IWDFDevice3::AssignS0IdleSettingsEx method (wudfddi.h)

Article
02/22/2024

[Warning: UMDF 2 is the latest version of UMDF and supersedes UMDF 1. All new UMDF drivers should be written using UMDF 2. No new features are being added to UMDF 1 and there is limited support for UMDF 1 on newer versions of Windows 10. Universal Windows drivers must use UMDF 2. For more info, see Getting Started with UMDF.]

The AssignS0IdleSettingsEx method provides driver-supplied information that the framework uses when a device is idle and the system is in its working (S0) state.

Syntax

HRESULT AssignS0IdleSettingsEx(
  [in] PWUDF_DEVICE_POWER_POLICY_IDLE_SETTINGS IdleSettings
);

Parameters

[in] IdleSettings

A pointer to a WUDF_DEVICE_POWER_POLICY_IDLE_SETTINGS structure that was initialized by a call to the WUDF_DEVICE_POWER_POLICY_IDLE_SETTINGS_INIT macro.

Return value

The method returns S_OK if the operation succeeds. Otherwise, this method returns one of the error codes that are defined in Winerror.h.

Remarks

A driver can call AssignS0IdleSettingsEx at any point after the driver calls IWDFDriver::CreateDevice. Before calling IWDFDriver::CreateDevice, the driver must call IWDFDeviceInitialize::SetPowerPolicyOwnership with the fTrue parameter set to TRUE. For an example of this call sequence, see IWDFDriver::CreateDevice.

If your driver calls AssignS0IdleSettingsEx more than once, follow the rules described in the Remarks section of AssignS0IdleSettings.

For more information about idle power-down, see Supporting Idle Power-Down in UMDF-based Drivers.

Examples

The following code example initializes a WUDF_DEVICE_POWER_POLICY_IDLE_SETTINGS structure and sets an idle time-out value of 10 seconds. The example then obtains the IWDFDevice3 interface and calls AssignS0IdleSettingsEx.

IWDFDevice3 *pIWDFDevice3 = NULL;
HRESULT hr;

WUDF_DEVICE_POWER_POLICY_IDLE_SETTINGS  idleSettings;

WUDF_DEVICE_POWER_POLICY_IDLE_SETTINGS_INIT(
                                           &idleSettings,
                                           IdleCanWakeFromS0
                                           );
idleSettings.IdleTimeout = 10000;

//
// Get a pointer to the IWDFDevice3 interface.
//

hr = pIWDFDevice->QueryInterface(__uuidof(IWDFDevice3),
                                 (void**) &pIWDFDevice3);
if (SUCCEEDED(hr)) 
   {
    
   hr = pIWDFDevice3->AssignS0IdleSettingsEx(&idleSettings
                                            );
   }
...

SAFE_RELEASE(pIWDFDevice3);

Requirements

Requirement	Value
End of support	Unavailable in UMDF 2.0 and later.
Target Platform	Desktop
Minimum UMDF version	1.11
Header	wudfddi.h
DLL	WUDFx.dll

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