VideoPortCompleteDma function (video.h)
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 |