PSET_DMA_ENGINE_STATE - NtDoc
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headers
// hdaudio.h
PSET_DMA_ENGINE_STATE PsetDmaEngineState;
NTSTATUS PsetDmaEngineState(
[in] PVOID _context,
[in] HDAUDIO_STREAM_STATE StreamState,
[in] ULONG NumberOfHandles,
[in] PHANDLE Handles
)
{...}
View the official Windows Driver Kit DDI referenceNo description available.
The SetDmaEngineState routine sets the state of one or more DMA engines to the Running, Stopped, Paused, or Reset state.
The function pointer type for a SetDmaEngineState routine is defined as follows.
_context [in]Specifies the context value from the Context member of the HDAUDIO_BUS_INTERFACE, HDAUDIO_BUS_INTERFACE_V2, or HDAUDIO_BUS_INTERFACE_BDL structure.
StreamState [in]Specifies the new stream state. Set this parameter to one of the following HDAUDIO_STREAM_STATE enumeration values:
In the current implementation, PauseState and StopState represent the same hardware state.
NumberOfHandles [in]Specifies the number of handles in the handles array. Set this parameter to a nonzero value.
Handles [in]Pointer to an array of handles to DMA engines. Specify a non-NULL value for this parameter.
SetDmaEngineState returns STATUS_SUCCESS if the call succeeds in changing the DMA engines' states. Otherwise, the routine returns an appropriate error code. The following table shows some of the possible return status codes.
| Return code | Description |
|---|---|
| STATUS_INVALID_HANDLE | Indicates that one of the handles is invalid. |
| STATUS_INVALID_PARAMETER | Indicates that one of the parameter values is incorrect (invalid parameter value or bad pointer). |
| STATUS_INVALID_DEVICE_REQUEST | Indicates that no buffer is currently allocated for one of the DMA engines. |
This routine changes the state of one or more DMA engines to the state that the streamState parameter specifies. The routine synchronizes the state transitions of all the DMA engines that the handles in the handles array identify. For more information, see Synchronizing Two or More Streams.
Before calling this routine, set up each DMA engine in the handles array:
If no DMA buffer is currently allocated for any DMA engine in the handles array, an attempt to change the stream to any state other than Reset causes the SetDmaEngineState call to fail and return error code STATUS_INVALID_DEVICE_REQUEST.
The stream state cannot transition directly between Running and Reset. Instead, the stream must first pass through an intermediate state of Paused or Stopped:
A WDM audio driver calls this routine during a call to its SetState method. For example, see IMiniportWaveCyclicStream::SetState.
IMiniportWaveCyclicStream::SetState