Why does Linux disable the Buck/LDO at startup?

[DMårt]

Hi!

I having some issues with Linux at startup. It seems that it disabling the Bucks/LDOs at startup.

vddio2: disabling
vddio3: disabling
vddio4: disabling
vddcore: disabling
v1v8: disabling
v3v3: disabling

Why does this occur?

Here is the complete output as attached file. As you can see, I have set up my own outputs for error handling. 

The device three can be found here:

https://github.com/DanielMartensson/Watermelon-Wine-1A/tree/linux-testing/watermelon-wine-os%2Fcubemx%2FCA35%2FDeviceTree%2Ffirmware

Good to know:

• clk_get_index = 143 is USART6.
• I have activated the RNG for TF-A only. It seems not to wake up. It's the same default configuration as DK.

 

[PatrickF]

Hi @DMårt 
also appear with Starter Package. I agree it is quite confusing (for me as well as I'm more HW expert).

[ 32.085289] vddio3: disabling
[ 32.085371] vddio4: disabling
[ 32.085653] vddcore: disabling
[ 32.088709] v1v8: disabling

I guess it is related on the usage of a particular supplies in the probed peripheral  (e.g. some of the 1v8 'request' could says 'disabled' if ADC is not used).
I guess it does not directly mean HW will disable them (if even possible) as STPMIC control is managed by Op-Tee which has also its own view of required supplies.
That might be cleaned by more accurately describing the HW in the DTS (if possible).

It does not hurt to ignore those messages.

Regards.