NTSTATUS
SoundAuxDispatch(
IN OUT PLOCAL_DEVICE_INFO pLDI,
IN PIRP pIrp,
IN PIO_STACK_LOCATION IrpStack
);
The SoundAuxDispatch function is the IRP control code dispatcher for auxiliary audio devices.
Parameters
pLDI
Pointer to a LOCAL_DEVICE_INFO structure.
pIrp
Pointer to an IRP.
IrpStack
Pointer to an I/O stack location.
Return Value
Returns STATUS_SUCCESS if the operation succeeds. Otherwise returns an NTSTATUS error code.
Comments
Kernel-mode auxiliary audio device drivers using soundlib.lib place the address of the SoundAuxDispatch function in the DispatchRoutine member of a SOUND_DEVICE_INIT structure. The function is called by soundlib.lib’s main dispatcher, SoundDispatch.
The function processes the following IRP control codes:
| IRP_MJ_CLEANUP |
| IRP_MJ_CLOSE |
| IRP_MJ_CREATE |
| IRP_MJ_DEVICE_CONTROL |
For IRP_MJ_DEVICE_CONTROL, the SoundAuxDispatch function processes the following I/O control codes:
| IOCTL_AUX_GET_CAPABILITIES |
| IOCTL_AUX_GET_VOLUME |
| IOCTL_AUX_SET_VOLUME |
| IOCTL_SOUND_GET_CHANGED_VOLUME |
Refer to the Kernel-Mode Drivers Reference for descriptions of PIRP and PIO_STACK_LOCATION types, along with IRP control codes and I/O control codes.