OK, thanks. Since this is a regression in the upstream kernel, at best you can report it to the upstream. https://docs.kernel.org/admin-guide/reporting-regressions.html https://docs.kernel.org/process/handling-regressions.html Care to report your problem? They'll likely ask you to perform git bisection. A hint for building your test kernel quickly is found at https://docs.kernel.org/admin-guide/quickly-build-trimmed-linux.html