *buf)
 {
 	printk("Acknownledgement from LIGHT_LIGHTNESS_SRV (Default)\n");
 	printk("Lightness = %04x\n", net_buf_simple_pull_le16(buf));
+    return 0;
 }
 
-static void light_lightness_range_status(struct bt_mesh_model *model,
+static int light_lightness_range_status(struct bt_mesh_model *model,
 					 struct bt_mesh_msg_ctx *ctx,
 					 struct os_mbuf *buf)
 {
@@ -1820,10 +1905,11 @@ static void light_lightness_range_status(struct bt_mesh_model *model,
 	printk("Status Code = %02x\n", net_buf_simple_pull_u8(buf));
 	printk("Range Min = %04x\n", net_buf_simple_pull_le16(buf));
 	printk("Range Max = %04x\n", net_buf_simple_pull_le16(buf));
+    return 0;
 }
 
 /* Light CTL Server message handlers */
-static void light_ctl_get(struct bt_mesh_model *model,
+static int light_ctl_get(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
@@ -1846,16 +1932,17 @@ static void light_ctl_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-void light_ctl_publish(struct bt_mesh_model *model)
+int light_ctl_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_ctl_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_LIGHT_CTL_STATUS);
@@ -1877,9 +1964,10 @@ void light_ctl_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void light_ctl_set_unack(struct bt_mesh_model *model,
+static int light_ctl_set_unack(struct bt_mesh_model *model,
 				struct bt_mesh_msg_ctx *ctx,
 				struct os_mbuf *buf)
 {
@@ -1895,7 +1983,7 @@ static void light_ctl_set_unack(struct bt_mesh_model *model,
 	tid = net_buf_simple_pull_u8(buf);
 
 	if (temp < TEMP_MIN || temp > TEMP_MAX) {
-		return;
+		return 0;
 	}
 
 	now = k_uptime_get();
@@ -1903,7 +1991,7 @@ static void light_ctl_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -1914,13 +2002,13 @@ static void light_ctl_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -1947,7 +2035,7 @@ static void light_ctl_set_unack(struct bt_mesh_model *model,
 		light_ctl_tt_values(state, tt, delay);
 	} else {
 		light_ctl_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -1960,9 +2048,10 @@ static void light_ctl_set_unack(struct bt_mesh_model *model,
 	state->transition->just_started = true;
 	light_ctl_publish(model);
 	light_ctl_handler(state);
+    return 0;
 }
 
-static void light_ctl_set(struct bt_mesh_model *model,
+static int light_ctl_set(struct bt_mesh_model *model,
 			  struct bt_mesh_msg_ctx *ctx,
 			  struct os_mbuf *buf)
 {
@@ -1978,7 +2067,7 @@ static void light_ctl_set(struct bt_mesh_model *model,
 	tid = net_buf_simple_pull_u8(buf);
 
 	if (temp < TEMP_MIN || temp > TEMP_MAX) {
-		return;
+		return 0;
 	}
 
 	now = k_uptime_get();
@@ -1987,7 +2076,7 @@ static void light_ctl_set(struct bt_mesh_model *model,
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
 		light_ctl_get(model, ctx, buf);
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -1998,13 +2087,13 @@ static void light_ctl_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -2032,7 +2121,7 @@ static void light_ctl_set(struct bt_mesh_model *model,
 	} else {
 		light_ctl_get(model, ctx, buf);
 		light_ctl_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -2046,14 +2135,16 @@ static void light_ctl_set(struct bt_mesh_model *model,
 	light_ctl_get(model, ctx, buf);
 	light_ctl_publish(model);
 	light_ctl_handler(state);
+    return 0;
 }
 
-static void light_ctl_temp_range_get(struct bt_mesh_model *model,
+static int light_ctl_temp_range_get(struct bt_mesh_model *model,
 				     struct bt_mesh_msg_ctx *ctx,
 				     struct os_mbuf *buf)
 {
 	struct os_mbuf *msg = NET_BUF_SIMPLE(2 + 5 + 4);
 	struct light_ctl_state *state = model->user_data;
+    int rc;
 
 	state->status_code = RANGE_SUCCESSFULLY_UPDATED;
 
@@ -2062,42 +2153,47 @@ static void light_ctl_temp_range_get(struct bt_mesh_model *model,
 	net_buf_simple_add_le16(msg, state->temp_range_min);
 	net_buf_simple_add_le16(msg, state->temp_range_max);
 
-	if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+	rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+	if (rc) {
 		printk("Unable to send LightCTL Temp Range Status response\n");
 	}
 
 	os_mbuf_free_chain(msg);
+    return rc;
 }
 
-static void light_ctl_default_get(struct bt_mesh_model *model,
+static int light_ctl_default_get(struct bt_mesh_model *model,
 				  struct bt_mesh_msg_ctx *ctx,
 				  struct os_mbuf *buf)
 {
 	struct os_mbuf *msg = NET_BUF_SIMPLE(2 + 6 + 4);
 	struct light_ctl_state *state = model->user_data;
+    int rc;
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_LIGHT_CTL_DEFAULT_STATUS);
 	net_buf_simple_add_le16(msg, state->lightness_def);
 	net_buf_simple_add_le16(msg, state->temp_def);
 	net_buf_simple_add_le16(msg, state->delta_uv_def);
 
-	if (bt_mesh_model_send(model, ctx, msg, NULL, NULL)) {
+	rc = bt_mesh_model_send(model, ctx, msg, NULL, NULL);
+	if (rc) {
 		printk("Unable to send LightCTL Default Status response\n");
 	}
 
 	os_mbuf_free_chain(msg);
+    return rc;
 }
 
 /* Light CTL Setup Server message handlers */
 
-static void light_ctl_default_publish(struct bt_mesh_model *model)
+static int light_ctl_default_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_ctl_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_LIGHT_CTL_DEFAULT_STATUS);
@@ -2109,6 +2205,7 @@ static void light_ctl_default_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
 static bool light_ctl_default_setunack(struct bt_mesh_model *model,
@@ -2147,33 +2244,35 @@ static bool light_ctl_default_setunack(struct bt_mesh_model *model,
 	return true;
 }
 
-static void light_ctl_default_set_unack(struct bt_mesh_model *model,
+static int light_ctl_default_set_unack(struct bt_mesh_model *model,
 					struct bt_mesh_msg_ctx *ctx,
 					struct os_mbuf *buf)
 {
 	if (light_ctl_default_setunack(model, ctx, buf) == true) {
-		light_ctl_default_publish(model);
+        return light_ctl_default_publish(model);
 	}
+    return 0;
 }
 
-static void light_ctl_default_set(struct bt_mesh_model *model,
+static int light_ctl_default_set(struct bt_mesh_model *model,
 				  struct bt_mesh_msg_ctx *ctx,
 				  struct os_mbuf *buf)
 {
 	if (light_ctl_default_setunack(model, ctx, buf) == true) {
 		light_ctl_default_get(model, ctx, buf);
-		light_ctl_default_publish(model);
+        return light_ctl_default_publish(model);
 	}
+    return 0;
 }
 
-static void light_ctl_temp_range_publish(struct bt_mesh_model *model)
+static int light_ctl_temp_range_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_ctl_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_LIGHT_CTL_TEMP_RANGE_STATUS);
@@ -2185,6 +2284,7 @@ static void light_ctl_temp_range_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
 static bool light_ctl_temp_range_setunack(struct bt_mesh_model *model,
@@ -2225,27 +2325,29 @@ static bool light_ctl_temp_range_setunack(struct bt_mesh_model *model,
 	return true;
 }
 
-static void light_ctl_temp_range_set_unack(struct bt_mesh_model *model,
+static int light_ctl_temp_range_set_unack(struct bt_mesh_model *model,
 					   struct bt_mesh_msg_ctx *ctx,
 					   struct os_mbuf *buf)
 {
 	if (light_ctl_temp_range_setunack(model, ctx, buf) == true) {
-		light_ctl_temp_range_publish(model);
+        return light_ctl_temp_range_publish(model);
 	}
+    return 0;
 }
 
-static void light_ctl_temp_range_set(struct bt_mesh_model *model,
+static int light_ctl_temp_range_set(struct bt_mesh_model *model,
 				     struct bt_mesh_msg_ctx *ctx,
 				     struct os_mbuf *buf)
 {
 	if (light_ctl_temp_range_setunack(model, ctx, buf) == true) {
 		light_ctl_temp_range_get(model, ctx, buf);
-		light_ctl_temp_range_publish(model);
+        return light_ctl_temp_range_publish(model);
 	}
+    return 0;
 }
 
 /* Light CTL Client message handlers */
-static void light_ctl_status(struct bt_mesh_model *model,
+static int light_ctl_status(struct bt_mesh_model *model,
 			     struct bt_mesh_msg_ctx *ctx,
 			     struct os_mbuf *buf)
 {
@@ -2261,9 +2363,10 @@ static void light_ctl_status(struct bt_mesh_model *model,
 		       net_buf_simple_pull_le16(buf));
 		printk("Remaining Time = %02x\n", net_buf_simple_pull_u8(buf));
 	}
+    return 0;
 }
 
-static void light_ctl_temp_range_status(struct bt_mesh_model *model,
+static int light_ctl_temp_range_status(struct bt_mesh_model *model,
 					struct bt_mesh_msg_ctx *ctx,
 					struct os_mbuf *buf)
 {
@@ -2271,9 +2374,10 @@ static void light_ctl_temp_range_status(struct bt_mesh_model *model,
 	printk("Status Code = %02x\n", net_buf_simple_pull_u8(buf));
 	printk("Range Min = %04x\n", net_buf_simple_pull_le16(buf));
 	printk("Range Max = %04x\n", net_buf_simple_pull_le16(buf));
+    return 0;
 }
 
-static void light_ctl_temp_status(struct bt_mesh_model *model,
+static int light_ctl_temp_status(struct bt_mesh_model *model,
 				  struct bt_mesh_msg_ctx *ctx,
 				  struct os_mbuf *buf)
 {
@@ -2290,9 +2394,10 @@ static void light_ctl_temp_status(struct bt_mesh_model *model,
 		       net_buf_simple_pull_le16(buf));
 		printk("Remaining Time = %02x\n", net_buf_simple_pull_u8(buf));
 	}
+    return 0;
 }
 
-static void light_ctl_default_status(struct bt_mesh_model *model,
+static int light_ctl_default_status(struct bt_mesh_model *model,
 				     struct bt_mesh_msg_ctx *ctx,
 				     struct os_mbuf *buf)
 {
@@ -2300,10 +2405,11 @@ static void light_ctl_default_status(struct bt_mesh_model *model,
 	printk("Lightness = %04x\n", net_buf_simple_pull_le16(buf));
 	printk("Temperature = %04x\n", net_buf_simple_pull_le16(buf));
 	printk("Delta UV = %04x\n", net_buf_simple_pull_le16(buf));
+    return 0;
 }
 
 /* Light CTL Temp. Server message handlers */
-static void light_ctl_temp_get(struct bt_mesh_model *model,
+static int light_ctl_temp_get(struct bt_mesh_model *model,
 			       struct bt_mesh_msg_ctx *ctx,
 			       struct os_mbuf *buf)
 {
@@ -2326,16 +2432,17 @@ static void light_ctl_temp_get(struct bt_mesh_model *model,
 	}
 
 	os_mbuf_free_chain(msg);
+    return 0;
 }
 
-void light_ctl_temp_publish(struct bt_mesh_model *model)
+int light_ctl_temp_publish(struct bt_mesh_model *model)
 {
 	int err;
 	struct os_mbuf *msg = model->pub->msg;
 	struct light_ctl_state *state = model->user_data;
 
 	if (model->pub->addr == BT_MESH_ADDR_UNASSIGNED) {
-		return;
+		return 0;
 	}
 
 	bt_mesh_model_msg_init(msg, BT_MESH_MODEL_LIGHT_CTL_TEMP_STATUS);
@@ -2353,9 +2460,10 @@ void light_ctl_temp_publish(struct bt_mesh_model *model)
 	if (err) {
 		printk("bt_mesh_model_publish err %d\n", err);
 	}
+    return err;
 }
 
-static void light_ctl_temp_set_unack(struct bt_mesh_model *model,
+static int light_ctl_temp_set_unack(struct bt_mesh_model *model,
 				     struct bt_mesh_msg_ctx *ctx,
 				     struct os_mbuf *buf)
 {
@@ -2370,7 +2478,7 @@ static void light_ctl_temp_set_unack(struct bt_mesh_model *model,
 	tid = net_buf_simple_pull_u8(buf);
 
 	if (temp < TEMP_MIN || temp > TEMP_MAX) {
-		return;
+		return 0;
 	}
 
 	now = k_uptime_get();
@@ -2378,7 +2486,7 @@ static void light_ctl_temp_set_unack(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		return;
+		return 0;
 	}
 
 	switch (buf->om_len) {
@@ -2389,13 +2497,13 @@ static void light_ctl_temp_set_unack(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -2420,7 +2528,7 @@ static void light_ctl_temp_set_unack(struct bt_mesh_model *model,
 		light_ctl_temp_tt_values(state, tt, delay);
 	} else {
 		light_ctl_temp_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -2432,9 +2540,10 @@ static void light_ctl_temp_set_unack(struct bt_mesh_model *model,
 	state->transition->just_started = true;
 	light_ctl_temp_publish(model);
 	light_ctl_temp_handler(state);
+    return 0;
 }
 
-static void light_ctl_temp_set(struct bt_mesh_model *model,
+static int light_ctl_temp_set(struct bt_mesh_model *model,
 			       struct bt_mesh_msg_ctx *ctx,
 			       struct os_mbuf *buf)
 {
@@ -2449,7 +2558,7 @@ static void light_ctl_temp_set(struct bt_mesh_model *model,
 	tid = net_buf_simple_pull_u8(buf);
 
 	if (temp < TEMP_MIN || temp > TEMP_MAX) {
-		return;
+		return 0;
 	}
 
 	now = k_uptime_get();
@@ -2457,8 +2566,7 @@ static void light_ctl_temp_set(struct bt_mesh_model *model,
 	    state->last_src_addr == ctx->addr &&
 	    state->last_dst_addr == ctx->recv_dst &&
 	    (now - state->last_msg_timestamp <= K_SECONDS(6))) {
-		light_ctl_temp_get(model, ctx, buf);
-		return;
+	    return light_ctl_temp_get(model, ctx, buf);
 	}
 
 	switch (buf->om_len) {
@@ -2469,13 +2577,13 @@ static void light_ctl_temp_set(struct bt_mesh_model *model,
 	case 0x02:	/* Optional fields are available */
 		tt = net_buf_simple_pull_u8(buf);
 		if ((tt & 0x3F) == 0x3F) {
-			return;
+			return 0;
 		}
 
 		delay = net_buf_simple_pull_u8(buf);
 		break;
 	default:
-		return;
+		return 0;
 	}
 
 	*ptr_counter = 0;
@@ -2501,7 +2609,7 @@ static void light_ctl_temp_set(struct bt_mesh_model *model,
 	} else {
 		light_ctl_temp_get(model, ctx, buf);
 		light_ctl_temp_publish(model);
-		return;
+		return 0;
 	}
 
 	/* For Instantaneous Transition */
@@ -2514,6 +2622,7 @@ static void light_ctl_temp_set(struct bt_mesh_model *model,
 	light_ctl_temp_get(model, ctx, buf);
 	light_ctl_temp_publish(model);
 	light_ctl_temp_handler(state);
+    return 0;
 }
 
 /* message handlers (End) */
diff --git a/apps/blemesh_models_example_2/src/device_composition.h b/apps/blemesh_models_example_2/src/device_composition.h
index d0f054ee2..1b5bf5f72 100644
--- a/apps/blemesh_models_example_2/src/device_composition.h
+++ b/apps/blemesh_models_example_2/src/device_composition.h
@@ -167,11 +167,11 @@ extern struct bt_mesh_model s0_models[];
 
 extern const struct bt_mesh_comp comp;
 
-void gen_onoff_publish(struct bt_mesh_model *model);
-void gen_level_publish(struct bt_mesh_model *model);
-void light_lightness_publish(struct bt_mesh_model *model);
-void light_lightness_linear_publish(struct bt_mesh_model *model);
-void light_ctl_publish(struct bt_mesh_model *model);
-void light_ctl_temp_publish(struct bt_mesh_model *model);
+int gen_onoff_publish(struct bt_mesh_model *model);
+int gen_level_publish(struct bt_mesh_model *model);
+int light_lightness_publish(struct bt_mesh_model *model);
+int light_lightness_linear_publish(struct bt_mesh_model *model);
+int light_ctl_publish(struct bt_mesh_model *model);
+int light_ctl_temp_publish(struct bt_mesh_model *model);
 
 #endif