[Letux-kernel] 1.5GHz problems

Michael Mrozek EvilDragon at openpandora.org
Sat Jul 30 21:14:25 CEST 2016

Am Sat, 30 Jul 2016 20:02:14 +0200 hat "H. Nikolaus Schaller"
<hns at goldelico.com> geschrieben:


> The CPU board I am running these test on has additional wires which
> allow to measure the voltages VDD_MPU, VDD_CORE, VDD_DDR3, VDD_MM,
> 1V8, VSYS.

This might be a good idea. Maybe the combination of Palmas and the
charger / battery chip causes an issue here and the voltage isn't
increased for some reason.

What you could also test would be setting 1GHz to run with a higher
voltage and measure whether the voltage REALLY is increased.
This way, the unit doesn't crash.

Another thing I'd like to remind here:
1,5GHz work fine (even with full load) with the EVM and the iGEPV5
So it probably is something that's different between those and our

* Are there differences in the board files that could cause
  our CPU to misbehave?

* Is there a difference in our hardware setup that could lead to that?
  We got different RAM, a different quartz, different power setup (we
  don't have a simple AC like the devboards, but a battery / charger

> Anyways, please all kernel developers think about potential kernel
> issues (scheduling, SMP, locking, interrupts, I&D-caches) that might
> lead to such a behaviour. And potential tests (I can add printk etc.
> where needed).

Mit freundlichen Grüßen,

Michael Mrozek

OpenPandora GmbH
Geschäftsführer: Michael Mrozek

Schäffbräustr. 11
85049 Ingolstadt
Tel.: 0841 / 990 5548
HRB 4879, Amtsgericht Ingolstadt
eMail: mrozek at openpandora.org

More information about the Letux-kernel mailing list