From: Dean Camera <dean@fourwalledcubicle.com>
Date: Tue, 15 Jul 2014 11:23:51 +0000 (+1000)
Subject: Only deque from the USBtoSerial's USB->USART buffer when the USART is idle.
X-Git-Tag: LUFA-140928~31
X-Git-Url: http://git.linex4red.de/pub/USBasp.git/commitdiff_plain/d90ef9aa2f97a5f8b5fd2cf0bd9564025d069f6e?ds=inline;hp=-c

Only deque from the USBtoSerial's USB->USART buffer when the USART is idle.
---

d90ef9aa2f97a5f8b5fd2cf0bd9564025d069f6e
diff --git a/LUFA/DoxygenPages/ChangeLog.txt b/LUFA/DoxygenPages/ChangeLog.txt
index a03d389b4..e16fcbec1 100644
--- a/LUFA/DoxygenPages/ChangeLog.txt
+++ b/LUFA/DoxygenPages/ChangeLog.txt
@@ -22,6 +22,7 @@
   *   - Fixed missing HID report ID prefix on HID class driver GetReport request responses (thanks to Bert van Hall)
   *  - Library Applications:
   *   - Fixed spurious 0xFE USART byte sent in the USBtoSerial project when the baud rate is changed (thanks to Carl Kjeldsen)
+  *   - Fixed blocking USART reads causing low throughput on slow baud rates in the USBtoSerial project (thanks to Nevada Smith)
   *
   *  \section Sec_ChangeLog140302 Version 140302
   *  <b>New:</b>
diff --git a/Projects/USBtoSerial/USBtoSerial.c b/Projects/USBtoSerial/USBtoSerial.c
index 1c791d95d..b51c7c258 100644
--- a/Projects/USBtoSerial/USBtoSerial.c
+++ b/Projects/USBtoSerial/USBtoSerial.c
@@ -133,8 +133,8 @@ int main(void)
 			}
 		}
 
-		/* Load the next byte from the USART transmit buffer into the USART */
-		if (!(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))
+		/* Load the next byte from the USART transmit buffer into the USART if transmit buffer space is available */
+		if (Serial_IsSendReady() && !(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))
 		  Serial_SendByte(RingBuffer_Remove(&USBtoUSART_Buffer));
 
 		CDC_Device_USBTask(&VirtualSerial_CDC_Interface);