[Community] GTA04A5 / Letux 2804

Christ van Willegen cvwillegen at gmail.com
Thu Jan 16 11:42:18 CET 2014

On Thu, Jan 16, 2014 at 11:21 AM, Dr. H. Nikolaus Schaller
<hns at goldelico.com> wrote:
> Yes, I agree that it has to be fixed. Volunteers?
> Ok, please help to fix the power management (in the latest kernel because
> everything else makes no sense to me and is unlikely to get outside
> support).

I have something in mind that _may_ point to a possible source of the
'missing mA's'...

I assume that most hardware is put into low/high power mode
(active/inactive) using GPIO settings. Is that correct?

My idea was to create a log file (somewhere in /tmp) from the kernel
code that does the GPIO switching. This file would look like:
[/sys/power/state] [GPIO number] [GPIO state]

That way, we could inspect if the GPIOs are in the correct state for
the correct power state. And, if not, try to figure out where the
GPIOs should (have) be(en) set to get the correct results.

Any other culprits may, perhaps, be found in a similar way (I2C
commands logged?)

Not sure if this would track _every_ mA, but perhaps it can point in
the right direction...

Also not sure if I can handle this, I did look into the (3.7) kernel
sources breifly, but building a kernel takes so mnuch time on GTA04
that it's not practical to do dev. work on it. Also, I don't have a
3.12 (or 3.13...) kernel source on it, but that could probably be

Christ van Willegen
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