EVT_UCX_CONTROLLER_QUERY_USB_CAPABILITY callback function

The client driver's implementation to determine if the controller supports a specific capability.

Syntax

EVT_UCX_CONTROLLER_QUERY_USB_CAPABILITY EvtUcxControllerQueryUsbCapability;

NTSTATUS EvtUcxControllerQueryUsbCapability(
  UCXCONTROLLER UcxController,
  PGUID CapabilityType,
  ULONG OutputBufferLength,
  PVOID OutputBuffer,
  PULONG ResultLength
)
{...}

Parameters

UcxController

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

CapabilityType

Pointer to a GUID specifying the requested capability. The possible PGUID values are as follows:

  • GUID_USB_CAPABILITY_CHAINED_MDLS
  • GUID_USB_CAPABILITY_STATIC_STREAMS
  • GUID_USB_CAPABILITY_SELECTIVE_SUSPEND
  • GUID_USB_CAPABILITY_FUNCTION_SUSPEND
  • GUID_USB_CAPABILITY_DEVICE_CONNECTION_HIGH_SPEED_COMPATIBLE
  • GUID_USB_CAPABILITY_DEVICE_CONNECTION_SUPER_SPEED_COMPATIBLE
  • GUID_USB_CAPABILITY_CLEAR_TT_BUFFER_ON_ASYNC_TRANSFER_CANCEL
    • For typical host controllers, the query must fail (STATUS_NOT_SUPPORTED). If the controller succeeds this capability, it is requesting a Clear TT Buffer when canceling Low Speed/Full Speed asynchronous (Bulk or Control) transfers that have been sent to a TT hub.
See the Remarks section of USBD_QueryUsbCapability for more information.

OutputBufferLength

The length, in bytes, of the request's output buffer, if an output buffer is available.

OutputBuffer

A pointer to a location that receives the buffer's address. Certain capabilities may need to provide additional information to UCX in this buffer.

ResultLength

A location that, on return, contains the size, in bytes, of the information that the callback function stored in OutputBuffer.

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.

Return code Description
STATUS_SUCCESS
The requested USB capability is supported.
STATUS_NOT_IMPLEMENTED
The requested USB capability is unknown and not supported.
STATUS_NOT_SUPPORTED
Controller does not support the requested USB capability.

For GUID_USB_CAPABILITY_CLEAR_TT_BUFFER_ON_ASYNC_TRANSFER_CANCEL, the controller did not request a Clear TT Buffer when canceling Low Speed/Full Speed asynchronous (Bulk or Control) transfers that were sent to a TT hub.

Remarks

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

Examples

NTSTATUS
Controller_EvtControllerQueryUsbCapability(
    UCXCONTROLLER   UcxController,
    PGUID           CapabilityType,
    ULONG           OutputBufferLength,
    PVOID           OutputBuffer,
    PULONG          ResultLength
)

{ NTSTATUS status;

UNREFERENCED_PARAMETER(UcxController);
UNREFERENCED_PARAMETER(OutputBufferLength);
UNREFERENCED_PARAMETER(OutputBuffer);

*ResultLength = 0;

if (RtlCompareMemory(CapabilityType,
                     &GUID_USB_CAPABILITY_CHAINED_MDLS,
                     sizeof(GUID)) == sizeof(GUID)) {

    //
    // TODO: Is GUID_USB_CAPABILITY_CHAINED_MDLS supported?
    //
    DbgTrace(TL_INFO, Controller, "GUID_USB_CAPABILITY_CHAINED_MDLS not supported");
    status = STATUS_NOT_SUPPORTED;
}
else if (RtlCompareMemory(CapabilityType,
                          &GUID_USB_CAPABILITY_STATIC_STREAMS,
                          sizeof(GUID)) == sizeof(GUID)) {

    //
    // TODO: Is GUID_USB_CAPABILITY_STATIC_STREAMS supported?
    //
    DbgTrace(TL_INFO, Controller, "GUID_USB_CAPABILITY_STATIC_STREAMS supported");
    status = STATUS_NOT_SUPPORTED;
}
else if (RtlCompareMemory(CapabilityType,
                          &GUID_USB_CAPABILITY_FUNCTION_SUSPEND,
                          sizeof(GUID)) == sizeof(GUID)) {

    //
    // TODO: Is GUID_USB_CAPABILITY_FUNCTION_SUSPEND supported?
    //
    DbgTrace(TL_INFO, Controller, "GUID_USB_CAPABILITY_FUNCTION_SUSPEND not supported");
    status = STATUS_NOT_SUPPORTED;
}
else if (RtlCompareMemory(CapabilityType,
                          &GUID_USB_CAPABILITY_SELECTIVE_SUSPEND,
                          sizeof(GUID)) == sizeof(GUID)) {

    DbgTrace(TL_INFO, Controller, "GUID_USB_CAPABILITY_SELECTIVE_SUSPEND supported");
    status = STATUS_SUCCESS;
}
else if (RtlCompareMemory(CapabilityType,
                          &GUID_USB_CAPABILITY_CLEAR_TT_BUFFER_ON_ASYNC_TRANSFER_CANCEL,
                          sizeof(GUID)) == sizeof(GUID)) {

    //
    // TODO: Is GUID_USB_CAPABILITY_CLEAR_TT_BUFFER_ON_ASYNC_TRANSFER_CANCEL supported?
    //
    DbgTrace(TL_INFO, Controller, "GUID_USB_CAPABILITY_CLEAR_TT_BUFFER_ON_ASYNC_TRANSFER_CANCEL not supported");
    status = STATUS_NOT_SUPPORTED;
}
else {
    DbgTrace(TL_INFO, Controller, "Unhandled USB capability");
    status = STATUS_NOT_IMPLEMENTED;
}

return status;

}

Requirements

   
Target Platform Windows
Minimum KMDF version 1.0
Minimum UMDF version 2.0
Header ucxcontroller.h (include Ucxclass.h)
IRQL PASSIVE_LEVEL

See Also

UcxControllerCreate