Wrong dev.cpu.0.freq_levels values

[Kevin Oberman]

> Date: Wed, 01 Apr 2009 23:16:13 -0400
> From: Pierre-Luc Drouin <pldrouin at pldrouin.net>
> Sender: owner-freebsd-acpi at freebsd.org
> 
> I tried disabling both p4tcc and acpi_throttle by putting the following 
> in /boot/device.hints:
> hint.p4tcc.0.disabled="1"
> hint.acpi_throttle.0.disabled="1"
> 
> It reduced the number of levels, but I still don't have a level 2000 as 
> I used to get:
> dev.cpu.0.freq: 1500
> dev.cpu.0.freq_levels: 1500/-1 1200/-1 1000/-1 800/-1 600/-1
> dev.est.0.%desc: Enhanced SpeedStep Frequency Control
> dev.est.0.freq_settings: 1500/-1 1200/-1 1000/-1 800/-1 600/-1
> 
> Pierre-Luc Drouin
> 
> Nate Lawson wrote:
> > Pierre-Luc Drouin wrote:
> >   
> >> Hello,
> >>
> >> I have noticed that FreeBSD gets the wrong CPU frequency levels for my
> >> Pentium M 2GHz. It used to work correctly with older versions of
> >> FreeBSD, but I noticed that this was not working properly when I
> >> installed 7.1 and this is still not working with -stable:
> >>
> >>     
> >
> >   
> >> dev.cpu.0.freq: 1500
> >> dev.cpu.0.freq_levels: 1500/-1 1312/-1 1200/-1 1050/-1 1000/-1 875/-1
> >> 800/-1 700/-1 600/-1 525/-1 450/-1 375/-1 300/-1 225/-1 150/-1 75/-1
> >> dev.est.0.%desc: Enhanced SpeedStep Frequency Control
> >> dev.est.0.freq_settings: 1500/-1 1200/-1 1000/-1 800/-1 600/-1
> >>
> >> Is there a way to fix this?
> >>     
> >
> > There's nothing wrong. You just got more levels using p4tcc (another
> > cpufreq device). So use it as-is, or disable the p4tcc driver and
> > acpi_throttle drivers.
> >

There is a problem, of course. I had the same issue with my 2GHz Pentium
M. It was easy to fix, but totally counter-intuitive.

Build your kernel without "device cpufreq" and it will all work
fine. Here is what I see without CPUFREQ:
dev.cpu.0.freq_levels: 2000/27000 1750/23625 1600/22600 1400/19775 1333/19666 1166/17207 1066/16733 932/14641 800/13800 700/12075 600/10350 500/8625 400/6900 300/5175 200/3450 100/1725

These are the correct values.

Also, when on battery, the CPU changes the available frequencies so that
the top one is 800 MHz. This is not a powerd thing. It's entirely BIOS.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634
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