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

[Peter Schumann]

Am 24.05.2014 12:44, schrieb Marek Vasut:

> 
> Please explain how you arrived to this conclusion.
> 
Hello Marek,

I started writing an powerblock driver for the i.MX233 to use the imx233
olimex board with a battery.
Short time (instant up to 90 seconds) after the 5v to battery handoff
the system reseted.
The system was running on DCDC prior to the handoff. I suspected that
some of the power rails where droping and trigger
hardware brownouts. But this was not the case. The DCDC got shutdown and
some ms after that the rails begun to drop.
I have some scope pic of this happening i it is of interest.

I than tried out some random bits in the MINPWR register and the reset
problem was gone. Than I track down it to this 1 bit causing the
instability.
> 
> This has been tested on i.MX28 , can you please check what the differences are 
> between these two chips and why it works only on one of them ?
>