Fix reconnection

src/USB2.cpp

@@ -521,12 +521,9 @@ void USB2::write(const Tango::DevVarCharArray *argin)
 				"", init_error.c_str(), __PRETTY_FUNCTION__);
 	}
 
-	if (max(output_queue_length(), 0) != 0) {
-		close();
-		open();
-		reconnections += 1;
+	if (max(output_queue_length(), 0) != 0 || ! dev_handle)
 		goto error;
-	}
+	
 	while (bytes_total < bytes_to_write) {
 		ssize_t bytes_written;
 		conn_state = libusb_bulk_transfer(dev_handle, ep_down, 
@@ -758,6 +755,9 @@ void USB2::_read(size_t bytes_to_read)
 	size_t bytes_total = data.size();
 	int bytes_readed;
 
+	if (! dev_handle)
+		goto error;
+
 	while (bytes_total < bytes_to_read) {
 		conn_state = libusb_bulk_transfer(dev_handle, ep_up, buffer,
 				maxPacketSize, &bytes_readed, timeout);