WdfDeviceGetDeviceStackIoType function (wdfdevice.h)

[Applies to UMDF only]

The WdfDeviceGetDeviceStackIoType method retrieves the buffer access methods that the framework is using for a device.

Syntax

void WdfDeviceGetDeviceStackIoType(
  [in]  WDFDEVICE          Device,
  [out] WDF_DEVICE_IO_TYPE *ReadWriteIoType,
  [out] WDF_DEVICE_IO_TYPE *IoControlIoType
);

Parameters

[in] Device

A handle to a framework device object.

[out] ReadWriteIoType

A pointer to a driver-allocated location that receives a WDF_DEVICE_IO_TYPE-typed value. This value identifies the buffer access method that the framework is using for a device's read and write requests.

[out] IoControlIoType

A pointer to a driver-allocated location that receives a WDF_DEVICE_IO_TYPE-typed value. This value that identifies the buffer access method that the framework is using for a device's I/O control requests.

Return value

None

Remarks

If your driver calls WdfDeviceGetDeviceStackIoType before the PnP manager has loaded all of the device's drivers, the values that WdfDeviceGetDeviceStackIoType retrieves might not be the values that it actually uses.

For more information about how the framework chooses a buffer access method, see Managing Buffer Access Methods in UMDF Drivers.

Requirements

See also

WdfDeviceInitSetIoTypeEx