From a6b7e8d975308371b21425faefcfbd14d267d353 Mon Sep 17 00:00:00 2001 From: Sherry Sun Date: Sun, 21 Aug 2022 18:15:27 +0800 Subject: [PATCH] tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete commit d5a2e0834364377a5d5a2fff1890a0b3f0bafd1f upstream. When the user initializes the uart port, and waits for the transmit engine to complete in lpuart32_set_termios(), if the UART TX fifo has dirty data and the UARTMODIR enable the flow control, the TX fifo may never be empty. So here we should disable the flow control first to make sure the transmit engin can complete. Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support") Cc: stable Signed-off-by: Sherry Sun Link: https://lore.kernel.org/r/20220821101527.10066-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 5c44dc7be62f..f3f582c3dc87 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1981,6 +1981,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios, uart_update_timeout(port, termios->c_cflag, baud); /* wait transmit engin complete */ + lpuart32_write(&sport->port, 0, UARTMODIR); lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC); /* disable transmit and receive */