ACPI temprature settings [WAS: Re: laptop very hot and noisy]

[Anton Shterenlikht]

On Thu, May 10, 2012 at 12:29:15AM +1000, Ian Smith wrote:
> In freebsd-questions Digest, Vol 414, Issue 3, Message: 2
> On Tue, 8 May 2012 15:06:04 +0100 Anton Shterenlikht <mexas at bristol.ac.uk> wrote:
>  > On Tue, May 01, 2012 at 07:59:58PM +0100, Chris Whitehouse wrote:
>  > > On 01/05/2012 13:41, Anton Shterenlikht wrote:
>  > > >So I might need to pull the laptop apart..
>  > > >I'm just not sure I could put it back
>  > > >together...
>  > > >
>  > > >Thanks anyway
>  > > 
>  > > service manual (c02834030.pdf):
>  > > http://h20000.www2.hp.com/bizsupport/TechSupport/CoreRedirect.jsp?redirectReason=DocIndexPDF&prodSeriesId=3368539&targetPage=http%3A%2F%2Fbizsupport1.austin.hp.com%2Fbc%2Fdocs%2Fsupport%2FSupportManual%2Fc02834030%2Fc02834030.pdf
>  > > 
>  > > short url:
>  > > http://bit.ly/Ivgs5C
>  > > 
>  > > HP are pretty good about service manuals.
>  > 
>  > yes, this is partly why I bought an HP laptop.
>  > I had previous experience with other HP/Compaq/Digital
>  > hardware and manuals - they are generally very good.
>  > 
>  > Anyway, this was easier than I expected.
>  > I removed a lot of dust from the fan
>  > and the heat sink gills. I also replaced
>  > the "thermal material".
>  > 
>  > I rebuilt gcc47 and saw the highest temperature of 75.
>  > This is on the southern side, so not too bad. The
>  > noise reduced too.
> 
> Happiness is a warm CPU .. so much easier the next time it needs doing.
> 
>  > Now, I'd just like to understand better the
>  > meaning of these console messages:
>  > 
>  > May  8 15:00:08 mech-aslap239 kernel: acpi_tz0: _AC3: temperature 64.0 >= setpoint 40.0
>  > May  8 15:00:08 mech-aslap239 kernel: acpi_tz0: _AC2: temperature 64.0 >= setpoint 50.0
>  > May  8 15:00:18 mech-aslap239 kernel: acpi_tz0: _AC3: temperature 64.0 >= setpoint 40.0
>  > May  8 15:00:18 mech-aslap239 kernel: acpi_tz0: _AC2: temperature 64.0 >= setpoint 50.0
>  > May  8 15:00:28 mech-aslap239 kernel: acpi_tz0: _AC3: temperature 64.0 >= setpoint 40.0
>  > May  8 15:00:28 mech-aslap239 kernel: acpi_tz0: _AC2: temperature 64.0 >= setpoint 50.0
>  > May  8 15:00:38 mech-aslap239 kernel: acpi_tz0: _AC3: temperature 64.0 >= setpoint 40.0
>  > May  8 15:00:38 mech-aslap239 kernel: acpi_tz0: _AC2: temperature 64.0 >= setpoint 50.0
>  > May  8 15:00:48 mech-aslap239 kernel: acpi_tz0: _AC3: temperature 65.0 >= setpoint 40.0
>  > May  8 15:00:48 mech-aslap239 kernel: acpi_tz0: _AC2: temperature 65.0 >= setpoint 50.0
>  > 
>  > Where are setpoints defined?
>  > What's acpi_tz?
>  > What are AC1, AC2, AC3?
>  > Which kernel tunables are involved in the
>  > switching from one fan speed to another
>  > (assuming AC1, AC2, AC3 are related to fan
>  > speed in some way)?
> 
> To add to What Chris said, perhaps more directly see acpi_thermal(4)
> 
> Please show us `sysctl hw.acpi`?  Particularly `sysctl hw.acpi.thermal` 
> shows your machine's thermal zone(s) settings.  These messages are re 
> your zone tz1, which sure looks like an active mode multi-setpoint fan.
> 
> This logging does appear strange; it suggests that the temperature is 
> always reading as 64 or 65C - which sounds reasonable given it peaks at 
> 75C - but since that's greater than either of the 40C and 50C setpoints, 
> I don't see why it should (appear to) change between _AC2 and _AC3 every 
> 10 seconds, most likely the value of hw.acpi.thermal.polling_rate
> 
> Do you hear a fan changing speed at that frequency?  Does that echo what
> hw.acpi.thermal.tz0.temperature reports from time to time?
> 
> Do you have any extra ACPI debugging enabled?  Or did you last boot with 
> verbose messages?  If so, maybe it's just reporting fan change activity?
> 
> Unless someone here has an explanation, I suspect this would be of 
> interest on the freebsd-acpi@ list, where core acpi folks hang out.
> 
>  > I had a quick look at ???aacpi(4),
>  > but none of the above are mentioned.
> 
> Searching acpi(4) for thermal|THERMAL gets you there, but yes, you first 
> needed to know that 'tz' means 'thermal zone'.  ACPI be deep and wide ..

yes, I got it now. It's quite easy really.
acpi_thermal(4) explains nearly all I need
to know.

I have 

GEN8> sysctl hw.acpi.thermal
hw.acpi.thermal.min_runtime: 0
hw.acpi.thermal.polling_rate: 10
hw.acpi.thermal.user_override: 0
hw.acpi.thermal.tz0.temperature: 64.0C
hw.acpi.thermal.tz0.active: 1
hw.acpi.thermal.tz0.passive_cooling: 1
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: 95.0C
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: 105.0C
hw.acpi.thermal.tz0._ACx: 75.0C 60.0C 50.0C 40.0C -1 -1 -1 -1 -1 -1
hw.acpi.thermal.tz0._TC1: 1
hw.acpi.thermal.tz0._TC2: 2
hw.acpi.thermal.tz0._TSP: 100
GEN8>

Which seems reasonable.

And yes, my previous post was from a vebose boot.

So all seems fine now.

Many thanks for your help.


-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
University Walk, Bristol BS8 1TR, UK
Tel: +44 (0)117 331 5944
Fax: +44 (0)117 929 4423