Merged in LP-457_fallthrough_fix (pull request #549)

LP-457 Fix build errors

Approved-by: Eric Price

flight/modules/GPS/ubx_autoconfig.c

@@ -450,6 +450,7 @@ static void configure(uint16_t *bytes_to_send)
             config_rate(bytes_to_send, min_rate);
             break;
         }
+    // fall through
 
     case LAST_CONFIG_SENT_START + 1:
         config_nav(bytes_to_send);
@@ -717,7 +718,7 @@ void gps_ubx_autoconfig_run(char * *buffer, uint16_t *bytes_to_send)
     // we can do that if we choose because we haven't sent any data in this state
     // set_current_step_if_untouched(INIT_STEP_SET_LOWRATE);
     // allow it enter the next state immmediately by not setting status->lastStepTimestampRaw = PIOS_DELAY_GetRaw();
-    // break;
+    // fall through
 
     case INIT_STEP_SET_LOWRATE:
         // Here we set minimal baudrate *before* changing gps baudrate

flight/pios/posix/pios_com.c

@@ -280,6 +280,26 @@ int32_t PIOS_COM_ChangeBaud(uint32_t com_id, uint32_t baud)
     return 0;
 }
 
+/**
+ * Clear Rx buffer
+ * \param[in] port COM port
+ * \return -1 if port not available
+ * \return 0 on success
+ */
+int32_t PIOS_COM_ClearRxBuffer(uint32_t com_id)
+{
+    struct pios_com_dev *com_dev = PIOS_COM_find_dev(com_id);
+
+    if (!PIOS_COM_validate(com_dev)) {
+        /* Undefined COM port for this board (see pios_board.c) */
+        return -1;
+    }
+
+    fifoBuf_clearData(&com_dev->rx);
+
+    return 0;
+}
+
 /**
  * Sends a package over given port
  * \param[in] port COM port