Re: HEADSUP: acpi mpsafe committed

Kevin Oberman wrote:
>>Date: Thu, 12 Aug 2004 23:35:48 -0700
>>From: Nate Lawson <nate_at_root.org>
>>Sender: owner-freebsd-acpi_at_freebsd.org
>>
>>Let me know if there are any problems.
>>
>>Thanks for testing:  Rong-En Fan <rafan.AT.infor.org>, Kevin Oberman 
>><oberman.AT.es.net>, marcel.
>>
>>(And now the same to you! :)
> 
> 
> Why do I see things right AFTER the commit? (O.K. I actually saw them
> late last night, but was too tired to do any testing and am still in the
> process of building kernels to do some real testing.)
> 
> Since I installed a kernel/modules with the mpsafe patches I have found
> that P4_TCC and throttling no longer work. They worked with an unpatched
> kernel/modules built on Wednesday and failed with the patched
> kernel/modules I am now running. I have not updated the sources between
> the two kernel builds, so I think it has to be the patches.
> 
> Now the admission of not knowing what I am doing. The P4 TCC stuff
> appears to be very similar to the ACPI throttling capability. I suspect
> that the latter simply controls the former, but I really don't know.
> 
> I guess that I really should have removed it when I was able to use ACPI
> throttling, but I never removed it and it continued to work until last
> night. When I went to battery, hw.p4tcc.cpuperf remained at 100 instead
> of dropping to hw.p4tcc.cpuperf_economy. Similarly,
> hw.acpi.cpu.thottle_state remains at 8 and hw.acpi.cw_lowest is at C1
> instead of C2 or C3. economy_throttle_state is set to 4 and
> economy_cx_lowest is at default (LOW).
> 
> Really takes down the old battery quickly!

Ah, I think I see it too.  It looks like the power profile change on AC 
line switch is not working.  I'll look into this.  For the time being, 
you can manually set your values low by doing:

sysctl hw.acpi.cpu.cx_lowest="C3"
sysctl hw.p4tcc.cpuperf="xxx"

TCC and throttling are unrelated in this respect, other than they both 
use the power profile stuff.

-Nate