Microsoft KB Archive/195389

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HOWTO: Get an Interrupt in a PCI/AGP Video Miniport Driver

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Q195389

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The information in this article applies to:


 * Microsoft Win32 Device Driver Kit (DDK) for Windows NT, version 4.0

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SUMMARY
This article documents and clarifies the Windows NT DDK Documentation for a video miniport driver to establish a Videoport callable interrupt routine. This article applies to PCI and AGP miniport drivers.

MORE INFORMATION
During the operating system's initialization in the miniport's DriverEntry routine, the function dispatch table entry named HwInterrupt needs to be initialized to point to the interrupt service routine. VideoportInitailize needs to be called as before.

Within the HwFindAdapter routine, you can call VideoportGetAccessRanges with the third and fourth parameters set to NULL. For PCI and AGP buses this allows VideoPortGetAccessRanges to call HalAssignSlotResources on your behalf and get the Bus-Relative values for InterruptLevel and InterruptVector fields in the ConfigInfo Structure.

HalAssignSlotResources will have already been called, but HalGetInterruptVector will be called after you return from HwFindAdapter if and only if HwInterrupt points to a function and, either InterruptLevel or InterruptVector fields contain a value.