IAdapterPowerManagement interface (portcls.h)

The IAdapterPowerManagement interface is used to manage the power state of an audio adapter. This interface is implemented by the adapter driver, which exposes the interface to the PortCls system driver. IAdapterPowerManagement inherits from the IUnknown interface.

The operating system manages power in a WDM audio adapter primarily through the IAdapterPowerManagement interface that the adapter driver registers with PortCls during the device-startup phase of device initialization (see Starting a Device). The adapter driver registers its IAdapterPowerManagement interface by calling the PortCls function PcRegisterAdapterPowerManagement. This function receives an IUnknown object from the adapter driver and determines whether the object supports the IAdapterPowerManagement interface by calling QueryInterface on this object with REFIID IID_IAdapterPowerManagement.

For more information, see Implementing IAdapterPowerManagement.


The IAdapterPowerManagement interface inherits from the IUnknown interface.


The IAdapterPowerManagement interface has these methods.


The PowerChangeState method requests that the device change to a new power state.

The QueryDeviceCapabilities method is called by PortCls in response to a Plug and Play IRP_MN_QUERY_CAPABILITIES IRP.

The QueryPowerChangeState method is called by PortCls in response to the receipt of an IRP_MN_QUERY_POWER power IRP.


Target Platform Windows
Header portcls.h