refuse synchronization with unknown SFPs
Right now when you plug an SFP that is not present in /wr/etc/sfp_database.conf the switch will print a warning message but will also run the synchronization with some default values of Tx/Rx delta and alpha. That resuls with bad synchronization performance and possibly the offset of few ns. Maybe it would be better to modify hal/ptp to refuse synchronization when unknown SFP is plugged to the port ?