Device Power Management Enabling

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Power-manageable stream devices can automatically notify the Power Manager of their presence when they are loaded by ActivateDeviceEx. If the GUID "{A32942B7-920C-486b-B0E6-92A702A99B35}" is part of their IClass value, which is a REG_MULTI_SZ, the Power Manager will receive a device notification when the device is loaded. The Power Manager requests notifications for all classes listed in the HKEY_LOCAL_MACHINE\CurrentControlSet\Control\Power\Interfaces registry key.

Devices can manage their own power by calling the DevicePowerNotify function when they receive the IOCTL_POWER_CAPABILITIES I/O control. The Power Manager will recognize requests issued while the device is processing the IOCTL.

If an OEM chooses to implement a device API outside of the stream interface, the OEM needs to customize the Power Manager to communicate using the new mechanism.

See Also

Device Interface Notifications | Device Power Management Guidelines | How to Add Power Management to a Device Driver

 Last updated on Tuesday, May 18, 2004

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