Dell Precision m4400 acline problems

[Ian Smith]

On Thu, 24 Jun 2010, Stefan Farfeleder wrote:
 > On Tue, Jun 22, 2010 at 01:36:03AM +1000, Ian Smith wrote:
 > > On Sun, 20 Jun 2010, Stefan Farfeleder wrote:
 > >  > Hello,
 > >  > 
 > >  > I'm running FreeBSD current on a Dell Precision m4400 notebook and got
 > >  > the following issue: When I unplug the notebook's power, the CPU
 > >  > performance goes down to < 50%. While this isn't nice, the real problem
 > >  > is that when I replug the power adapter, the performance stays low. So I
 > >  > basically have to reboot to get back at full performance :(
 > >  > 
 > >  > I suspect this is an ACPI-related problem.  You can find dmesg output,
 > >  > ACPI tables and ASL at http://people.freebsd.org/~stefanf/m4400/ .
 > >  > 
 > >  > BTW I'm not using powerd.
 > > 
 > > Whether or not using powerd, /etc/rc.d/power_profile (run by devd) will 
 > > set CPU frequency according to values in {performance,economy}_cpu_freq 
 > > whenever state changes between offline (battery) and online (AC).  Such 
 > > events are typically logged in /var/log/messages.
 > > 
 > > The /etc/defaults/rc.conf value for both of these is 'NONE' and you'll 
 > > see in power_profile that a 'NONE' value causes no change, where 'HIGH" 
 > > or 'LOW' values adjust CPU freq to the highest or lowest values from
 > > sysctl dev.cpu.0.freq_levels - or you can specify one freq from those 
 > > levels to apply for either state.
 > > 
 > > If you have no overrides in /etc/rc.conf, you may want to set values 
 > > there for *_cpu_freq .. it may be that your ACPI chooses some default 
 > > frequency on these events, perhaps according to your BIOS settings?
 > 
 > Thanks. I think I solved my problem. I do not use power profiles and
 > thus the dev.cpu.0.freq stays at 2801. However going offline evidently
 > causes the frequency to decrease internally, ie. without dev.cpu.0.freq
 > knowing, so when I manually reset the frequency to 2801, the system is
 > fast again.

Goodo.  But adding these to /etc/rc.conf would save that manual bother:
 performance_cpu_freq="HIGH"
 economy_cpu_freq="HIGH"
since /etc/rc.d/power_profile is run on ACAD events anyway, at least 
with the default /etc/devd.conf

cheers, Ian