Re: mixing SCMI and PSCI power domain hierarchy

[Kevin Hilman <khilman@baylibre.com>]

Kevin Hilman <khilman@baylibre.com> writes:

> Ulf Hansson <ulf.hansson@linaro.org> writes:

[...]

>>
>> Attaching a single PM domain is managed by bus-level code via
>> dev_pm_domain_attach().
>>
>> If a device has multiple PM domains, the driver/bus for it needs to
>> manage that specifically, typically by using
>> dev_pm_domain_attach_list().
>
> OK, I see.  But in my quick experiment with this, I found that adding a
> 2nd domain to a devices power-domain property, it disappeared from the
> first domain also.  Any idea what is happening there?

Just to answer my own question, I found that genpd_dev_pm_attach() has
an explicit check for the number of PM domains a device has[1].  If it
is not 1, the device is not attached to any domain.

I had assumed that maybe the first domain would get attached and the
others are ignored, but in fact all the domains are ignored.

Kevin

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pmdomain/core.c?h=v6.14#n3035