Some USB Ethernet devices using the cdc_ncm driver produce several of
these messages per second:
Jun 03 19:25:17 s kernel: cdc_ncm 3-2.2:2.0 enx(mac address): 1000 mbit/s downlink 1000 mbit/s uplink
This results in substantial log noise and disk usage.
Please consider backporting
net: usb: cdc_ncm: don't spew notifications
(git commit de658a195ee23ca6aaffe197d1d2ea040beea0a2)
to the 5.10.x stable kernel, to fix this problem.
Thanks,
Josh Triplett