Re: [PATCH 8/9] PM / Domains: Add support for multi PM domains per device to genpd

[Ulf Hansson]

[...]

>>>
>>> * genpd_dev_pm_attach_by_id() - Attach a device to one of its PM domain.
>>> * @dev: Device to attach.
>>> * @index: The index of the PM domain.
>>>
>>> This naming and description is a bit misleading, because really it is not
>>> attaching the device that is passed, but creating a new device to attach
>>> a
>>> PM domain to. So we should consider renaming and changing the description
>>> and indicate that users need to link the device.
>>
>>
>> I picked the name to be consistent with the existing
>> genpd_dev_pm_attach(). Do you have a better suggestion?
>
>
> Well, it appears to get more of a 'get' function and so I don't see why we
> could not have 'genpd_dev_get_by_id()' and then we could have a
> genpd_dev_put() as well (which would call genpd_dev_pm_detach).
>
>> I agree, some details is missing to the description, let me try to
>> improve it. Actually, I was trying to follow existing descriptions
>> from genpd_dev_pm_attach(), so perhaps that also needs a little
>> update.
>>
>> However, do note that, neither genpd_dev_pm_attach() or
>> genpd_dev_pm_attach_by_id() is supposed to be called by drivers, but
>> rather only by the driver core. So description may not be so
>> important.
>>
>> In regards to good descriptions, for sure the API added in patch9,
>> dev_pm_domain_attach_by_id(), needs a good one, as this is what
>> drivers should be using.
>
>
> OK. Same appears to apply here to the description as I mentioned above.
> Still seems to be more of a 'get' than an attach. So I wonder if it should
> be dev_pm_domain_get_by_id() instead?

Regarding "get" vs "attach", I suggest we continue to discuss that in
patch 9. Whatever is decided, $subject patch needs to follow.

>
>>> Finally, how is a PM domain attached via calling
>>> genpd_dev_pm_attach_by_id()
>>> detached?
>>
>>
>> Via the existing genpd_dev_pm_detach(), according to what I have
>> described in the change log. I clarify the description in regards to
>> this as well.
>
>
> OK, so this bit is a to-do as that is not yet exposed AFAICT. I see that you
> said 'although we need to extend it to cover cleanup of the earlier
> registered device, via calling device_unregister().' So if we do this then
> that would be fine.

Let me clarify the changelog. It's not a to-do, as it's already done
as part of $subject patch.

So I guess we are in agreement that we don't need another API to deal
with detach?

Kind regards
Uffe