Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
The VideoPortCompleteDma function flushes any data remaining in a bus-master adapter's internal cache at the end of a DMA transfer operation, and then frees the previously allocated map registers and scatter/gather list used in scatter/gather DMA operations.
Syntax
VIDEOPORT_DEPRECATED VIDEOPORT_API VP_STATUS VideoPortCompleteDma(
[in] IN PVOID HwDeviceExtension,
[in] IN PVP_DMA_ADAPTER VpDmaAdapter,
[in] IN PVP_SCATTER_GATHER_LIST VpScatterGather,
[in] IN BOOLEAN WriteToDevice
);
Parameters
[in] HwDeviceExtension
Pointer to the miniport driver's device extension.
[in] VpDmaAdapter
Pointer to a VP_DMA_ADAPTER structure that represents the bus-master adapter. This structure was returned by a call to VideoPortGetDmaAdapter.
[in] VpScatterGather
Pointer to the VP_SCATTER_GATHER_LIST structure previously passed to the miniport driver callback routine, HwVidExecuteDma.
[in] WriteToDevice
Specifies the direction of the DMA transfer. A value of TRUE denotes a transfer from the buffer to the device, and a value of FALSE denotes a transfer from the device to the buffer.
Return value
VideoPortCompleteDma returns NO_ERROR.
Remarks
The video miniport driver should call VideoPortCompleteDma immediately to free up system resources after a DMA transfer has been completed.
It is important to note that the scatter/gather list built by VideoPortStartDma becomes invalid when VideoPortCompleteDma is called..
Requirements
Requirement | Value |
---|---|
Minimum supported client | Available in Windows XP and later versions of the Windows operating systems. |
Target Platform | Desktop |
Header | video.h (include Video.h) |
Library | Videoprt.lib |
DLL | Videoprt.sys |
IRQL | <=DISPATCH_LEVEL |