[PATCH net-next] net: phy: mdio-i2c: defer RollBall bridge probe to PHY discovery

[Petr Wozniak]

Hi Maxime,

Thank you for the question — it revealed a gap in the commit message.

The regression turns out to affect both boot-inserted and hotplugged
genuine RollBall modules. Aleksander Bajkowski confirmed that his FLYPRO
SFP-10GT-CS-30M (with Aquantia AQR113C) is broken even when hotplugged —
the PHY is no longer detected after 8fe125892f40.

So the root cause is not boot vs. hotplug specifically: sfp_sm_add_mdio_bus()
in SFP_S_INIT gives the bridge only a 200 ms window, which is insufficient on
hardware where bridge initialization takes longer, regardless of insertion
timing.

Jan Hoffmann also correctly pointed out that the commit message was wrong
about the state: the probe runs in SFP_S_INIT (which follows SFP_S_WAIT),
not "before initialization delays."

v2 with both corrections is at:
https://lore.kernel.org/netdev/20260605053056.1977-1-petr.wozniak@gmail.com/

Thanks,
Petr