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From:   Yu Tu <yu.tu@amlogic.com>
To:     <linux-serial@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-amlogic@lists.infradead.org>, <linux-kernel@vger.kernel.org>
CC:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Yu Tu <yu.tu@amlogic.com>
Subject: [PATCH V7 5/6] tty: serial: meson: The system stuck when you run the stty command on the console to change the baud rate
Date:   Fri, 25 Feb 2022 15:39:21 +0800
Message-ID: <20220225073922.3947-6-yu.tu@amlogic.com>
In-Reply-To: <20220225073922.3947-1-yu.tu@amlogic.com>
References: <20220225073922.3947-1-yu.tu@amlogic.com>
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Start the console and run the following commands in turn:
stty -F /dev/ttyAML0 115200 and stty -F /dev/ttyAML0 921600. The
system will stuck.

Signed-off-by: Yu Tu <yu.tu@amlogic.com>
---
 drivers/tty/serial/meson_uart.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index ba8dc203b9cb..d19349ead738 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -365,8 +365,13 @@ static void meson_uart_set_termios(struct uart_port *port,
 	writel(val, port->membase + AML_UART_CONTROL);
 
 	baud = uart_get_baud_rate(port, termios, old, 50, 4000000);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
 	meson_uart_change_speed(port, baud);
 
+	spin_lock_irqsave(&port->lock, flags);
+
 	port->read_status_mask = AML_UART_TX_FIFO_WERR;
 	if (iflags & INPCK)
 		port->read_status_mask |= AML_UART_PARITY_ERR |
-- 
2.33.1