--- zzzz-none-000/linux-5.4.213/drivers/tty/serdev/serdev-ttyport.c	2022-09-15 10:04:56.000000000 +0000
+++ alder-5690pro-762/linux-5.4.213/drivers/tty/serdev/serdev-ttyport.c	2024-08-14 09:02:08.000000000 +0000
@@ -247,6 +247,18 @@
 	return tty->ops->tiocmset(tty, set, clear);
 }
 
+static int ttyport_ioctl(struct serdev_controller *ctrl,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!tty->ops->ioctl)
+		return -EOPNOTSUPP;
+
+	return tty->ops->ioctl(tty, cmd, arg);
+}
+
 static const struct serdev_controller_ops ctrl_ops = {
 	.write_buf = ttyport_write_buf,
 	.write_flush = ttyport_write_flush,
@@ -259,6 +271,7 @@
 	.wait_until_sent = ttyport_wait_until_sent,
 	.get_tiocm = ttyport_get_tiocm,
 	.set_tiocm = ttyport_set_tiocm,
+	.ioctl = ttyport_ioctl,
 };
 
 struct device *serdev_tty_port_register(struct tty_port *port,