Raising temperature threshold

[Matthew Flanagan]

On 22 Jun 2005 11:46:31 -0400, Lowell Gilbert
<freebsd-questions-local at be-well.ilk.org> wrote:
> Matthew Flanagan <flanagan.matt at gmail.com> writes:
> 
> > I`ve installed a FreeBSD 5.4-STABLE and I was building some ports when 
> > suddenly my system shut down. Upon rebooting it and checking 
> > /var/log/messages, I found the following lines:
> > 
> > Jun 21 16:01:30 bell root: WARNING: system temperature too high,
> > shutting down soon!
> > Jun 21 16:01:40 bell kernel: acpi_tz0: WARNING - current temperature
> > (60.0C) exceeds safe limits
> > 
> > Then I realized what had happened. My acpi_thermal sysctl's are:
> > 
> > hw.acpi.thermal.min_runtime: 0
> > hw.acpi.thermal.polling_rate: 10
> > hw.acpi.thermal.tz0.temperature: 50.0C
> > hw.acpi.thermal.tz0.active: 0
> > hw.acpi.thermal.tz0.thermal_flags: 1
> > hw.acpi.thermal.tz0._PSV: 50.0C
> > hw.acpi.thermal.tz0._HOT: -1
> > hw.acpi.thermal.tz0._CRT: 60.0C
> > hw.acpi.thermal.tz0._ACx: 50.0C -1 -1 -1 -1 -1 -1 -1 -1 -1
> > 
> > When I try to raise hw.acpi.thermal.tz0._CRT to 85C (which is the
> threshold in
> > the BIOS setup) it doesn't work:
> > 
> > bell# sysctl hw.acpi.thermal.tz0._CRT=3580  # 3580 tenths of Kelvin=85C
> > sysctl: oid 'hw.acpi.thermal.tz0._CRT' is read only
> > 
> > I've tried /etc/sysctl.conf as well, but I get the same error.
> > 
> > Now, my question is: how do I change this value? I've read several
> manpages
> > (acpi(4), acpi_thermal(4), acpiconf(8), and many others) and checked the
> > handbook, to no avail. Can anyone point me to the right direction?
> 
> Can it be set at boot time?  [from the loader?]

Perhaps, but loader(8) lists the kernel tunable parameters available, and
hw.acpi.thermal.tz%d._CRT isn't one of them.

Cheers,
Matt