Dear Maintainer, It seems that since kernel 6.10 circ_buf xmit structure has been removed in favor of kfifo inside tty_port in the struct uart_state (linux/serial_core.h):
This is the commit with the change: https://github.com/torvalds/linux/commit/1788cf6a91d9fa9aa61fc2917afe192c23d67f6a Regards, Sergio
