From 7159dced6ffb444571ac40e85f5d5aa837d17247 Mon Sep 17 00:00:00 2001 From: Sherry Sun Date: Fri, 25 Nov 2022 18:19:53 +0800 Subject: [PATCH] tty: serial: fsl_lpuart: clear LPUART Status Register in lpuart32_shutdown() [ 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 Link: https://lore.kernel.org/r/20221125101953.18753-4-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- 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 24f9001d10242..ccfd6dd5fbf4e 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1807,6 +1807,10 @@ 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); -- 2.30.2