[PATCH V7 5/6] tty: serial: meson: The system stuck when you run the stty command on the console to change the baud rate

[Yu Tu <yu.tu@xxxxxxxxxxx>]

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@xxxxxxxxxxx>
---
 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