mediatek: fix DTS defining mt7530 switch phys but not referencing them

[dangowrt]

mediatek: fix DTS defining mt7530 switch phys but not referencing them

The upstream solution to define the MDIO bus in DT is a bit more strict than our previous downstream solution doing the same thing and now requires switch PHYs to be referenced in DT as well.

Arınç Ünal told us in #15141:
"With [the now upstream patch written by him which we backported], the switch MDIO bus won't be assigned to ds->user_mii_bus when the switch MDIO bus is defined on the device tree anymore. This was not the case with the downstream patch.
When ds->user_mii_bus is populated, DSA will 1:1 map the port with PHY. Meaning port with address 1 will be mapped to PHY with address 1.
Because that ds->user_mii_bus is not populated when the switch MDIO bus is defined on the device tree, on every port node, the PHY address must be supplied by the phy-handle property."

Add those phy-handles to affected devices' DT.

Fixes: 4354b34 ("generic: 6.6: sync mt7530 DSA driver with upstream")
Fixes: 401a6cc ("generic: 6.1: sync mt7530 DSA driver with upstream")
Signed-off-by: Daniel Golle daniel@makrotopia.org

[arinc9]

Looks like the upstream solution to define the MDIO bus in DT is a bit more strict than our previous downstream solution doing the same thing and now requires switch PHYs to be referenced in DT as well.

I don't think this is the case.

Read Andrew's comment:

Arınç:

Like you said, if the mdio node is not defined, the driver will assume 1:1
mapping. If not, it will need all the PHYs to be defined on the mdio node
along with on the ports node.

Andrew:

The problem is __of_mdiobus_register() :-(

If there is a node in DT, the scanning of all addresses is
disabled. It looks at just the addresses listed in DT. Plain
mdiobus_register() by default looks at all addresses to discover if a
PHY is there.

Hence when slave.c tries to connect to the PHY, only the PHY you
listed in DT has been found.

I don't see a way around this, at least not without adding a new
variant of of_mdiobus_register which combined DT with a bus scan.

https://patchwork.kernel.org/comment/25318259/

Edit: I will compile an OpenWrt snapshot to get to the bottom of this.

[arinc9]

With my patch, the switch MDIO bus won't be assigned to ds->user_mii_bus when the switch MDIO bus is defined on the device tree anymore. This was not the case with the downstream patch.

When ds->user_mii_bus is populated, DSA will 1:1 map the port with PHY. Meaning port with address 1 will be mapped to PHY with address 1. Because that ds->user_mii_bus is not populated when the switch MDIO bus is defined on the device tree, on every port node, the PHY address must be supplied by the phy-handle property.

Daniel, you can add above to your patch log here.

[Gingernut1978]

Working perfect. Tested on Asus TUF-AX4200.

Sat Apr 13 08:18:11 2024 kern.info kernel: [    2.766557] mt7530-mdio mdio-bus:1f: configuring for fixed/2500base-x link mode
Sat Apr 13 08:18:11 2024 kern.info kernel: [    2.775534] mt7530-mdio mdio-bus:1f: Link is Up - 2.5Gbps/Full - flow control rx/tx
Sat Apr 13 08:18:11 2024 kern.warn kernel: [    2.784651] MediaTek MT7531 PHY mt7530-0:01: Configure LED registers (num=14)
Sat Apr 13 08:18:11 2024 kern.info kernel: [    2.799289] mt7530-mdio mdio-bus:1f lan1 (uninitialized): PHY [mt7530-0:01] driver [MediaTek MT7531 PHY] (irq=POLL)
Sat Apr 13 08:18:11 2024 kern.warn kernel: [    2.819393] MediaTek MT7531 PHY mt7530-0:02: Configure LED registers (num=14)
Sat Apr 13 08:18:11 2024 kern.info kernel: [    2.833935] mt7530-mdio mdio-bus:1f lan2 (uninitialized): PHY [mt7530-0:02] driver [MediaTek MT7531 PHY] (irq=POLL)
Sat Apr 13 08:18:11 2024 kern.warn kernel: [    2.853718] MediaTek MT7531 PHY mt7530-0:03: Configure LED registers (num=14)
Sat Apr 13 08:18:11 2024 kern.info kernel: [    2.868250] mt7530-mdio mdio-bus:1f lan3 (uninitialized): PHY [mt7530-0:03] driver [MediaTek MT7531 PHY] (irq=POLL)
Sat Apr 13 08:18:11 2024 kern.warn kernel: [    2.888025] MediaTek MT7531 PHY mt7530-0:04: Configure LED registers (num=14)
Sat Apr 13 08:18:11 2024 kern.info kernel: [    2.902562] mt7530-mdio mdio-bus:1f lan4 (uninitialized): PHY [mt7530-0:04] driver [MediaTek MT7531 PHY] (irq=POLL)

A big thanks as always.