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

[Anton Shterenlikht]

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.

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)?

I had a quick look at ⌡aacpi(4),
but none of the above are mentioned.

Many thanks for all 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