[U-Boot] [PATCH] mx23: Put back RAM voltage level to its original value

[Marek Vasut]

Dear Fabio Estevam,

> On Fri, Apr 26, 2013 at 1:24 PM, Eric Bénard <eric at eukrea.com> wrote:
> > what are the values of these levels (previous one and new one) in mV ?
> 
> 0x10 ==> 2.5V
> 0x12 ==> 2.6V
> 
> 46v32m16

Eh? What's this code above?

> says that VDD is : 2.5V +/- 0.2V, so 2.6V is a valid supply
> voltage.
> 
> Not sure why 2.5V fails though.

http://s8.postimg.org/dn7jhntut/imx233_olinuxino_maxi_2_5_V_rising.jpg check 
this, this is as much as I got from tsvetan so far, it's the VDDMEM ramping. I 
dunno what's that weird drop before it starts going from 1V5 to 2V5, but it's 
strange at best and I don't like it. I think that's also the source of our 
problems, the DRAM suffers undervolt and quickly afterwards is configured for 
regular operation ... I'd say check mx23_mem_setup_vddmem() and inspect the 
result with a scope. I think we need some slow ramping function like 
mxs_power_set_vddx().

Best regards,
Marek Vasut