PUNREGISTER_EVENT_CALLBACK callback function (hdaudio.h)
The UnregisterEventCallback routine deletes the registration of an event callback that was previously registered by a call to RegisterEventCallback.
The function pointer type for an UnregisterEventCallback routine is defined as follows.
Syntax
PUNREGISTER_EVENT_CALLBACK PunregisterEventCallback;
NTSTATUS PunregisterEventCallback(
[in] PVOID _context,
[in] UCHAR Tag
)
{...}
Parameters
[in] _context
Specifies the context value from the Context member of the HDAUDIO_BUS_INTERFACE, HDAUDIO_BUS_INTERFACE_V2, or HDAUDIO_BUS_INTERFACE_BDL structure.
[in] Tag
Specifies the tag value that was associated with the callback by the preceding call to RegisterEventCallback.
Return value
UnregisterEventCallback 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 a possible return status code.
| Return code | Description |
|---|---|
|
Indicates that the specified tag is not valid. |
Remarks
Before calling this routine, the function driver is responsible for programming the codec or codecs to remove the association of the callback with the specified tag.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | hdaudio.h (include Hdaudio.h) |
| IRQL | PASSIVE_LEVEL |