Re: [PATCH] regulator: core: Skip balancing of the enabled regulators in regulator_enable()

From: Marek Szyprowski
Date: Tue Oct 08 2019 - 08:39:01 EST

Hi Mark,

On 08.10.2019 14:06, Mark Brown wrote:
> On Tue, Oct 08, 2019 at 02:01:15PM +0200, Marek Szyprowski wrote:
>> On 08.10.2019 13:50, Mark Brown wrote:
>>> This then means that for users that might legitimately enable and
>>> disable regulators that need to be constrained are forced to change the
>>> voltage when they enable the regualtors in order to have their
>>> constraints take effect which seems bad. I'd rather change the the
>>> cpufreq consumers to either not do the enable (since there really should
>>> be an always-on constraint this should be redundant, we might need to
>>> fix the core to take account of their settings though I think we lost
>>> that) or to set the voltage to whatever they need prior to doing their
>>> first enable, that seems more robust.
>> Well, I'm open for other ways of fixing this issue. Calling enable on
>> always-on regulator imho should not change its rate...
> Yes, although there is the whole "don't touch things until a consumer
> tells us to" thing going on. I had expected that this was kicking in
> because we weren't paying attention to the constraints of disabled
> regulators but I can't see the code implementing that any more so I
> guess we removed it at some point (it was always debatable).

Then if I get it right, the issue is caused by the commit 7f93ff73f7c8
("opp: core: add regulators enable and disable"). I've checked and
indeed reverting it fixes Peach Pi to boot properly. The question is if
this is desired behavior or not?

I've CC: Viresh, Kamil and Bartlomiej, here is the link to the beginning
of this thread:

Best regards
Marek Szyprowski, PhD
Samsung R&D Institute Poland