ChangerReinitializeUnit function (mcd.h)
ChangerReinitializeUnit handles the device-specific aspects of a device-control IRP with the IOCTL code IOCTL_CHANGER_REINITIALIZE_TRANSPORT.
Syntax
NTSTATUS ChangerReinitializeUnit(
[in] PDEVICE_OBJECT DeviceObject,
[in] PIRP Irp
);
Parameters
[in] DeviceObject
Pointer to the device object that represents the changer.
[in] Irp
Pointer to the IRP.
Return value
If the changer supports recalibrating a transport element, ChangerReinitializeUnit returns the STATUS_XXX value returned by the system port driver, or one of the following values:
STATUS_SUCCESS
STATUS_INVALID_ELEMENT_ADDRESS
STATUS_INVALID_PARAMETER
STATUS_INSUFFICIENT_RESOURCES
If the changer does not support recalibrating a transport element, ChangerReinitializeUnit returns STATUS_INVALID_DEVICE_REQUEST.
Remarks
This routine is required.
ChangerReinitializeUnit causes the changer to recalibrate its transport element. Depending on the changer, this may return the transport to a "home" position. The changer class driver typically calls ChangerReinitializeUnit after the changer has been powered on or a calling application has initiated a recovery operation. The CHANGER_DEVICE_REINITIALIZE_CAPABLE flag in Features0 of GET_CHANGER_PARAMETERS indicates whether the changer's transport supports recalibration in those circumstances.
The changer class driver checks the input buffer length in the I/O stack location before calling ChangerReinitializeUnit. Irp->SystemBuffer points to a CHANGER_ELEMENT structure that indicates the element to recalibrate.
ChangerReinitializeUnit builds an SRB with a CDB to position the transport element and sends it to the system port driver.
ChangerReinitializeUnit sets the Information field in the I/O status block to sizeof(CHANGER_ELEMENT) before returning to the changer class driver.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | mcd.h (include Mcd.h, Ntddchgr.h) |
| IRQL | PASSIVE_LEVEL |