2 files changed, 52 insertions, 5 deletions

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 1bef39828ca7..28133dbd2808 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -132,6 +132,33 @@ void serdev_device_close(struct serdev_device *serdev)
 }
 EXPORT_SYMBOL_GPL(serdev_device_close);
 
+static void devm_serdev_device_release(struct device *dev, void *dr)
+{
+	serdev_device_close(*(struct serdev_device **)dr);
+}
+
+int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
+{
+	struct serdev_device **dr;
+	int ret;
+
+	dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	*dr = serdev;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_serdev_device_open);
+
 void serdev_device_write_wakeup(struct serdev_device *serdev)
 {
 	complete(&serdev->write_comp);
@@ -268,8 +295,8 @@ static int serdev_drv_probe(struct device *dev)
 static int serdev_drv_remove(struct device *dev)
 {
 	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
-
-	sdrv->remove(to_serdev_device(dev));
+	if (sdrv->remove)
+		sdrv->remove(to_serdev_device(dev));
 	return 0;
 }
 
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index ce7ad0acee7a..247788a16f0b 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -27,23 +27,41 @@ static int ttyport_receive_buf(struct tty_port *port, const unsigned char *cp,
 {
 	struct serdev_controller *ctrl = port->client_data;
 	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	int ret;
 
 	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
 		return 0;
 
-	return serdev_controller_receive_buf(ctrl, cp, count);
+	ret = serdev_controller_receive_buf(ctrl, cp, count);
+
+	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
+				"receive_buf returns %d (count = %zu)\n",
+				ret, count);
+	if (ret < 0)
+		return 0;
+	else if (ret > count)
+		return count;
+
+	return ret;
 }
 
 static void ttyport_write_wakeup(struct tty_port *port)
 {
 	struct serdev_controller *ctrl = port->client_data;
 	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty;
+
+	tty = tty_port_tty_get(port);
+	if (!tty)
+		return;
 
-	if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &port->tty->flags) &&
+	if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
 	    test_bit(SERPORT_ACTIVE, &serport->flags))
 		serdev_controller_write_wakeup(ctrl);
 
-	wake_up_interruptible_poll(&port->tty->write_wait, POLLOUT);
+	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+
+	tty_kref_put(tty);
 }
 
 static const struct tty_port_client_operations client_ops = {
@@ -136,8 +154,10 @@ static void ttyport_close(struct serdev_controller *ctrl)
 
 	clear_bit(SERPORT_ACTIVE, &serport->flags);
 
+	tty_lock(tty);
 	if (tty->ops->close)
 		tty->ops->close(tty, NULL);
+	tty_unlock(tty);
 
 	tty_release_struct(tty, serport->tty_idx);
 }