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

From: Dmitry Osipenko
Date: Tue Oct 08 2019 - 13:05:09 EST


08.10.2019 19:15, Mark Brown ÐÐÑÐÑ:
> On Tue, Oct 08, 2019 at 06:02:36PM +0300, Dmitry Osipenko wrote:
>
> Please fix your mail client to word wrap within paragraphs at something
> substantially less than 80 columns. Doing this makes your messages much
> easier to read and reply to.

Indeed, thanks!

>> That OPP patch caused the same problem for the NVIDIA Tegra20 CPUFreq
>> driver (in-progress) and I resolved it in the coupler's code [0].
>> Perhaps the generic coupler could do the same thing by assuming that
>> min_uV=current_uV until any consumer sets the voltage, i.e. if
>> regulator_check_consumers(min_uV=0) returns min_uV=0.
>
> That sounds like it might just postpone the inevitable - if you set the
> wrong voltage first it might decide to drop down some voltage that
> wasn't expected. There's a bit of a bootstrapping issue. I think it
> would be safer to just say that anything that is within spec won't get
> changed any time we balance, we'd only change things if needed to bring
> them back into spec.

Yes, the case of changing voltage before regulator is enabled seems
won't work as expected.

Maybe it won't hurt to disallow a non always-on regulators to be coupled
until there will be a real user for that case.