RK3576: rockchip-pm-domain fw_devlink device-link failures for nested power-domain nodes

[Muhammed Subair]

|Hi Rockchip/kernel folks, I am bringing up an RK3576 board on a 7.1.x 
based kernel and I see the following early boot errors from 
fw_devlink/device-links: [ 0.260388] rockchip-pm-domain 
27380000.power-management:power-controller: Failed to create device link 
(0x180) with supplier soc for 
/soc/power-management at 27380000/power-controller/power-domain at 0/power-domain at 1 
[ 0.262168] rockchip-pm-domain 
27380000.power-management:power-controller: Failed to create device link 
(0x180) with supplier soc for 
/soc/power-management at 27380000/power-controller/power-domain at 0/power-domain at 1/power-domain at 2 
... [ 0.285927] rockchip-pm-domain 
27380000.power-management:power-controller: Failed to create device link 
(0x180) with supplier soc for 
/soc/power-management at 27380000/power-controller/power-domain at 18/power-domain at 17 
The board otherwise boots and the affected domains appear functional. 
PCIe/NVMe, HDMI, Ethernet, etc. are working. The RK3576 power-controller 
node has nested power-domain children. These child domain nodes contain 
properties such as `clocks` and `pm_qos`, similar to RK3588/RK3568, and 
`#power-domain-cells` is present as required by 
`rockchip,power-controller.yaml`. My current understanding is that the 
Rockchip PM domain driver consumes these child nodes internally and 
registers the provider from the top-level `power-controller` via 
`of_genpd_add_provider_onecell()`. However, fw_devlink recurses into the 
child fwnodes and tries to create proxy supplier links for dependencies 
such as `clocks`. Since the child power-domain nodes are not normal 
devices, this ends up as failed links from `rockchip-pm-domain` to 
supplier `soc`. Is this expected noise for nested Rockchip power-domain 
nodes, or is RK3576 missing a DT/driver annotation to prevent fw_devlink 
from trying to create device links for these internal child nodes? I 
compared with RK3588/RK3568 and did not find an obvious missing property 
in RK3576. I also do not want to use `fw_devlink=off`, since that hides 
the issue globally. Could you advise whether the right fix should be: 1. 
a DT change for RK3576 power-domain nodes, 2. a Rockchip PM-domain 
driver change to mark child fwnodes as internal/not devices for 
fw_devlink, or 3. an OF/fw_devlink change to avoid creating proxy links 
from generic power-domain child nodes? Thanks, Subair|