Advanced Configuration and Power Interface Specification

ACPI Software Programming Model
Value
1 Device Check. Used to notify OSPM that the device either appeared or disappeared. If the
device has appeared, OSPM will re-enumerate from the parent. If the device has
disappeared, OSPM will invalidate the state of the device. OSPM may optimize out reenumeration.
If _DCK is present, then Notify(object,1) is assumed to indicate an undock
request. If the device is a bridge, OSPM may re-enumerate the bridge and the child bus.
2 Device Wake. Used to notify OSPM that the device has signaled its wake event, and that
OSPM needs to notify OSPM native device driver for the device. This is only used for
devices that support _PRW.
3 Eject Request. Used to notify OSPM that the device should be ejected, and that OSPM
needs to perform the Plug and Play ejection operation. OSPM will run the _EJx method.
4 Device Check Light. Used to notify OSPM that the device either appeared or disappeared.
If the device has appeared, OSPM will re-enumerate from the device itself, not the parent. If
the device has disappeared, OSPM will invalidate the state of the device.
5 Frequency Mismatch. Used to notify OSPM that a device inserted into a slot cannot be
attached to the bus because the device cannot be operated at the current frequency of the
bus. For example, this would be used if a user tried to hot-plug a 33 MHz PCI device into a
slot that was on a bus running at greater than 33 MHz.
6 Bus Mode Mismatch. Used to notify OSPM that a device has been inserted into a slot or
bay that cannot support the device in its current mode of operation. For example, this would
be used if a user tried to hot-plug a PCI device into a slot that was on a bus running in PCI-X
mode.
7 Power Fault. Used to notify OSPM that a device cannot be moved out of the D3 state
because of a power fault.
8 Capabilities Check. This notification is performed on a device object to indicate to OSPM
that it needs to re-evaluate the _OSC control method associated with the device.
9 Device _PLD Check. Used to notify OSPM to reevaluate the _PLD object, as the Device’s
connection point has changed.
0xA
Reserved.
0xB
0x0C
0x0D
0x0E-0x7F
Description
System Locality Information Update. Dynamic reconfiguration of the system may cause
existing relative distance information to change. The platform sends the System Locality
Information Update notification to a point on a device tree to indicate to OSPM that it needs
to invoke the _SLI objects associated with the System Localities on the device tree starting
from the point notified.
Graceful Shutdown Request. Used to notify OSPM that a graceful shutdown of the
operating system has been requested. Once the operating system has finished its graceful
shutdown procedure it should initiate a transition to the G2 "soft off" state. See Section 6.3.5
for a description of shutdown processing.
System Resource Affinity Update. Dynamic migration of devices may cause existing
system resource affinity to change. The platform software issues the System Resource
Affinity Update notification to a point on a device tree to indicate to OSPM that it needs to
invoke the _PXM object of the notified device to update the resource affinity.
Reserved.
Below are the notification values defined for specific ACPI devices. For more information
concerning the object-specific notification, see the section on the corresponding device/object.
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