PRB: ACPI System Fails to Hibernate Due to Display Device

ID: Q190525

The information in this article applies to:

• Microsoft Win32 Device Driver Kit (DDK) for Windows 98

SYMPTOMS

A Windows 98 ACPI system might fail to hibernate (transition to S4). The debug build of configmg.vxd displays a debug output that lists any devices that failed the transition to S4. The display device might be listed as the device preventing S4.

CAUSE

In Windows 98 ACPI systems, the display device miniVDD should support OnNow by responding to power state commands and by providing information on what power states are supported by the hardware device. The miniVDD GET_ADAPTER_POWER_STATE_CAPS function returns a bitmask indicating the power states supported by the display adapter. This function should return with the CM_POWERSTATE_D3 flag set in order to support S4.

RESOLUTION

To work around display drivers that do not support OnNow, you need to make a registry entry in the device's software branch named "REPOST" to allow the display device to transition to D3 and the system to hibernate. The "REPOST" registry entry should be placed in HKLM/System/CurrentControlSet/Services/Class/Display/XXXX/Default, where XXXX is a number, and it should be set to a STRING value of "1".

STATUS

This behavior is by design.

REFERENCES

Windows 98 DDK Documentation

Additional query words:

Keywords          : kbmm kbWinOS98 
Issue type        : kbprb

Last Reviewed: August 5, 1998