--- zzzz-none-000/linux-3.10.107/sound/usb/mixer_quirks.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/sound/usb/mixer_quirks.h	2021-02-04 17:41:59.000000000 +0000
@@ -9,5 +9,9 @@
 void snd_usb_mixer_rc_memory_change(struct usb_mixer_interface *mixer,
 				    int unitid);
 
+void snd_usb_mixer_fu_apply_quirk(struct usb_mixer_interface *mixer,
+				  struct usb_mixer_elem_info *cval, int unitid,
+				  struct snd_kcontrol *kctl);
+
 #endif /* SND_USB_MIXER_QUIRKS_H */