DXGKCB_SETPOWERCOMPONENTLATENCY callback function (d3dkmddi.h)
A display miniport driver calls DXGKCB_SETPOWERCOMPONENTLATENCY to set the latency tolerance for a power component of type DXGK_POWER_COMPONENT_OTHER.
Syntax
DXGKCB_SETPOWERCOMPONENTLATENCY DxgkcbSetpowercomponentlatency;
void DxgkcbSetpowercomponentlatency(
[in] IN_CONST_HANDLE hAdapter,
[in] UINT ComponentIndex,
[in] ULONGLONG Latency
)
{...}
Parameters
[in] 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.
[in] ComponentIndex
The power component index specified by DXGKARG_QUERYADAPTERINFO.pInputData in a call to the DxgkDdiQueryAdapterInfo function.
[in] 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. See Remarks.
Return value
None
Remarks
Note
The display miniport driver should call this function only if the component type is DXGK_POWER_COMPONENT_OTHER. The DirectX graphics kernel subsystem sets the latency tolerance value for other component types.
DXGKCB_XXX functions are implemented by Dxgkrnl. To use this callback function, call DxgkCbSetPowerComponentLatency via the DXGKRNL_INTERFACE.
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
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 8 (WDDM 1.2) |
| Minimum supported server | Windows Server 2012 |
| Target Platform | Desktop |
| Header | d3dkmddi.h (include D3dkmddi.h) |
| IRQL | <= DISPATCH_LEVEL |