X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/508e905d8d39c3968927aa2c1a45350f49452df1..ec537fd84d6ad3fd0dfa1b55efa2c2d554c1db48:/Projects/XPLAINBridge/XPLAINBridge.c

diff --git a/Projects/XPLAINBridge/XPLAINBridge.c b/Projects/XPLAINBridge/XPLAINBridge.c
index ded80c22e..912e68367 100644
--- a/Projects/XPLAINBridge/XPLAINBridge.c
+++ b/Projects/XPLAINBridge/XPLAINBridge.c
@@ -1,21 +1,21 @@
 /*
              LUFA Library
      Copyright (C) Dean Camera, 2010.
-              
+
   dean [at] fourwalledcubicle [dot] com
-      www.fourwalledcubicle.com
+           www.lufa-lib.org
 */
 
 /*
   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
 
-  Permission to use, copy, modify, distribute, and sell this 
+  Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted
-  without fee, provided that the above copyright notice appear in 
+  without fee, provided that the above copyright notice appear in
   all copies and that both that the copyright notice and this
-  permission notice and warranty disclaimer appear in supporting 
-  documentation, and that the name of the author not be used in 
-  advertising or publicity pertaining to distribution of the 
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
   software without specific, written prior permission.
 
   The author disclaim all warranties with regard to this
@@ -31,7 +31,7 @@
 /** \file
  *
  *  Main source file for the XPLAINBridge project. This file contains the main tasks of
- *  the demo and is responsible for the initial application hardware configuration.
+ *  the project and is responsible for the initial application hardware configuration.
  */
 
 #include "XPLAINBridge.h"
@@ -45,7 +45,7 @@ bool CurrentFirmwareMode = MODE_USART_BRIDGE;
  */
 USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
 	{
-		.Config = 
+		.Config =
 			{
 				.ControlInterfaceNumber         = 0,
 
@@ -100,7 +100,7 @@ void AVRISP_Task(void)
 	V2Params_UpdateParamValues();
 
 	Endpoint_SelectEndpoint(AVRISP_DATA_OUT_EPNUM);
-	
+
 	/* Check to see if a V2 Protocol command has been received */
 	if (Endpoint_IsOUTReceived())
 	{
@@ -119,20 +119,36 @@ void UARTBridge_Task(void)
 	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
-	/* Read bytes from the USB OUT endpoint into the UART transmit buffer */
-	int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
-	if (!(ReceivedByte < 0) && !(RingBuffer_IsFull(&USBtoUART_Buffer)))
-	  RingBuffer_Insert(&USBtoUART_Buffer, ReceivedByte);
+	/* Only try to read in bytes from the CDC interface if the transmit buffer is not full */
+	if (!(RingBuffer_IsFull(&USBtoUART_Buffer)))
+	{
+		int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
+
+		/* Read bytes from the USB OUT endpoint into the UART transmit buffer */
+		if (!(ReceivedByte < 0))
+		  RingBuffer_Insert(&USBtoUART_Buffer, ReceivedByte);
+	}
 	
 	/* Check if the UART receive buffer flush timer has expired or buffer is nearly full */
 	RingBuff_Count_t BufferCount = RingBuffer_GetCount(&UARTtoUSB_Buffer);
 	if ((TIFR0 & (1 << TOV0)) || (BufferCount > 200))
 	{
+		/* Clear flush timer expiry flag */
 		TIFR0 |= (1 << TOV0);
 
-		/* Read bytes from the UART receive buffer into the USB IN endpoint */
+		/* Read bytes from the USART receive buffer into the USB IN endpoint */
 		while (BufferCount--)
-		  CDC_Device_SendByte(&VirtualSerial_CDC_Interface, RingBuffer_Remove(&UARTtoUSB_Buffer));
+		{
+			/* Try to send the next byte of data to the host, abort if there is an error without dequeuing */
+			if (CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
+									RingBuffer_Peek(&UARTtoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
+			{
+				break;
+			}
+
+			/* Dequeue the already sent byte from the buffer now we have confirmed that no transmission error occurred */
+			RingBuffer_Remove(&UARTtoUSB_Buffer);
+		}
 	}
 
 	CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
@@ -185,7 +201,7 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 		/* Initialize ring buffers used to hold serial data between USB and software UART interfaces */
 		RingBuffer_InitBuffer(&USBtoUART_Buffer);
 		RingBuffer_InitBuffer(&UARTtoUSB_Buffer);
-		
+
 		/* Start the software USART */
 		SoftUART_Init();
 	}
@@ -198,7 +214,7 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 		ConfigSuccess &= Endpoint_ConfigureEndpoint(AVRISP_DATA_IN_EPNUM, EP_TYPE_BULK, ENDPOINT_DIR_IN,
 		                                            AVRISP_DATA_EPSIZE, ENDPOINT_BANK_SINGLE);
 		#endif
-	
+
 		/* Configure the V2 protocol packet handler */
 		V2Protocol_Init();
 	}
@@ -206,8 +222,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 	LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 }
 
-/** Event handler for the library USB Unhandled Control Request event. */
-void EVENT_USB_Device_UnhandledControlRequest(void)
+/** Event handler for the library USB Control Request reception event. */
+void EVENT_USB_Device_ControlRequest(void)
 {
 	if (CurrentFirmwareMode == MODE_USART_BRIDGE)
 	  CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
@@ -249,7 +265,7 @@ void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCI
  */
 uint16_t CALLBACK_USB_GetDescriptor(const uint16_t wValue,
                                     const uint8_t wIndex,
-                                    void** const DescriptorAddress)
+                                    const void** const DescriptorAddress)
 {
 	/* Return the correct descriptors based on the selected mode */
 	if (CurrentFirmwareMode == MODE_USART_BRIDGE)
@@ -257,3 +273,4 @@ uint16_t CALLBACK_USB_GetDescriptor(const uint16_t wValue,
 	else
 	  return AVRISP_GetDescriptor(wValue, wIndex, DescriptorAddress);
 }
+