I have a Buffalo WZR-HP-AG300H that I use as AP. After updating it to 21.02.0, the uplink port eth1 that is connected to a switch is negotiating at 100 Mb/s.
I'm sure that before the upgrade this link was working at 1000Mb/s. I've tested the cable and is perfectly fine and if I force the 1000 Mb speed in the switch the link is marked as down. Also 1000BaseT is no longer advertised as a supported mode in ethtool.
I've already workarounded the issue using an unused port in the internal switch, but it'd be nice if it can be fixed.
Thanks.
# ethtool eth1
Settings for eth1:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 4
Transceiver: external
Auto-negotiation: on
Current message level: 0x000000ff (255)
drv probe link timer ifdown ifup rx_err tx_err
Link detected: yes
# dmesg | grep eth1
[ 2.579283] eth1: Atheros AG71xx at 0xba000000, irq 5, mode: rgmii
[ 76.682973] eth1: link up (100Mbps/Full duplex)
# uname -a
Linux gluon 5.4.143 #0 Tue Aug 31 22:20:08 2021 mips GNU/Linux