From e6642ca0dc3e6fbc2502871abca5e9a8da48bbae Mon Sep 17 00:00:00 2001
From: Nico <nico-2006@web.de>
Date: Mon, 2 Feb 2015 20:36:12 +0100
Subject: [PATCH] Correct undefined Serial Buffer Size

https://github.com/arduino/Arduino/pull/2597
---
 .gitignore                     | 3 +--
 avr/cores/hid/HardwareSerial.h | 9 +++++++--
 avr/cores/hid/USB-Core/CDC.h   | 5 +++++
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/.gitignore b/.gitignore
index 117ca86..432031f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1 @@
-dev/*
-*.pdn
\ No newline at end of file
+dev/*
\ No newline at end of file
diff --git a/avr/cores/hid/HardwareSerial.h b/avr/cores/hid/HardwareSerial.h
index 7dc2aa9..203008d 100644
--- a/avr/cores/hid/HardwareSerial.h
+++ b/avr/cores/hid/HardwareSerial.h
@@ -34,12 +34,17 @@
 // location from which to read.
 // NOTE: a "power of 2" buffer size is reccomended to dramatically
 //       optimize all the modulo operations for ring buffers.
-#if !(defined(SERIAL_TX_BUFFER_SIZE) && defined(SERIAL_RX_BUFFER_SIZE))
+#if !(defined(SERIAL_TX_BUFFER_SIZE)
 #if (RAMEND < 1000)
 #define SERIAL_TX_BUFFER_SIZE 16
-#define SERIAL_RX_BUFFER_SIZE 16
 #else
 #define SERIAL_TX_BUFFER_SIZE 64
+#endif
+#endif
+#if !defined(SERIAL_RX_BUFFER_SIZE))
+#if (RAMEND < 1000)
+#define SERIAL_RX_BUFFER_SIZE 16
+#else
 #define SERIAL_RX_BUFFER_SIZE 64
 #endif
 #endif
diff --git a/avr/cores/hid/USB-Core/CDC.h b/avr/cores/hid/USB-Core/CDC.h
index f58bc0d..99b62fa 100644
--- a/avr/cores/hid/USB-Core/CDC.h
+++ b/avr/cores/hid/USB-Core/CDC.h
@@ -56,11 +56,16 @@ THE SOFTWARE.
 
 struct ring_buffer;
 
+#ifndef SERIAL_BUFFER_SIZE
 #if (RAMEND < 1000)
 #define SERIAL_BUFFER_SIZE 16
 #else
 #define SERIAL_BUFFER_SIZE 64
 #endif
+#endif
+#if (SERIAL_BUFFER_SIZE>256)
+#error Please lower the CDC Buffer size
+#endif
 
 class Serial_ : public Stream
 {