[PATCH 3/4] soc: rockchip: power-domain: Add regulator support

[Michael Riesch]

Hi Mark,

Sorry for the long pause!

On 12/22/21 14:40, Mark Brown wrote:
> On Wed, Dec 22, 2021 at 02:29:23PM +0100, Michael Riesch wrote:
>> On 12/22/21 2:25 PM, Mark Brown wrote:
> 
>>> In that case I would tend to assume that unless otherwise stated it's
>>> safer to keep the supply enabled when everything else is enabled.  It's
>>> the default thing and so is more likely to be what was designed for and
>>> less likely to result in nasty surprises.
> 
>> Based on my experience with the RK3568 EVB1 the vdd_gpu supply turns
>> after startup if it is unused and the SoC works fine. Let's take the
>> energy efficient route here :-)
> 
> One of the issues is that it may not actually be energy efficient if it
> ends up leaking current through the SoC from the other supplies (and
> long term that leakage probably won't do any good for hardware).  A very
> lightly loaded regulator can be the better option.

OK, I see. So in summary we don't know the behavior of the SoC and
should go for the safe route (set the GPU regulator to always on)? I'll
submit a patch for the RK3568 EVB1 -- the other boards enable this
regulator always as well.

Best regards,
Michael