DXGKCB_SETPOWERCOMPONENTLATENCY callback function

Called by the display miniport driver to set the latency tolerance for a power component of type DXGK_POWER_COMPONENT_OTHER.

Syntax

DXGKCB_SETPOWERCOMPONENTLATENCY DxgkcbSetpowercomponentlatency;

void DxgkcbSetpowercomponentlatency(
  IN_CONST_HANDLE hAdapter,
  UINT ComponentIndex,
  ULONGLONG Latency
)
{...}

Parameters

hAdapter

A handle to the display adapter. The display miniport driver receives the handle from the DeviceHandle member of the DXGKRNL_INTERFACE structure in a call to its DxgkDdiStartDevice function.

ComponentIndex

The power component index specified by DXGKARG_QUERYADAPTERINFO.pInputData in a call to the DxgkDdiQueryAdapterInfo function.

Latency

The latency tolerance—the maximum time, in units of 100 nanoseconds, that the display miniport driver should take to awaken a power component from an idle state. The Power Management Framework uses this information to select an appropriate idle state for the component that does not violate the requested latency tolerance. The latency tolerance specified by Latency remains in effect until the driver calls this function again to update it.

For more information, see Remarks.

Return Value

This callback function does not return a value.

Remarks

Note The display miniport driver should call this function only if the component type is DXGK_POWER_COMPONENT_OTHER. The Microsoft DirectX graphics kernel subsystem sets the latency tolerance value for other component types.
If the power component is in an idle state when this function is called, the Power Management Framework might change the component's F-state to meet the latency tolerance specified by Latency.

If the driver sets Latency to a value of PO_FX_UNKNOWN_TIME (defined in Wdm.h), the Power Engine Plug-in (PEP) might be unable to set the component to an F-state lower than F0.

Requirements

   
Windows version Windows 8 Windows 8
Target Platform Desktop
Header d3dkmddi.h (include D3dkmddi.h)
IRQL "<=DISPATCH_LEVEL"

See Also

DXGKRNL_INTERFACE

DxgkDdiQueryAdapterInfo

DXGKARG_QUERYADAPTERINFO

DxgkDdiStartDevice

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