PDEVICE_EXTENSION DeviceExtension; /* device extension */
PDEVICE_OBJECT LowerDevice; /* lower device*/
LIST_ENTRY IrpListHead; /* irp list*/
+ LIST_ENTRY DoneIrpListHead; /* irp done list head */
+ KSPIN_LOCK IrpListLock; /* irp list lock*/
PUCHAR Buffer; /* iso buffer*/
ULONG BufferSize; /* iso buffer size */
PUSB_INTERFACE_DESCRIPTOR InterfaceDescriptor; /* interface descriptor */