DXGKDDI_SETVIDPNSOURCEADDRESS callback function (d3dkmddi.h)

Article
11/04/2022

The DxgkDdiSetVidPnSourceAddress function sets the address of the primary surface that is associated with a particular video present source.

Syntax

DXGKDDI_SETVIDPNSOURCEADDRESS DxgkddiSetvidpnsourceaddress;

NTSTATUS DxgkddiSetvidpnsourceaddress(
  IN_CONST_HANDLE hAdapter,
  IN_CONST_PDXGKARG_SETVIDPNSOURCEADDRESS pSetVidPnSourceAddress
)
{...}

Parameters

hAdapter

A handle to a context block that is associated with a display adapter. The display miniport driver previously provided this handle to the DirectX graphics kernel subsystem in the MiniportDeviceContext output parameter of the DxgkDdiAddDevice function.

pSetVidPnSourceAddress

A pointer to a DXGKARG_SETVIDPNSOURCEADDRESS structure that contains function arguments.

Return value

DxgkDdiSetVidPnSourceAddress returns STATUS_SUCCESS if it succeeds; otherwise, it returns one of the error codes defined in Ntstatus.h.

Starting with Windows 8, the display miniport driver can fail a call to DxgkDdiSetVidPnSourceAddress, returning STATUS_INVALID_PARAMETER, when the SharedPrimaryTransition member is set in pSetVidPnSourceAddress->Flags. However, such a failure is not expected unless there is an error in either the user mode driver's implementation of the CheckDirectFlipSupport function or in the DWM. If such a failure occurs, the operating system will not seamlessly fail back to composition mode, and presentation will be incorrect.

Remarks

DxgkDdiSetVidPnSourceAddress is called only with primaries that fit with the currently committed video present network (VidPN) topology. For example, the D3DDDIFMT_A8R8G8B8 format is determined to fit with a VidPN that is committed to a D3DDDIFMT_X8R8G8B8 format, and vice versa.

The DirectX graphics kernel subsystem calls DxgkDdiSetVidPnSourceAddress to switch the display mode and to perform memory-mapped I/O (MMIO)–based flip operations. The bit-field flags in the Flags member of the DXGKARG_SETVIDPNSOURCEADDRESS structure that is pointed to by the pSetVidPnSourceAddress parameter indicates the type of display operation to perform. To switch the display mode, the graphics kernel subsystem sets the ContextCount member of DXGKARG_SETVIDPNSOURCEADDRESS to zero. In this situation, the content of the array that the Context member of DXGKARG_SETVIDPNSOURCEADDRESS specifies is undefined. To perform a flip operation, the graphics kernel subsystem sets ContextCount to the number of contexts and Context to the array of driver context handles for the contexts that contribute to the flip operation.

If the display miniport driver previously indicated, in a call to its DxgkDdiQueryAdapterInfo function, that it supports a MMIO-based flip (by setting the FlipOnVSyncMmIo bit-field flag in the FlipCaps member of the DXGK_DRIVERCAPS structure to TRUE), the driver's DxgkDdiSetVidPnSourceAddress function is subsequently called at device interrupt request level (DIRQL) for flip purposes. The driver's DxgkDdiSetVidPnSourceAddress function must program the DAC and start scanning out, at the following vertical sync, the primary surface whose address is specified in the PrimaryAddress member of DXGKARG_SETVIDPNSOURCEADDRESS. The driver also must pass the DXGK_INTERRUPT_CRTC_VSYNC interrupt type in the InterruptType parameter in a call to the DxgkCbNotifyInterrupt function to report the effective scan address. The driver must follow the call to DxgkCbNotifyInterrupt with a call to the DxgkCbNotifyDpc function.

DxgkDdiSetVidPnSourceAddress must be in nonpageable memory. DxgkDdiSetVidPnSourceAddress must not call any code that is in pageable memory and must not manipulate any data that is in pageable memory.

Clone-View Situations

In clone-view situations, the display miniport driver should handle flip operations appropriately as described in this section.

When the DWM is running, the DirectX graphics kernel subsystem flip-synchronizes when a vertical sync occurs. However, the DirectX graphics kernel subsystem can synchronize only when a vertical sync of a single graphics adapter output signal occurs. The DirectX graphics kernel subsystem must immediately flip any other graphics adapter output signals to avoid tearing.

The GPU scheduler will detect a single vertical sync and will determine that the flipped surface is available as soon as the first monitor flip occurs. As a result, the display miniport driver might be rendering to a surface that the second monitor is still displaying.

Video applications (for example, Windows Media Player) are unaware of clone-view situations and expect to have a predictable vertical-sync interval. If the GPU scheduler detected the vertical syncs of both monitors, the vertical sync interval (and therefore the flip) would be unpredictable and would drift over time, which would cause the DWM and video applications to not operate correctly.

For clone-view situations, the display miniport driver must perform a vertical-sync flip on the primary monitor and an MMIO-based immediate flip on the secondary monitor.

The display miniport driver's DxgkDdiSetVidPnSourceAddress function should record the address that is being flipped to in the graphics adapter object.

To direct the display miniport driver to not wait for the next vertical retrace of the secondary monitor, the DirectX graphics kernel subsystem sets the FlipImmediate bit-field flag to TRUE in a call to the driver's DxgkDdiSetVidPnSourceAddress function.

See requirements on calling this function with multiplane overlays in Multiplane overlay VidPN presentation.

Requirements

Requirement	Value
Minimum supported client	Windows Vista
Header	d3dkmddi.h
IRQL	PASSIVE_LEVEL. Called at DIRQL if the driver supports a MMIO-based flip.

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