Call USB_USBTask() in the Endpoint stream functions between packets if INTERRUPT_CONTROL_ENDPOINT is not set. Remove calls to USB_USBTask in the Mass Storage class driver stream read/write continuation checks, since this is now done inside the stream function.

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

@@ -166,10 +166,6 @@ static bool MS_Device_ReadInCommandBlock(USB_ClassInfo_MS_Device_t* const MSInte
 	                               (sizeof(MS_CommandBlockWrapper_t) - 16), &BytesProcessed) ==
 	                               ENDPOINT_RWSTREAM_IncompleteTransfer)
 	{
-		#if !defined(INTERRUPT_CONTROL_ENDPOINT)
-		USB_USBTask();
-		#endif
-
 		if (MSInterfaceInfo->State.IsMassStoreReset)
 		  return false;
 	}
@@ -192,10 +188,6 @@ static bool MS_Device_ReadInCommandBlock(USB_ClassInfo_MS_Device_t* const MSInte
 	                                MSInterfaceInfo->State.CommandBlock.SCSICommandLength, &BytesProcessed) ==
 	                                ENDPOINT_RWSTREAM_IncompleteTransfer)
 	{
-		#if !defined(INTERRUPT_CONTROL_ENDPOINT)
-		USB_USBTask();
-		#endif
-
 		if (MSInterfaceInfo->State.IsMassStoreReset)
 		  return false;
 	}
@@ -236,10 +228,6 @@ static void MS_Device_ReturnCommandStatus(USB_ClassInfo_MS_Device_t* const MSInt
 	                                sizeof(MS_CommandStatusWrapper_t), &BytesProcessed) ==
 	                                ENDPOINT_RWSTREAM_IncompleteTransfer)
 	{
-		#if !defined(INTERRUPT_CONTROL_ENDPOINT)
-		USB_USBTask();
-		#endif
-
 		if (MSInterfaceInfo->State.IsMassStoreReset)
 		  return;
 	}

LUFA/Drivers/USB/HighLevel/PipeStream.c

@@ -102,6 +102,8 @@ uint8_t Pipe_Null_Stream(uint16_t Length,
 				return PIPE_RWSTREAM_IncompleteTransfer;
 			}
 			
+			USB_USBTask();
+
 			if ((ErrorCode = Pipe_WaitUntilReady()))
 			  return ErrorCode;
 		}

LUFA/Drivers/USB/HighLevel/Template/Template_Endpoint_RW.c

@@ -27,6 +27,10 @@ uint8_t TEMPLATE_FUNC_NAME (TEMPLATE_BUFFER_TYPE Buffer,
 				return ENDPOINT_RWSTREAM_IncompleteTransfer;
 			}
 
+			#if !defined(INTERRUPT_CONTROL_ENDPOINT)
+			USB_USBTask();
+			#endif
+
 			if ((ErrorCode = Endpoint_WaitUntilReady()))
 			  return ErrorCode;
 		}

LUFA/Drivers/USB/LowLevel/Endpoint.c

@@ -156,10 +156,6 @@ uint8_t Endpoint_WaitUntilReady(void)
 			  return ENDPOINT_READYWAIT_NoError;
 		}
 		
-		#if !defined(INTERRUPT_CONTROL_ENDPOINT)
-		USB_USBTask();
-		#endif
-		
 		uint8_t USB_DeviceState_LCL = USB_DeviceState;
 
 		if (USB_DeviceState_LCL == DEVICE_STATE_Unattached)

LUFA/Drivers/USB/LowLevel/Pipe.c

@@ -172,10 +172,6 @@ uint8_t Pipe_WaitUntilReady(void)
 			  return PIPE_READYWAIT_NoError;
 		}
 
-		#if !defined(INTERRUPT_CONTROL_ENDPOINT)
-		USB_USBTask();
-		#endif
-
 		if (Pipe_IsStalled())
 		  return PIPE_READYWAIT_PipeStalled;
 		else if (USB_HostState == HOST_STATE_Unattached)