--- zzzz-none-000/linux-4.4.60/sound/usb/mixer.h	2017-04-08 07:53:53.000000000 +0000
+++ hawkeye-5590-729/linux-4.4.60/sound/usb/mixer.h	2022-03-30 14:21:53.000000000 +0000
@@ -22,6 +22,8 @@
 	struct urb *rc_urb;
 	struct usb_ctrlrequest *rc_setup_packet;
 	u8 rc_buffer[6];
+
+	bool disconnected;
 };
 
 #define MAX_CHANNELS	16	/* max logical channels */