diff --git a/drivers/net/wireless/ath/carl9170/usb.c b/drivers/net/wireless/ath/carl9170/usb.c
index fde918d0..1e7c274 100644
--- a/drivers/net/wireless/ath/carl9170/usb.c
+++ b/drivers/net/wireless/ath/carl9170/usb.c
@@ -367,6 +367,9 @@
 {
 	struct ar9170 *ar = (struct ar9170 *) data;
 
+	if (!IS_INITIALIZED(ar))
+		return;
+
 	carl9170_usb_rx_work(ar);
 
 	/*