From 7043738f3b9e0bf530219a972799d4e7bd09b42e Mon Sep 17 00:00:00 2001
From: Michael du Breuil <wicked.shell.scripts@gmail.com>
Date: Wed, 20 Jun 2018 02:00:28 -0700
Subject: [PATCH] AP_HAL_Linux: Clear UART buffers when opening a port

---
 libraries/AP_HAL_Linux/UARTDriver.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libraries/AP_HAL_Linux/UARTDriver.cpp b/libraries/AP_HAL_Linux/UARTDriver.cpp
index e3e518fc82..f8308ddaa1 100644
--- a/libraries/AP_HAL_Linux/UARTDriver.cpp
+++ b/libraries/AP_HAL_Linux/UARTDriver.cpp
@@ -108,6 +108,10 @@ void UARTDriver::_allocate_buffers(uint16_t rxS, uint16_t txS)
     if (_writebuf.set_size(txS) && _readbuf.set_size(rxS)) {
         _initialised = true;
     }
+    if (hal.console != this) { // don't clear USB buffers (allows early startup messages to escape)
+        _readbuf.clear();
+        _writebuf.clear();
+    }
 }
 
 void UARTDriver::_deallocate_buffers()