Fix to HID device mode Class driver, so that new reports are compared against the old, and updated reports made within the idle period are sent immediately to the host.

Demos/Device/ClassDriver/CDC/CDC.c

@@ -91,7 +91,7 @@ int main(void)
 	for (;;)
 	{
 		CheckJoystickMovement();
-		
+		 
 		/* Must throw away unused bytes from the host, or it will lock up while waiting for the device */
 		while (CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface))
 		  CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);

Demos/Device/ClassDriver/GenericHID/GenericHID.c

@@ -48,8 +48,6 @@ USB_ClassInfo_HID_Device_t Generic_HID_Interface =
 
 				.ReportINEndpointNumber  = GENERIC_IN_EPNUM,
 				.ReportINEndpointSize    = GENERIC_EPSIZE,
-				
-				.ReportINBufferSize      = GENERIC_REPORT_SIZE,
 			},
 	};
 

Demos/Device/ClassDriver/Joystick/Joystick.c

@@ -48,8 +48,6 @@ USB_ClassInfo_HID_Device_t Joystick_HID_Interface =
 
 				.ReportINEndpointNumber  = JOYSTICK_EPNUM,
 				.ReportINEndpointSize    = JOYSTICK_EPSIZE,
-				
-				.ReportINBufferSize      = sizeof(USB_JoystickReport_Data_t),
 			},
 	};
 

Demos/Device/ClassDriver/Keyboard/Keyboard.c

@@ -49,8 +49,6 @@ USB_ClassInfo_HID_Device_t Keyboard_HID_Interface =
 
 				.ReportINEndpointNumber  = KEYBOARD_EPNUM,
 				.ReportINEndpointSize    = KEYBOARD_EPSIZE,
-
-				.ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
 			},
     };
 

Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.c

@@ -50,8 +50,6 @@ USB_ClassInfo_HID_Device_t Keyboard_HID_Interface =
 
 				.ReportINEndpointNumber  = KEYBOARD_IN_EPNUM,
 				.ReportINEndpointSize    = HID_EPSIZE,
-				
-				.ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
 			},
 	};
 	
@@ -68,8 +66,6 @@ USB_ClassInfo_HID_Device_t Mouse_HID_Interface =
 
 				.ReportINEndpointNumber  = MOUSE_IN_EPNUM,
 				.ReportINEndpointSize    = HID_EPSIZE,
-
-				.ReportINBufferSize      = sizeof(USB_MouseReport_Data_t),
 			},
 			
 		.State =

Demos/Device/ClassDriver/Mouse/Mouse.c

@@ -48,8 +48,6 @@ USB_ClassInfo_HID_Device_t Mouse_HID_Interface =
 
 				.ReportINEndpointNumber  = MOUSE_EPNUM,
 				.ReportINEndpointSize    = MOUSE_EPSIZE,
-
-				.ReportINBufferSize      = sizeof(USB_MouseReport_Data_t),
 			},
 	};
 

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

@@ -51,7 +51,7 @@ void HID_Device_ProcessControlPacket(USB_ClassInfo_HID_Device_t* const HIDInterf
 			{
 				Endpoint_ClearSETUP();	
 
-				uint8_t  ReportINData[HIDInterfaceInfo->Config.ReportINBufferSize];
+				uint8_t  ReportINData[HID_MAX_REPORT_SIZE];
 				uint16_t ReportINSize;
 				uint8_t  ReportID = (USB_ControlRequest.wValue & 0xFF);
 
@@ -150,27 +150,32 @@ bool HID_Device_ConfigureEndpoints(USB_ClassInfo_HID_Device_t* const HIDInterfac
 		
 void HID_Device_USBTask(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo)
 {
+	static uint8_t PreviousReportINData[HID_MAX_REPORT_SIZE];
+
 	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	Endpoint_SelectEndpoint(HIDInterfaceInfo->Config.ReportINEndpointNumber);
 	
-	if (Endpoint_IsReadWriteAllowed() &&
-	    !(HIDInterfaceInfo->State.IdleCount && HIDInterfaceInfo->State.IdleMSRemaining))
+	if (Endpoint_IsReadWriteAllowed())
 	{
-		if (HIDInterfaceInfo->State.IdleCount && !(HIDInterfaceInfo->State.IdleMSRemaining))
-		  HIDInterfaceInfo->State.IdleMSRemaining = HIDInterfaceInfo->State.IdleCount;
-
-		uint8_t  ReportINData[HIDInterfaceInfo->Config.ReportINBufferSize];
-		uint16_t ReportINSize;
+		uint8_t  ReportINData[HID_MAX_REPORT_SIZE];
 		uint8_t  ReportID = 0;
+		uint16_t ReportINSize;
 
 		memset(ReportINData, 0, sizeof(ReportINData));
 
-		ReportINSize = CALLBACK_HID_Device_CreateHIDReport(HIDInterfaceInfo, &ReportID, ReportINData);
+		ReportINSize  = CALLBACK_HID_Device_CreateHIDReport(HIDInterfaceInfo, &ReportID, ReportINData);
 
-		if (ReportINSize)
+		bool StatesChanged     = (memcmp(ReportINData, PreviousReportINData, ReportINSize) != 0);
+		bool IdlePeriodElapsed = (HIDInterfaceInfo->State.IdleCount && !(HIDInterfaceInfo->State.IdleMSRemaining));
+		
+		memcpy(PreviousReportINData, ReportINData, ReportINSize);
+
+		if (ReportINSize && (StatesChanged || IdlePeriodElapsed))
 		{
+			HIDInterfaceInfo->State.IdleMSRemaining = HIDInterfaceInfo->State.IdleCount;
+
 			if (ReportID)
 			  Endpoint_Write_Stream_LE(&ReportID, sizeof(ReportID), NO_STREAM_CALLBACK);
 

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

@@ -56,6 +56,17 @@
 		#endif
 
 	/* Public Interface - May be used in end-application: */
+		/* Macros: */
+			#if !defined(HID_MAX_REPORT_SIZE)
+				/** Maximum size of an IN report which can be generated by the device and sent to the host, in bytes.
+				 *
+				 *  \note If larger reports than the default specified here are to be generated by the device, this
+				 *        value can be overridden by defining this token to the required value in the project makefile
+				 *        and passing it to the compiler via the -D switch.
+				 */
+				#define HID_MAX_REPORT_SIZE     16
+			#endif
+	
 		/* Type Defines: */
 			/** Class state structure. An instance of this structure should be made for each HID interface
 			 *  within the user application, and passed to each of the HID class driver functions as the
@@ -68,19 +79,15 @@
 					uint8_t  InterfaceNumber; /**< Interface number of the HID interface within the device */
 
 					uint8_t  ReportINEndpointNumber; /**< Endpoint number of the HID interface's IN report endpoint */
-					uint16_t ReportINEndpointSize; /**< Size in bytes of the HID interface's IN report endpoint */
-					
-					uint8_t  ReportINBufferSize; /**< Size of the largest possible report to send to the host, for
-												  *   buffer allocation purposes
-												  */
+					uint16_t ReportINEndpointSize; /**< Size in bytes of the HID interface's IN report endpoint */					
 				} Config; /**< Config data for the USB class interface within the device. All elements in this section
 				           *   <b>must</b> be set or the interface will fail to enumerate and operate correctly.
 				           */										 
 				struct
 				{
 					bool     UsingReportProtocol; /**< Indicates if the HID interface is set to Boot or Report protocol mode */
-					uint16_t IdleCount; /**< Report idle period, in ms, set by the host */
-					uint16_t IdleMSRemaining; /**< Total number of ms remaining before the idle period elapsed - this should be
+					uint16_t IdleCount; /**< Report idle period, in mS, set by the host */
+					uint16_t IdleMSRemaining; /**< Total number of mS remaining before the idle period elapsed - this should be
 											   *   decremented by the user application if non-zero each millisecond */			
 				} State; /**< State data for the USB class interface within the device. All elements in this section
 				          *   are reset to their defaults when the interface is enumerated.

Projects/Magstripe/Magstripe.c

@@ -57,8 +57,6 @@ USB_ClassInfo_HID_Device_t Keyboard_HID_Interface =
 
 				.ReportINEndpointNumber  = KEYBOARD_EPNUM,
 				.ReportINEndpointSize    = KEYBOARD_EPSIZE,
-				
-				.ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
 			},
 	};