STOR_POFX_COMPONENT_IDLE_STATE structure (storport.h)

The STOR_POFX_COMPONENT_IDLE_STATE structure specifies the attributes of an functional power state (F-state) of a component in a storage device.

Syntax

typedef struct _STOR_POFX_COMPONENT_IDLE_STATE {
  ULONG     Version;
  ULONG     Size;
  ULONGLONG TransitionLatency;
  ULONGLONG ResidencyRequirement;
  ULONG     NominalPower;
} STOR_POFX_COMPONENT_IDLE_STATE, *PSTOR_POFX_COMPONENT_IDLE_STATE;

Members

Version

The version of this structure. Set this member to STOR_POFX_COMPONENT_IDLE_STATE_VERSION_V1.

Size

The size of this structure. Set this value to STOR_POFX_COMPONENT_IDLE_STATE_SIZE.

TransitionLatency

The transition latency. This latency is the amount of time, in 100-nanosecond units, that the component requires to return from this F-state to the F0 state. For a STOR_POFX_COMPONENT_IDLE_STATE structure that specifies the attributes of the F0 state, set this member to zero. Set this member to STOR_PO_FX_UNKNOWN_TIME to indicate that the power management framework (PoFx) should ignore (treat as negligible) the component's transition latency from this F-state when PoFx evaluates which power state to switch to when the component is idle.

ResidencyRequirement

The residency requirement. The residency requirement is the minimum amount of time, in 100-nanosecond units, that the component must spend in this F-state to make a transition to this F-state worthwhile. PoFx uses this member value as a hint to avoid switching a component to an F-state unless the component is likely to remain in this state for at least the amount of time specified by ResidencyRequirement. For a STOR_PO_FX_COMPONENT_IDLE_STATE structure that describes the attributes of the F0 state, set this member to zero. Set this member to STOR_PO_FX_UNKNOWN_TIME to indicate that PoFx should ignore (treat as negligible) the component's residency requirement for this F-state when PoFx evaluates which power state to switch to when the component is idle.

NominalPower

The power, in microwatts, that the component consumes in this F-state. Set this member to STOR_PO_FX_UNKNOWN_POWER to indicate that PoFx should ignore (treat as negligible) the component's internal power consumption in this F-state when PoFx evaluates which power state to switch to when the component is idle.

Remarks

The STOR_POFX_COMPONENT structure contains an array of STOR_POFX_COMPONENT_IDLE_STATE structures. Each array element specifies the attributes of an F-state. Element 0 describes F0, element 1 describes F1, and so on.

When the miniport driver registers a device with the Storport power management framework, the driver supplies an array of STOR_POFX_COMPONENT structures. Each array element describes the power attributes of a component in the device.

Requirements

See also

STOR_POFX_COMPONENT