The IDmaOperations interface encapsulates selected DMA_OPERATIONS functions to make them conveniently accessible to audio drivers. This interface also replaces the functionality of obsolete function calls such as HalAllocateCommonBuffer.

Note   This interface is not implemented in any current version of Windows, but the PortCls system driver might support this interface in a future version of Windows.

To determine whether a DMA channel (IDmaChannel or IDmaChannelSlave) object created by PortCls supports the IDmaOperations interface, a miniport driver calls the object's QueryInterface method with REFIID IID_IDmaOperations. IDmaOperations inherits from the IUnknown interface.

In addition to the methods that IDmaOperations inherits from the IUnknown interface, IDmaOperations supports the following method:




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