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 |
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Header |
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See also
