Re: [PATCH v4 4/4] ARM: mvebu: Armada 385 GP: Add regulators to the SATA port

[Hans de Goede]

Hi,

On 16-01-15 16:34, Mark Brown wrote:
> On Fri, Jan 16, 2015 at 03:27:00PM +0100, Gregory CLEMENT wrote:
> > On 16/01/2015 13:37, Mark Brown wrote:
>
> > > regulator-always-on is a bit fuzzy for suspend, if the regulator has
> > > suspend control it'll kick in - it's really about the Linux refcounting
> > > while it's running.  What's more concerning here is that the quick
> > > sample of the regulators flagged as always on like the above that I
> > > looked at in the patch don't seem to have any enable control in the DT
> > > so this will have absolutely no effect.
>
> > Actually the reg_sata[0-4] are controlled by gpio, so there is a mean
> > to enable/disable them. For the reg_5v_sata[0-4] and reg_12v_sata[0-4]
> > they depend on their respective reg_sata and I just propagated the
> > regulator-always-on, this was maybe a mistake.
>
> It certainly makes everything confusing if you have control related
> stuff on regulators that are not directly controllable.
>
> > > > It is probably a good idea to use regulator-boot-on and
> > > > then test things this way, and if that works use
> > > > regulator-boot-on.
>
> > > No, it's unlikely that boot-on makes sense here - it's there for cases
> > > where we can't read back the hardware state at power on.  Generally
> > > drivers should work regardless of the initial state of the regulator
> > > (and modular drivers will actually break if they try to rely on boot-on
> > > since we clean up unused regulators at boot).
>
> > As pointed by Hans my concern here was be sure that during boot the disk
> > are not power off. In this case which property would be accurate?
>
> None, the core won't do anything with the regulator until the end of
> init anyway.

That us simply not true, see my other mail gpio enabled regulators will
be turned off *at register time* unless they have regulator-boot-on set.

Regards,

Hans

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