Revert "err !"

This reverts commit eac229f82a23517fe47244830a80be748e8d17e8.
Revert "[WIP] 3.0.31"

This reverts commit 43ff935d41fcd8226979b25d199852d7fbcc2231.
Revert "revert some serial settings"

This reverts commit f55cb0987ec1b115e2e9052d4d6a5895e47a4ca1.