Need to clear the UARTSTAT and UARTMODIR registers when shutdown the uart port, also clear the Rx/Tx DMA enable bits and loopback configuration bit. Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> --- drivers/tty/serial/fsl_lpuart.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index f5a0a14fa366..43d9d6a6e94a 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1771,11 +1771,22 @@ static void lpuart32_shutdown(struct uart_port *port) spin_lock_irqsave(&port->lock, flags); + /* clear statue */ + temp = lpuart32_read(&sport->port, UARTSTAT); + lpuart32_write(&sport->port, temp, UARTSTAT); + + /* disable Rx/Tx DMA */ + temp = lpuart32_read(port, UARTBAUD); + temp &= ~(UARTBAUD_TDMAE | UARTBAUD_RDMAE); + lpuart32_write(port, temp, UARTBAUD); + /* disable Rx/Tx and interrupts */ temp = lpuart32_read(port, UARTCTRL); temp &= ~(UARTCTRL_TE | UARTCTRL_RE | UARTCTRL_ILIE | - UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE); + UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE | + UARTCTRL_LOOPS); lpuart32_write(port, temp, UARTCTRL); + lpuart32_write(port, 0, UARTMODIR); spin_unlock_irqrestore(&port->lock, flags); -- 2.17.1
