Ensure all USB device class drivers have the same three main functions as their interface for consistency.

Demos/Device/AudioInput/AudioInput.c

@@ -62,6 +62,7 @@ int main(void)
 		if (Microphone_Audio_Interface.InterfaceEnabled)
 		  ProcessNextSample();
 
+		USB_Audio_USBTask(&Microphone_Audio_Interface);
 		USB_USBTask();
 	}
 }

Demos/Device/AudioOutput/AudioOutput.c

@@ -62,6 +62,7 @@ int main(void)
 		if (Speaker_Audio_Interface.InterfaceEnabled)
 		  ProcessNextSample();
 
+		USB_Audio_USBTask(&Speaker_Audio_Interface);
 		USB_USBTask();
 	}
 }

Demos/Device/MIDI/MIDI.c

@@ -64,6 +64,7 @@ int main(void)
 	{
 		CheckJoystickMovement();
 	
+		USB_MIDI_USBTask(&Keyboard_MIDI_Interface);
 		USB_USBTask();
 	}
 }
@@ -168,3 +169,9 @@ void EVENT_USB_ConfigurationChanged(void)
 	if (!(USB_MIDI_ConfigureEndpoints(&Keyboard_MIDI_Interface)))
 	  LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
 }
+
+/** Event handler for the library USB Unhandled Control Packet event. */
+void EVENT_USB_UnhandledControlPacket(void)
+{
+	USB_MIDI_ProcessControlPacket(&Keyboard_MIDI_Interface);
+}

LUFA/Drivers/USB/Class/Device/Audio.c

@@ -80,6 +80,11 @@ bool USB_Audio_ConfigureEndpoints(USB_ClassInfo_Audio_t* AudioInterfaceInfo)
 	return true;
 }
 
+void USB_Audio_USBTask(USB_ClassInfo_Audio_t* AudioInterfaceInfo)
+{
+
+}
+
 int8_t USB_Audio_ReadSample8(void)
 {
 	int8_t Sample;

LUFA/Drivers/USB/Class/Device/MIDI.c

@@ -30,6 +30,11 @@
 
 #include "MIDI.h"
 
+void USB_MIDI_ProcessControlPacket(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo)
+{
+
+}
+
 bool USB_MIDI_ConfigureEndpoints(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo)
 {
 	if (MIDIInterfaceInfo->DataINEndpointNumber)
@@ -55,6 +60,11 @@ bool USB_MIDI_ConfigureEndpoints(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo)
 	return true;
 }
 
+void USB_MIDI_USBTask(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo)
+{
+
+}
+
 void USB_MIDI_SendEventPacket(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo, USB_MIDI_EventPacket_t* Event)
 {
 	if (!(USB_IsConnected))

LUFA/Drivers/USB/Class/Device/MIDI.h

@@ -155,6 +155,7 @@
 		
 	/* Function Prototypes: */
 		bool USB_MIDI_ConfigureEndpoints(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo);
+		void USB_MIDI_ProcessControlPacket(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo);
 		void USB_MIDI_USBTask(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo);
 
 		void USB_MIDI_SendEventPacket(USB_ClassInfo_MIDI_t* MIDIInterfaceInfo, USB_MIDI_EventPacket_t* Event);