[PATCH net-next v2 0/3] net: mdio: support dynamic OF device changes

MDIO buses enumerate firmware children only when the bus is registered. A
later devicetree overlay or status transition is ignored, unlike on I2C and
SPI buses. Supporting live reconfiguration also means that population and
removal can race address scanning, PHY attachment and bus teardown.

Patch 1 factors fixed-address child registration and legacy PHY scanning
into helpers shared by initial and dynamic population.

Patch 2 serializes MDIO device-map changes, reserves addresses while
registration is in progress, and coordinates scans, attachment, removal
and bus teardown. Dynamically removed devices remain pinned until bus
teardown, preserving the borrowed-pointer convention of
mdiobus_get_phy().

Patch 3 adds the OF reconfiguration notifier. It supports fixed-address
PHYs and generic MDIO devices, scanned PHY addresses, and Ethernet PHY
packages. It also preflights overlay removal and rejects removal of
attached or in-flight PHYs before their firmware nodes can disappear.

Build-tested on net-next with arm64 defconfig and x86_64 allmodconfig and
allyesconfig configurations under W=1. No warning was emitted from a
changed file. Runtime-tested on Allwinner H616 hardware with
notifier-driven addition of an AC300 control endpoint at a fixed MDIO
address, 20 relay-driven cold boots, 20 complete MAC/MDIO teardown and
recreation cycles, and link traffic after each topology was populated.

Changes v1 -> v2:
  - split the generic MDIO work from the ACx00 series
  - rebase onto current net-next
  - move touched declarations to function scope for netdev style
  - Link to v1:
    https://patch.msgid.link/[email protected]

Signed-off-by: James Hilliard <[email protected]>
---
James Hilliard (3):
      net: mdio: factor out OF child registration helpers
      net: mdio: make device map changes hotplug-safe
      net: mdio: support dynamic OF device changes

 drivers/net/mdio/of_mdio.c          | 508 +++++++++++++++++++++++++++++++++---
 drivers/net/phy/mdio_bus.c          |  14 +-
 drivers/net/phy/mdio_bus_provider.c | 141 +++++++---
 drivers/net/phy/mdio_device.c       | 235 +++++++++++++++--
 drivers/net/phy/phy_device.c        | 102 ++++++--
 drivers/net/phy/phylib-internal.h   |   4 +-
 include/linux/mdio.h                |   6 +
 include/linux/phy.h                 |  18 ++
 8 files changed, 908 insertions(+), 120 deletions(-)
---
base-commit: d661abdc30c254649c32ef6e0aa1e621e04ff0a7
change-id: 20260803-submit-mdio-of-dynamic-v2-90560ca159b9

Best regards,
--  
James Hilliard <[email protected]>