Re-enable the console device after suspending, causes its cflags, ispeed and ospeed to be set anew, basing on the values stored in uport->cons. These values are set only once, when parsing console parameters after boot (see uart_set_options()), next after configuring a port in uart_port_startup() these parameters (cflags, ispeed and ospeed) are copied to termios structure and the original one (stored in uport->cons) are cleared, but there is no place in code where those fields are checked against 0. When kernel calls uart_resume_port() and setups console, it copies cflags, ispeed and ospeed values from uart->cons, but those are already cleared. The effect is that the console is broken. This patch address the issue by preserving the cflags, ispeed and ospeed fields in uart->cons during uart_port_startup().
Signed-off-by: Lukasz Majczak lma@semihalf.com Cc: stable@vger.kernel.org # 4.14+ --- drivers/tty/serial/serial_core.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 2bd32c8ece39..394a05c09d87 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -225,9 +225,6 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, tty->termios.c_cflag = uport->cons->cflag; tty->termios.c_ispeed = uport->cons->ispeed; tty->termios.c_ospeed = uport->cons->ospeed; - uport->cons->cflag = 0; - uport->cons->ispeed = 0; - uport->cons->ospeed = 0; } /* * Initialise the hardware port settings.