ttyport_open() calls tty_init_dev() to initialize a tty device, but tty_get_device() cannot get the correct tty->dev for serdev tty in alloc_tty_struct(), because serdev framework does not set tty_class, so class_find_device_by_devt(tty_class, devt) may always return NULL. For serdev framework, we need to assign the correct ctrl->dev to tty->dev. Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver") Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> --- drivers/tty/serdev/serdev-ttyport.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c index d367803e2044..bba37ab90215 100644 --- a/drivers/tty/serdev/serdev-ttyport.c +++ b/drivers/tty/serdev/serdev-ttyport.c @@ -112,6 +112,7 @@ static int ttyport_open(struct serdev_controller *ctrl) tty = tty_init_dev(serport->tty_drv, serport->tty_idx); if (IS_ERR(tty)) return PTR_ERR(tty); + tty->dev = &ctrl->dev; serport->tty = tty; if (!tty->ops->open || !tty->ops->close) { -- 2.17.1