From 4029dfc034febb54f6dd8ea83568accc943bc088 Mon Sep 17 00:00:00 2001
From: Sherry Sun <sherry.sun@nxp.com>
Date: Fri, 25 Nov 2022 18:19:53 +0800
Subject: [PATCH] tty: serial: fsl_lpuart: clear LPUART Status Register in lpuart32_shutdown()
Git-commit: 4029dfc034febb54f6dd8ea83568accc943bc088
Patch-mainline: v6.3-rc1
References: git-fixes
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 88697ddcd8c4..8918e08bb19e 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1799,6 +1799,10 @@ 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);
--
2.35.3