No acpi.thermal on ASUS M2A-VM HDMI

John Baldwin jhb at freebsd.org
Fri Dec 28 11:39:43 PST 2007


On Thursday 27 December 2007 05:32:26 pm Nate Lawson wrote:
> Gordon work wrote:
> > Hi all,
> > 
> > I have an ASUS M2A-VM HDMI motherboard running the latest BIOS.
> > All power management features, in particular AMD "Cool and Quiet"
> > and Q-Fan control are enabled, but the system seems oblivious to
> > temperature and the fans always runs at the same (noisy) speed.
> > The temperature is always given as 40C, which I have read elsewhere
> > is a default value.
> > 
> > I would like to control the fan speed.  I am not concerned with other
> > ACPI features.
> > 
> > Does anyone happen to know of any kernel or APM tweaks that might get
> > ACPI thermal working on this board?
> > 
> > System particulars follow:
> > 
> > % uname -a
> > FreeBSD localhost 7.0-BETA3 FreeBSD 7.0-BETA3 #4: Sun Dec 16 12:45:34 CST 
2007     root at localhost:/usr/obj/usr/src/sys/CUSTOM  amd64
> > 
> > % kldstat
> > Id Refs Address            Size     Name
> >  1    5 0xffffffff80100000 7600d8   kernel
> >  2    1 0xffffffff80861000 1a570    snd_hda.ko
> >  3    2 0xffffffff8087c000 673b8    sound.ko
> >  4    1 0xffffffff808e4000 5fd0     acpi_asus.ko
> > 
> > % 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: 40.0C
> > 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: 73.0C
> > hw.acpi.thermal.tz0._HOT: -1
> > hw.acpi.thermal.tz0._CRT: 75.0C
> > hw.acpi.thermal.tz0._ACx: 73.0C -1 -1 -1 -1 -1 -1 -1 -1 -1
> 
> If it's just returning a fixed value of 40C, you should try an external
> application that reads the temp directly.  For instance, the lmsensors port.
> 
> The ASL itself has the hardcoded value in it, meaning the BIOS vendor
> never intended to give ACPI access to the temperature.

Actually IIRC, some truly evil BIOSen will alter the AML at runtime via SMI# 
rather than making _TMP query the value.  In that case, _TMP can 
still "work", but it would always appear as a constant in ASL dumps.

-- 
John Baldwin


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