Bluetooth: Controller: llcp: add missing handling LL_UNKNOWN in CTE llcp

There was missing handling of LL_UNKNOWN_RSP in CTE request control
procedure.In case there is a pending CTE request and peer responses
with LL_UNKNOWN_RSP then Host should be notified with HCI_LE_CTE_-
Request_Failed event. The pending CTE request procedure should be
completed.
Signed-off-by: Piotr Pryga <[email protected]>

Author: ppryga-nordic

subsys/bluetooth/controller/hci/hci.c

@@ -7908,7 +7908,11 @@ static void le_unknown_rsp(struct pdu_data *pdu_data, uint16_t handle,
 		le_remote_feat_complete(BT_HCI_ERR_UNSUPP_REMOTE_FEATURE,
 					    NULL, handle, buf);
 		break;
-
+#if defined(CONFIG_BT_CTLR_DF_CONN_CTE_REQ)
+	case PDU_DATA_LLCTRL_TYPE_CTE_REQ:
+		le_df_cte_req_failed(BT_HCI_ERR_UNSUPP_REMOTE_FEATURE, handle, buf);
+		break;
+#endif /* CONFIG_BT_CTLR_DF_CONN_CTE_REQ */
 	default:
 		BT_WARN("type: 0x%02x",	pdu_data->llctrl.unknown_rsp.type);
 		break;

subsys/bluetooth/controller/ll_sw/ull_conn_types.h

@@ -404,7 +404,17 @@ struct llcp_struct {
 	struct {
 		uint8_t sent;
 		uint8_t valid;
+		/*
+		 * Stores features supported by peer device. The content of the member may be
+		 * verified when feature exchange procedure has completed, valid member is set to 1.
+		 */
 		uint64_t features_peer;
+		/*
+		 * Stores features common for two connected devices. Before feature exchange
+		 * procedure is completed, the member stores information about all features
+		 * supported by local device. After completion of the procedure, the feature set
+		 * may be limited to features that are common.
+		 */
 		uint64_t features_used;
 	} fex;
 

subsys/bluetooth/controller/ll_sw/ull_llcp.c

@@ -971,6 +971,19 @@ uint8_t ull_cp_cte_req(struct ll_conn *conn, uint8_t min_cte_len, uint8_t cte_ty
 {
 	struct proc_ctx *ctx;
 
+	/* If Controller gained, awareness:
+	 * - by Feature Exchange control procedure that peer device does not support CTE response,
+	 * - by reception LL_UNKNOWN_RSP with unknown type LL_CTE_REQ that peer device does not
+	 *   recognize CTE request,
+	 * then response to Host that CTE request enable command is not possible due to unsupported
+	 * remote feature.
+	 */
+	if ((conn->llcp.fex.valid &&
+	     (!(conn->llcp.fex.features_peer & BIT64(BT_LE_FEAT_BIT_CONN_CTE_RESP)))) ||
+	    (!conn->llcp.fex.valid && !feature_cte_req(conn))) {
+		return BT_HCI_ERR_UNSUPP_REMOTE_FEATURE;
+	}
+
 	/* The request may be started by periodic CTE request procedure, so it skips earlier
 	 * verification of PHY. In case the PHY has changed to CODE the request should be stopped.
 	 */

subsys/bluetooth/controller/ll_sw/ull_llcp_common.c

@@ -219,6 +219,9 @@ static void lp_comm_ntf_cte_req(struct ll_conn *conn, struct proc_ctx *ctx, stru
 			llcp_ntf_encode_cte_req(pdu);
 		}
 		break;
+	case PDU_DATA_LLCTRL_TYPE_UNKNOWN_RSP:
+		llcp_ntf_encode_unknown_rsp(ctx, pdu);
+		break;
 	case PDU_DATA_LLCTRL_TYPE_REJECT_EXT_IND:
 		llcp_ntf_encode_reject_ext_ind(ctx, pdu);
 		break;
@@ -228,6 +231,17 @@ static void lp_comm_ntf_cte_req(struct ll_conn *conn, struct proc_ctx *ctx, stru
 	}
 }
 
+static void lp_comm_ntf_cte_req_tx(struct ll_conn *conn, struct proc_ctx *ctx)
+{
+	if (llcp_ntf_alloc_is_available()) {
+		lp_comm_ntf(conn, ctx);
+		ull_cp_cte_req_set_disable(conn);
+		ctx->state = LP_COMMON_STATE_IDLE;
+	} else {
+		ctx->state = LP_COMMON_STATE_WAIT_NTF;
+	}
+}
+
 static void lp_comm_complete_cte_req(struct ll_conn *conn, struct proc_ctx *ctx)
 {
 	if (conn->llcp.cte_req.is_enabled) {
@@ -238,22 +252,19 @@ static void lp_comm_complete_cte_req(struct ll_conn *conn, struct proc_ctx *ctx)
 						conn->llcp.cte_req.req_interval;
 				}
 				ctx->state = LP_COMMON_STATE_IDLE;
-			} else if (llcp_ntf_alloc_is_available()) {
-				lp_comm_ntf(conn, ctx);
-				ull_cp_cte_req_set_disable(conn);
-				ctx->state = LP_COMMON_STATE_IDLE;
 			} else {
-				ctx->state = LP_COMMON_STATE_WAIT_NTF;
+				lp_comm_ntf_cte_req_tx(conn, ctx);
 			}
 		} else if (ctx->response_opcode == PDU_DATA_LLCTRL_TYPE_REJECT_EXT_IND &&
-			ctx->reject_ext_ind.reject_opcode == PDU_DATA_LLCTRL_TYPE_CTE_REQ) {
-			if (llcp_ntf_alloc_is_available()) {
-				lp_comm_ntf(conn, ctx);
-				ull_cp_cte_req_set_disable(conn);
-				ctx->state = LP_COMMON_STATE_IDLE;
-			} else {
-				ctx->state = LP_COMMON_STATE_WAIT_NTF;
-			}
+			   ctx->reject_ext_ind.reject_opcode == PDU_DATA_LLCTRL_TYPE_CTE_REQ) {
+			lp_comm_ntf_cte_req_tx(conn, ctx);
+		} else if (ctx->response_opcode == PDU_DATA_LLCTRL_TYPE_UNKNOWN_RSP &&
+			   ctx->unknown_response.type == PDU_DATA_LLCTRL_TYPE_CTE_REQ) {
+			/* CTE response is unsupported in peer, so disable locally for this
+			 * connection
+			 */
+			feature_unmask_features(conn, LL_FEAT_BIT_CONNECTION_CTE_REQ);
+			lp_comm_ntf_cte_req_tx(conn, ctx);
 		} 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

subsys/bluetooth/controller/ll_sw/ull_llcp_features.h

@@ -117,6 +117,15 @@ static inline bool feature_phy_coded(struct ll_conn *conn)
 #endif
 }
 
+static inline bool feature_cte_req(struct ll_conn *conn)
+{
+#if defined(CONFIG_BT_CTLR_DF) && defined(CONFIG_BT_CTLR_DF_CONN_CTE_REQ)
+	return conn->llcp.fex.features_used & LL_FEAT_BIT_CONNECTION_CTE_REQ;
+#else
+	return 0;
+#endif
+}
+
 /*
  * for asymmetric features we can check either if we support it
  * or if the peer supports it
@@ -148,10 +157,6 @@ static inline bool feature_peer_smi_tx(struct ll_conn *conn)
  * per_adv
  * pwr_class1
  * min_chann
- * CTE_req
- * CTE_rsp
- * CTE_tx
- * CTE_rx
  * ant_sw_CTE_tx
  * ant_sw_CTE_rx
  * tone_ext