From: Sherry Sun sherry.sun@nxp.com
[ Upstream commit 4029dfc034febb54f6dd8ea83568accc943bc088 ]
The LPUART Status Register needs to be cleared when closing the uart port to get a clean environment when reopening the uart.
Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support") Signed-off-by: Sherry Sun sherry.sun@nxp.com Link: https://lore.kernel.org/r/20221125101953.18753-4-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/fsl_lpuart.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 262b059e3ee11..110c8720af47a 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1791,6 +1791,10 @@ static void lpuart32_shutdown(struct uart_port *port)
spin_lock_irqsave(&port->lock, flags);
+ /* clear status */ + 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);