QueryBusInformation routine

The QueryBusInformation routine gets information about the bus.

Syntax


NTSTATUS QueryBusInformation(
  _In_       PVOID BusContext,
  _In_       ULONG Level,
  _Inout_    PVOID BusInformationBuffer,
  _Out_      PULONG BusInformationBufferLength,
  _Out_opt_  PULONG BusInformationActualLength
);

Parameters

BusContext [in]: Handle returned in the BusContext member of the USB_BUS_INTERFACE_USBDI_V0 structure by an IRP_MN_QUERY_INTERFACE request.
Level [in]: Specifies the level of information to be returned. If Level is 0, the function returns the total bandwidth and the total consumed bandwidth in bits per second. If Level is 1, the function returns the symbolic name of the controller in Unicode, in addition to the total bandwidth and the total consumed bandwidth.
BusInformationBuffer [in, out]: Pointer to a buffer that receives the requested bus information.
BusInformationBufferLength [out]: On input, the length of the buffer specified by BusInformationBuffer. On output, the length of the output data.
BusInformationActualLength [out, optional]: Specifies the length of the output data.

Return value

QueryBusInformation returns one of the following values:

Return code	Description
STATUS_SUCCESS	The call completed successfully.
STATUS_BUFFER_TOO_SMALL	The buffer was too small. This error code is returned in two cases: Whenever Level = 0, this error code is returned if the size of the buffer pointed to by BusInformationBuffer is less than the size of the USB_BUS_INFORMATION_LEVEL_0 structure. Whenever Level = 1, this error code is returned if the size of the buffer pointed to by BusInformationBuffer less than the size of the USB_BUS_INFORMATION_LEVEL_1 structure.

Return code

Description

STATUS_SUCCESS

The call completed successfully.

STATUS_BUFFER_TOO_SMALL

The buffer was too small. This error code is returned in two cases:

Whenever Level = 0, this error code is returned if the size of the buffer pointed to by BusInformationBuffer is less than the size of the USB_BUS_INFORMATION_LEVEL_0 structure.

Whenever Level = 1, this error code is returned if the size of the buffer pointed to by BusInformationBuffer less than the size of the USB_BUS_INFORMATION_LEVEL_1 structure.

Remarks

The exact information returned by this routine depends on the value of the Level parameter. This routine replaces the USBD_QueryBusInformation library function provided by usbd.sys.

The function definition that is provided on this reference page is an example routine whose parameters are just placeholder names. The actual prototype of the function is declared in usbbusif.h as follows:

typedef NTSTATUS
  (USB_BUSIFFN *PUSB_BUSIFFN_QUERY_BUS_INFORMATION) (
    IN PVOID,
    IN ULONG,
    IN OUT PVOID,
    IN OUT PULONG,
    OUT PULONG
  );

Requirements