Upgrade from linux-lts-5.10.25 to linux-lts 5.10.26 breaks bonding.
From: James Feeney <hidden>
Date: 2021-03-27 18:33:30
Downgrading the kernel resolves the problem, but I don't see any bonding commits between linux-lts-5.10.25 and linux-lts 5.10.26.
My mistake - 9392b8219b62b0536df25c9de82b33f8a00881ef *was* included in 5.10.26. Thus the "Invalid argument" message. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-rolling-lts&id=9392b8219b62b0536df25c9de82b33f8a00881ef James