typedef struct _POP_DEVICE_SYS_STATE
{
     UCHAR IrpMinor;
     SYSTEM_POWER_STATE SystemState;
     ULONG SpinLock;
     PKTHREAD Thread;
     PKEVENT AbortEvent;
     PKSEMAPHORE ReadySemaphore;
     PKSEMAPHORE FinishedSemaphore;
     UCHAR GetNewDeviceList;
     PO_DEVICE_NOTIFY_ORDER Order;
     LONG NotifyGdiLevelForPowerOn;
     LONG NotifyGdiLevelForResumeUI;
     LIST_ENTRY Pending;
     LONG Status;
     PDEVICE_OBJECT FailedDevice;
     UCHAR Waking;
     UCHAR Cancelled;
     UCHAR IgnoreErrors;
     UCHAR IgnoreNotImplemented;
     UCHAR TimeRefreshLockAcquired;
} POP_DEVICE_SYS_STATE, *PPOP_DEVICE_SYS_STATE;

Windows Vista Kernel Structures