CFM protocol

configname: CONFIG_BRIDGE_CFM

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>CFM protocol
In linux kernel since version 5.2 (release Date: 2019-07-07)  
If you say Y here, then the Ethernet bridge will be able to run CFM
protocol according to 802.1Q section 12.14

Say N to exclude this support and reduce the binary size.

If unsure, say N.