According to the lpuart reference manual, need to writing a 1 and then a 0 to the UARTCTRL_SBK field queues a break character in the transmit data stream. Only writing a 1 cannot trigger the break character, so fix it. Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support") Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> --- drivers/tty/serial/fsl_lpuart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index b6365566a460..8a4aae7dbd99 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1486,7 +1486,7 @@ static void lpuart32_break_ctl(struct uart_port *port, int break_state) temp = lpuart32_read(port, UARTCTRL) & ~UARTCTRL_SBK; if (break_state != 0) - temp |= UARTCTRL_SBK; + lpuart32_write(port, temp | UARTCTRL_SBK, UARTCTRL); lpuart32_write(port, temp, UARTCTRL); } -- 2.17.1