VOID HwVidTimer(
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PVOID HwDeviceExtension | |
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HwVidTimer is an optional miniport driver function to which calls are enabled and disabled with VideoPortStartTimer and VideoPortStopTimer, respectively.
Any miniport driver can have a HwVidTimer function at the discretion of the driver designer. For example, a HwVidTimer function could be used to read the state of the “VGA” registers on a high-end video adapter so that the miniport can emulate VGA-compatible behavior on an as-needed basis.
After a call to VideoPortStartTimer, the video port driver calls a miniport’s HwVidTimer function approximately once each second until the miniport calls VideoPortStopTimer.
The HwVidTimer function can disable the timer with a call to VideoPortStopTimer. Another miniport function can re-enable the timer later with a call to VideoPortStartTimer.