lower_headroom    531 net/batman-adv/hard-interface.c 	unsigned short lower_headroom = 0;
lower_headroom    546 net/batman-adv/hard-interface.c 		lower_headroom = max_t(unsigned short, lower_headroom,
lower_headroom    554 net/batman-adv/hard-interface.c 	needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);