acpi_tz0: _CRT value is absurd, ignored (256.0C) (was pr kern/105537)

[Chris Whitehouse]

Alexandre "Sunny" Kovalenko wrote:
> To be fair, if all you want is to override _CRT, you should be able to
> put something to the tune of
> 
> hw.acpi.thermal.user_override=1
> hw.acpi.thermal.tz0._CRT=90C
> 
> in your /etc/sysctl.conf and not deal with the ASL at all.

I tried this and it sets hw.acpi.thermal.tz0._CRT correctly until 
hw.acpi.thermal.tz0.active and hw.acpi.thermal.tz0.temperature change 
values at which point hw.acpi.thermal.tz0._CRT reverts to -1.

At idle having set hw.acpi.thermal.tz0._CRT to 90C with sysctl:

chrisw at muji% sysctl hw.acpi.thermal.tz0
hw.acpi.thermal.tz0.temperature: 55.0C
hw.acpi.thermal.tz0.active: 3
hw.acpi.thermal.tz0.passive_cooling: 0
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: -1
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: 90.0C
hw.acpi.thermal.tz0._ACx: 80.0C 70.0C 60.0C 45.0C -1 -1 -1 -1 -1 -1
hw.acpi.thermal.tz0._TC1: -1
hw.acpi.thermal.tz0._TC2: -1
hw.acpi.thermal.tz0._TSP: -1

Heat it up a bit with cpuburn:

chrisw at muji% sysctl hw.acpi.thermal.tz0
hw.acpi.thermal.tz0.temperature: 60.0C
hw.acpi.thermal.tz0.active: 2
hw.acpi.thermal.tz0.passive_cooling: 0
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: -1
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: -1
hw.acpi.thermal.tz0._ACx: 80.0C 70.0C 55.0C 45.0C -1 -1 -1 -1 -1 -1
hw.acpi.thermal.tz0._TC1: -1
hw.acpi.thermal.tz0._TC2: -1
hw.acpi.thermal.tz0._TSP: -1

hw.acpi.thermal.tz0._CRT will now stay at -1 until I reset it with sysctl.

So I suppose I need to find out where hw.acpi.thermal.tz0._CRT is 
getting its value from - which must be the ASL.

acpidump -td says

         ThermalZone (TZ0)
         {

snip

             Method (_CRT, 0, Serialized)
             {
                 Return (C316 (0x04, 0x00))
             }

snip

          }

The whole asl is fetch(1)able as www.fishercroft.plus.com/nc6320.asl.gz

Watching /var/log/messages I can't see a correlation between when the 
warning messages appear and changing the temperature states so I don't 
even know what is actually triggering them.

I've started reading the ACPI specs as suggested but in the meantime all 
suggestions welcome.

Thanks

Chris

> 
> You might want to take a look at your output of 'sysctl hw.acpi.thermal'
> -- your specific thermal zone, might be different from the one, I have
> used as an example above. In fact, on my laptop, it is tz1 and not tz0.
> 
> In either case, I would recommend reading thermal chapter of the ACPI
> specification -- it is short, well-written and has an example, I was
> stealing stuff from, shamelessly, in the past.
> 
> HTH,
>