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

From: Yu Tu
Date: Tue Mar 01 2022 - 00:44:46 EST


Hi Jerome,
Thank you for your reply.

On 2022/2/28 18:58, Jerome Brunet wrote:
[ EXTERNAL EMAIL ]


On Fri 25 Feb 2022 at 15:39, Yu Tu <yu.tu@xxxxxxxxxxx> wrote:

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);

Already told you before, you can make meson_change_speed()
clk_set_rate() uses mutex and may sleep.
Sorry, I may have only paid attention to how you asked me to change to using the clock before, instead of paying attention to this suggestion.

+
port->read_status_mask = AML_UART_TX_FIFO_WERR;
if (iflags & INPCK)
port->read_status_mask |= AML_UART_PARITY_ERR |