[ltp] frequency scaling using APM?

Norman Ramsey linux-thinkpad@linux-thinkpad.org
Sat, 16 Apr 2005 13:06:36 -0400


 > Le jeudi 14 avril 2005 à 12:31 -0400, Norman Ramsey a ecrit :
 > > The Thinkpad Wiki seems to suggest that it is possible to
 > > do cpu frequency scaling using APM (rather than ACPI).
 > > And indeed, I found it possible to load a module called
 > > cpufreq-userspace.  But I can't see that this module does
 > > anything, and when I try to start cpufreqd, it looks for
 > > and does not find yummy files in /dev or /proc.
 > > 
 > > Has anyone made frequency scaling work using APM?
 > > Has anyone seen documentation for the cpufreq-userspace
 > > module?  (I read the source code but didn't have enough
 > > background to learn anything other than /proc/sys/cpu
 > > is deprecated :-)
 > > 
 > > 
 > > Norman Ramsey
 > 
 > I am using frequency scaling with APM. It is totaly independant of the
 > Power Management. 
 > 
 > You need to load cpufreq-userspace but also some other modules. See the
 > Debian installation page for Thinkpad R50 on the Thinkpad Wiki for more
 > informations

I have successfully loaded the cpufreq-powersave module, but when I
attempt to load speedstep-centrino, I get these error messages:

: nr@toller 13321 ; sudo modprobe speedstep-centrino
WARNING: Error inserting processor (/lib/modules/2.6.8.1-emp1/kernel/drivers/acpi/processor.ko): No such device
FATAL: Error inserting speedstep_centrino (/lib/modules/2.6.8.1-emp1/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): Unknown symbol in module, or unknown parameter (see dmesg)

The message from dmesg is:

speedstep_centrino: Unknown symbol acpi_processor_unregister_performance
speedstep_centrino: Unknown symbol acpi_processor_register_performance

So it appears my speedstep-centrino is compiled to work with ACPI only.
Anybody have any idea what kernel config I should use to recompile it
to work with APM?  


Norman