net: dsa: realtek: rtl8365mb: reject unsupported topologies
Explicitly enforce the presence of a CPU port (-EINVAL) and reject DSA
cascade links (-EOPNOTSUPP) during setup to prevent silent failures.
These topologies were already non-functional. Without a CPU port, the
driver does not activate CPU tagging. Additionally, the switch hardware
was not designed to be cascaded, and DSA links never worked because
CPU tagging is not enabled for them.
Reviewed-by: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://patch.msgid.link/20260606-realtek_forward-v13-2-b9e409687cbe@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
projects / linux / commit