ac100 team mailing list archive

[Gordan Bobic <gordan@xxxxxxxxxx>]

On 08/21/2011 10:13 PM, Julian Andres Klode wrote:
> On Sun, Aug 21, 2011 at 08:19:35PM +0200, Julian Andres Klode wrote:
> > On Sun, Aug 21, 2011 at 07:07:38PM +0100, Gordan Bobic wrote:
> > > On 08/21/2011 06:50 PM, Julian Andres Klode wrote:
> > > > On Sun, Aug 21, 2011 at 01:09:09PM +0100, Gordan Bobic wrote:
> > > > > On 08/21/2011 12:27 PM, Julian Andres Klode wrote:
> > > > > > On Sun, Aug 21, 2011 at 12:06:39PM +0100, Gordan Bobic wrote:
> > > > > I'm also curious how come my powertop is showing 1000MHz with no
> > > > > errors in the log when I set SM1 to 975mV.
> > > > Buggy powertop?
> > >
> > > Plausible, but /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_cur_freq
> > > also reports 1GHz.
> > Look at /sys/kernel/debug/clock/dvfs, it shows frequencies and
> > voltages, as scaled by DVFS and maybe attach it to your next
> > email.
> >
> > > I'll have to test the speed to establish it for sure, but if what
> > > you are saying is true, then setting SM1 upper limit to 1200 should
> > > have no effect anyway, because upping the voltage limit without
> > > changing it in all the other places you list here won't cause the
> > > voltage to get as high as 1200 as per what is in the git tree. Is
> > > that right?
> > Indeed. While the regulator could scale that high, the DVFS code will
> > only call it to scale from 750 mV to 1100 mV. At least that's what I
> > get told by the code.
>
> We now have some more sane regulator ranges in git:
>
> 	SM0:  725 - 1200 =>  725 - 1300
> 	SM1:  725 - 1200 =>  725 - 1125
> 	LDO2: 725 - 1200 =>  725 - 1275
>
> They now actually support the default voltage levels set by the DVFS.

I removed my modified board-paz00-power.c and pulled the latest git, 
rebuilt the kernel, and guess what - at 1GHz my CPU still defaults to 
975mV according to  /proc/sys/debug/clock/dvfs:

vdd_cpu 975 mV:
  cpu 1000000000 975 mV
vdd_core 1200mV:
  vdd_cpu 975 mV 1200 mV
[...]
vdd_aon 1200mV:
  vdd_cpu 975mV 1200mV
  vdd_core 1200mV 1200mV

Where to look next? I'm tempted to port the seaboard voltage slew patch 
to paz00, but since I'm running with the performance governor I'm not 
convinced it would actually help. Probably won't really do any harm, 
either, though.

Gordan