All ::flush_chars(), ::hangup(), and ::wait_until_sent() from struct tty_operations are optional. There is no need to provide them with empty bodies. tty_operations::put_char() needs not be provided if it is the same as tty_operations::write(tty, &ch, 1). So drop all of them. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Link: https://lore.kernel.org/r/20230810091510.13006-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>