uart_circ_clear 192 drivers/tty/serial/8250/8250_mtk.c uart_circ_clear(&port->state->xmit); uart_circ_clear 208 drivers/tty/serial/serial_core.c uart_circ_clear(&state->xmit); uart_circ_clear 663 drivers/tty/serial/serial_core.c uart_circ_clear(&state->xmit);