EVT_UCX_USBDEVICE_GET_CHARACTERISTIC callback function (ucxusbdevice.h)

UCX invokes this callback to retrieve the device characteristics.



NTSTATUS EvtUcxUsbdeviceGetCharacteristic(
  [in]      UCXCONTROLLER UcxController,
  [in]      UCXUSBDEVICE UcxUsbDevice,
  [in, out] PUCX_USBDEVICE_CHARACTERISTIC UcxUsbDeviceCharacteristic


[in] UcxController

A handle to the UCX controller that the client driver received in a previous call to the UcxControllerCreate method.

[in] UcxUsbDevice

A handle to a UCX object that represents the USB device that the client driver received in a previous call to the UcxUsbDeviceCreate method.

[in, out] UcxUsbDeviceCharacteristic

A pointer to a UCX_USBDEVICE_CHARACTERISTIC structure that contains the type of characteristic in which the caller is interested. The client driver fills the value of the requested characteristic. For example, if the type indicates UCX_USBDEVICE_CHARACTERISTIC_PATH_DELAY, the driver fills the UCX_USBDEVICE_CHARACTERISTIC_PATH_DELAY structure, pointed to by PathDelay member, with the appropriate maximum and send path delay values.

Return value

If the operation is successful, the callback function must return STATUS_SUCCESS, or another status value for which NT_SUCCESS(status) equals TRUE. Otherwise it must return a status value for which NT_SUCCESS(status) equals FALSE.


The UCX client driver registers its implementation with the USB host controller extension (UCX) by calling the UcxUsbDeviceCreate method.


Minimum supported client Windows 10, version 1709
Minimum supported server Windows Server 2016
Target Platform Windows
Minimum KMDF version 1.0
Minimum UMDF version 2.0
Header ucxusbdevice.h (include Ucxclass.h)