diff --git a/sound/usb/card.c b/sound/usb/card.c
index 84a5ce70a2b0fda6ee2cca45b23475e34f00bb6d..220c6167dd86d5ed2164db0c73b97afac1ba6ec5 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -48,6 +48,7 @@
 #include <linux/usb/audio.h>
 #include <linux/usb/audio-v2.h>
 
+#include <sound/control.h>
 #include <sound/core.h>
 #include <sound/info.h>
 #include <sound/pcm.h>
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index ba19bfdfdc9e9e09d8243cced170fd7d8155b8a4..c22fa76e363ae5699e9885cc548fdc28d25607b3 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -86,16 +86,6 @@ struct mixer_build {
 	const struct usbmix_selector_map *selector_map;
 };
 
-enum {
-	USB_MIXER_BOOLEAN,
-	USB_MIXER_INV_BOOLEAN,
-	USB_MIXER_S8,
-	USB_MIXER_U8,
-	USB_MIXER_S16,
-	USB_MIXER_U16,
-};
-
-
 /*E-mu 0202/0404/0204 eXtension Unit(XU) control*/
 enum {
 	USB_XU_CLOCK_RATE 		= 0xe301,
@@ -985,6 +975,9 @@ static struct snd_kcontrol_new usb_feature_unit_ctl_ro = {
 	.put = NULL,
 };
 
+/* This symbol is exported in order to allow the mixer quirks to
+ * hook up to the standard feature unit control mechanism */
+struct snd_kcontrol_new *snd_usb_feature_unit_ctl = &usb_feature_unit_ctl;
 
 /*
  * build a feature control
diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 459551ac53ae3b132c239b5df0fe6b72a3916732..ae1a14dcfe82cf51753da7265bcdaf6ce95969f4 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -24,7 +24,16 @@ struct usb_mixer_interface {
 	u8 xonar_u1_status;
 };
 
-#define MAX_CHANNELS	10	/* max logical channels */
+#define MAX_CHANNELS	16	/* max logical channels */
+
+enum {
+	USB_MIXER_BOOLEAN,
+	USB_MIXER_INV_BOOLEAN,
+	USB_MIXER_S8,
+	USB_MIXER_U8,
+	USB_MIXER_S16,
+	USB_MIXER_U16,
+};
 
 struct usb_mixer_elem_info {
 	struct usb_mixer_interface *mixer;
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index bd13d7257240528f97cc2a0caf5b134a0b9d58ac..2546dc808e43b0e4ca682b46b96145c1c7952c84 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -19,6 +19,7 @@
 #include <linux/usb.h>
 #include <linux/usb/audio.h>
 
+#include <sound/control.h>
 #include <sound/core.h>
 #include <sound/info.h>
 #include <sound/pcm.h>