[PATCH 5.19 455/717] serial: 8250: Fix restoring termios speed after suspend

Greg Kroah-Hartman
2022-10-22T08:18:50Z

From: Pali Rohár <pali@kernel.org>

[ Upstream commit 379a33786d489ab81885ff0b3935cfeb36137fea ]

Since commit edc6afc54968 ("tty: switch to ktermios and new framework")
termios speed is no longer stored only in c_cflag member but also in new
additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag
then termios speed is stored only in these new members.

Since commit 027b57170bf8 ("serial: core: Fix initializing and restoring
termios speed") termios speed is available also in struct console.

So properly restore also c_ispeed and c_ospeed members after suspend to fix
restoring termios speed which is not represented by Bnnn constant.

Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend")
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20220924104324.4035-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/8250/8250_port.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index d5f9b56fdbab..c66a029882e6 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -3325,8 +3325,13 @@ static void serial8250_console_restore(struct uart_8250_port *up)
unsigned int baud, quot, frac = 0;

termios.c_cflag = port->cons->cflag;
- if (port->state->port.tty && termios.c_cflag == 0)
+ termios.c_ispeed = port->cons->ispeed;
+ termios.c_ospeed = port->cons->ospeed;
+ if (port->state->port.tty && termios.c_cflag == 0) {
termios.c_cflag = port->state->port.tty->termios.c_cflag;
+ termios.c_ispeed = port->state->port.tty->termios.c_ispeed;
+ termios.c_ospeed = port->state->port.tty->termios.c_ospeed;
+ }

baud = serial8250_get_baud_rate(port, &termios, NULL);
quot = serial8250_get_divisor(port, baud, &frac);
--
2.35.1