WDF_POWER_POLICY_IDLE_TIMEOUT_TYPE enumeration

[Applies to KMDF and UMDF]

The WDF_POWER_POLICY_IDLE_TIMEOUT_TYPE enumeration identifies how the idle timeout for a device is determined.

Syntax


typedef enum _WDF_POWER_POLICY_IDLE_TIMEOUT_TYPE { 
  DriverManagedIdleTimeout          = 0,
  SystemManagedIdleTimeout          = 1,
  SystemManagedIdleTimeoutWithHint  = 2
} WDF_POWER_POLICY_IDLE_TIMEOUT_TYPE, *PWDF_POWER_POLICY_IDLE_TIMEOUT_TYPE;

Constants

DriverManagedIdleTimeout

The idle timeout value is determined by the IdleTimeout member of the WDF_DEVICE_POWER_POLICY_IDLE_SETTINGS structure.

SystemManagedIdleTimeout

Starting in Windows 8, the timeout value is determined by the power framework (PoFx). The value of the IdleTimeout member is not used.

On operating systems earlier than Windows 8, the behavior is same as DriverManagedIdleTimeout.

SystemManagedIdleTimeoutWithHint

Starting in Windows 8, the PoFx uses the value specified in the IdleTimeout member as an input when determining at what point after all the components are idle to transition the device to a low-power (Dx) state. This option enables the driver to delay the transition to a low-power state.

Typically, PoFx waits until the end of the time-out interval to initiate the power transition. However, if PoFx is preparing to enter a low-power system state, PoFx might end the time-out interval early.

The IdleTimeout value is only advisory. The actual duration after which the PoFx allows the device to enter a low-power state might be greater than or less than the IdleTimeout value.

On operating systems earlier than Windows 8, the behavior is the same as DriverManagedIdleTimeout.

Remarks

The WDF_POWER_POLICY_IDLE_TIMEOUT_TYPE enumeration is used in the WDF_DEVICE_POWER_POLICY_IDLE_SETTINGS structure.

Requirements

Minimum KMDF version

1.11

Minimum UMDF version

2.0

Header

Wdfdevice.h (include Wdf.h)

See also

WDF_DEVICE_POWER_POLICY_IDLE_SETTINGS

 

 

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