I have an issue with both 10G RJ45 WAN & 10G RJ45 LAN ports, when connected to a 1G partner.
The link functions correctly under high rx achieving ~995Mbit/s using iperf3 (both udp and tcp), but in the other direction with tx > ~100Mbit/s, the interface goes down, 100% reproducible.
I’ve tested this with both a dell precision 7680 laptop (Intel i219LM) & cisco EPC3940L cable modem.
the BPI R4 PRO is running the image it came with:
The issue does not reproduce with the 2.5G lan port or 1G lan port (which i’ve now repurposed for uplink), so i think the ethernet cables i tested with can be ruled out as cause.
Logs:
Dec 24 00:38:57 10.222.1.2 netifd: Network device 'eth1' link is up
Dec 24 00:38:57 10.222.1.2 kernel: [256130.672313] mtk_soc_eth 15100000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
...
Dec 24 00:40:36 10.222.1.2 kernel: [256229.115052] mtk_soc_eth 15100000.ethernet eth1: Link is Down
Dec 24 00:40:36 10.222.1.2 netifd: Network device 'eth1' link is down
Dec 24 04:30:51 10.222.1.2 kernel: [270044.316592] mxl862xx mdio-bus:10 mxl_lan5: Link is Up - 1Gbps/Full - flow control rx/tx
Dec 24 04:30:51 10.222.1.2 kernel: [270044.316612] br-lan: port 6(mxl_lan5) entered blocking state
Dec 24 04:30:51 10.222.1.2 kernel: [270044.330348] br-lan: port 6(mxl_lan5) entered forwarding state
...
Dec 24 04:44:24 10.222.1.2 netifd: Network device 'mxl_lan5' link is down
Dec 24 04:44:24 10.222.1.2 kernel: [270857.132131] mxl862xx mdio-bus:10 mxl_lan5: Link is Down
Dec 24 04:44:24 10.222.1.2 kernel: [270857.138601] br-lan: port 6(mxl_lan5) entered disabled state
Is this a known issue?
Any workarounds or next troubleshooting steps that can be recommended?
I am not sure if this is helpful; I also observed link flapping with the BPi-R4 (non-pro), however unlike your issue this was only observed at peak loads, >=1Gbps RX from WAN to LAN. This is reproducible, but not with synthetic loads such as iperf.
Dec 15 18:39:30 bpi kernel: mtk_soc_eth 15100000.ethernet end0: Link is Down
Dec 15 18:39:30 bpi kernel: mtk_soc_eth 15100000.ethernet: warm reset failed
Dec 15 18:39:30 bpi kernel: mtk_soc_eth 15100000.ethernet end0: configuring for fixed/internal link mode
Dec 15 18:39:30 bpi kernel: mtk_soc_eth 15100000.ethernet end0: Link is Up - 10Gbps/Full - flow control rx/tx
Dec 15 18:40:20 bpi kernel: mtk_soc_eth 15100000.ethernet end0: Link is Down
Dec 15 18:40:20 bpi kernel: mtk_soc_eth 15100000.ethernet: warm reset failed
Dec 15 18:40:20 bpi kernel: mtk_soc_eth 15100000.ethernet end0: configuring for fixed/internal link mode
Dec 15 18:40:20 bpi kernel: mtk_soc_eth 15100000.ethernet end0: Link is Up - 10Gbps/Full - flow control rx/tx
Dec 15 18:40:45 bpi kernel: mtk_soc_eth 15100000.ethernet end0: Link is Down
Dec 15 18:40:45 bpi kernel: mtk_soc_eth 15100000.ethernet: warm reset failed
Dec 15 18:40:45 bpi kernel: mtk_soc_eth 15100000.ethernet end0: configuring for fixed/internal link mode
Dec 15 18:40:45 bpi kernel: mtk_soc_eth 15100000.ethernet end0: Link is Up - 10Gbps/Full - flow control rx/tx
This was with Frank-W’s kernel ontop of my own custom NixOS install: Linux bpi 6.12.61-bpi-r4 #1-NixOS SMP Tue Jan 1 00:00:00 UTC 1980 aarch64 GNU/Linux
I observed this for the first time with 6.12.61, and I have been using this router in production for over a year before that without issue.