WDDM 设置电源状态

电源状态使用DxgkDdiSetPowerState来实现

    InitialData.DxgkDdiSetPowerState                = BddDdiSetPowerState;

当驱动工作时方可进行电源状态的设置

NTSTATUS
BddDdiSetPowerState(
    _In_  VOID*              pDeviceContext,
    _In_  ULONG              HardwareUid,
    _In_  DEVICE_POWER_STATE DevicePowerState,
    _In_  POWER_ACTION       ActionType)
{
    PAGED_CODE();
    BDD_ASSERT_CHK(pDeviceContext != NULL);

    BASIC_DISPLAY_DRIVER* pBDD = reinterpret_cast<BASIC_DISPLAY_DRIVER*>(pDeviceContext);
    if (!pBDD->IsDriverActive())
    {
        // If the driver isn't active, SetPowerState can still be called, however in BDD's case
        // this shouldn't do anything, as it could for instance be called on BDD Fallback after
        // Fallback has been stopped and BDD PnP is being started. Fallback doesn't have control
        // of the hardware in this case.
        return STATUS_SUCCESS;
    }
    return pBDD->SetPowerState(HardwareUid, DevicePowerState, ActionType);
}

当电源状态从D3到D0即工作时，关闭设备的可见性。

NTSTATUS BASIC_DISPLAY_DRIVER::SetPowerState(_In_  ULONG              HardwareUid,
                                             _In_  DEVICE_POWER_STATE DevicePowerState,
                                             _In_  POWER_ACTION       ActionType)
{
    PAGED_CODE();

    UNREFERENCED_PARAMETER(ActionType);

    BDD_ASSERT((HardwareUid < MAX_CHILDREN) || (HardwareUid == DISPLAY_ADAPTER_HW_ID));

    if (HardwareUid == DISPLAY_ADAPTER_HW_ID)
    {
        if (DevicePowerState == PowerDeviceD0)
        {

            // When returning from D3 the device visibility defined to be off for all targets
            if (m_AdapterPowerState == PowerDeviceD3)
            {
                DXGKARG_SETVIDPNSOURCEVISIBILITY Visibility;
                Visibility.VidPnSourceId = D3DDDI_ID_ALL;
                Visibility.Visible = FALSE;
                SetVidPnSourceVisibility(&Visibility);
            }
        }

        // Store new adapter power state
        m_AdapterPowerState = DevicePowerState;

        // There is nothing to do to specifically power up/down the display adapter
        return STATUS_SUCCESS;
    }
    else
    {
        // TODO: This is where the specified monitor should be powered up/down
        NOTHING;
        return STATUS_SUCCESS;
    }
}

NTSTATUS BASIC_DISPLAY_DRIVER::SetVidPnSourceVisibility(_In_ CONST DXGKARG_SETVIDPNSOURCEVISIBILITY* pSetVidPnSourceVisibility)
{
    PAGED_CODE();

    BDD_ASSERT(pSetVidPnSourceVisibility != NULL);
    BDD_ASSERT((pSetVidPnSourceVisibility->VidPnSourceId < MAX_VIEWS) ||
               (pSetVidPnSourceVisibility->VidPnSourceId == D3DDDI_ID_ALL));

    UINT StartVidPnSourceId = (pSetVidPnSourceVisibility->VidPnSourceId == D3DDDI_ID_ALL) ? 0 : pSetVidPnSourceVisibility->VidPnSourceId;
    UINT MaxVidPnSourceId = (pSetVidPnSourceVisibility->VidPnSourceId == D3DDDI_ID_ALL) ? MAX_VIEWS : pSetVidPnSourceVisibility->VidPnSourceId + 1;

    for (UINT SourceId = StartVidPnSourceId; SourceId < MaxVidPnSourceId; ++SourceId)
    {
        if (pSetVidPnSourceVisibility->Visible)
        {
            m_CurrentModes[SourceId].Flags.FullscreenPresent = TRUE;
        }
        else
        {
            BlackOutScreen(SourceId);
        }

        // Store current visibility so it can be dealt with during Present call
        m_CurrentModes[SourceId].Flags.SourceNotVisible = !(pSetVidPnSourceVisibility->Visible);
    }

    return STATUS_SUCCESS;
}

DISPLAY_ADAPTER_HW_ID表示设备本身。