Module Name: src Committed By: jruoho Date: Sun Apr 25 06:04:59 UTC 2010
Modified Files: src/share/man/man4: acpitz.4 Log Message: Update this. Remove the nonsense about passive cooling. As there is no known bugs, speak about CAVEATS instead, and add few items to this section as a TODO. To generate a diff of this commit: cvs rdiff -u -r1.9 -r1.10 src/share/man/man4/acpitz.4 Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/share/man/man4/acpitz.4 diff -u src/share/man/man4/acpitz.4:1.9 src/share/man/man4/acpitz.4:1.10 --- src/share/man/man4/acpitz.4:1.9 Sun Nov 9 14:00:48 2008 +++ src/share/man/man4/acpitz.4 Sun Apr 25 06:04:59 2010 @@ -1,4 +1,4 @@ -.\" $NetBSD: acpitz.4,v 1.9 2008/11/09 14:00:48 pgoyette Exp $ +.\" $NetBSD: acpitz.4,v 1.10 2010/04/25 06:04:59 jruoho Exp $ .\" .\" Copyright (c) 2003, 2004 The NetBSD Foundation, Inc. .\" All rights reserved. @@ -24,7 +24,7 @@ .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" -.Dd November 9, 2008 +.Dd April 25, 2010 .Dt ACPITZ 4 .Os .Sh NAME @@ -35,13 +35,36 @@ .Sh DESCRIPTION The .Nm -driver supports ACPI Thermal Zones. -.Pp +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 . .Sh EVENTS The .Nm @@ -51,23 +74,17 @@ The driver is able to send events to .Xr powerd 8 when the sensor's state has changed. -When a Thermal Zone is critical, a -.Em critical-over -event will be sent or if the Thermal Zone is hot, a -.Em warning-over -event will be sent to the +When a Thermal Zone is either critical or +.Dq hot , +the .Pa /etc/powerd/scripts/sensor_temperature -script. +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. -.\" The hot temperature is the temperature threshold for S4 sleep. -.\" S4 is only supported on small subset of machines and is not known to work. -The passive temperature is the passive cooling temperature threshold. -Passive cooling means the Thermal Zone hardware -doesn't have any software control. -On capable hardware, active cooling can power on and off fans, for example. .Sh SEE ALSO .Xr acpi 4 , .Xr envsys 4 , @@ -79,5 +96,23 @@ driver appeared in .Nx 2.0 . -.Sh BUGS -Any policy control such as fan control is not implemented. +.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