"Interesting" behavior of ACPI power management on T43 with CURRENT

Alexandre "Sunny" Kovalenko alex.kovalenko at verizon.net
Fri Jul 20 01:08:07 UTC 2007

On Tue, 2007-07-17 at 09:27 -0700, Kevin Oberman wrote:
> My system seems to have grown added power management capabilities
> without cpufreq and maybe powerd. The behavior of my laptop (Lenovo/IBM
> T43) as regards power management with CURRENT is suddenly very
> different. I am pretty sure that this behavior first appeared in the
> past few months, so come change in FreeBSD (probably in ACPI code)
> triggered the change.
> This changes has really improved the battery life of my system and I
> like it, I am simply baffled as to why it is doing it and if it is
> ThinkPad specific or if others are seeing this.
Is it possible that you have done BIOS update between then and now?

Another alternative could be that ACPI code started calling some ASL it
did not call before -- at some point I used to own laptop where fan
control was neatly tucked in the _TMP method, so every time system will
ask BIOS for the temperature sensor readout, fan speed will get

Just some thoughts.

Alexandre "Sunny" Kovalenko

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