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DXGKDDI_DISPLAYMUX_UPDATE_STATE callback function (dispmprt.h)

  • Article

Dxgkrnl calls the kernel-mode display driver's (KMD) DxgkddiDisplayMuxUpdateState function to notify the driver of the current mux state.

Syntax

DXGKDDI_DISPLAYMUX_UPDATE_STATE DxgkddiDisplaymuxUpdateState;

void DxgkddiDisplaymuxUpdateState(
  PVOID DriverContext,
  ULONG VidPnTargetId,
  BOOLEAN MuxSwitchedToTarget
)
{...}

Parameters

DriverContext

[in] Handle to a context block that is associated with a display adapter. KMD's DxgkDdiAddDevice function previously provided this handle to Dxgkrnl.

VidPnTargetId

[in] The VidPN target that the DDI is being called for.

MuxSwitchedToTarget

[in] A Boolean value that indicates whether the mux is currently switched to connect the specified VidPnTargetId to the panel.

Return value

None

Remarks

This DDI is called under synchronization level 2.

Dxgkrnl calls DxgkDdiDisplayMuxUpdateState to provide the driver with the current mux state in the following cases:

  • At driver start, which allows the driver to avoid timely polling sequences when the panel isn't connected.
  • On return from sleep (to D0 power state from Dx). When returning from some power states (for example, hibernate) the firmware might have to reset the mux and hence the driver doesn't know the state.

DxgkDdiDisplayMuxUpdateState is called before any display-related DDIs involving the target that the mux is connected to.

For more information, see Automatic Display Switch.

Requirements

Requirement Value
Minimum supported client Windows 11, version 24H2, update 2025.01
Header dispmprt.h
IRQL PASSIVE_LEVEL