ac100 team mailing list archive

[Gordan Bobic <gordan@xxxxxxxxxx>]

> > > > > > Which kernel are you using?
> > > > >
> > > > > A somewhat older build of Marc's kernel (one month), the one
> > > > > I have in my Debian repository + the change to use 1000 instead
> > > > > of 1200.
> > > >
> > > > I presume you mean 1200mV rather than 1200MHz. If it's 1200MHz, I'd
> > > > like to know where to tweak that. ;)
> > >
> > > I never said anything of Hz. It's all mV (if it's mV, what are 1.2V
> > > used for? The voltage from the battery/charger is clearly 10-12V).
> > >
> > > > Well, my testing has been going on for 6+ hours. Considering I
> > > > couldn't get an hour without errors before (and sometimes
> > > > several/hour, and that's just the detected ones), I'd say it's a
> > > > very definitive improvement. So much so that I'm vaguely tempted to
> > > > try reducing it to 950mV. ;)
> > >
> > > Given that the minimum it currently scales to would be 725, 950
> > > is certainly save.
> >
> > Seems there are limits in hardware. I built a kernel with the upper
> > bound set to 900, and now I get a lot of this in the logs, while the CPU
> > is stuck at 216MHz:
> >
> > Failed to set dvfs regulator vdd_cpu
> > Failed to set regulator vdd_cpu for clock cpu to 875mV
>
> ^^^^^^^^^^^^^^^^
> This should have read 975mV
>
> > cpu-tegra: Failed to set cpu frequency to 1000000kHz
> >
> > over, and over and over.
> >
> > Seems 975mV may be the lower limit, going to try that next.

I can confirm that 975mV works without throwing any errors and the CPU 
does get up to 1GHz. Going to leave it load testing for a few hours and 
see if it's stable.

Gordan