After reading about the OpenWRT effort here
we reran some tests on plain Linux kernel version 6.2.8 with only the new devicetrees added. And again, connecting 2 CN9130 with fiber optics caused very frequent link losses in the order up to a 100 times a second:
[ 64.370308] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[ 64.379168] mvpp2 f2000000.ethernet eth0: Link is Down
[ 64.384398] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[ 64.393332] mvpp2 f2000000.ethernet eth0: Link is Down
[ 64.398535] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[ 64.407406] mvpp2 f2000000.ethernet eth0: Link is Down
[ 64.412612] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[ 64.421522] mvpp2 f2000000.ethernet eth0: Link is Down
[ 64.426819] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[ 64.435701] mvpp2 f2000000.ethernet eth0: Link is Down
At this point we haven’t managed to find a single working configuration. The only options remain using DACs or some other link partner that is not using marvel hardware.