Bluetooth: Controller: Add CTE REQ disable when change PHY to CODED

Accodring to BT 5.3 Core Vol 4, Part E section 7.8.85 the CTE request
procedure has to be disabled as if Host issued the HCI_LE_Connection-
CTE_Request_Enable with enable property set to 0. It means a Controller
should automaticall  disable the procedure.

There were no handling of this part of specification.

Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>

subsys/bluetooth/controller/ll_sw/ull_conn.c

@@ -1654,9 +1654,24 @@ void ull_conn_done(struct node_rx_event_done *done)
 		if (conn->llcp.cte_req.req_expire > elapsed_event) {
 			conn->llcp.cte_req.req_expire -= elapsed_event;
 		} else {
+			uint8_t err;
+
 			conn->llcp.cte_req.req_expire = 0U;
-			ull_cp_cte_req(conn, conn->llcp.cte_req.min_cte_len,
+
-				       conn->llcp.cte_req.cte_type);
+			err = ull_cp_cte_req(conn, conn->llcp.cte_req.min_cte_len,
+					     conn->llcp.cte_req.cte_type);
+
+			if (err == BT_HCI_ERR_CMD_DISALLOWED) {
+				/* Conditions has changed e.g. PHY was changed to CODED.
+				 * New CTE REQ is not possible. Disable the periodic requests.
+				 *
+				 * If the CTE REQ is in active state, let it complete and disable
+				 * in regular control procedure way.
+				 */
+				if (!conn->llcp.cte_req.is_active) {
+					ull_cp_cte_req_set_disable(conn);
+				}
+			}
 		}
 	}
 #endif /* CONFIG_BT_CTLR_DF_CONN_CTE_REQ */

subsys/bluetooth/controller/ll_sw/ull_llcp.c

@@ -903,19 +903,30 @@ uint8_t ull_cp_cte_req(struct ll_conn *conn, uint8_t min_cte_len, uint8_t cte_ty
 {
 	struct proc_ctx *ctx;
 
-	ctx = llcp_create_local_procedure(PROC_CTE_REQ);
+	/* The request may be started by periodic CTE request procedure, so it skips earlier
-	if (!ctx) {
+	 * verification of PHY. In case the PHY has changed to CODE the request should be stopped.
-		return BT_HCI_ERR_CMD_DISALLOWED;
+	 */
+#if defined(CONFIG_BT_CTLR_PHY)
+	if (conn->lll.phy_rx != PHY_CODED) {
+#else
+	if (1) {
+#endif /* CONFIG_BT_CTLR_PHY */
+		ctx = llcp_create_local_procedure(PROC_CTE_REQ);
+		if (!ctx) {
+			return BT_HCI_ERR_CMD_DISALLOWED;
+		}
+
+		ctx->data.cte_req.min_len = min_cte_len;
+		ctx->data.cte_req.type = cte_type;
+
+		conn->llcp.cte_req.is_active = 1U;
+
+		llcp_lr_enqueue(conn, ctx);
+
+		return BT_HCI_ERR_SUCCESS;
 	}
 
-	ctx->data.cte_req.min_len = min_cte_len;
+	return BT_HCI_ERR_CMD_DISALLOWED;
-	ctx->data.cte_req.type = cte_type;
-
-	conn->llcp.cte_req.is_active = 1U;
-
-	llcp_lr_enqueue(conn, ctx);
-
-	return BT_HCI_ERR_SUCCESS;
 }
 
 void ull_cp_cte_req_set_disable(struct ll_conn *conn)

subsys/bluetooth/controller/ll_sw/ull_llcp_common.c

@@ -353,14 +353,22 @@ static void lp_comm_complete(struct ll_conn *conn, struct proc_ctx *ctx, uint8_t
 			    conn->llcp.cte_req.req_interval != 0U) {
 				conn->llcp.cte_req.req_expire = conn->llcp.cte_req.req_interval;
 			} else {
-				conn->llcp.cte_req.is_enabled = 0U;
+				/* TODO: add wait for notification buffer */
 				lp_comm_ntf(conn, ctx);
 				ull_cp_cte_req_set_disable(conn);
 			}
 		} else if (ctx->response_opcode == PDU_DATA_LLCTRL_TYPE_REJECT_EXT_IND &&
 			   ctx->reject_ext_ind.reject_opcode == PDU_DATA_LLCTRL_TYPE_CTE_REQ) {
+			/* TODO: add wait for notification buffer */
 			lp_comm_ntf(conn, ctx);
-			conn->llcp.cte_req.is_enabled = 0U;
+			ull_cp_cte_req_set_disable(conn);
+		} else if (ctx->response_opcode == PDU_DATA_LLCTRL_TYPE_UNUSED) {
+			/* This path is related with handling disable the CTE REQ when PHY
+			 * has been changed to CODED PHY. BT 5.3 Core Vol 4 Part E 7.8.85
+			 * says CTE REQ has to be automatically disabled as if it had been requested
+			 * by Host. There is no notification send to Host.
+			 */
+			ull_cp_cte_req_set_disable(conn);
 		}
 
 		llcp_rr_set_paused_cmd(conn, PROC_NONE);
@@ -467,12 +475,30 @@ static void lp_comm_send_req(struct ll_conn *conn, struct proc_ctx *ctx, uint8_t
 #endif /* CONFIG_BT_CTLR_DATA_LENGTH */
 #if defined(CONFIG_BT_CTLR_DF_CONN_CTE_REQ)
 	case PROC_CTE_REQ:
-		if (ctx->pause || !llcp_tx_alloc_peek(conn, ctx) ||
+#if defined(CONFIG_BT_CTLR_PHY)
-		    (llcp_rr_get_paused_cmd(conn) == PROC_CTE_REQ)) {
+		if (conn->lll.phy_rx != PHY_CODED) {
-			ctx->state = LP_COMMON_STATE_WAIT_TX;
+#else
+		if (1) {
+#endif /* CONFIG_BT_CTLR_PHY */
+			if (ctx->pause || !llcp_tx_alloc_peek(conn, ctx) ||
+			    (llcp_rr_get_paused_cmd(conn) == PROC_CTE_REQ)) {
+				ctx->state = LP_COMMON_STATE_WAIT_TX;
+			} else {
+				lp_comm_tx(conn, ctx);
+				ctx->state = LP_COMMON_STATE_WAIT_RX;
+			}
 		} else {
-			lp_comm_tx(conn, ctx);
+			/* The PHY was changed to CODED when the request was waiting in a local
-			ctx->state = LP_COMMON_STATE_WAIT_RX;
+			 * request queue.
+			 *
+			 * Use of pair: proc PROC_CTE_REQ and rx_opcode PDU_DATA_LLCTRL_TYPE_UNUSED
+			 * to complete the procedure before sending a request to peer.
+			 * This is a special complete execution path to disable the procedure
+			 * due to change of RX PHY to CODED.
+			 */
+			ctx->rx_opcode = PDU_DATA_LLCTRL_TYPE_UNUSED;
+			ctx->state = LP_COMMON_STATE_IDLE;
+			llcp_lr_complete(conn);
 		}
 		break;
 #endif /* CONFIG_BT_CTLR_DF_CONN_CTE_REQ */