PO_FX_COMPONENT_PERF_STATE_CALLBACK callback function (wdm.h)

Article
02/22/2024

The ComponentPerfStateCallback callback routine notifies the driver that its request to change the performance state of a component is complete.

Syntax

PO_FX_COMPONENT_PERF_STATE_CALLBACK PoFxComponentPerfStateCallback;

void PoFxComponentPerfStateCallback(
  [in] PVOID Context,
  [in] ULONG Component,
  [in] BOOLEAN Succeeded,
  [in] PVOID RequestContext
)
{...}

Parameters

[in] Context

A pointer to the device context. The device driver uses this context to store information about the current power state of the device. The device driver specified this pointer in the DeviceContext member of the PO_FX_DEVICE structure that the driver used to register the device with the power management framework (PoFx). This context is opaque to PoFx.

[in] Component

Specifies the index that identifies the component. This parameter is an index into the Components array in the PO_FX_DEVICE structure that the device driver used to register the device with PoFx. If the Components array contains N elements, component indexes range from 0 to N–1.

[in] Succeeded

If TRUE, the platform extension plug-in (PEP) succeeded the performance state change. If FALSE, the PEP failed the performance state change. For more information, see the Remarks section.

[in] RequestContext

Pointer to the optional driver or device context that was specified by the Context parameter of the PoFxIssueComponentPerfStateChange or PoFxIssueComponentPerfStateChangeMultiple routine.

Return value

None

Remarks

When a device driver requests a performance state change by calling the PoFxIssueComponentPerfStateChange or PoFxIssueComponentPerfStateChangeMultiple routine, PoFx calls the ComponentPerfStateCallback routine to notify the driver when the request is complete.

To specify a ComponentPerfStateCallback routine, use the ComponentPerfStateCallback parameter of the PoFxRegisterComponentPerfStates routine when the driver registers for performance state management by PoFx. The ComponentPerfStateCallback routine may be the same for all components and all devices.

If Succeeded is TRUE, the driver should perform whatever work is necessary to change the performance state in the hardware. If Succeeded is FALSE, the driver may choose to do nothing or retry the request with the same performance state or an alternate performance state.

Requirements

Requirement	Value
Minimum supported client	Supported starting with Windows 10.
Target Platform	Desktop
Header	wdm.h
IRQL	Called at IRQL <= DISPATCH_LEVEL.