taglinefilesource code
IXON1733drivers/char/tty_io.ctty_std_termios.c_iflag = ICRNL | IXON;
IXON120drivers/char/tty_ioctl.cint old_flow = ((old_termios.c_iflag & IXON) &&
IXON253drivers/char/tty_ioctl.ctermios->c_iflag = ICRNL | IXON;
IXON138include/linux/tty.h#define I_IXON(tty)  _I_FLAG((tty),IXON)