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

[Hans de Goede <hdegoede@redhat.com>]

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