Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Field Format Description
TripPoint
Speed
NoiseLevel
Power
Integer
(DWORD)
Integer
(DWORD)
Integer
(DWORD)
Integer
(DWORD)
0-9: The active cooling trip point number that corresponds to this performance
state. If the _ART object is defined, OSPM may optionally use information
provided by the _ART object and _FPS objects to select alternative fan
performance states. Only one entry per unique trip point number is allowed in
the _FPS.
0x0A- 0xFFFFFFFE: Reserved
0x0FFFFFFFF: Indicates that this performance state does not correspond with
a specific active cooling trip point.
Indicates the speed of the fan in revolutions per minute in this performance
state.
This optional field indicates the audible noise emitted by the fan in this
performance state. The value represents the noise in 10ths of decibels. For
example, if the fan emits noise at 28.3dB in this performance state, the value of
this field would be 283. A value of 0xFFFFFFFF indicates that this field is not
populated.
This optional field indicates the power consumption (in milliwatts) of the fan in
this performance state. For example, if the fan consumes .5W in this
performance state, the value of this field would be 500. A value of
0xFFFFFFFF indicates that this field is not populated.
11.3.1.3 FSL (Fan Set Level)
The optional _FSL object is a control method that OSPM evaluates to set a fan device’s speed
(performance state) to a specific level
Arguments: (1)
Arg0 – Level (Integer): conveys to the platform the fan speed level to be set.
Return Value:
None
Argument Information
Arg0: Level. If the fan supports fine-grained control, Level is a percentage of maximum level (0-
100) that the platform is to engage the fan. If the fan does not support fine-grained control, Level is a
Control field value from a package in the _FPS object’s package list. A Level value of zero causes
the platform to turn off the fan.
11.3.1.4 _FST (Fan Status)
The optional _FST object provides status information for the fan device.
Arguments:
None
Return Value:
A Package containing fan device status information as described in Table 11-285 below
_FST evaluation returns a package of the following format:
606 April, 2015 Version 6.0