Echo on serial must be only a "best effort" and not mangle with ongoing transmissions

diff --git a/drivers/serial.c b/drivers/serial.c
index 47dd72c..f5e561d 100644 (file)
--- a/drivers/serial.c
+++ b/drivers/serial.c
@@ -105,8 +105,10 @@ static void uart_check_rx(struct uart_device* uart, uint32_t intr)
                        /* Call the Rx callback */
                        uart->rx_callback(data);
                } else {
-                       /* Echo */
-                       uart->regs->tx_data = data;
+                       /* Echo ? */
+                       if (!uart->sending) {
+                               uart->regs->tx_data = data;
+                       }
                }
        }
        /* FIXME : handle RX erors */