[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Peter Schumann]

Am 17.06.2014 18:00, schrieb Stefano Babic:
> Hi peter,
> ...
> On 17/06/2014 00:19, Marek Vasut wrote:
> Agree. Reason is that this change is for all boards, and without a
> proper testing I will avoid to merge it in the release.
> 
> Best regards,
> Stefano Babic
> 
> 
> 

Hi Stefano,

I've only the imx233 olimex board for testing. The DOUBLE_FETS switch in
HW_POWER_MINPWR is some thing were maybe problems emerge.

I have very little load on the powerrails (imx233 + DRAM), so maybe with
more current demand DOUBLE_FETS is working OK and even more may require
it to be set.

The DOUBLE_FETS and HALF_FETS switches control the switching MOSFET size
in the DCDC Converter. My assumption is that if we have a to big FET
setting and to low current demand we trigger some failsafe mechanism.
Because the required "on time" of the FET is smaller than the minimum
possible "on time" of then DCDC FET control logic.

I don't have an easy way to test this assumption without an adjustable load.

The other change regarding mxs_power_enable_4p2() should be relatively
safe to apply.

If I can help with some testing let me know.

Best regards,
Peter Schumann