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Re: Modify Thermal trip points, modern kernel acpi /sys/class/thermal/thermal_zone0/

On Tue, 05 Jun 2012 19:30:06 +0800, Bob wrote:

> On 05/31/2012 12:48 AM, Camaleón wrote:
>> On Wed, 30 May 2012 13:37:35 +0800, Bob wrote:
>>> Hi on my laptop (ASUS EeePC 1215b) an AMD E-450 based system the
>>> current open source drivers in Wheezy don't manage power very well so
>>> the system overheats&  the battery doesn't last long. [0]
>> You mean the heat problematic comes exclusively from the GPU? :-?
> No it's just that the current open source drivers don't do power saving
> very well with newer hardware, it'll come good but for the moment fglrx
> is the way to go, if you google something like linux radeon "open
> source" overheat laptop you see it's not a new issue.

Yes, I already heard about this problem about the overheating in radeon 
chipsets when using the open source driver. Have you considered the ATI 
driver insetad?

As for the battery power management, IIRC there was a kernel issue with 
ASPM but this should have been already solved, at least in 3.2.x 
branches :-?

>> I would also check that cpufreqd is propelry loaded and set with a low
>> power consuming profile. Also, if your netbook has an option to switch
>> to a lower VGA mode it can be also something worth to try.
> It is on Ondemand and happily idles at 800 MHz jumping to 1.65 GHz when
> the demand is there, I could lower the display resolution but my desktop
> runs at 3840 x 1200 and the netbook in question is 1366x768 which
> already feels tight on the elbows, not sure I want to go any lower.

Lowering the display resolution won't be of any help here, I guess.

>>> I've got squeeze running quite nicely with kernel, fglrx&  their
>>> dependencies coming from backports, but even then if you tax both
>>> cores the CPU temperature climes quite quickly.
>> Mmm... is also hot with ATI closed-source driver?
> Not as badly and only when the CPU or CPU & GPU are really taxed.

That's better than nothing.

>>> What I'd like to do is lower the temperature at which active cooling
>>> starts
>> Changing that values manually can be a risk as this is usually set by
>> the BIOS or the VGA card.
> Yes but it maybe the only option, see below

If your computer runs very hot you'll have to cool it by other means, for 
instance, by forcing the fan to be always on, but altering the trip 
points can severely damage your hardware.

>> Those "thermal" trip point values seems to be wrong (passive should be
>> reached before critical, that is, when the computer is at a lower
>> temperature).
>> Install and configure "sensors" (or another power-management tool for
>> eeepc) and see what it says, to compare both results.
> Ok
> root@USBHDebian:~# sensors
> acpitz-virtual-0
> Adapter: Virtual device
> temp1:        +55.0°C  (crit = +95.0°C)
> k10temp-pci-00c3
> Adapter: PCI adapter
> temp1:        +55.4°C  (high = +70.0°C)
> radeon-pci-0008
> Adapter: PCI adapter
> temp1:        +55.0°C

Mmm, being a netbook you should be plenty of sensors but there are only 
two detected... Did you already configure lm-sensors? I miss the fan rpm 
value, for instance :-?

>> root@USBHDebian:~# acpi -V
>> Battery 0: Discharging, 77%, 05:46:05 remaining 
>> Battery 0: design capacity 5200 mAh, last full capacity 5107 mAh = 98%
>> Adapter 0: off-line
>> Thermal 0: ok, 55.0 degrees C
>> Thermal 0: trip point 0 switches to mode critical at temperature 95.0 degrees C 
>> Thermal 0: trip point 1 switches to mode passive at temperature 120.0 degrees C 
>> Cooling 0: LCD 5 of 10
>> Cooling 1: Processor 0 of 10
>> Cooling 2: Processor 0 of 10
> So they aggree on the actual temperature and the critical temp, there is
> no BIOS page where I can see the temps so I can't verify that way.


>>> How do I modify these numbers now the /proc/acpi thermal stuff is
>>> deprecated?
>> I wouldn't tweak these values manually. Maybe you can install a tool
>> that make your fan to be always "on" but a hot computer usually means
>> something is wrong: either you have not loaded the proper modules to
>> control power management or there's a bug in some place (drivers,
>> BIOS...).
> Sadly I don't think fan controls are exposed in this chip-set
> root@USBHDebian:~# grep FAN /var/log/dmesg 
> root@USBHDebian:~# grep fan /var/log/dmesg [    7.276594] [drm] Internal thermal controller without fan control

I wonder if that's normal for your eeepc :-?

Maybe you can ask at the EEEPC mailing list or IIRC listed here:


Or you can also take a look at the docs:


> Can you think of another way of getting the fan to kick in at lower
> temperatures?

There has to be a software to manually activate it (on-demand).

> Thanks for the help, sorry for the delay, my wife is using the NetBook
> (under windows) for her work while her MacBook is getting repaired so I
> have limited access.

Don't worry. We sometimes forget that we have a real life to feed ;-)



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