diff --git a/sound/soc/codecs/cx20442.c b/sound/soc/codecs/cx20442.c
index 13258f3ca9aae..20981773f59f5 100644
--- a/sound/soc/codecs/cx20442.c
+++ b/sound/soc/codecs/cx20442.c
@@ -279,6 +279,11 @@ static void v253_receive(struct tty_struct *tty, const unsigned char *cp,
 	}
 }
 
+/* Line discipline .write_wakeup() */
+static void v253_wakeup(struct tty_struct *tty)
+{
+}
+
 struct tty_ldisc_ops v253_ops = {
 	.name = "cx20442",
 	.owner = THIS_MODULE,
@@ -286,6 +291,7 @@ struct tty_ldisc_ops v253_ops = {
 	.close = v253_close,
 	.hangup = v253_hangup,
 	.receive_buf = v253_receive,
+	.write_wakeup = v253_wakeup,
 };
 EXPORT_SYMBOL_GPL(v253_ops);