VideoPortUnmapMemory function

The VideoPortUnmapMemory function releases a mapping between a logical address range for the adapter and a virtual address range in the user-mode address space of a particular thread. This function is the complement of VideoPortMapMemory.

Syntax


VP_STATUS VideoPortUnmapMemory(
   PVOID  HwDeviceExtension,
   PVOID  VirtualAddress,
   HANDLE ProcessHandle
);

Parameters

HwDeviceExtension

Pointer to the miniport driver's device extension.

VirtualAddress

Pointer to a virtual address within the mapped range to be released.

ProcessHandle

Should be set to zero, or to the process handle specified when the miniport driver called VideoPortMapMemory.

Return value

VideoPortUnmapMemory returns NO_ERROR if the mapping was released. Otherwise, it returns ERROR_INVALID_PARAMETER.

Remarks

A miniport driver cannot release a subrange of the mapping between a logical device range and the user-space virtual address range of its corresponding display driver. Whether the VirtualAddress parameter is the base virtual address for the mapped range that was returned by VideoPortMapMemory, or is an offset into that mapped virtual range, VideoPortUnmapMemory releases the mapping for the full range.

Requirements

Target platform

Desktop

Version

Available in Windows 2000 and later versions of the Windows operating systems.

Header

Video.h (include Video.h)

Library

Videoprt.lib

DLL

Videoprt.sys

IRQL

PASSIVE_LEVEL

See also

VideoPortMapMemory

 

 

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