On 4 July 2013 12:27, Renato Golin <renato.go...@linaro.org> wrote:

> On 3 July 2013 18:33, Richard Earnshaw <rearn...@arm.com> wrote:
>
>> keep lowering the clock limit (.../cpufreq/scaling_max_freq) until you
>> get stability.  If you don't, then it isn't a heating problem.
>>
>
> It might be a bit too soon, but I just got a few 7h builds out of the
> boards at 920MHz without a single glitch, whereas before, they wouldn't run
> for more than 4hs in a row. Both boards are running non-stop since 8pm
> yesterday.
>

Yesterday I turned one of the boards back to 1.2GHz (3pm), and it died
during the night (2am). The 920MHz is still working. The room temperature
didn't go over 26C (the thermometer is by the boards).

I do not believe it is possible to run the 4460 at 1.2GHz on full load
without decent thermal management. I can see the frequency changing due to
load on my log, so the kernel is doing "something", but I don't think it's
actively slowing things down due to temperature concerns.

The heat sink improved the load periods (based on lab data), but as Richard
said, thermal conductivity has to be minimum along all the path out, and
the plastic casing does not help.

I've run the cpuburn at 920MHz and it runs indefinitely at around 70% max
temperature (51C). When I set the maximum to 1.2GHz, it dies in 5 seconds.

Does anyone know how to turn on thermal management on the Linux kernel for
the OMAP chips?

cheers,
--renato
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