PUNREGISTER_NOTIFICATION_CALLBACK callback function (hdaudio.h)

Article
02/22/2024

The PUNREGISTER_NOTIFICATION_CALLBACK callback function deletes the registration of a notification callback routine that was previously registered by a call to RegisterNotificationCallback.

Syntax

PUNREGISTER_NOTIFICATION_CALLBACK PunregisterNotificationCallback;

NTSTATUS PunregisterNotificationCallback(
  PVOID _context,
  HANDLE Handle,
  PHDAUDIO_DMA_NOTIFICATION_CALLBACK NotificationCallback,
  PVOID CallbackContext
)
{...}

Parameters

_context

Specifies the context value from the Context member of the HDAUDIO_BUS_INTERFACE_V3 structure.

Handle

Handle that identifies the DMA engine. This handle value was obtained from a previous call to AllocateCaptureDmaEngine or AllocateRenderDmaEngine.

NotificationCallback

A callback routine that was previously registered for DMA progress notification with a call to PREGISTER_NOTIFICATION_CALLBACK.

CallbackContext

Driver-specific context value for the callback routine.

Return value

PUNREGISTER_NOTIFICATION_CALLBACK returns STATUS_SUCCESS if the call successfully unregisters the notification event. Otherwise, the routine returns STATUS_INVALID_PARAMETER to indicate that the specified callback routine and context are not valid.

For more information, see NTSTATUS Values.

Remarks

PUNREGISTER_NOTIFICATION_CALLBACK will use both the NotificationCallback and CallbackContext to find the matching previously-registered callback routine to remove.

The HD Audio bus driver will release the reference it took on the driver FDO when the notification callback routine was previously registered.

Requirements

Requirement	Value
Minimum supported client	19H1
Header	hdaudio.h
IRQL	PASSIVE_LEVEL