diff --git a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
index 71bd68548c9c87d3359a458efe9069c59a81e81a..4126552c90556ede32ec1bf2aee53c4d3afc3811 100644
--- a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
+++ b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
@@ -336,6 +336,7 @@ static int rain_connect(struct serio *serio, struct serio_driver *drv)
 	serio_set_drvdata(serio, rain);
 	INIT_WORK(&rain->work, rain_irq_work_handler);
 	mutex_init(&rain->write_lock);
+	spin_lock_init(&rain->buf_lock);
 
 	err = serio_open(serio, drv);
 	if (err)