IOCTL_GET_PHYSICAL_DESCRIPTOR IOCTL (hidclass.h)

The IOCTL_GET_PHYSICAL_DESCRIPTOR request obtains the physical descriptor of a top-level collection. For a minidriver, this descriptor is the descriptor of the HIDClass device.

For general information about HIDClass devices, see HID Collections.

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

Parameters.DeviceIoControl.OutputBufferLength in the I/O stack location of the IRP indicates the size, in bytes, of the output buffer.

Output buffer

Irp->MdlAddress must point to the buffer that will receive the physical descriptor.

The HID minidriver copies the physical descriptor into the user buffer at Irp->UserBuffer.

Status block

The HID class driver sets the Status member of Irp->IoStatus to STATUS_SUCCESS if the transfer completed without error. Otherwise, it is set to an appropriate NTSTATUS error code.

HID minidrivers that carry out the I/O to the device set the following fields of Irp->IoStatus:

• Information is set to the number of bytes transferred from the device.
• Status is set to STATUS_SUCCESS if the transfer completed without error. Otherwise, it is set to an appropriate NTSTATUS error code.

HID minidrivers that call other drivers with this IRP to carry out the I/O to their device should ensure that the Information field of the status block is correct and not change the contents of the Status field.

Requirements

Requirement	Value
Header	hidclass.h (include Hidclass.h)

See also

HidD_GetPhysicalDescriptor