Hi, In WaveRT miniport driver I am exposing one device interface for use by custom application by means of IoRegisterDeviceInterface. I want to handle the IRPs that come for this interface in miniport driver itself. For the same I have registered my own handlers for IRP_MJ_CREATE and IRP_MJ_DEVICE_CONTROL. What I am observing is when there is no activity for my device my driver enters D3 state as expected. After which when I launch my custom application I receive calls to IRP_MJ_CREATE and then IRP_MJ_DEVICE_CONTROL for registered interface as expected but all this time driver state remains D3. I do not get a call to change driver state to D0 before receiving these IRP calls. Is this expected behaviour? Should miniport driver make call to PoSetPowerState for IRPs that are not passed on portclass? regards, Surabhi