Drivers of devices with internal caches for data and drivers that maintain internal buffers for data must handle this request in a DispatchFlushBuffers routine.
Receipt of a flush request indicates that the driver should flush the device's cache or its internal buffer, or, possibly, should discard the data in its internal buffer.
The driver transfers any data currently cached in the device or held in the driver's internal buffers before completing the flush request. The driver of an input-only device that buffers data internally might simply discard the currently buffered device data before completing the flush IRP, depending on the nature of its device.
Build date: 5/22/2013