LoRaWAN: Terminate RX when receiving uplink messages

This prevents RX2 window to be enabled at the same time when repeating
transmission, when QoS repeated TX is in effect. Failure to do so
seems to place the LoRaWAN stack in a state where send() always fails
with WOULD_BLOCK error.

Author: Teijo Kinnunen

features/lorawan/lorastack/mac/LoRaMac.cpp

@@ -738,6 +738,15 @@ void LoRaMac::on_radio_rx_done(const uint8_t *const payload, uint16_t size,
             break;
 
         default:
+            //  This can happen e.g. if we happen to receive uplink of another device
+            //  during the receive window. Block RX2 window since it can overlap with
+            //  QOS TX and cause a mess.
+            tr_debug("RX unexpected mtype %u", mac_hdr.bits.mtype);
+            if (get_current_slot() == RX_SLOT_WIN_1) {
+                _lora_time.stop(_params.timers.rx_window2_timer);
+            }
+            _mcps_indication.status = LORAMAC_EVENT_INFO_STATUS_ADDRESS_FAIL;
+            _mcps_indication.pending = false;
             break;
     }
 }