129 lines
3.9 KiB
Groff
129 lines
3.9 KiB
Groff
.\" $NetBSD: acpitz.4,v 1.14 2014/03/18 18:20:39 riastradh Exp $
|
|
.\"
|
|
.\" Copyright (c) 2003, 2004, 2011 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.Dd January 9, 2011
|
|
.Dt ACPITZ 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm acpitz
|
|
.Nd ACPI Thermal Zone
|
|
.Sh SYNOPSIS
|
|
.Cd "acpitz* at acpi?"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
driver supports so-called
|
|
.Tn ACPI
|
|
.Dq Thermal Zones .
|
|
The temperature can be monitored by the
|
|
.Xr envsys 4
|
|
API or the
|
|
.Xr envstat 8
|
|
command.
|
|
.Pp
|
|
The distinction between
|
|
.Dq active
|
|
and
|
|
.Dq passive
|
|
cooling is central to the abstractions behind
|
|
.Nm .
|
|
These are inversely related to each other:
|
|
.Bl -enum -offset 2n
|
|
.It
|
|
Active cooling means that the system increases the power consumption of the
|
|
machine by performing active thermal management (for example, by turning on
|
|
a fan) in order to reduce the temperatures.
|
|
.It
|
|
Passive cooling means that the system reduces the power consumption of
|
|
devices at the cost of system performance (for example, by lowering the
|
|
.Tn CPU
|
|
frequencies) in order to reduce the temperatures.
|
|
.El
|
|
.Pp
|
|
Only active cooling is currently supported on
|
|
.Nx .
|
|
.Pp
|
|
It should be also noted that the internal
|
|
functioning of these cooling policies vary across machines.
|
|
On some machines the operating system may have little control over
|
|
the thermal zones as the firmware manages the thermal control internally,
|
|
whereas on other machines the policies may be exposed to the implementation
|
|
at their full extent.
|
|
.Sh EVENTS
|
|
The
|
|
.Nm
|
|
driver knows about the active cooling levels, the current
|
|
temperatures, and critical, hot, and passive temperature thresholds
|
|
(as supported by the hardware).
|
|
The driver is able to send events to
|
|
.Xr powerd 8
|
|
when the sensor's state has changed.
|
|
When a Thermal Zone is either critical or
|
|
.Dq hot ,
|
|
the
|
|
.Pa /etc/powerd/scripts/sensor_temperature
|
|
script will be invoked with a
|
|
.Em critical-over
|
|
event.
|
|
.Pp
|
|
The critical temperature is the threshold for system shutdown.
|
|
Depending on the hardware, the mainboard will take down the system
|
|
instantly and no event will have a chance to be sent.
|
|
.Sh SEE ALSO
|
|
.Xr acpi 4 ,
|
|
.Xr acpifan 4 ,
|
|
.Xr envsys 4 ,
|
|
.Xr envstat 8 ,
|
|
.Xr powerd 8
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
driver
|
|
appeared in
|
|
.Nx 2.0 .
|
|
.Sh AUTHORS
|
|
.An Jared D. McNeill Aq Mt jmcneill@invisible.ca
|
|
.Sh CAVEATS
|
|
While no pronounced bugs are known to exist,
|
|
several caveats can be mentioned:
|
|
.Bl -bullet
|
|
.It
|
|
Passive cooling is not implemented.
|
|
.It
|
|
There is no user-controllable way to switch between active and passive
|
|
cooling, although the specifications support such transforms on some machines.
|
|
.It
|
|
The
|
|
.Dq hot
|
|
temperature is a threshold in which the system ought to be put into
|
|
.Tn S4
|
|
sleep.
|
|
This sleep state
|
|
.Pq Dq suspend to disk
|
|
is not supported on
|
|
.Nx .
|
|
.El
|