WDF_DEVICE_IO_TYPE
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WDF_DEVICE_IO_TYPE enumeration

[Applies to KMDF and UMDF]

The WDF_DEVICE_IO_TYPE enumeration is used to specify a method for accessing data buffers.

Syntax


typedef enum _WDF_DEVICE_IO_TYPE { 
  WdfDeviceIoUndefined         = 0,
  WdfDeviceIoNeither           = 1,
  WdfDeviceIoBuffered          = 2,
  WdfDeviceIoDirect            = 3,
  WdfDeviceIoBufferedOrDirect  = 4
} WDF_DEVICE_IO_TYPE, *PWDF_DEVICE_IO_TYPE;

Constants

WdfDeviceIoUndefined

Reserved for system use.

WdfDeviceIoNeither

UMDF This value is not used by UMDF drivers. A UMDF driver can access device I/O control requests that specify the METHOD_NEITHER buffer access method by setting the UmdfMethodNeitherAction INF directive and using WdfDeviceIoBuffered or WdfDeviceIoDirect. For more information, see Specifying WDF Directives in INF Files.

KMDF Neither buffered nor direct I/O will be used to access data buffers.

WdfDeviceIoBuffered

Buffered I/O will be used to access data buffers.

WdfDeviceIoDirect

Direct I/O will be used to access data buffers.

WdfDeviceIoBufferedOrDirect

This value is not used by KMDF drivers.

UMDF Buffered I/O or direct I/O will be used to access data buffers.

Remarks

The WDF_DEVICE_IO_TYPE enumeration is used to specify buffer access method types in the WDF_IO_TYPE_CONFIG structure.

The WDF_IO_TYPE_CONFIG structure is used as input to WdfDeviceInitSetIoTypeEx and WdfDeviceInitSetIoType.

Requirements

Minimum KMDF version

1.0

Minimum UMDF version

2.0

Header

Wdfdevice.h (include Wdf.h)

See also

WDF_IO_TYPE_CONFIG
WdfDeviceInitSetIoType
WdfDeviceInitSetIoTypeEx

 

 

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