Hello, I've been looking for days.
I believe that when ready it works on the 57840?
Because I put a GPON stick that negotiates in 2.5gb, but because of that it is limited to 1gb.
root@OpenWrt:~# ethtool eth4
Settings for eth4:
Supported ports: [ FIBRE ]
Supported link modes: 1000baseT/Full
10000baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: No
Supported FEC modes: Not reported
Advertised link modes: Not reported
Advertised pause frame use: No
Advertised auto-negotiation: No
Advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Other
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000000 (0)
Link detected: yes