From: Serge Semin Sergey.Semin@baikalelectronics.ru
[ Upstream commit c8dff3aa824177013d90967687f09f713a55d13f ]
It is erroneous to update the TTY port baud rate if it hasn't been initialized yet, because in that case the TTY struct isn't set. So there is no termios structure to get and re-calculate the baud if the current baud can't be reached. Let's skip the baud rate update then until the port is fully initialized.
Note the update UART clock method still sets the uartclk member with a new ref clock value even if the port is turned off. The new UART ref clock rate will be used later on the port starting up procedure.
Fixes: 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method") Tested-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Serge Semin Sergey.Semin@baikalelectronics.ru Link: https://lore.kernel.org/r/20200923161950.6237-3-Sergey.Semin@baikalelectroni... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/8250/8250_port.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 1259fb6b66b38..b0af13074cd36 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -2653,6 +2653,10 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk) goto out_lock;
port->uartclk = uartclk; + + if (!tty_port_initialized(&port->state->port)) + goto out_lock; + termios = &port->state->port.tty->termios;
baud = serial8250_get_baud_rate(port, termios, NULL);