Merge branch 'for-next' into for-linus

19 files changed, 1915 insertions, 713 deletions

diff --git a/sound/usb/6fire/control.c b/sound/usb/6fire/control.c
index 184e3987ac2..54656eed6e2 100644
--- a/sound/usb/6fire/control.c
+++ b/sound/usb/6fire/control.c
@@ -25,8 +25,8 @@
 #include "comm.h"
 #include "chip.h"
 
-static char *opt_coax_texts[2] = { "Optical", "Coax" };
-static char *line_phono_texts[2] = { "Line", "Phono" };
+static const char * const opt_coax_texts[2] = { "Optical", "Coax" };
+static const char * const line_phono_texts[2] = { "Line", "Phono" };
 
 /*
  * data that needs to be sent to device. sets up card internal stuff.
@@ -327,14 +327,7 @@ static int usb6fire_control_input_vol_get(struct snd_kcontrol *kcontrol,
 static int usb6fire_control_line_phono_info(struct snd_kcontrol *kcontrol,
 		struct snd_ctl_elem_info *uinfo)
 {
-	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	uinfo->count = 1;
-	uinfo->value.enumerated.items = 2;
-	if (uinfo->value.enumerated.item > 1)
-		uinfo->value.enumerated.item = 1;
-	strcpy(uinfo->value.enumerated.name,
-			line_phono_texts[uinfo->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(uinfo, 1, 2, line_phono_texts);
 }
 
 static int usb6fire_control_line_phono_put(struct snd_kcontrol *kcontrol,
@@ -361,14 +354,7 @@ static int usb6fire_control_line_phono_get(struct snd_kcontrol *kcontrol,
 static int usb6fire_control_opt_coax_info(struct snd_kcontrol *kcontrol,
 		struct snd_ctl_elem_info *uinfo)
 {
-	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	uinfo->count = 1;
-	uinfo->value.enumerated.items = 2;
-	if (uinfo->value.enumerated.item > 1)
-		uinfo->value.enumerated.item = 1;
-	strcpy(uinfo->value.enumerated.name,
-			opt_coax_texts[uinfo->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(uinfo, 1, 2, opt_coax_texts);
 }
 
 static int usb6fire_control_opt_coax_put(struct snd_kcontrol *kcontrol,
diff --git a/sound/usb/6fire/firmware.c b/sound/usb/6fire/firmware.c
index 3b02e54b8f6..62c25e74f0e 100644
--- a/sound/usb/6fire/firmware.c
+++ b/sound/usb/6fire/firmware.c
@@ -316,7 +316,7 @@ static int usb6fire_fw_fpga_upload(
 
 	while (c != end) {
 		for (i = 0; c != end && i < FPGA_BUFSIZE; i++, c++)
-			buffer[i] = byte_rev_table[(u8) *c];
+			buffer[i] = bitrev8((u8)*c);
 
 		ret = usb6fire_fw_fpga_write(device, buffer, i);
 		if (ret < 0) {
diff --git a/sound/usb/6fire/pcm.c b/sound/usb/6fire/pcm.c
index ba40489b2de..36f4115eb1c 100644
--- a/sound/usb/6fire/pcm.c
+++ b/sound/usb/6fire/pcm.c
@@ -679,25 +679,16 @@ int usb6fire_pcm_init(struct sfire_chip *chip)
 void usb6fire_pcm_abort(struct sfire_chip *chip)
 {
 	struct pcm_runtime *rt = chip->pcm;
-	unsigned long flags;
 	int i;
 
 	if (rt) {
 		rt->panic = true;
 
-		if (rt->playback.instance) {
-			snd_pcm_stream_lock_irqsave(rt->playback.instance, flags);
-			snd_pcm_stop(rt->playback.instance,
-					SNDRV_PCM_STATE_XRUN);
-			snd_pcm_stream_unlock_irqrestore(rt->playback.instance, flags);
-		}
+		if (rt->playback.instance)
+			snd_pcm_stop_xrun(rt->playback.instance);
 
-		if (rt->capture.instance) {
-			snd_pcm_stream_lock_irqsave(rt->capture.instance, flags);
-			snd_pcm_stop(rt->capture.instance,
-					SNDRV_PCM_STATE_XRUN);
-			snd_pcm_stream_unlock_irqrestore(rt->capture.instance, flags);
-		}
+		if (rt->capture.instance)
+			snd_pcm_stop_xrun(rt->capture.instance);
 
 		for (i = 0; i < PCM_N_URBS; i++) {
 			usb_poison_urb(&rt->in_urbs[i].instance);
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 2b92f0dcbc4..bcee4060fd1 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -9,6 +9,7 @@ snd-usb-audio-objs := 	card.o \
 			helper.o \
 			mixer.o \
 			mixer_quirks.o \
+			mixer_scarlett.o \
 			pcm.o \
 			proc.o \
 			quirks.o \
diff --git a/sound/usb/card.c b/sound/usb/card.c
index f61ebb17cc6..1fab9778807 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -112,15 +112,13 @@ static struct usb_driver usb_audio_driver;
 
 /*
  * disconnect streams
- * called from snd_usb_audio_disconnect()
+ * called from usb_audio_disconnect()
  */
-static void snd_usb_stream_disconnect(struct list_head *head)
+static void snd_usb_stream_disconnect(struct snd_usb_stream *as)
 {
 	int idx;
-	struct snd_usb_stream *as;
 	struct snd_usb_substream *subs;
 
-	as = list_entry(head, struct snd_usb_stream, list);
 	for (idx = 0; idx < 2; idx++) {
 		subs = &as->substream[idx];
 		if (!subs->num_formats)
@@ -307,10 +305,10 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 
 static int snd_usb_audio_free(struct snd_usb_audio *chip)
 {
-	struct list_head *p, *n;
+	struct snd_usb_endpoint *ep, *n;
 
-	list_for_each_safe(p, n, &chip->ep_list)
-		snd_usb_endpoint_free(p);
+	list_for_each_entry_safe(ep, n, &chip->ep_list, list)
+		snd_usb_endpoint_free(ep);
 
 	mutex_destroy(&chip->mutex);
 	kfree(chip);
@@ -323,16 +321,6 @@ static int snd_usb_audio_dev_free(struct snd_device *device)
 	return snd_usb_audio_free(chip);
 }
 
-static void remove_trailing_spaces(char *str)
-{
-	char *p;
-
-	if (!*str)
-		return;
-	for (p = str + strlen(str) - 1; p >= str && isspace(*p); p--)
-		*p = 0;
-}
-
 /*
  * create a chip instance and set its names.
  */
@@ -416,7 +404,7 @@ static int snd_usb_audio_create(struct usb_interface *intf,
 				USB_ID_PRODUCT(chip->usb_id));
 		}
 	}
-	remove_trailing_spaces(card->shortname);
+	strim(card->shortname);
 
 	/* retrieve the vendor and device strings as longname */
 	if (quirk && quirk->vendor_name && *quirk->vendor_name) {
@@ -430,7 +418,7 @@ static int snd_usb_audio_create(struct usb_interface *intf,
 		/* we don't really care if there isn't any vendor string */
 	}
 	if (len > 0) {
-		remove_trailing_spaces(card->longname);
+		strim(card->longname);
 		if (*card->longname)
 			strlcat(card->longname, " ", sizeof(card->longname));
 	}
@@ -475,14 +463,14 @@ static int snd_usb_audio_create(struct usb_interface *intf,
  * only at the first time.  the successive calls of this function will
  * append the pcm interface to the corresponding card.
  */
-static struct snd_usb_audio *
-snd_usb_audio_probe(struct usb_device *dev,
-		    struct usb_interface *intf,
-		    const struct usb_device_id *usb_id)
+static int usb_audio_probe(struct usb_interface *intf,
+			   const struct usb_device_id *usb_id)
 {
-	const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
-	int i, err;
+	struct usb_device *dev = interface_to_usbdev(intf);
+	const struct snd_usb_audio_quirk *quirk =
+		(const struct snd_usb_audio_quirk *)usb_id->driver_info;
 	struct snd_usb_audio *chip;
+	int i, err;
 	struct usb_host_interface *alts;
 	int ifnum;
 	u32 id;
@@ -492,10 +480,11 @@ snd_usb_audio_probe(struct usb_device *dev,
 	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 		    le16_to_cpu(dev->descriptor.idProduct));
 	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
-		goto __err_val;
+		return -ENXIO;
 
-	if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
-		goto __err_val;
+	err = snd_usb_apply_boot_quirk(dev, intf, quirk);
+	if (err < 0)
+		return err;
 
 	/*
 	 * found a config.  now register to ALSA
@@ -508,6 +497,7 @@ snd_usb_audio_probe(struct usb_device *dev,
 		if (usb_chip[i] && usb_chip[i]->dev == dev) {
 			if (usb_chip[i]->shutdown) {
 				dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
+				err = -EIO;
 				goto __error;
 			}
 			chip = usb_chip[i];
@@ -523,15 +513,16 @@ snd_usb_audio_probe(struct usb_device *dev,
 			if (enable[i] && ! usb_chip[i] &&
 			    (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
 			    (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
-				if (snd_usb_audio_create(intf, dev, i, quirk,
-							 &chip) < 0) {
+				err = snd_usb_audio_create(intf, dev, i, quirk,
+							   &chip);
+				if (err < 0)
 					goto __error;
-				}
 				chip->pm_intf = intf;
 				break;
 			}
 		if (!chip) {
 			dev_err(&dev->dev, "no available usb audio device\n");
+			err = -ENODEV;
 			goto __error;
 		}
 	}
@@ -548,28 +539,32 @@ snd_usb_audio_probe(struct usb_device *dev,
 	err = 1; /* continue */
 	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
 		/* need some special handlings */
-		if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
+		err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
+		if (err < 0)
 			goto __error;
 	}
 
 	if (err > 0) {
 		/* create normal USB audio interfaces */
-		if (snd_usb_create_streams(chip, ifnum) < 0 ||
-		    snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
+		err = snd_usb_create_streams(chip, ifnum);
+		if (err < 0)
+			goto __error;
+		err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
+		if (err < 0)
 			goto __error;
-		}
 	}
 
 	/* we are allowed to call snd_card_register() many times */
-	if (snd_card_register(chip->card) < 0) {
+	err = snd_card_register(chip->card);
+	if (err < 0)
 		goto __error;
-	}
 
 	usb_chip[chip->index] = chip;
 	chip->num_interfaces++;
 	chip->probing = 0;
+	usb_set_intfdata(intf, chip);
 	mutex_unlock(&register_mutex);
-	return chip;
+	return 0;
 
  __error:
 	if (chip) {
@@ -578,17 +573,16 @@ snd_usb_audio_probe(struct usb_device *dev,
 		chip->probing = 0;
 	}
 	mutex_unlock(&register_mutex);
- __err_val:
-	return NULL;
+	return err;
 }
 
 /*
  * we need to take care of counter, since disconnection can be called also
  * many times as well as usb_audio_probe().
  */
-static void snd_usb_audio_disconnect(struct usb_device *dev,
-				     struct snd_usb_audio *chip)
+static void usb_audio_disconnect(struct usb_interface *intf)
 {
+	struct snd_usb_audio *chip = usb_get_intfdata(intf);
 	struct snd_card *card;
 	struct list_head *p;
 	bool was_shutdown;
@@ -604,12 +598,14 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
 
 	mutex_lock(&register_mutex);
 	if (!was_shutdown) {
+		struct snd_usb_stream *as;
 		struct snd_usb_endpoint *ep;
+		struct usb_mixer_interface *mixer;
 
 		snd_card_disconnect(card);
 		/* release the pcm resources */
-		list_for_each(p, &chip->pcm_list) {
-			snd_usb_stream_disconnect(p);
+		list_for_each_entry(as, &chip->pcm_list, list) {
+			snd_usb_stream_disconnect(as);
 		}
 		/* release the endpoint resources */
 		list_for_each_entry(ep, &chip->ep_list, list) {
@@ -620,8 +616,8 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
 			snd_usbmidi_disconnect(p);
 		}
 		/* release mixer resources */
-		list_for_each(p, &chip->mixer_list) {
-			snd_usb_mixer_disconnect(p);
+		list_for_each_entry(mixer, &chip->mixer_list, list) {
+			snd_usb_mixer_disconnect(mixer);
 		}
 	}
 
@@ -635,27 +631,6 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
 	}
 }
 
-/*
- * new 2.5 USB kernel API
- */
-static int usb_audio_probe(struct usb_interface *intf,
-			   const struct usb_device_id *id)
-{
-	struct snd_usb_audio *chip;
-	chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
-	if (chip) {
-		usb_set_intfdata(intf, chip);
-		return 0;
-	} else
-		return -EIO;
-}
-
-static void usb_audio_disconnect(struct usb_interface *intf)
-{
-	snd_usb_audio_disconnect(interface_to_usbdev(intf),
-				 usb_get_intfdata(intf));
-}
-
 #ifdef CONFIG_PM
 
 int snd_usb_autoresume(struct snd_usb_audio *chip)
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 114e3e7ff51..03b07441996 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -348,6 +348,8 @@ static void snd_complete_urb(struct urb *urb)
 {
 	struct snd_urb_ctx *ctx = urb->context;
 	struct snd_usb_endpoint *ep = ctx->ep;
+	struct snd_pcm_substream *substream;
+	unsigned long flags;
 	int err;
 
 	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
@@ -364,8 +366,6 @@ static void snd_complete_urb(struct urb *urb)
 			goto exit_clear;
 
 		if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
-			unsigned long flags;
-
 			spin_lock_irqsave(&ep->lock, flags);
 			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
 			spin_unlock_irqrestore(&ep->lock, flags);
@@ -389,7 +389,10 @@ static void snd_complete_urb(struct urb *urb)
 		return;
 
 	usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
-	//snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+	if (ep->data_subs && ep->data_subs->pcm_substream) {
+		substream = ep->data_subs->pcm_substream;
+		snd_pcm_stop_xrun(substream);
+	}
 
 exit_clear:
 	clear_bit(ctx->index, &ep->active_mask);
@@ -1002,15 +1005,12 @@ void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
 /**
  * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
  *
- * @ep: the list header of the endpoint to free
+ * @ep: the endpoint to free
  *
  * This free all resources of the given ep.
  */
-void snd_usb_endpoint_free(struct list_head *head)
+void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
 {
-	struct snd_usb_endpoint *ep;
-
-	ep = list_entry(head, struct snd_usb_endpoint, list);
 	kfree(ep);
 }
 
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
index e61ee5c356a..6428392d8f6 100644
--- a/sound/usb/endpoint.h
+++ b/sound/usb/endpoint.h
@@ -24,7 +24,7 @@ void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep);
 int  snd_usb_endpoint_activate(struct snd_usb_endpoint *ep);
 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep);
 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep);
-void snd_usb_endpoint_free(struct list_head *head);
+void snd_usb_endpoint_free(struct snd_usb_endpoint *ep);
 
 int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep);
 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep);
diff --git a/sound/usb/misc/ua101.c b/sound/usb/misc/ua101.c
index a1bab149df4..9581089c28c 100644
--- a/sound/usb/misc/ua101.c
+++ b/sound/usb/misc/ua101.c
@@ -613,24 +613,14 @@ static int start_usb_playback(struct ua101 *ua)
 
 static void abort_alsa_capture(struct ua101 *ua)
 {
-	unsigned long flags;
-
-	if (test_bit(ALSA_CAPTURE_RUNNING, &ua->states)) {
-		snd_pcm_stream_lock_irqsave(ua->capture.substream, flags);
-		snd_pcm_stop(ua->capture.substream, SNDRV_PCM_STATE_XRUN);
-		snd_pcm_stream_unlock_irqrestore(ua->capture.substream, flags);
-	}
+	if (test_bit(ALSA_CAPTURE_RUNNING, &ua->states))
+		snd_pcm_stop_xrun(ua->capture.substream);
 }
 
 static void abort_alsa_playback(struct ua101 *ua)
 {
-	unsigned long flags;
-
-	if (test_bit(ALSA_PLAYBACK_RUNNING, &ua->states)) {
-		snd_pcm_stream_lock_irqsave(ua->playback.substream, flags);
-		snd_pcm_stop(ua->playback.substream, SNDRV_PCM_STATE_XRUN);
-		snd_pcm_stream_unlock_irqrestore(ua->playback.substream, flags);
-	}
+	if (test_bit(ALSA_PLAYBACK_RUNNING, &ua->states))
+		snd_pcm_stop_xrun(ua->playback.substream);
 }
 
 static int set_stream_hw(struct ua101 *ua, struct snd_pcm_substream *substream,
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 6e354d32685..41650d5b93b 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -136,6 +136,10 @@ check_mapped_name(const struct usbmix_name_map *p, char *buf, int buflen)
 	return strlcpy(buf, p->name, buflen);
 }
 
+/* ignore the error value if ignore_ctl_error flag is set */
+#define filter_error(cval, err) \
+	((cval)->head.mixer->ignore_ctl_error ? 0 : (err))
+
 /* check whether the control should be ignored */
 static inline int
 check_ignored_ctl(const struct usbmix_name_map *p)
@@ -286,13 +290,13 @@ static int get_abs_value(struct usb_mixer_elem_info *cval, int val)
 static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request,
 			    int validx, int *value_ret)
 {
-	struct snd_usb_audio *chip = cval->mixer->chip;
+	struct snd_usb_audio *chip = cval->head.mixer->chip;
 	unsigned char buf[2];
 	int val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
 	int timeout = 10;
 	int idx = 0, err;
 
-	err = snd_usb_autoresume(cval->mixer->chip);
+	err = snd_usb_autoresume(chip);
 	if (err < 0)
 		return -EIO;
 
@@ -300,7 +304,7 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request,
 	while (timeout-- > 0) {
 		if (chip->shutdown)
 			break;
-		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
+		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
 		if (snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), request,
 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 				    validx, idx, buf, val_len) >= val_len) {
@@ -316,14 +320,14 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request,
 
  out:
 	up_read(&chip->shutdown_rwsem);
-	snd_usb_autosuspend(cval->mixer->chip);
+	snd_usb_autosuspend(chip);
 	return err;
 }
 
 static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
 			    int validx, int *value_ret)
 {
-	struct snd_usb_audio *chip = cval->mixer->chip;
+	struct snd_usb_audio *chip = cval->head.mixer->chip;
 	unsigned char buf[2 + 3 * sizeof(__u16)]; /* enough space for one range */
 	unsigned char *val;
 	int idx = 0, ret, size;
@@ -347,7 +351,7 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
 	if (chip->shutdown) {
 		ret = -ENODEV;
 	} else {
-		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
+		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
 		ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), bRequest,
 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 			      validx, idx, buf, size);
@@ -392,7 +396,7 @@ static int get_ctl_value(struct usb_mixer_elem_info *cval, int request,
 {
 	validx += cval->idx_off;
 
-	return (cval->mixer->protocol == UAC_VERSION_1) ?
+	return (cval->head.mixer->protocol == UAC_VERSION_1) ?
 		get_ctl_value_v1(cval, request, validx, value_ret) :
 		get_ctl_value_v2(cval, request, validx, value_ret);
 }
@@ -412,7 +416,7 @@ static inline int get_cur_mix_raw(struct usb_mixer_elem_info *cval,
 			     value);
 }
 
-static int get_cur_mix_value(struct usb_mixer_elem_info *cval,
+int snd_usb_get_cur_mix_value(struct usb_mixer_elem_info *cval,
 			     int channel, int index, int *value)
 {
 	int err;
@@ -423,8 +427,8 @@ static int get_cur_mix_value(struct usb_mixer_elem_info *cval,
 	}
 	err = get_cur_mix_raw(cval, channel, value);
 	if (err < 0) {
-		if (!cval->mixer->ignore_ctl_error)
-			usb_audio_dbg(cval->mixer->chip,
+		if (!cval->head.mixer->ignore_ctl_error)
+			usb_audio_dbg(cval->head.mixer->chip,
 				"cannot get current value for control %d ch %d: err = %d\n",
 				      cval->control, channel, err);
 		return err;
@@ -441,13 +445,13 @@ static int get_cur_mix_value(struct usb_mixer_elem_info *cval,
 int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
 				int request, int validx, int value_set)
 {
-	struct snd_usb_audio *chip = cval->mixer->chip;
+	struct snd_usb_audio *chip = cval->head.mixer->chip;
 	unsigned char buf[2];
 	int idx = 0, val_len, err, timeout = 10;
 
 	validx += cval->idx_off;
 
-	if (cval->mixer->protocol == UAC_VERSION_1) {
+	if (cval->head.mixer->protocol == UAC_VERSION_1) {
 		val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
 	} else { /* UAC_VERSION_2 */
 		/* audio class v2 controls are always 2 bytes in size */
@@ -472,7 +476,7 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
 	while (timeout-- > 0) {
 		if (chip->shutdown)
 			break;
-		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
+		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
 		if (snd_usb_ctl_msg(chip->dev,
 				    usb_sndctrlpipe(chip->dev, 0), request,
 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
@@ -497,7 +501,7 @@ static int set_cur_ctl_value(struct usb_mixer_elem_info *cval,
 	return snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, validx, value);
 }
 
-static int set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
+int snd_usb_set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
 			     int index, int value)
 {
 	int err;
@@ -506,7 +510,7 @@ static int set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
 		cval->ch_readonly & (1 << (channel - 1));
 
 	if (read_only) {
-		usb_audio_dbg(cval->mixer->chip,
+		usb_audio_dbg(cval->head.mixer->chip,
 			      "%s(): channel %d of control %d is read_only\n",
 			    __func__, channel, cval->control);
 		return 0;
@@ -565,10 +569,10 @@ static int check_matrix_bitmap(unsigned char *bmap,
  * if failed, give up and free the control instance.
  */
 
-int snd_usb_mixer_add_control(struct usb_mixer_interface *mixer,
+int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list,
 			      struct snd_kcontrol *kctl)
 {
-	struct usb_mixer_elem_info *cval = kctl->private_data;
+	struct usb_mixer_interface *mixer = list->mixer;
 	int err;
 
 	while (snd_ctl_find_id(mixer->chip->card, &kctl->id))
@@ -578,9 +582,9 @@ int snd_usb_mixer_add_control(struct usb_mixer_interface *mixer,
 			      err);
 		return err;
 	}
-	cval->elem_id = &kctl->id;
-	cval->next_id_elem = mixer->id_elems[cval->id];
-	mixer->id_elems[cval->id] = cval;
+	list->kctl = kctl;
+	list->next_id_elem = mixer->id_elems[list->id];
+	mixer->id_elems[list->id] = list;
 	return 0;
 }
 
@@ -815,7 +819,7 @@ static struct usb_feature_control_info audio_feature_info[] = {
 };
 
 /* private_free callback */
-static void usb_mixer_elem_free(struct snd_kcontrol *kctl)
+void snd_usb_mixer_elem_free(struct snd_kcontrol *kctl)
 {
 	kfree(kctl->private_data);
 	kctl->private_data = NULL;
@@ -829,7 +833,7 @@ static void usb_mixer_elem_free(struct snd_kcontrol *kctl)
 static void volume_control_quirks(struct usb_mixer_elem_info *cval,
 				  struct snd_kcontrol *kctl)
 {
-	struct snd_usb_audio *chip = cval->mixer->chip;
+	struct snd_usb_audio *chip = cval->head.mixer->chip;
 	switch (chip->usb_id) {
 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
@@ -954,10 +958,10 @@ static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
 		}
 		if (get_ctl_value(cval, UAC_GET_MAX, (cval->control << 8) | minchn, &cval->max) < 0 ||
 		    get_ctl_value(cval, UAC_GET_MIN, (cval->control << 8) | minchn, &cval->min) < 0) {
-			usb_audio_err(cval->mixer->chip,
+			usb_audio_err(cval->head.mixer->chip,
 				      "%d:%d: cannot get min/max values for control %d (id %d)\n",
-				   cval->id, snd_usb_ctrl_intf(cval->mixer->chip),
-							       cval->control, cval->id);
+				   cval->head.id, snd_usb_ctrl_intf(cval->head.mixer->chip),
+							       cval->control, cval->head.id);
 			return -EINVAL;
 		}
 		if (get_ctl_value(cval, UAC_GET_RES,
@@ -998,7 +1002,7 @@ static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
 				else
 					test -= cval->res;
 				if (test < cval->min || test > cval->max ||
-				    set_cur_mix_value(cval, minchn, 0, test) ||
+				    snd_usb_set_cur_mix_value(cval, minchn, 0, test) ||
 				    get_cur_mix_raw(cval, minchn, &check)) {
 					cval->res = last_valid_res;
 					break;
@@ -1007,7 +1011,7 @@ static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
 					break;
 				cval->res *= 2;
 			}
-			set_cur_mix_value(cval, minchn, 0, saved);
+			snd_usb_set_cur_mix_value(cval, minchn, 0, saved);
 		}
 
 		cval->initialized = 1;
@@ -1061,7 +1065,7 @@ static int mixer_ctl_feature_info(struct snd_kcontrol *kcontrol,
 				kcontrol->vd[0].access &= 
 					~(SNDRV_CTL_ELEM_ACCESS_TLV_READ |
 					  SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
-				snd_ctl_notify(cval->mixer->chip->card,
+				snd_ctl_notify(cval->head.mixer->chip->card,
 					       SNDRV_CTL_EVENT_MASK_INFO,
 					       &kcontrol->id);
 			}
@@ -1086,9 +1090,9 @@ static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol,
 		for (c = 0; c < MAX_CHANNELS; c++) {
 			if (!(cval->cmask & (1 << c)))
 				continue;
-			err = get_cur_mix_value(cval, c + 1, cnt, &val);
+			err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &val);
 			if (err < 0)
-				return cval->mixer->ignore_ctl_error ? 0 : err;
+				return filter_error(cval, err);
 			val = get_relative_value(cval, val);
 			ucontrol->value.integer.value[cnt] = val;
 			cnt++;
@@ -1096,9 +1100,9 @@ static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol,
 		return 0;
 	} else {
 		/* master channel */
-		err = get_cur_mix_value(cval, 0, 0, &val);
+		err = snd_usb_get_cur_mix_value(cval, 0, 0, &val);
 		if (err < 0)
-			return cval->mixer->ignore_ctl_error ? 0 : err;
+			return filter_error(cval, err);
 		val = get_relative_value(cval, val);
 		ucontrol->value.integer.value[0] = val;
 	}
@@ -1118,26 +1122,26 @@ static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol,
 		for (c = 0; c < MAX_CHANNELS; c++) {
 			if (!(cval->cmask & (1 << c)))
 				continue;
-			err = get_cur_mix_value(cval, c + 1, cnt, &oval);
+			err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &oval);
 			if (err < 0)
-				return cval->mixer->ignore_ctl_error ? 0 : err;
+				return filter_error(cval, err);
 			val = ucontrol->value.integer.value[cnt];
 			val = get_abs_value(cval, val);
 			if (oval != val) {
-				set_cur_mix_value(cval, c + 1, cnt, val);
+				snd_usb_set_cur_mix_value(cval, c + 1, cnt, val);
 				changed = 1;
 			}
 			cnt++;
 		}
 	} else {
 		/* master channel */
-		err = get_cur_mix_value(cval, 0, 0, &oval);
+		err = snd_usb_get_cur_mix_value(cval, 0, 0, &oval);
 		if (err < 0)
-			return cval->mixer->ignore_ctl_error ? 0 : err;
+			return filter_error(cval, err);
 		val = ucontrol->value.integer.value[0];
 		val = get_abs_value(cval, val);
 		if (val != oval) {
-			set_cur_mix_value(cval, 0, 0, val);
+			snd_usb_set_cur_mix_value(cval, 0, 0, val);
 			changed = 1;
 		}
 	}
@@ -1231,8 +1235,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
 	if (!cval)
 		return;
-	cval->mixer = state->mixer;
-	cval->id = unitid;
+	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
 	cval->control = control;
 	cval->cmask = ctl_mask;
 	cval->val_type = audio_feature_info[control-1].type;
@@ -1250,7 +1253,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 
 	/*
 	 * If all channels in the mask are marked read-only, make the control
-	 * read-only. set_cur_mix_value() will check the mask again and won't
+	 * read-only. snd_usb_set_cur_mix_value() will check the mask again and won't
 	 * issue write commands to read-only channels.
 	 */
 	if (cval->channels == readonly_mask)
@@ -1263,7 +1266,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 		kfree(cval);
 		return;
 	}
-	kctl->private_free = usb_mixer_elem_free;
+	kctl->private_free = snd_usb_mixer_elem_free;
 
 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
 	mapped_name = len != 0;
@@ -1290,9 +1293,8 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 						    kctl->id.name,
 						    sizeof(kctl->id.name), 1);
 			if (!len)
-				len = snprintf(kctl->id.name,
-					       sizeof(kctl->id.name),
-					       "Feature %d", unitid);
+				snprintf(kctl->id.name, sizeof(kctl->id.name),
+					 "Feature %d", unitid);
 		}
 
 		if (!mapped_name)
@@ -1305,9 +1307,9 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 		 */
 		if (!mapped_name && !(state->oterm.type >> 16)) {
 			if ((state->oterm.type & 0xff00) == 0x0100)
-				len = append_ctl_name(kctl, " Capture");
+				append_ctl_name(kctl, " Capture");
 			else
-				len = append_ctl_name(kctl, " Playback");
+				append_ctl_name(kctl, " Playback");
 		}
 		append_ctl_name(kctl, control == UAC_FU_MUTE ?
 				" Switch" : " Volume");
@@ -1344,14 +1346,14 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 			       range);
 		usb_audio_warn(state->chip,
 			       "[%d] FU [%s] ch = %d, val = %d/%d/%d",
-			       cval->id, kctl->id.name, cval->channels,
+			       cval->head.id, kctl->id.name, cval->channels,
 			       cval->min, cval->max, cval->res);
 	}
 
 	usb_audio_dbg(state->chip, "[%d] FU [%s] ch = %d, val = %d/%d/%d\n",
-		      cval->id, kctl->id.name, cval->channels,
+		      cval->head.id, kctl->id.name, cval->channels,
 		      cval->min, cval->max, cval->res);
-	snd_usb_mixer_add_control(state->mixer, kctl);
+	snd_usb_mixer_add_control(&cval->head, kctl);
 }
 
 /*
@@ -1525,8 +1527,7 @@ static void build_mixer_unit_ctl(struct mixer_build *state,
 	if (!cval)
 		return;
 
-	cval->mixer = state->mixer;
-	cval->id = unitid;
+	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
 	cval->control = in_ch + 1; /* based on 1 */
 	cval->val_type = USB_MIXER_S16;
 	for (i = 0; i < num_outs; i++) {
@@ -1547,7 +1548,7 @@ static void build_mixer_unit_ctl(struct mixer_build *state,
 		kfree(cval);
 		return;
 	}
-	kctl->private_free = usb_mixer_elem_free;
+	kctl->private_free = snd_usb_mixer_elem_free;
 
 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
 	if (!len)
@@ -1558,8 +1559,8 @@ static void build_mixer_unit_ctl(struct mixer_build *state,
 	append_ctl_name(kctl, " Volume");
 
 	usb_audio_dbg(state->chip, "[%d] MU [%s] ch = %d, val = %d/%d\n",
-		    cval->id, kctl->id.name, cval->channels, cval->min, cval->max);
-	snd_usb_mixer_add_control(state->mixer, kctl);
+		    cval->head.id, kctl->id.name, cval->channels, cval->min, cval->max);
+	snd_usb_mixer_add_control(&cval->head, kctl);
 }
 
 /*
@@ -1629,12 +1630,10 @@ static int mixer_ctl_procunit_get(struct snd_kcontrol *kcontrol,
 	int err, val;
 
 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
-	if (err < 0 && cval->mixer->ignore_ctl_error) {
+	if (err < 0) {
 		ucontrol->value.integer.value[0] = cval->min;
-		return 0;
+		return filter_error(cval, err);
 	}
-	if (err < 0)
-		return err;
 	val = get_relative_value(cval, val);
 	ucontrol->value.integer.value[0] = val;
 	return 0;
@@ -1648,11 +1647,8 @@ static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol,
 	int val, oval, err;
 
 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
-	if (err < 0) {
-		if (cval->mixer->ignore_ctl_error)
-			return 0;
-		return err;
-	}
+	if (err < 0)
+		return filter_error(cval, err);
 	val = ucontrol->value.integer.value[0];
 	val = get_abs_value(cval, val);
 	if (val != oval) {
@@ -1814,8 +1810,7 @@ static int build_audio_procunit(struct mixer_build *state, int unitid,
 		cval = kzalloc(sizeof(*cval), GFP_KERNEL);
 		if (!cval)
 			return -ENOMEM;
-		cval->mixer = state->mixer;
-		cval->id = unitid;
+		snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
 		cval->control = valinfo->control;
 		cval->val_type = valinfo->val_type;
 		cval->channels = 1;
@@ -1847,7 +1842,7 @@ static int build_audio_procunit(struct mixer_build *state, int unitid,
 			kfree(cval);
 			return -ENOMEM;
 		}
-		kctl->private_free = usb_mixer_elem_free;
+		kctl->private_free = snd_usb_mixer_elem_free;
 
 		if (check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name))) {
 			/* nothing */ ;
@@ -1868,10 +1863,10 @@ static int build_audio_procunit(struct mixer_build *state, int unitid,
 
 		usb_audio_dbg(state->chip,
 			      "[%d] PU [%s] ch = %d, val = %d/%d\n",
-			      cval->id, kctl->id.name, cval->channels,
+			      cval->head.id, kctl->id.name, cval->channels,
 			      cval->min, cval->max);
 
-		err = snd_usb_mixer_add_control(state->mixer, kctl);
+		err = snd_usb_mixer_add_control(&cval->head, kctl);
 		if (err < 0)
 			return err;
 	}
@@ -1924,11 +1919,8 @@ static int mixer_ctl_selector_get(struct snd_kcontrol *kcontrol,
 
 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
 	if (err < 0) {
-		if (cval->mixer->ignore_ctl_error) {
-			ucontrol->value.enumerated.item[0] = 0;
-			return 0;
-		}
-		return err;
+		ucontrol->value.enumerated.item[0] = 0;
+		return filter_error(cval, err);
 	}
 	val = get_relative_value(cval, val);
 	ucontrol->value.enumerated.item[0] = val;
@@ -1943,11 +1935,8 @@ static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol,
 	int val, oval, err;
 
 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
-	if (err < 0) {
-		if (cval->mixer->ignore_ctl_error)
-			return 0;
-		return err;
-	}
+	if (err < 0)
+		return filter_error(cval, err);
 	val = ucontrol->value.enumerated.item[0];
 	val = get_abs_value(cval, val);
 	if (val != oval) {
@@ -2024,8 +2013,7 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
 	if (!cval)
 		return -ENOMEM;
-	cval->mixer = state->mixer;
-	cval->id = unitid;
+	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
 	cval->val_type = USB_MIXER_U8;
 	cval->channels = 1;
 	cval->min = 1;
@@ -2096,11 +2084,8 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
 	}
 
 	usb_audio_dbg(state->chip, "[%d] SU [%s] items = %d\n",
-		    cval->id, kctl->id.name, desc->bNrInPins);
-	if ((err = snd_usb_mixer_add_control(state->mixer, kctl)) < 0)
-		return err;
-
-	return 0;
+		    cval->head.id, kctl->id.name, desc->bNrInPins);
+	return snd_usb_mixer_add_control(&cval->head, kctl);
 }
 
 /*
@@ -2245,25 +2230,21 @@ static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
 
 void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
 {
-	struct usb_mixer_elem_info *info;
+	struct usb_mixer_elem_list *list;
 
-	for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem)
+	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem)
 		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
-			       info->elem_id);
+			       &list->kctl->id);
 }
 
 static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,
-				    int unitid,
-				    struct usb_mixer_elem_info *cval)
+				    struct usb_mixer_elem_list *list)
 {
+	struct usb_mixer_elem_info *cval = (struct usb_mixer_elem_info *)list;
 	static char *val_types[] = {"BOOLEAN", "INV_BOOLEAN",
 				    "S8", "U8", "S16", "U16"};
-	snd_iprintf(buffer, "  Unit: %i\n", unitid);
-	if (cval->elem_id)
-		snd_iprintf(buffer, "    Control: name=\"%s\", index=%i\n",
-				cval->elem_id->name, cval->elem_id->index);
 	snd_iprintf(buffer, "    Info: id=%i, control=%i, cmask=0x%x, "
-			    "channels=%i, type=\"%s\"\n", cval->id,
+			    "channels=%i, type=\"%s\"\n", cval->head.id,
 			    cval->control, cval->cmask, cval->channels,
 			    val_types[cval->val_type]);
 	snd_iprintf(buffer, "    Volume: min=%i, max=%i, dBmin=%i, dBmax=%i\n",
@@ -2275,7 +2256,7 @@ static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
 {
 	struct snd_usb_audio *chip = entry->private_data;
 	struct usb_mixer_interface *mixer;
-	struct usb_mixer_elem_info *cval;
+	struct usb_mixer_elem_list *list;
 	int unitid;
 
 	list_for_each_entry(mixer, &chip->mixer_list, list) {
@@ -2285,9 +2266,17 @@ static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
 				mixer->ignore_ctl_error);
 		snd_iprintf(buffer, "Card: %s\n", chip->card->longname);
 		for (unitid = 0; unitid < MAX_ID_ELEMS; unitid++) {
-			for (cval = mixer->id_elems[unitid]; cval;
-						cval = cval->next_id_elem)
-				snd_usb_mixer_dump_cval(buffer, unitid, cval);
+			for (list = mixer->id_elems[unitid]; list;
+			     list = list->next_id_elem) {
+				snd_iprintf(buffer, "  Unit: %i\n", list->id);
+				if (list->kctl)
+					snd_iprintf(buffer,
+						    "    Control: name=\"%s\", index=%i\n",
+						    list->kctl->id.name,
+						    list->kctl->id.index);
+				if (list->dump)
+					list->dump(buffer, list);
+			}
 		}
 	}
 }
@@ -2295,7 +2284,7 @@ static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
 static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
 				       int attribute, int value, int index)
 {
-	struct usb_mixer_elem_info *info;
+	struct usb_mixer_elem_list *list;
 	__u8 unitid = (index >> 8) & 0xff;
 	__u8 control = (value >> 8) & 0xff;
 	__u8 channel = value & 0xff;
@@ -2307,7 +2296,13 @@ static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
 		return;
 	}
 
-	for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem) {
+	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem) {
+		struct usb_mixer_elem_info *info;
+
+		if (!list->kctl)
+			continue;
+
+		info = (struct usb_mixer_elem_info *)list;
 		if (info->control != control)
 			continue;
 
@@ -2320,7 +2315,7 @@ static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
 				info->cached = 0;
 
 			snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
-					info->elem_id);
+				       &info->head.kctl->id);
 			break;
 
 		case UAC2_CS_RANGE:
@@ -2485,11 +2480,8 @@ _error:
 	return err;
 }
 
-void snd_usb_mixer_disconnect(struct list_head *p)
+void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer)
 {
-	struct usb_mixer_interface *mixer;
-
-	mixer = list_entry(p, struct usb_mixer_interface, list);
 	usb_kill_urb(mixer->urb);
 	usb_kill_urb(mixer->rc_urb);
 }
@@ -2521,8 +2513,9 @@ int snd_usb_mixer_suspend(struct usb_mixer_interface *mixer)
 	return 0;
 }
 
-static int restore_mixer_value(struct usb_mixer_elem_info *cval)
+static int restore_mixer_value(struct usb_mixer_elem_list *list)
 {
+	struct usb_mixer_elem_info *cval = (struct usb_mixer_elem_info *)list;
 	int c, err, idx;
 
 	if (cval->cmask) {
@@ -2531,7 +2524,7 @@ static int restore_mixer_value(struct usb_mixer_elem_info *cval)
 			if (!(cval->cmask & (1 << c)))
 				continue;
 			if (cval->cached & (1 << c)) {
-				err = set_cur_mix_value(cval, c + 1, idx,
+				err = snd_usb_set_cur_mix_value(cval, c + 1, idx,
 							cval->cache_val[idx]);
 				if (err < 0)
 					return err;
@@ -2541,7 +2534,7 @@ static int restore_mixer_value(struct usb_mixer_elem_info *cval)
 	} else {
 		/* master */
 		if (cval->cached) {
-			err = set_cur_mix_value(cval, 0, 0, *cval->cache_val);
+			err = snd_usb_set_cur_mix_value(cval, 0, 0, *cval->cache_val);
 			if (err < 0)
 				return err;
 		}
@@ -2552,19 +2545,19 @@ static int restore_mixer_value(struct usb_mixer_elem_info *cval)
 
 int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume)
 {
-	struct usb_mixer_elem_info *cval;
+	struct usb_mixer_elem_list *list;
 	int id, err;
 
-	/* FIXME: any mixer quirks? */
-
 	if (reset_resume) {
 		/* restore cached mixer values */
 		for (id = 0; id < MAX_ID_ELEMS; id++) {
-			for (cval = mixer->id_elems[id]; cval;
-			     cval = cval->next_id_elem) {
-				err = restore_mixer_value(cval);
-				if (err < 0)
-					return err;
+			for (list = mixer->id_elems[id]; list;
+			     list = list->next_id_elem) {
+				if (list->resume) {
+					err = list->resume(list);
+					if (err < 0)
+						return err;
+				}
 			}
 		}
 	}
@@ -2572,3 +2565,15 @@ int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume)
 	return snd_usb_mixer_activate(mixer);
 }
 #endif
+
+void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list,
+				 struct usb_mixer_interface *mixer,
+				 int unitid)
+{
+	list->mixer = mixer;
+	list->id = unitid;
+	list->dump = snd_usb_mixer_dump_cval;
+#ifdef CONFIG_PM
+	list->resume = restore_mixer_value;
+#endif
+}
diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 73b1f649447..d3268f0ee2b 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -1,6 +1,8 @@
 #ifndef __USBMIXER_H
 #define __USBMIXER_H
 
+#include <sound/info.h>
+
 struct usb_mixer_interface {
 	struct snd_usb_audio *chip;
 	struct usb_host_interface *hostif;
@@ -8,7 +10,7 @@ struct usb_mixer_interface {
 	unsigned int ignore_ctl_error;
 	struct urb *urb;
 	/* array[MAX_ID_ELEMS], indexed by unit id */
-	struct usb_mixer_elem_info **id_elems;
+	struct usb_mixer_elem_list **id_elems;
 
 	/* the usb audio specification version this interface complies to */
 	int protocol;
@@ -20,9 +22,6 @@ struct usb_mixer_interface {
 	struct urb *rc_urb;
 	struct usb_ctrlrequest *rc_setup_packet;
 	u8 rc_buffer[6];
-
-	u8 audigy2nx_leds[3];
-	u8 xonar_u1_status;
 };
 
 #define MAX_CHANNELS	16	/* max logical channels */
@@ -36,11 +35,21 @@ enum {
 	USB_MIXER_U16,
 };
 
-struct usb_mixer_elem_info {
+typedef void (*usb_mixer_elem_dump_func_t)(struct snd_info_buffer *buffer,
+					 struct usb_mixer_elem_list *list);
+typedef int (*usb_mixer_elem_resume_func_t)(struct usb_mixer_elem_list *elem);
+
+struct usb_mixer_elem_list {
 	struct usb_mixer_interface *mixer;
-	struct usb_mixer_elem_info *next_id_elem; /* list of controls with same id */
-	struct snd_ctl_elem_id *elem_id;
+	struct usb_mixer_elem_list *next_id_elem; /* list of controls with same id */
+	struct snd_kcontrol *kctl;
 	unsigned int id;
+	usb_mixer_elem_dump_func_t dump;
+	usb_mixer_elem_resume_func_t resume;
+};
+
+struct usb_mixer_elem_info {
+	struct usb_mixer_elem_list head;
 	unsigned int control;	/* CS or ICN (high byte) */
 	unsigned int cmask; /* channel mask bitmap: 0 = master */
 	unsigned int idx_off; /* Control index offset */
@@ -53,20 +62,25 @@ struct usb_mixer_elem_info {
 	int cached;
 	int cache_val[MAX_CHANNELS];
 	u8 initialized;
+	void *private_data;
 };
 
 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
 			 int ignore_error);
-void snd_usb_mixer_disconnect(struct list_head *p);
+void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer);
 
 void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid);
 
 int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
 				int request, int validx, int value_set);
 
-int snd_usb_mixer_add_control(struct usb_mixer_interface *mixer,
+int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list,
 			      struct snd_kcontrol *kctl);
 
+void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list,
+				 struct usb_mixer_interface *mixer,
+				 int unitid);
+
 int snd_usb_mixer_vol_tlv(struct snd_kcontrol *kcontrol, int op_flag,
 			  unsigned int size, unsigned int __user *_tlv);
 
@@ -75,4 +89,12 @@ int snd_usb_mixer_suspend(struct usb_mixer_interface *mixer);
 int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume);
 #endif
 
+int snd_usb_set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
+                             int index, int value);
+
+int snd_usb_get_cur_mix_value(struct usb_mixer_elem_info *cval,
+                             int channel, int index, int *value);
+
+extern void snd_usb_mixer_elem_free(struct snd_kcontrol *kctl);
+
 #endif /* __USBMIXER_H */
diff --git a/sound/usb/mixer_maps.c b/sound/usb/mixer_maps.c
index d1d72ff5034..1994d41348f 100644
--- a/sound/usb/mixer_maps.c
+++ b/sound/usb/mixer_maps.c
@@ -179,6 +179,11 @@ static struct usbmix_name_map audigy2nx_map[] = {
 	{ 0 } /* terminator */
 };
 
+static struct usbmix_name_map mbox1_map[] = {
+	{ 1, "Clock" },
+	{ 0 } /* terminator */
+};
+
 static struct usbmix_selector_map c400_selectors[] = {
 	{
 		.id = 0x80,
@@ -416,6 +421,10 @@ static struct usbmix_ctl_map usbmix_ctl_maps[] = {
 		.map = aureon_51_2_map,
 	},
 	{
+		.id = USB_ID(0x0dba, 0x1000),
+		.map = mbox1_map,
+	},
+	{
 		.id = USB_ID(0x13e5, 0x0001),
 		.map = scratch_live_map,
 		.ignore_ctl_error = 1,
diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c
index 8c9bf4b7aaf..dc9df007d3e 100644
--- a/sound/usb/mixer_quirks.c
+++ b/sound/usb/mixer_quirks.c
@@ -41,6 +41,7 @@
 #include "usbaudio.h"
 #include "mixer.h"
 #include "mixer_quirks.h"
+#include "mixer_scarlett.h"
 #include "helper.h"
 
 extern struct snd_kcontrol_new *snd_usb_feature_unit_ctl;
@@ -52,13 +53,6 @@ struct std_mono_table {
 	snd_kcontrol_tlv_rw_t *tlv_callback;
 };
 
-/* private_free callback */
-static void usb_mixer_elem_free(struct snd_kcontrol *kctl)
-{
-	kfree(kctl->private_data);
-	kctl->private_data = NULL;
-}
-
 /* This function allows for the creation of standard UAC controls.
  * See the quirks for M-Audio FTUs or Ebox-44.
  * If you don't want to set a TLV callback pass NULL.
@@ -75,7 +69,6 @@ static int snd_create_std_mono_ctl_offset(struct usb_mixer_interface *mixer,
 				const char *name,
 				snd_kcontrol_tlv_rw_t *tlv_callback)
 {
-	int err;
 	struct usb_mixer_elem_info *cval;
 	struct snd_kcontrol *kctl;
 
@@ -83,8 +76,7 @@ static int snd_create_std_mono_ctl_offset(struct usb_mixer_interface *mixer,
 	if (!cval)
 		return -ENOMEM;
 
-	cval->id = unitid;
-	cval->mixer = mixer;
+	snd_usb_mixer_elem_init_std(&cval->head, mixer, unitid);
 	cval->val_type = val_type;
 	cval->channels = 1;
 	cval->control = control;
@@ -108,7 +100,7 @@ static int snd_create_std_mono_ctl_offset(struct usb_mixer_interface *mixer,
 
 	/* Set name */
 	snprintf(kctl->id.name, sizeof(kctl->id.name), name);
-	kctl->private_free = usb_mixer_elem_free;
+	kctl->private_free = snd_usb_mixer_elem_free;
 
 	/* set TLV */
 	if (tlv_callback) {
@@ -118,11 +110,7 @@ static int snd_create_std_mono_ctl_offset(struct usb_mixer_interface *mixer,
 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
 	}
 	/* Add control to mixer */
-	err = snd_usb_mixer_add_control(mixer, kctl);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return snd_usb_mixer_add_control(&cval->head, kctl);
 }
 
 static int snd_create_std_mono_ctl(struct usb_mixer_interface *mixer,
@@ -156,6 +144,32 @@ static int snd_create_std_mono_table(struct usb_mixer_interface *mixer,
 	return 0;
 }
 
+static int add_single_ctl_with_resume(struct usb_mixer_interface *mixer,
+				      int id,
+				      usb_mixer_elem_resume_func_t resume,
+				      const struct snd_kcontrol_new *knew,
+				      struct usb_mixer_elem_list **listp)
+{
+	struct usb_mixer_elem_list *list;
+	struct snd_kcontrol *kctl;
+
+	list = kzalloc(sizeof(*list), GFP_KERNEL);
+	if (!list)
+		return -ENOMEM;
+	if (listp)
+		*listp = list;
+	list->mixer = mixer;
+	list->id = id;
+	list->resume = resume;
+	kctl = snd_ctl_new1(knew, list);
+	if (!kctl) {
+		kfree(list);
+		return -ENOMEM;
+	}
+	kctl->private_free = snd_usb_mixer_elem_free;
+	return snd_usb_mixer_add_control(list, kctl);
+}
+
 /*
  * Sound Blaster remote control configuration
  *
@@ -283,84 +297,90 @@ static int snd_usb_soundblaster_remote_init(struct usb_mixer_interface *mixer)
 
 static int snd_audigy2nx_led_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
-	int index = kcontrol->private_value;
-
-	ucontrol->value.integer.value[0] = mixer->audigy2nx_leds[index];
+	ucontrol->value.integer.value[0] = kcontrol->private_value >> 8;
 	return 0;
 }
 
-static int snd_audigy2nx_led_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
+static int snd_audigy2nx_led_update(struct usb_mixer_interface *mixer,
+				    int value, int index)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
-	int index = kcontrol->private_value;
-	int value = ucontrol->value.integer.value[0];
-	int err, changed;
+	struct snd_usb_audio *chip = mixer->chip;
+	int err;
 
-	if (value > 1)
-		return -EINVAL;
-	changed = value != mixer->audigy2nx_leds[index];
-	down_read(&mixer->chip->shutdown_rwsem);
-	if (mixer->chip->shutdown) {
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown) {
 		err = -ENODEV;
 		goto out;
 	}
-	if (mixer->chip->usb_id == USB_ID(0x041e, 0x3042))
-		err = snd_usb_ctl_msg(mixer->chip->dev,
-			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x24,
+	if (chip->usb_id == USB_ID(0x041e, 0x3042))
+		err = snd_usb_ctl_msg(chip->dev,
+			      usb_sndctrlpipe(chip->dev, 0), 0x24,
 			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
 			      !value, 0, NULL, 0);
 	/* USB X-Fi S51 Pro */
-	if (mixer->chip->usb_id == USB_ID(0x041e, 0x30df))
-		err = snd_usb_ctl_msg(mixer->chip->dev,
-			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x24,
+	if (chip->usb_id == USB_ID(0x041e, 0x30df))
+		err = snd_usb_ctl_msg(chip->dev,
+			      usb_sndctrlpipe(chip->dev, 0), 0x24,
 			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
 			      !value, 0, NULL, 0);
 	else
-		err = snd_usb_ctl_msg(mixer->chip->dev,
-			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x24,
+		err = snd_usb_ctl_msg(chip->dev,
+			      usb_sndctrlpipe(chip->dev, 0), 0x24,
 			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
 			      value, index + 2, NULL, 0);
  out:
-	up_read(&mixer->chip->shutdown_rwsem);
-	if (err < 0)
-		return err;
-	mixer->audigy2nx_leds[index] = value;
-	return changed;
+	up_read(&chip->shutdown_rwsem);
+	return err;
 }
 
-static struct snd_kcontrol_new snd_audigy2nx_controls[] = {
-	{
-		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
-		.name = "CMSS LED Switch",
-		.info = snd_audigy2nx_led_info,
-		.get = snd_audigy2nx_led_get,
-		.put = snd_audigy2nx_led_put,
-		.private_value = 0,
-	},
-	{
-		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
-		.name = "Power LED Switch",
-		.info = snd_audigy2nx_led_info,
-		.get = snd_audigy2nx_led_get,
-		.put = snd_audigy2nx_led_put,
-		.private_value = 1,
-	},
-	{
-		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
-		.name = "Dolby Digital LED Switch",
-		.info = snd_audigy2nx_led_info,
-		.get = snd_audigy2nx_led_get,
-		.put = snd_audigy2nx_led_put,
-		.private_value = 2,
-	},
+static int snd_audigy2nx_led_put(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kcontrol);
+	struct usb_mixer_interface *mixer = list->mixer;
+	int index = kcontrol->private_value & 0xff;
+	int value = ucontrol->value.integer.value[0];
+	int old_value = kcontrol->private_value >> 8;
+	int err;
+
+	if (value > 1)
+		return -EINVAL;
+	if (value == old_value)
+		return 0;
+	kcontrol->private_value = (value << 8) | index;
+	err = snd_audigy2nx_led_update(mixer, value, index);
+	return err < 0 ? err : 1;
+}
+
+static int snd_audigy2nx_led_resume(struct usb_mixer_elem_list *list)
+{
+	int priv_value = list->kctl->private_value;
+
+	return snd_audigy2nx_led_update(list->mixer, priv_value >> 8,
+					priv_value & 0xff);
+}
+
+/* name and private_value are set dynamically */
+static struct snd_kcontrol_new snd_audigy2nx_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.info = snd_audigy2nx_led_info,
+	.get = snd_audigy2nx_led_get,
+	.put = snd_audigy2nx_led_put,
+};
+
+static const char * const snd_audigy2nx_led_names[] = {
+	"CMSS LED Switch",
+	"Power LED Switch",
+	"Dolby Digital LED Switch",
 };
 
 static int snd_audigy2nx_controls_create(struct usb_mixer_interface *mixer)
 {
 	int i, err;
 
-	for (i = 0; i < ARRAY_SIZE(snd_audigy2nx_controls); ++i) {
+	for (i = 0; i < ARRAY_SIZE(snd_audigy2nx_led_names); ++i) {
+		struct snd_kcontrol_new knew;
+
 		/* USB X-Fi S51 doesn't have a CMSS LED */
 		if ((mixer->chip->usb_id == USB_ID(0x041e, 0x3042)) && i == 0)
 			continue;
@@ -373,12 +393,16 @@ static int snd_audigy2nx_controls_create(struct usb_mixer_interface *mixer)
 			 mixer->chip->usb_id == USB_ID(0x041e, 0x30df) ||
 			 mixer->chip->usb_id == USB_ID(0x041e, 0x3048)))
 			break; 
-		err = snd_ctl_add(mixer->chip->card,
-				  snd_ctl_new1(&snd_audigy2nx_controls[i], mixer));
+
+		knew = snd_audigy2nx_control;
+		knew.name = snd_audigy2nx_led_names[i];
+		knew.private_value = (1 << 8) | i; /* LED on as default */
+		err = add_single_ctl_with_resume(mixer, 0,
+						 snd_audigy2nx_led_resume,
+						 &knew, NULL);
 		if (err < 0)
 			return err;
 	}
-	mixer->audigy2nx_leds[1] = 1; /* Power LED is on by default */
 	return 0;
 }
 
@@ -437,19 +461,9 @@ static void snd_audigy2nx_proc_read(struct snd_info_entry *entry,
 static int snd_emu0204_ch_switch_info(struct snd_kcontrol *kcontrol,
 				      struct snd_ctl_elem_info *uinfo)
 {
-	static const char *texts[2] = {"1/2",
-				       "3/4"
-	};
+	static const char * const texts[2] = {"1/2", "3/4"};
 
-	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	uinfo->count = 1;
-	uinfo->value.enumerated.items = 2;
-	if (uinfo->value.enumerated.item > 1)
-		uinfo->value.enumerated.item = 1;
-	strcpy(uinfo->value.enumerated.name,
-		texts[uinfo->value.enumerated.item]);
-
-	return 0;
+	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
 }
 
 static int snd_emu0204_ch_switch_get(struct snd_kcontrol *kcontrol,
@@ -459,100 +473,122 @@ static int snd_emu0204_ch_switch_get(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
-static int snd_emu0204_ch_switch_put(struct snd_kcontrol *kcontrol,
-				     struct snd_ctl_elem_value *ucontrol)
+static int snd_emu0204_ch_switch_update(struct usb_mixer_interface *mixer,
+					int value)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
-	unsigned int value = ucontrol->value.enumerated.item[0];
-	int err, changed;
+	struct snd_usb_audio *chip = mixer->chip;
+	int err;
 	unsigned char buf[2];
 
-	if (value > 1)
-		return -EINVAL;
-
-	buf[0] = 0x01;
-	buf[1] = value ? 0x02 : 0x01;
-
-	changed = value != kcontrol->private_value;
-	down_read(&mixer->chip->shutdown_rwsem);
+	down_read(&chip->shutdown_rwsem);
 	if (mixer->chip->shutdown) {
 		err = -ENODEV;
 		goto out;
 	}
-	err = snd_usb_ctl_msg(mixer->chip->dev,
-		      usb_sndctrlpipe(mixer->chip->dev, 0), UAC_SET_CUR,
+
+	buf[0] = 0x01;
+	buf[1] = value ? 0x02 : 0x01;
+	err = snd_usb_ctl_msg(chip->dev,
+		      usb_sndctrlpipe(chip->dev, 0), UAC_SET_CUR,
 		      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
 		      0x0400, 0x0e00, buf, 2);
  out:
-	up_read(&mixer->chip->shutdown_rwsem);
-	if (err < 0)
-		return err;
+	up_read(&chip->shutdown_rwsem);
+	return err;
+}
+
+static int snd_emu0204_ch_switch_put(struct snd_kcontrol *kcontrol,
+				     struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kcontrol);
+	struct usb_mixer_interface *mixer = list->mixer;
+	unsigned int value = ucontrol->value.enumerated.item[0];
+	int err;
+
+	if (value > 1)
+		return -EINVAL;
+
+	if (value == kcontrol->private_value)
+		return 0;
+
 	kcontrol->private_value = value;
-	return changed;
+	err = snd_emu0204_ch_switch_update(mixer, value);
+	return err < 0 ? err : 1;
 }
 
+static int snd_emu0204_ch_switch_resume(struct usb_mixer_elem_list *list)
+{
+	return snd_emu0204_ch_switch_update(list->mixer,
+					    list->kctl->private_value);
+}
 
-static struct snd_kcontrol_new snd_emu0204_controls[] = {
-	{
-		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
-		.name = "Front Jack Channels",
-		.info = snd_emu0204_ch_switch_info,
-		.get = snd_emu0204_ch_switch_get,
-		.put = snd_emu0204_ch_switch_put,
-		.private_value = 0,
-	},
+static struct snd_kcontrol_new snd_emu0204_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Front Jack Channels",
+	.info = snd_emu0204_ch_switch_info,
+	.get = snd_emu0204_ch_switch_get,
+	.put = snd_emu0204_ch_switch_put,
+	.private_value = 0,
 };
 
 static int snd_emu0204_controls_create(struct usb_mixer_interface *mixer)
 {
-	int i, err;
-
-	for (i = 0; i < ARRAY_SIZE(snd_emu0204_controls); ++i) {
-		err = snd_ctl_add(mixer->chip->card,
-			snd_ctl_new1(&snd_emu0204_controls[i], mixer));
-		if (err < 0)
-			return err;
-	}
-
-	return 0;
+	return add_single_ctl_with_resume(mixer, 0,
+					  snd_emu0204_ch_switch_resume,
+					  &snd_emu0204_control, NULL);
 }
+
 /* ASUS Xonar U1 / U3 controls */
 
 static int snd_xonar_u1_switch_get(struct snd_kcontrol *kcontrol,
 				   struct snd_ctl_elem_value *ucontrol)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
-
-	ucontrol->value.integer.value[0] = !!(mixer->xonar_u1_status & 0x02);
+	ucontrol->value.integer.value[0] = !!(kcontrol->private_value & 0x02);
 	return 0;
 }
 
+static int snd_xonar_u1_switch_update(struct usb_mixer_interface *mixer,
+				      unsigned char status)
+{
+	struct snd_usb_audio *chip = mixer->chip;
+	int err;
+
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown)
+		err = -ENODEV;
+	else
+		err = snd_usb_ctl_msg(chip->dev,
+			      usb_sndctrlpipe(chip->dev, 0), 0x08,
+			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
+			      50, 0, &status, 1);
+	up_read(&chip->shutdown_rwsem);
+	return err;
+}
+
 static int snd_xonar_u1_switch_put(struct snd_kcontrol *kcontrol,
 				   struct snd_ctl_elem_value *ucontrol)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kcontrol);
 	u8 old_status, new_status;
-	int err, changed;
+	int err;
 
-	old_status = mixer->xonar_u1_status;
+	old_status = kcontrol->private_value;
 	if (ucontrol->value.integer.value[0])
 		new_status = old_status | 0x02;
 	else
 		new_status = old_status & ~0x02;
-	changed = new_status != old_status;
-	down_read(&mixer->chip->shutdown_rwsem);
-	if (mixer->chip->shutdown)
-		err = -ENODEV;
-	else
-		err = snd_usb_ctl_msg(mixer->chip->dev,
-			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x08,
-			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
-			      50, 0, &new_status, 1);
-	up_read(&mixer->chip->shutdown_rwsem);
-	if (err < 0)
-		return err;
-	mixer->xonar_u1_status = new_status;
-	return changed;
+	if (new_status == old_status)
+		return 0;
+
+	kcontrol->private_value = new_status;
+	err = snd_xonar_u1_switch_update(list->mixer, new_status);
+	return err < 0 ? err : 1;
+}
+
+static int snd_xonar_u1_switch_resume(struct usb_mixer_elem_list *list)
+{
+	return snd_xonar_u1_switch_update(list->mixer,
+					  list->kctl->private_value);
 }
 
 static struct snd_kcontrol_new snd_xonar_u1_output_switch = {
@@ -561,82 +597,213 @@ static struct snd_kcontrol_new snd_xonar_u1_output_switch = {
 	.info = snd_ctl_boolean_mono_info,
 	.get = snd_xonar_u1_switch_get,
 	.put = snd_xonar_u1_switch_put,
+	.private_value = 0x05,
 };
 
 static int snd_xonar_u1_controls_create(struct usb_mixer_interface *mixer)
 {
+	return add_single_ctl_with_resume(mixer, 0,
+					  snd_xonar_u1_switch_resume,
+					  &snd_xonar_u1_output_switch, NULL);
+}
+
+/* Digidesign Mbox 1 clock source switch (internal/spdif) */
+
+static int snd_mbox1_switch_get(struct snd_kcontrol *kctl,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.enumerated.item[0] = kctl->private_value;
+	return 0;
+}
+
+static int snd_mbox1_switch_update(struct usb_mixer_interface *mixer, int val)
+{
+	struct snd_usb_audio *chip = mixer->chip;
 	int err;
+	unsigned char buff[3];
+
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown) {
+		err = -ENODEV;
+		goto err;
+	}
 
-	err = snd_ctl_add(mixer->chip->card,
-			  snd_ctl_new1(&snd_xonar_u1_output_switch, mixer));
+	/* Prepare for magic command to toggle clock source */
+	err = snd_usb_ctl_msg(chip->dev,
+				usb_rcvctrlpipe(chip->dev, 0), 0x81,
+				USB_DIR_IN |
+				USB_TYPE_CLASS |
+				USB_RECIP_INTERFACE, 0x00, 0x500, buff, 1);
 	if (err < 0)
-		return err;
-	mixer->xonar_u1_status = 0x05;
-	return 0;
+		goto err;
+	err = snd_usb_ctl_msg(chip->dev,
+				usb_rcvctrlpipe(chip->dev, 0), 0x81,
+				USB_DIR_IN |
+				USB_TYPE_CLASS |
+				USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
+	if (err < 0)
+		goto err;
+
+	/* 2 possibilities:	Internal    -> send sample rate
+	 *			S/PDIF sync -> send zeroes
+	 * NB: Sample rate locked to 48kHz on purpose to
+	 *     prevent user from resetting the sample rate
+	 *     while S/PDIF sync is enabled and confusing
+	 *     this configuration.
+	 */
+	if (val == 0) {
+		buff[0] = 0x80;
+		buff[1] = 0xbb;
+		buff[2] = 0x00;
+	} else {
+		buff[0] = buff[1] = buff[2] = 0x00;
+	}
+
+	/* Send the magic command to toggle the clock source */
+	err = snd_usb_ctl_msg(chip->dev,
+				usb_sndctrlpipe(chip->dev, 0), 0x1,
+				USB_TYPE_CLASS |
+				USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
+	if (err < 0)
+		goto err;
+	err = snd_usb_ctl_msg(chip->dev,
+				usb_rcvctrlpipe(chip->dev, 0), 0x81,
+				USB_DIR_IN |
+				USB_TYPE_CLASS |
+				USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
+	if (err < 0)
+		goto err;
+	err = snd_usb_ctl_msg(chip->dev,
+				usb_rcvctrlpipe(chip->dev, 0), 0x81,
+				USB_DIR_IN |
+				USB_TYPE_CLASS |
+				USB_RECIP_ENDPOINT, 0x100, 0x2, buff, 3);
+	if (err < 0)
+		goto err;
+
+err:
+	up_read(&chip->shutdown_rwsem);
+	return err;
+}
+
+static int snd_mbox1_switch_put(struct snd_kcontrol *kctl,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kctl);
+	struct usb_mixer_interface *mixer = list->mixer;
+	int err;
+	bool cur_val, new_val;
+
+	cur_val = kctl->private_value;
+	new_val = ucontrol->value.enumerated.item[0];
+	if (cur_val == new_val)
+		return 0;
+
+	kctl->private_value = new_val;
+	err = snd_mbox1_switch_update(mixer, new_val);
+	return err < 0 ? err : 1;
+}
+
+static int snd_mbox1_switch_info(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_info *uinfo)
+{
+	static const char *const texts[2] = {
+		"Internal",
+		"S/PDIF"
+	};
+
+	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
+}
+
+static int snd_mbox1_switch_resume(struct usb_mixer_elem_list *list)
+{
+	return snd_mbox1_switch_update(list->mixer, list->kctl->private_value);
+}
+
+static struct snd_kcontrol_new snd_mbox1_switch = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Clock Source",
+	.index = 0,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+	.info = snd_mbox1_switch_info,
+	.get = snd_mbox1_switch_get,
+	.put = snd_mbox1_switch_put,
+	.private_value = 0
+};
+
+static int snd_mbox1_create_sync_switch(struct usb_mixer_interface *mixer)
+{
+	return add_single_ctl_with_resume(mixer, 0,
+					  snd_mbox1_switch_resume,
+					  &snd_mbox1_switch, NULL);
 }
 
 /* Native Instruments device quirks */
 
 #define _MAKE_NI_CONTROL(bRequest,wIndex) ((bRequest) << 16 | (wIndex))
 
-static int snd_nativeinstruments_control_get(struct snd_kcontrol *kcontrol,
-					     struct snd_ctl_elem_value *ucontrol)
+static int snd_ni_control_init_val(struct usb_mixer_interface *mixer,
+				   struct snd_kcontrol *kctl)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
 	struct usb_device *dev = mixer->chip->dev;
-	u8 bRequest = (kcontrol->private_value >> 16) & 0xff;
-	u16 wIndex = kcontrol->private_value & 0xffff;
-	u8 tmp;
-	int ret;
-
-	down_read(&mixer->chip->shutdown_rwsem);
-	if (mixer->chip->shutdown)
-		ret = -ENODEV;
-	else
-		ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), bRequest,
-				  USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
-				  0, wIndex,
-				  &tmp, sizeof(tmp));
-	up_read(&mixer->chip->shutdown_rwsem);
+	unsigned int pval = kctl->private_value;
+	u8 value;
+	int err;
 
-	if (ret < 0) {
+	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
+			      (pval >> 16) & 0xff,
+			      USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
+			      0, pval & 0xffff, &value, 1);
+	if (err < 0) {
 		dev_err(&dev->dev,
-			"unable to issue vendor read request (ret = %d)", ret);
-		return ret;
+			"unable to issue vendor read request (ret = %d)", err);
+		return err;
 	}
 
-	ucontrol->value.integer.value[0] = tmp;
+	kctl->private_value |= (value << 24);
+	return 0;
+}
 
+static int snd_nativeinstruments_control_get(struct snd_kcontrol *kcontrol,
+					     struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.integer.value[0] = kcontrol->private_value >> 24;
 	return 0;
 }
 
+static int snd_ni_update_cur_val(struct usb_mixer_elem_list *list)
+{
+	struct snd_usb_audio *chip = list->mixer->chip;
+	unsigned int pval = list->kctl->private_value;
+	int err;
+
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown)
+		err = -ENODEV;
+	else
+		err = usb_control_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
+				      (pval >> 16) & 0xff,
+				      USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+				      pval >> 24, pval & 0xffff, NULL, 0, 1000);
+	up_read(&chip->shutdown_rwsem);
+	return err;
+}
+
 static int snd_nativeinstruments_control_put(struct snd_kcontrol *kcontrol,
 					     struct snd_ctl_elem_value *ucontrol)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
-	struct usb_device *dev = mixer->chip->dev;
-	u8 bRequest = (kcontrol->private_value >> 16) & 0xff;
-	u16 wIndex = kcontrol->private_value & 0xffff;
-	u16 wValue = ucontrol->value.integer.value[0];
-	int ret;
-
-	down_read(&mixer->chip->shutdown_rwsem);
-	if (mixer->chip->shutdown)
-		ret = -ENODEV;
-	else
-		ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), bRequest,
-				  USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
-				  wValue, wIndex,
-				  NULL, 0, 1000);
-	up_read(&mixer->chip->shutdown_rwsem);
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kcontrol);
+	u8 oldval = (kcontrol->private_value >> 24) & 0xff;
+	u8 newval = ucontrol->value.integer.value[0];
+	int err;
 
-	if (ret < 0) {
-		dev_err(&dev->dev,
-			"unable to issue vendor write request (ret = %d)", ret);
-		return ret;
-	}
+	if (oldval == newval)
+		return 0;
 
-	return 0;
+	kcontrol->private_value &= ~(0xff << 24);
+	kcontrol->private_value |= newval;
+	err = snd_ni_update_cur_val(list);
+	return err < 0 ? err : 1;
 }
 
 static struct snd_kcontrol_new snd_nativeinstruments_ta6_mixers[] = {
@@ -707,16 +874,17 @@ static int snd_nativeinstruments_create_mixer(struct usb_mixer_interface *mixer,
 	};
 
 	for (i = 0; i < count; i++) {
-		struct snd_kcontrol *c;
+		struct usb_mixer_elem_list *list;
 
 		template.name = kc[i].name;
 		template.private_value = kc[i].private_value;
 
-		c = snd_ctl_new1(&template, mixer);
-		err = snd_ctl_add(mixer->chip->card, c);
-
+		err = add_single_ctl_with_resume(mixer, 0,
+						 snd_ni_update_cur_val,
+						 &template, &list);
 		if (err < 0)
 			break;
+		snd_ni_control_init_val(mixer, list->kctl);
 	}
 
 	return err;
@@ -724,170 +892,88 @@ static int snd_nativeinstruments_create_mixer(struct usb_mixer_interface *mixer,
 
 /* M-Audio FastTrack Ultra quirks */
 /* FTU Effect switch (also used by C400/C600) */
-struct snd_ftu_eff_switch_priv_val {
-	struct usb_mixer_interface *mixer;
-	int cached_value;
-	int is_cached;
-	int bUnitID;
-	int validx;
-};
-
 static int snd_ftu_eff_switch_info(struct snd_kcontrol *kcontrol,
 					struct snd_ctl_elem_info *uinfo)
 {
-	static const char *texts[8] = {"Room 1",
-				       "Room 2",
-				       "Room 3",
-				       "Hall 1",
-				       "Hall 2",
-				       "Plate",
-				       "Delay",
-				       "Echo"
+	static const char *const texts[8] = {
+		"Room 1", "Room 2", "Room 3", "Hall 1",
+		"Hall 2", "Plate", "Delay", "Echo"
 	};
 
-	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	uinfo->count = 1;
-	uinfo->value.enumerated.items = 8;
-	if (uinfo->value.enumerated.item > 7)
-		uinfo->value.enumerated.item = 7;
-	strcpy(uinfo->value.enumerated.name,
-		texts[uinfo->value.enumerated.item]);
-
-	return 0;
+	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
 }
 
-static int snd_ftu_eff_switch_get(struct snd_kcontrol *kctl,
-					struct snd_ctl_elem_value *ucontrol)
+static int snd_ftu_eff_switch_init(struct usb_mixer_interface *mixer,
+				   struct snd_kcontrol *kctl)
 {
-	struct snd_usb_audio *chip;
-	struct usb_mixer_interface *mixer;
-	struct snd_ftu_eff_switch_priv_val *pval;
+	struct usb_device *dev = mixer->chip->dev;
+	unsigned int pval = kctl->private_value;
 	int err;
 	unsigned char value[2];
-	int id, validx;
-
-	const int val_len = 2;
 
 	value[0] = 0x00;
 	value[1] = 0x00;
 
-	pval = (struct snd_ftu_eff_switch_priv_val *)
-		kctl->private_value;
+	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
+			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
+			      pval & 0xff00,
+			      snd_usb_ctrl_intf(mixer->chip) | ((pval & 0xff) << 8),
+			      value, 2);
+	if (err < 0)
+		return err;
 
-	if (pval->is_cached) {
-		ucontrol->value.enumerated.item[0] = pval->cached_value;
-		return 0;
-	}
+	kctl->private_value |= value[0] << 24;
+	return 0;
+}
 
-	mixer = (struct usb_mixer_interface *) pval->mixer;
-	if (snd_BUG_ON(!mixer))
-		return -EINVAL;
+static int snd_ftu_eff_switch_get(struct snd_kcontrol *kctl,
+					struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.enumerated.item[0] = kctl->private_value >> 24;
+	return 0;
+}
 
-	chip = (struct snd_usb_audio *) mixer->chip;
-	if (snd_BUG_ON(!chip))
-		return -EINVAL;
+static int snd_ftu_eff_switch_update(struct usb_mixer_elem_list *list)
+{
+	struct snd_usb_audio *chip = list->mixer->chip;
+	unsigned int pval = list->kctl->private_value;
+	unsigned char value[2];
+	int err;
 
-	id = pval->bUnitID;
-	validx = pval->validx;
+	value[0] = pval >> 24;
+	value[1] = 0;
 
-	down_read(&mixer->chip->shutdown_rwsem);
-	if (mixer->chip->shutdown)
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown)
 		err = -ENODEV;
 	else
 		err = snd_usb_ctl_msg(chip->dev,
-			usb_rcvctrlpipe(chip->dev, 0), UAC_GET_CUR,
-			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
-			validx << 8, snd_usb_ctrl_intf(chip) | (id << 8),
-			value, val_len);
-	up_read(&mixer->chip->shutdown_rwsem);
-	if (err < 0)
-		return err;
-
-	ucontrol->value.enumerated.item[0] = value[0];
-	pval->cached_value = value[0];
-	pval->is_cached = 1;
-
-	return 0;
+				      usb_sndctrlpipe(chip->dev, 0),
+				      UAC_SET_CUR,
+				      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
+				      pval & 0xff00,
+				      snd_usb_ctrl_intf(chip) | ((pval & 0xff) << 8),
+				      value, 2);
+	up_read(&chip->shutdown_rwsem);
+	return err;
 }
 
 static int snd_ftu_eff_switch_put(struct snd_kcontrol *kctl,
 					struct snd_ctl_elem_value *ucontrol)
 {
-	struct snd_usb_audio *chip;
-	struct snd_ftu_eff_switch_priv_val *pval;
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kctl);
+	unsigned int pval = list->kctl->private_value;
+	int cur_val, err, new_val;
 
-	struct usb_mixer_interface *mixer;
-	int changed, cur_val, err, new_val;
-	unsigned char value[2];
-	int id, validx;
-
-	const int val_len = 2;
-
-	changed = 0;
-
-	pval = (struct snd_ftu_eff_switch_priv_val *)
-		kctl->private_value;
-	cur_val = pval->cached_value;
+	cur_val = pval >> 24;
 	new_val = ucontrol->value.enumerated.item[0];
+	if (cur_val == new_val)
+		return 0;
 
-	mixer = (struct usb_mixer_interface *) pval->mixer;
-	if (snd_BUG_ON(!mixer))
-		return -EINVAL;
-
-	chip = (struct snd_usb_audio *) mixer->chip;
-	if (snd_BUG_ON(!chip))
-		return -EINVAL;
-
-	id = pval->bUnitID;
-	validx = pval->validx;
-
-	if (!pval->is_cached) {
-		/* Read current value */
-		down_read(&mixer->chip->shutdown_rwsem);
-		if (mixer->chip->shutdown)
-			err = -ENODEV;
-		else
-			err = snd_usb_ctl_msg(chip->dev,
-				usb_rcvctrlpipe(chip->dev, 0), UAC_GET_CUR,
-				USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
-				validx << 8, snd_usb_ctrl_intf(chip) | (id << 8),
-				value, val_len);
-		up_read(&mixer->chip->shutdown_rwsem);
-		if (err < 0)
-			return err;
-
-		cur_val = value[0];
-		pval->cached_value = cur_val;
-		pval->is_cached = 1;
-	}
-	/* update value if needed */
-	if (cur_val != new_val) {
-		value[0] = new_val;
-		value[1] = 0;
-		down_read(&mixer->chip->shutdown_rwsem);
-		if (mixer->chip->shutdown)
-			err = -ENODEV;
-		else
-			err = snd_usb_ctl_msg(chip->dev,
-				usb_sndctrlpipe(chip->dev, 0), UAC_SET_CUR,
-				USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
-				validx << 8, snd_usb_ctrl_intf(chip) | (id << 8),
-				value, val_len);
-		up_read(&mixer->chip->shutdown_rwsem);
-		if (err < 0)
-			return err;
-
-		pval->cached_value = new_val;
-		pval->is_cached = 1;
-		changed = 1;
-	}
-
-	return changed;
-}
-
-static void kctl_private_value_free(struct snd_kcontrol *kctl)
-{
-	kfree((void *)kctl->private_value);
+	kctl->private_value &= ~(0xff << 24);
+	kctl->private_value |= new_val << 24;
+	err = snd_ftu_eff_switch_update(list);
+	return err < 0 ? err : 1;
 }
 
 static int snd_ftu_create_effect_switch(struct usb_mixer_interface *mixer,
@@ -902,33 +988,16 @@ static int snd_ftu_create_effect_switch(struct usb_mixer_interface *mixer,
 		.get = snd_ftu_eff_switch_get,
 		.put = snd_ftu_eff_switch_put
 	};
-
+	struct usb_mixer_elem_list *list;
 	int err;
-	struct snd_kcontrol *kctl;
-	struct snd_ftu_eff_switch_priv_val *pval;
-
-	pval = kzalloc(sizeof(*pval), GFP_KERNEL);
-	if (!pval)
-		return -ENOMEM;
-
-	pval->cached_value = 0;
-	pval->is_cached = 0;
-	pval->mixer = mixer;
-	pval->bUnitID = bUnitID;
-	pval->validx = validx;
-
-	template.private_value = (unsigned long) pval;
-	kctl = snd_ctl_new1(&template, mixer->chip);
-	if (!kctl) {
-		kfree(pval);
-		return -ENOMEM;
-	}
 
-	kctl->private_free = kctl_private_value_free;
-	err = snd_ctl_add(mixer->chip->card, kctl);
+	err = add_single_ctl_with_resume(mixer, bUnitID,
+					 snd_ftu_eff_switch_update,
+					 &template, &list);
 	if (err < 0)
 		return err;
-
+	list->kctl->private_value = (validx << 8) | bUnitID;
+	snd_ftu_eff_switch_init(mixer, list->kctl);
 	return 0;
 }
 
@@ -1110,7 +1179,7 @@ void snd_emuusb_set_samplerate(struct snd_usb_audio *chip,
 	int unitid = 12; /* SamleRate ExtensionUnit ID */
 
 	list_for_each_entry(mixer, &chip->mixer_list, list) {
-		cval = mixer->id_elems[unitid];
+		cval = (struct usb_mixer_elem_info *)mixer->id_elems[unitid];
 		if (cval) {
 			snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR,
 						    cval->control << 8,
@@ -1440,7 +1509,8 @@ static int snd_microii_spdif_info(struct snd_kcontrol *kcontrol,
 static int snd_microii_spdif_default_get(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kcontrol);
+	struct snd_usb_audio *chip = list->mixer->chip;
 	int err;
 	struct usb_interface *iface;
 	struct usb_host_interface *alts;
@@ -1448,17 +1518,23 @@ static int snd_microii_spdif_default_get(struct snd_kcontrol *kcontrol,
 	unsigned char data[3];
 	int rate;
 
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown) {
+		err = -ENODEV;
+		goto end;
+	}
+
 	ucontrol->value.iec958.status[0] = kcontrol->private_value & 0xff;
 	ucontrol->value.iec958.status[1] = (kcontrol->private_value >> 8) & 0xff;
 	ucontrol->value.iec958.status[2] = 0x00;
 
 	/* use known values for that card: interface#1 altsetting#1 */
-	iface = usb_ifnum_to_if(mixer->chip->dev, 1);
+	iface = usb_ifnum_to_if(chip->dev, 1);
 	alts = &iface->altsetting[1];
 	ep = get_endpoint(alts, 0)->bEndpointAddress;
 
-	err = snd_usb_ctl_msg(mixer->chip->dev,
-			usb_rcvctrlpipe(mixer->chip->dev, 0),
+	err = snd_usb_ctl_msg(chip->dev,
+			usb_rcvctrlpipe(chip->dev, 0),
 			UAC_GET_CUR,
 			USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 			UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
@@ -1473,22 +1549,27 @@ static int snd_microii_spdif_default_get(struct snd_kcontrol *kcontrol,
 			IEC958_AES3_CON_FS_48000 : IEC958_AES3_CON_FS_44100;
 
 	err = 0;
-end:
+ end:
+	up_read(&chip->shutdown_rwsem);
 	return err;
 }
 
-static int snd_microii_spdif_default_put(struct snd_kcontrol *kcontrol,
-	struct snd_ctl_elem_value *ucontrol)
+static int snd_microii_spdif_default_update(struct usb_mixer_elem_list *list)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
-	int err;
+	struct snd_usb_audio *chip = list->mixer->chip;
+	unsigned int pval = list->kctl->private_value;
 	u8 reg;
-	unsigned long priv_backup = kcontrol->private_value;
+	int err;
 
-	reg = ((ucontrol->value.iec958.status[1] & 0x0f) << 4) |
-			(ucontrol->value.iec958.status[0] & 0x0f);
-	err = snd_usb_ctl_msg(mixer->chip->dev,
-			usb_sndctrlpipe(mixer->chip->dev, 0),
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown) {
+		err = -ENODEV;
+		goto end;
+	}
+
+	reg = ((pval >> 4) & 0xf0) | (pval & 0x0f);
+	err = snd_usb_ctl_msg(chip->dev,
+			usb_sndctrlpipe(chip->dev, 0),
 			UAC_SET_CUR,
 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
 			reg,
@@ -1498,15 +1579,10 @@ static int snd_microii_spdif_default_put(struct snd_kcontrol *kcontrol,
 	if (err < 0)
 		goto end;
 
-	kcontrol->private_value &= 0xfffff0f0;
-	kcontrol->private_value |= (ucontrol->value.iec958.status[1] & 0x0f) << 8;
-	kcontrol->private_value |= (ucontrol->value.iec958.status[0] & 0x0f);
-
-	reg = (ucontrol->value.iec958.status[0] & IEC958_AES0_NONAUDIO) ?
-			0xa0 : 0x20;
-	reg |= (ucontrol->value.iec958.status[1] >> 4) & 0x0f;
-	err = snd_usb_ctl_msg(mixer->chip->dev,
-			usb_sndctrlpipe(mixer->chip->dev, 0),
+	reg = (pval & IEC958_AES0_NONAUDIO) ? 0xa0 : 0x20;
+	reg |= (pval >> 12) & 0x0f;
+	err = snd_usb_ctl_msg(chip->dev,
+			usb_sndctrlpipe(chip->dev, 0),
 			UAC_SET_CUR,
 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
 			reg,
@@ -1516,16 +1592,36 @@ static int snd_microii_spdif_default_put(struct snd_kcontrol *kcontrol,
 	if (err < 0)
 		goto end;
 
-	kcontrol->private_value &= 0xffff0fff;
-	kcontrol->private_value |= (ucontrol->value.iec958.status[1] & 0xf0) << 8;
+ end:
+	up_read(&chip->shutdown_rwsem);
+	return err;
+}
+
+static int snd_microii_spdif_default_put(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kcontrol);
+	unsigned int pval, pval_old;
+	int err;
+
+	pval = pval_old = kcontrol->private_value;
+	pval &= 0xfffff0f0;
+	pval |= (ucontrol->value.iec958.status[1] & 0x0f) << 8;
+	pval |= (ucontrol->value.iec958.status[0] & 0x0f);
+
+	pval &= 0xffff0fff;
+	pval |= (ucontrol->value.iec958.status[1] & 0xf0) << 8;
 
 	/* The frequency bits in AES3 cannot be set via register access. */
 
 	/* Silently ignore any bits from the request that cannot be set. */
 
-	err = (priv_backup != kcontrol->private_value);
-end:
-	return err;
+	if (pval == pval_old)
+		return 0;
+
+	kcontrol->private_value = pval;
+	err = snd_microii_spdif_default_update(list);
+	return err < 0 ? err : 1;
 }
 
 static int snd_microii_spdif_mask_get(struct snd_kcontrol *kcontrol,
@@ -1547,15 +1643,20 @@ static int snd_microii_spdif_switch_get(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
-static int snd_microii_spdif_switch_put(struct snd_kcontrol *kcontrol,
-	struct snd_ctl_elem_value *ucontrol)
+static int snd_microii_spdif_switch_update(struct usb_mixer_elem_list *list)
 {
-	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
+	struct snd_usb_audio *chip = list->mixer->chip;
+	u8 reg = list->kctl->private_value;
 	int err;
-	u8 reg = ucontrol->value.integer.value[0] ? 0x28 : 0x2a;
 
-	err = snd_usb_ctl_msg(mixer->chip->dev,
-			usb_sndctrlpipe(mixer->chip->dev, 0),
+	down_read(&chip->shutdown_rwsem);
+	if (chip->shutdown) {
+		err = -ENODEV;
+		goto end;
+	}
+
+	err = snd_usb_ctl_msg(chip->dev,
+			usb_sndctrlpipe(chip->dev, 0),
 			UAC_SET_CUR,
 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
 			reg,
@@ -1563,15 +1664,27 @@ static int snd_microii_spdif_switch_put(struct snd_kcontrol *kcontrol,
 			NULL,
 			0);
 
-	if (!err) {
-		err = (reg != (kcontrol->private_value & 0x0ff));
-		if (err)
-			kcontrol->private_value = reg;
-	}
-
+ end:
+	up_read(&chip->shutdown_rwsem);
 	return err;
 }
 
+static int snd_microii_spdif_switch_put(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kcontrol);
+	u8 reg;
+	int err;
+
+	reg = ucontrol->value.integer.value[0] ? 0x28 : 0x2a;
+	if (reg != list->kctl->private_value)
+		return 0;
+
+	kcontrol->private_value = reg;
+	err = snd_microii_spdif_switch_update(list);
+	return err < 0 ? err : 1;
+}
+
 static struct snd_kcontrol_new snd_microii_mixer_spdif[] = {
 	{
 		.iface =    SNDRV_CTL_ELEM_IFACE_PCM,
@@ -1601,10 +1714,17 @@ static struct snd_kcontrol_new snd_microii_mixer_spdif[] = {
 static int snd_microii_controls_create(struct usb_mixer_interface *mixer)
 {
 	int err, i;
+	static usb_mixer_elem_resume_func_t resume_funcs[] = {
+		snd_microii_spdif_default_update,
+		NULL,
+		snd_microii_spdif_switch_update
+	};
 
 	for (i = 0; i < ARRAY_SIZE(snd_microii_mixer_spdif); ++i) {
-		err = snd_ctl_add(mixer->chip->card,
-			snd_ctl_new1(&snd_microii_mixer_spdif[i], mixer));
+		err = add_single_ctl_with_resume(mixer, 0,
+						 resume_funcs[i],
+						 &snd_microii_mixer_spdif[i],
+						 NULL);
 		if (err < 0)
 			return err;
 	}
@@ -1661,6 +1781,10 @@ int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer)
 		err = snd_microii_controls_create(mixer);
 		break;
 
+	case USB_ID(0x0dba, 0x1000): /* Digidesign Mbox 1 */
+		err = snd_mbox1_create_sync_switch(mixer);
+		break;
+
 	case USB_ID(0x17cc, 0x1011): /* Traktor Audio 6 */
 		err = snd_nativeinstruments_create_mixer(mixer,
 				snd_nativeinstruments_ta6_mixers,
@@ -1677,6 +1801,14 @@ int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer)
 		/* detection is disabled in mixer_maps.c */
 		err = snd_create_std_mono_table(mixer, ebox44_table);
 		break;
+
+	case USB_ID(0x1235, 0x8012): /* Focusrite Scarlett 6i6 */
+	case USB_ID(0x1235, 0x8002): /* Focusrite Scarlett 8i6 */
+	case USB_ID(0x1235, 0x8004): /* Focusrite Scarlett 18i6 */
+	case USB_ID(0x1235, 0x8014): /* Focusrite Scarlett 18i8 */
+	case USB_ID(0x1235, 0x800c): /* Focusrite Scarlett 18i20 */
+		err = snd_scarlett_controls_create(mixer);
+		break;
 	}
 
 	return err;
diff --git a/sound/usb/mixer_scarlett.c b/sound/usb/mixer_scarlett.c
new file mode 100644
index 00000000000..9109652b88b
--- /dev/null
+++ b/sound/usb/mixer_scarlett.c
@@ -0,0 +1,1004 @@
+/*
+ *   Scarlett Driver for ALSA
+ *
+ *   Copyright (c) 2013 by Tobias Hoffmann
+ *   Copyright (c) 2013 by Robin Gareus <robin at gareus.org>
+ *   Copyright (c) 2002 by Takashi Iwai <tiwai at suse.de>
+ *   Copyright (c) 2014 by Chris J Arges <chris.j.arges at canonical.com>
+ *
+ *   Many codes borrowed from audio.c by
+ *	    Alan Cox (alan at lxorguk.ukuu.org.uk)
+ *	    Thomas Sailer (sailer at ife.ee.ethz.ch)
+ *
+ *   Code cleanup:
+ *   David Henningsson <david.henningsson at canonical.com>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ */
+
+/*
+ * Rewritten and extended to support more models, e.g. Scarlett 18i8.
+ *
+ * Auto-detection via UAC2 is not feasible to properly discover the vast
+ * majority of features. It's related to both Linux/ALSA's UAC2 as well as
+ * Focusrite's implementation of it. Eventually quirks may be sufficient but
+ * right now it's a major headache to work arount these things.
+ *
+ * NB. Neither the OSX nor the win driver provided by Focusrite performs
+ * discovery, they seem to operate the same as this driver.
+ */
+
+/* Mixer Interface for the Focusrite Scarlett 18i6 audio interface.
+ *
+ * The protocol was reverse engineered by looking at communication between
+ * Scarlett MixControl (v 1.2.128.0) and the Focusrite(R) Scarlett 18i6
+ * (firmware v305) using wireshark and usbmon in January 2013.
+ * Extended in July 2013.
+ *
+ * this mixer gives complete access to all features of the device:
+ *  - change Impedance of inputs (Line-in, Mic / Instrument, Hi-Z)
+ *  - select clock source
+ *  - dynamic input to mixer-matrix assignment
+ *  - 18 x 6 mixer-matrix gain stages
+ *  - bus routing & volume control
+ *  - automatic re-initialization on connect if device was power-cycled
+ *
+ * USB URB commands overview (bRequest = 0x01 = UAC2_CS_CUR)
+ * wIndex
+ * 0x01 Analog Input line/instrument impedance switch, wValue=0x0901 +
+ *      channel, data=Line/Inst (2bytes)
+ *      pad (-10dB) switch, wValue=0x0b01 + channel, data=Off/On (2bytes)
+ *      ?? wValue=0x0803/04, ?? (2bytes)
+ * 0x0a Master Volume, wValue=0x0200+bus[0:all + only 1..4?] data(2bytes)
+ *      Bus Mute/Unmute wValue=0x0100+bus[0:all + only 1..4?], data(2bytes)
+ * 0x28 Clock source, wValue=0x0100, data={1:int,2:spdif,3:adat} (1byte)
+ * 0x29 Set Sample-rate, wValue=0x0100, data=sample-rate(4bytes)
+ * 0x32 Mixer mux, wValue=0x0600 + mixer-channel, data=input-to-connect(2bytes)
+ * 0x33 Output mux, wValue=bus, data=input-to-connect(2bytes)
+ * 0x34 Capture mux, wValue=0...18, data=input-to-connect(2bytes)
+ * 0x3c Matrix Mixer gains, wValue=mixer-node  data=gain(2bytes)
+ *      ?? [sometimes](4bytes, e.g 0x000003be 0x000003bf ...03ff)
+ *
+ * USB reads: (i.e. actually issued by original software)
+ * 0x01 wValue=0x0901+channel (1byte!!), wValue=0x0b01+channed (1byte!!)
+ * 0x29 wValue=0x0100 sample-rate(4bytes)
+ *      wValue=0x0200 ?? 1byte (only once)
+ * 0x2a wValue=0x0100 ?? 4bytes, sample-rate2 ??
+ *
+ * USB reads with bRequest = 0x03 = UAC2_CS_MEM
+ * 0x3c wValue=0x0002 1byte: sync status (locked=1)
+ *      wValue=0x0000 18*2byte: peak meter (inputs)
+ *      wValue=0x0001 8(?)*2byte: peak meter (mix)
+ *      wValue=0x0003 6*2byte: peak meter (pcm/daw)
+ *
+ * USB write with bRequest = 0x03
+ * 0x3c Save settings to hardware: wValue=0x005a, data=0xa5
+ *
+ *
+ * <ditaa>
+ *  /--------------\    18chn            6chn    /--------------\
+ *  | Hardware  in +--+-------\        /------+--+ ALSA PCM out |
+ *  \--------------/  |       |        |      |  \--------------/
+ *                    |       |        |      |
+ *                    |       v        v      |
+ *                    |   +---------------+   |
+ *                    |    \ Matrix  Mux /    |
+ *                    |     +-----+-----+     |
+ *                    |           |           |
+ *                    |           | 18chn     |
+ *                    |           v           |
+ *                    |     +-----------+     |
+ *                    |     | Mixer     |     |
+ *                    |     |    Matrix |     |
+ *                    |     |           |     |
+ *                    |     | 18x6 Gain |     |
+ *                    |     |   stages  |     |
+ *                    |     +-----+-----+     |
+ *                    |           |           |
+ *                    |           |           |
+ *                    | 18chn     | 6chn      | 6chn
+ *                    v           v           v
+ *                    =========================
+ *             +---------------+     +--—------------+
+ *              \ Output  Mux /       \ Capture Mux /
+ *               +-----+-----+         +-----+-----+
+ *                     |                     |
+ *                     | 6chn                |
+ *                     v                     |
+ *              +-------------+              |
+ *              | Master Gain |              |
+ *              +------+------+              |
+ *                     |                     |
+ *                     | 6chn                | 18chn
+ *                     | (3 stereo pairs)    |
+ *  /--------------\   |                     |   /--------------\
+ *  | Hardware out |<--/                     \-->| ALSA PCM  in |
+ *  \--------------/                             \--------------/
+ * </ditaa>
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/audio-v2.h>
+
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+
+#include "usbaudio.h"
+#include "mixer.h"
+#include "helper.h"
+#include "power.h"
+
+#include "mixer_scarlett.h"
+
+/* some gui mixers can't handle negative ctl values */
+#define SND_SCARLETT_LEVEL_BIAS 128
+#define SND_SCARLETT_MATRIX_IN_MAX 18
+#define SND_SCARLETT_CONTROLS_MAX 10
+#define SND_SCARLETT_OFFSETS_MAX 5
+
+enum {
+	SCARLETT_OUTPUTS,
+	SCARLETT_SWITCH_IMPEDANCE,
+	SCARLETT_SWITCH_PAD,
+};
+
+enum {
+	SCARLETT_OFFSET_PCM = 0,
+	SCARLETT_OFFSET_ANALOG = 1,
+	SCARLETT_OFFSET_SPDIF = 2,
+	SCARLETT_OFFSET_ADAT = 3,
+	SCARLETT_OFFSET_MIX = 4,
+};
+
+struct scarlett_mixer_elem_enum_info {
+	int start;
+	int len;
+	int offsets[SND_SCARLETT_OFFSETS_MAX];
+	char const * const *names;
+};
+
+struct scarlett_mixer_control {
+	unsigned char num;
+	unsigned char type;
+	const char *name;
+};
+
+struct scarlett_device_info {
+	int matrix_in;
+	int matrix_out;
+	int input_len;
+	int output_len;
+
+	struct scarlett_mixer_elem_enum_info opt_master;
+	struct scarlett_mixer_elem_enum_info opt_matrix;
+
+	/* initial values for matrix mux */
+	int matrix_mux_init[SND_SCARLETT_MATRIX_IN_MAX];
+
+	int num_controls;	/* number of items in controls */
+	const struct scarlett_mixer_control controls[SND_SCARLETT_CONTROLS_MAX];
+};
+
+/********************** Enum Strings *************************/
+
+static const struct scarlett_mixer_elem_enum_info opt_pad = {
+	.start = 0,
+	.len = 2,
+	.offsets = {},
+	.names = (char const * const []){
+		"0dB", "-10dB"
+	}
+};
+
+static const struct scarlett_mixer_elem_enum_info opt_impedance = {
+	.start = 0,
+	.len = 2,
+	.offsets = {},
+	.names = (char const * const []){
+		"Line", "Hi-Z"
+	}
+};
+
+static const struct scarlett_mixer_elem_enum_info opt_clock = {
+	.start = 1,
+	.len = 3,
+	.offsets = {},
+	.names = (char const * const []){
+		"Internal", "SPDIF", "ADAT"
+	}
+};
+
+static const struct scarlett_mixer_elem_enum_info opt_sync = {
+	.start = 0,
+	.len = 2,
+	.offsets = {},
+	.names = (char const * const []){
+		"No Lock", "Locked"
+	}
+};
+
+static int scarlett_ctl_switch_info(struct snd_kcontrol *kctl,
+		struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = elem->channels;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+	return 0;
+}
+
+static int scarlett_ctl_switch_get(struct snd_kcontrol *kctl,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, err, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
+		if (err < 0)
+			return err;
+
+		val = !val; /* invert mute logic for mixer */
+		ucontrol->value.integer.value[i] = val;
+	}
+
+	return 0;
+}
+
+static int scarlett_ctl_switch_put(struct snd_kcontrol *kctl,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, changed = 0;
+	int err, oval, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
+		if (err < 0)
+			return err;
+
+		val = ucontrol->value.integer.value[i];
+		val = !val;
+		if (oval != val) {
+			err = snd_usb_set_cur_mix_value(elem, i, i, val);
+			if (err < 0)
+				return err;
+
+			changed = 1;
+		}
+	}
+
+	return changed;
+}
+
+static int scarlett_ctl_resume(struct usb_mixer_elem_list *list)
+{
+	struct usb_mixer_elem_info *elem =
+		container_of(list, struct usb_mixer_elem_info, head);
+	int i;
+
+	for (i = 0; i < elem->channels; i++)
+		if (elem->cached & (1 << i))
+			snd_usb_set_cur_mix_value(elem, i, i,
+						  elem->cache_val[i]);
+	return 0;
+}
+
+static int scarlett_ctl_info(struct snd_kcontrol *kctl,
+			     struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = elem->channels;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = (int)kctl->private_value +
+		SND_SCARLETT_LEVEL_BIAS;
+	uinfo->value.integer.step = 1;
+	return 0;
+}
+
+static int scarlett_ctl_get(struct snd_kcontrol *kctl,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, err, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
+		if (err < 0)
+			return err;
+
+		val = clamp(val / 256, -128, (int)kctl->private_value) +
+				    SND_SCARLETT_LEVEL_BIAS;
+		ucontrol->value.integer.value[i] = val;
+	}
+
+	return 0;
+}
+
+static int scarlett_ctl_put(struct snd_kcontrol *kctl,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, changed = 0;
+	int err, oval, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
+		if (err < 0)
+			return err;
+
+		val = ucontrol->value.integer.value[i] -
+			SND_SCARLETT_LEVEL_BIAS;
+		val = val * 256;
+		if (oval != val) {
+			err = snd_usb_set_cur_mix_value(elem, i, i, val);
+			if (err < 0)
+				return err;
+
+			changed = 1;
+		}
+	}
+
+	return changed;
+}
+
+static void scarlett_generate_name(int i, char *dst, int offsets[])
+{
+	if (i > offsets[SCARLETT_OFFSET_MIX])
+		sprintf(dst, "Mix %c",
+			'A'+(i - offsets[SCARLETT_OFFSET_MIX] - 1));
+	else if (i > offsets[SCARLETT_OFFSET_ADAT])
+		sprintf(dst, "ADAT %d", i - offsets[SCARLETT_OFFSET_ADAT]);
+	else if (i > offsets[SCARLETT_OFFSET_SPDIF])
+		sprintf(dst, "SPDIF %d", i - offsets[SCARLETT_OFFSET_SPDIF]);
+	else if (i > offsets[SCARLETT_OFFSET_ANALOG])
+		sprintf(dst, "Analog %d", i - offsets[SCARLETT_OFFSET_ANALOG]);
+	else if (i > offsets[SCARLETT_OFFSET_PCM])
+		sprintf(dst, "PCM %d", i - offsets[SCARLETT_OFFSET_PCM]);
+	else
+		sprintf(dst, "Off");
+}
+
+static int scarlett_ctl_enum_dynamic_info(struct snd_kcontrol *kctl,
+					  struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+	unsigned int items = opt->len;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
+	uinfo->count = elem->channels;
+	uinfo->value.enumerated.items = items;
+
+	if (uinfo->value.enumerated.item >= items)
+		uinfo->value.enumerated.item = items - 1;
+
+	/* generate name dynamically based on item number and offset info */
+	scarlett_generate_name(uinfo->value.enumerated.item,
+			       uinfo->value.enumerated.name,
+			       opt->offsets);
+
+	return 0;
+}
+
+static int scarlett_ctl_enum_info(struct snd_kcontrol *kctl,
+				  struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+
+	return snd_ctl_enum_info(uinfo, elem->channels, opt->len,
+				 (const char * const *)opt->names);
+}
+
+static int scarlett_ctl_enum_get(struct snd_kcontrol *kctl,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+	int err, val;
+
+	err = snd_usb_get_cur_mix_value(elem, 0, 0, &val);
+	if (err < 0)
+		return err;
+
+	val = clamp(val - opt->start, 0, opt->len-1);
+
+	ucontrol->value.enumerated.item[0] = val;
+
+	return 0;
+}
+
+static int scarlett_ctl_enum_put(struct snd_kcontrol *kctl,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+	int err, oval, val;
+
+	err = snd_usb_get_cur_mix_value(elem, 0, 0, &oval);
+	if (err < 0)
+		return err;
+
+	val = ucontrol->value.integer.value[0];
+	val = val + opt->start;
+	if (val != oval) {
+		snd_usb_set_cur_mix_value(elem, 0, 0, val);
+		return 1;
+	}
+	return 0;
+}
+
+static int scarlett_ctl_enum_resume(struct usb_mixer_elem_list *list)
+{
+	struct usb_mixer_elem_info *elem =
+		container_of(list, struct usb_mixer_elem_info, head);
+
+	if (elem->cached)
+		snd_usb_set_cur_mix_value(elem, 0, 0, *elem->cache_val);
+	return 0;
+}
+
+static int scarlett_ctl_meter_get(struct snd_kcontrol *kctl,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct snd_usb_audio *chip = elem->head.mixer->chip;
+	unsigned char buf[2 * MAX_CHANNELS] = {0, };
+	int wValue = (elem->control << 8) | elem->idx_off;
+	int idx = snd_usb_ctrl_intf(chip) | (elem->head.id << 8);
+	int err;
+
+	err = snd_usb_ctl_msg(chip->dev,
+				usb_rcvctrlpipe(chip->dev, 0),
+				UAC2_CS_MEM,
+				USB_RECIP_INTERFACE | USB_TYPE_CLASS |
+				USB_DIR_IN, wValue, idx, buf, elem->channels);
+	if (err < 0)
+		return err;
+
+	ucontrol->value.enumerated.item[0] = clamp((int)buf[0], 0, 1);
+	return 0;
+}
+
+static struct snd_kcontrol_new usb_scarlett_ctl_switch = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett_ctl_switch_info,
+	.get =  scarlett_ctl_switch_get,
+	.put =  scarlett_ctl_switch_put,
+};
+
+static const DECLARE_TLV_DB_SCALE(db_scale_scarlett_gain, -12800, 100, 0);
+
+static struct snd_kcontrol_new usb_scarlett_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.name = "",
+	.info = scarlett_ctl_info,
+	.get =  scarlett_ctl_get,
+	.put =  scarlett_ctl_put,
+	.private_value = 6,  /* max value */
+	.tlv = { .p = db_scale_scarlett_gain }
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_master = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.name = "",
+	.info = scarlett_ctl_info,
+	.get =  scarlett_ctl_get,
+	.put =  scarlett_ctl_put,
+	.private_value = 6,  /* max value */
+	.tlv = { .p = db_scale_scarlett_gain }
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_enum = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett_ctl_enum_info,
+	.get =  scarlett_ctl_enum_get,
+	.put =  scarlett_ctl_enum_put,
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_dynamic_enum = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett_ctl_enum_dynamic_info,
+	.get =  scarlett_ctl_enum_get,
+	.put =  scarlett_ctl_enum_put,
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_sync = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+	.name = "",
+	.info = scarlett_ctl_enum_info,
+	.get =  scarlett_ctl_meter_get,
+};
+
+static int add_new_ctl(struct usb_mixer_interface *mixer,
+		       const struct snd_kcontrol_new *ncontrol,
+		       usb_mixer_elem_resume_func_t resume,
+		       int index, int offset, int num,
+		       int val_type, int channels, const char *name,
+		       const struct scarlett_mixer_elem_enum_info *opt,
+		       struct usb_mixer_elem_info **elem_ret
+)
+{
+	struct snd_kcontrol *kctl;
+	struct usb_mixer_elem_info *elem;
+	int err;
+
+	elem = kzalloc(sizeof(*elem), GFP_KERNEL);
+	if (!elem)
+		return -ENOMEM;
+
+	elem->head.mixer = mixer;
+	elem->head.resume = resume;
+	elem->control = offset;
+	elem->idx_off = num;
+	elem->head.id = index;
+	elem->val_type = val_type;
+
+	elem->channels = channels;
+
+	/* add scarlett_mixer_elem_enum_info struct */
+	elem->private_data = (void *)opt;
+
+	kctl = snd_ctl_new1(ncontrol, elem);
+	if (!kctl) {
+		kfree(elem);
+		return -ENOMEM;
+	}
+	kctl->private_free = snd_usb_mixer_elem_free;
+
+	strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
+
+	err = snd_usb_mixer_add_control(&elem->head, kctl);
+	if (err < 0)
+		return err;
+
+	if (elem_ret)
+		*elem_ret = elem;
+
+	return 0;
+}
+
+static int add_output_ctls(struct usb_mixer_interface *mixer,
+			   int index, const char *name,
+			   const struct scarlett_device_info *info)
+{
+	int err;
+	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	struct usb_mixer_elem_info *elem;
+
+	/* Add mute switch */
+	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Switch",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
+			  scarlett_ctl_resume, 0x0a, 0x01,
+			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
+	if (err < 0)
+		return err;
+
+	/* Add volume control and initialize to 0 */
+	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Volume",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
+			  scarlett_ctl_resume, 0x0a, 0x02,
+			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
+	if (err < 0)
+		return err;
+
+	/* Add L channel source playback enumeration */
+	snprintf(mx, sizeof(mx), "Master %dL (%s) Source Playback Enum",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+			  scarlett_ctl_enum_resume, 0x33, 0x00,
+			  2*index, USB_MIXER_S16, 1, mx, &info->opt_master,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	/* Add R channel source playback enumeration */
+	snprintf(mx, sizeof(mx), "Master %dR (%s) Source Playback Enum",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+			  scarlett_ctl_enum_resume, 0x33, 0x00,
+			  2*index+1, USB_MIXER_S16, 1, mx, &info->opt_master,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+/********************** device-specific config *************************/
+
+/*  untested...  */
+static struct scarlett_device_info s6i6_info = {
+	.matrix_in = 18,
+	.matrix_out = 8,
+	.input_len = 6,
+	.output_len = 6,
+
+	.opt_master = {
+		.start = -1,
+		.len = 27,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 19,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.num_controls = 0,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+	},
+
+	.matrix_mux_init = {
+		12, 13, 14, 15,                 /* Analog -> 1..4 */
+		16, 17,                          /* SPDIF -> 5,6 */
+		0, 1, 2, 3, 4, 5, 6, 7,     /* PCM[1..12] -> 7..18 */
+		8, 9, 10, 11
+	}
+};
+
+/*  untested...  */
+static struct scarlett_device_info s8i6_info = {
+	.matrix_in = 18,
+	.matrix_out = 6,
+	.input_len = 8,
+	.output_len = 6,
+
+	.opt_master = {
+		.start = -1,
+		.len = 25,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 19,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.num_controls = 7,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+	},
+
+	.matrix_mux_init = {
+		12, 13, 14, 15,                 /* Analog -> 1..4 */
+		16, 17,                          /* SPDIF -> 5,6 */
+		0, 1, 2, 3, 4, 5, 6, 7,     /* PCM[1..12] -> 7..18 */
+		8, 9, 10, 11
+	}
+};
+
+static struct scarlett_device_info s18i6_info = {
+	.matrix_in = 18,
+	.matrix_out = 6,
+	.input_len = 18,
+	.output_len = 6,
+
+	.opt_master = {
+		.start = -1,
+		.len = 31,
+		.offsets = {0, 6, 14, 16, 24},
+		.names = NULL,
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 25,
+		.offsets = {0, 6, 14, 16, 24},
+		.names = NULL,
+	},
+
+	.num_controls = 5,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+	},
+
+	.matrix_mux_init = {
+		 6,  7,  8,  9, 10, 11, 12, 13, /* Analog -> 1..8 */
+		16, 17, 18, 19, 20, 21,     /* ADAT[1..6] -> 9..14 */
+		14, 15,                          /* SPDIF -> 15,16 */
+		0, 1                          /* PCM[1,2] -> 17,18 */
+	}
+};
+
+static struct scarlett_device_info s18i8_info = {
+	.matrix_in = 18,
+	.matrix_out = 8,
+	.input_len = 18,
+	.output_len = 8,
+
+	.opt_master = {
+		.start = -1,
+		.len = 35,
+		.offsets = {0, 8, 16, 18, 26},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 27,
+		.offsets = {0, 8, 16, 18, 26},
+		.names = NULL
+	},
+
+	.num_controls = 10,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone 1" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Headphone 2" },
+		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+	},
+
+	.matrix_mux_init = {
+		 8,  9, 10, 11, 12, 13, 14, 15, /* Analog -> 1..8 */
+		18, 19, 20, 21, 22, 23,     /* ADAT[1..6] -> 9..14 */
+		16, 17,                          /* SPDIF -> 15,16 */
+		0, 1                          /* PCM[1,2] -> 17,18 */
+	}
+};
+
+static struct scarlett_device_info s18i20_info = {
+	.matrix_in = 18,
+	.matrix_out = 8,
+	.input_len = 18,
+	.output_len = 20,
+
+	.opt_master = {
+		.start = -1,
+		.len = 47,
+		.offsets = {0, 20, 28, 30, 38},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 39,
+		.offsets = {0, 20, 28, 30, 38},
+		.names = NULL
+	},
+
+	.num_controls = 10,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Line 3/4" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Line 5/6" },
+		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "Line 7/8" },
+		{ .num = 4, .type = SCARLETT_OUTPUTS, .name = "Line 9/10" },
+		{ .num = 5, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 6, .type = SCARLETT_OUTPUTS, .name = "ADAT 1/2" },
+		{ .num = 7, .type = SCARLETT_OUTPUTS, .name = "ADAT 3/4" },
+		{ .num = 8, .type = SCARLETT_OUTPUTS, .name = "ADAT 5/6" },
+		{ .num = 9, .type = SCARLETT_OUTPUTS, .name = "ADAT 7/8" },
+		/*{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},*/
+	},
+
+	.matrix_mux_init = {
+		20, 21, 22, 23, 24, 25, 26, 27, /* Analog -> 1..8 */
+		30, 31, 32, 33, 34, 35,     /* ADAT[1..6] -> 9..14 */
+		28, 29,                          /* SPDIF -> 15,16 */
+		0, 1                          /* PCM[1,2] -> 17,18 */
+	}
+};
+
+
+static int scarlett_controls_create_generic(struct usb_mixer_interface *mixer,
+	struct scarlett_device_info *info)
+{
+	int i, err;
+	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	const struct scarlett_mixer_control *ctl;
+	struct usb_mixer_elem_info *elem;
+
+	/* create master switch and playback volume */
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
+			  scarlett_ctl_resume, 0x0a, 0x01, 0,
+			  USB_MIXER_S16, 1, "Master Playback Switch", NULL,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
+			  scarlett_ctl_resume, 0x0a, 0x02, 0,
+			  USB_MIXER_S16, 1, "Master Playback Volume", NULL,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	/* iterate through controls in info struct and create each one */
+	for (i = 0; i < info->num_controls; i++) {
+		ctl = &info->controls[i];
+
+		switch (ctl->type) {
+		case SCARLETT_OUTPUTS:
+			err = add_output_ctls(mixer, ctl->num, ctl->name, info);
+			if (err < 0)
+				return err;
+			break;
+		case SCARLETT_SWITCH_IMPEDANCE:
+			sprintf(mx, "Input %d Impedance Switch", ctl->num);
+			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
+					  scarlett_ctl_enum_resume, 0x01,
+					  0x09, ctl->num, USB_MIXER_S16, 1, mx,
+					  &opt_impedance, &elem);
+			if (err < 0)
+				return err;
+			break;
+		case SCARLETT_SWITCH_PAD:
+			sprintf(mx, "Input %d Pad Switch", ctl->num);
+			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
+					  scarlett_ctl_enum_resume, 0x01,
+					  0x0b, ctl->num, USB_MIXER_S16, 1, mx,
+					  &opt_pad, &elem);
+			if (err < 0)
+				return err;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Create and initialize a mixer for the Focusrite(R) Scarlett
+ */
+int snd_scarlett_controls_create(struct usb_mixer_interface *mixer)
+{
+	int err, i, o;
+	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	struct scarlett_device_info *info;
+	struct usb_mixer_elem_info *elem;
+	static char sample_rate_buffer[4] = { '\x80', '\xbb', '\x00', '\x00' };
+
+	/* only use UAC_VERSION_2 */
+	if (!mixer->protocol)
+		return 0;
+
+	switch (mixer->chip->usb_id) {
+	case USB_ID(0x1235, 0x8012):
+		info = &s6i6_info;
+		break;
+	case USB_ID(0x1235, 0x8002):
+		info = &s8i6_info;
+		break;
+	case USB_ID(0x1235, 0x8004):
+		info = &s18i6_info;
+		break;
+	case USB_ID(0x1235, 0x8014):
+		info = &s18i8_info;
+		break;
+	case USB_ID(0x1235, 0x800c):
+		info = &s18i20_info;
+		break;
+	default: /* device not (yet) supported */
+		return -EINVAL;
+	}
+
+	/* generic function to create controls */
+	err = scarlett_controls_create_generic(mixer, info);
+	if (err < 0)
+		return err;
+
+	/* setup matrix controls */
+	for (i = 0; i < info->matrix_in; i++) {
+		snprintf(mx, sizeof(mx), "Matrix %02d Input Playback Route",
+			 i+1);
+		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+				  scarlett_ctl_enum_resume, 0x32,
+				  0x06, i, USB_MIXER_S16, 1, mx,
+				  &info->opt_matrix, &elem);
+		if (err < 0)
+			return err;
+
+		for (o = 0; o < info->matrix_out; o++) {
+			sprintf(mx, "Matrix %02d Mix %c Playback Volume", i+1,
+				o+'A');
+			err = add_new_ctl(mixer, &usb_scarlett_ctl,
+					  scarlett_ctl_resume, 0x3c, 0x00,
+					  (i << 3) + (o & 0x07), USB_MIXER_S16,
+					  1, mx, NULL, &elem);
+			if (err < 0)
+				return err;
+
+		}
+	}
+
+	for (i = 0; i < info->input_len; i++) {
+		snprintf(mx, sizeof(mx), "Input Source %02d Capture Route",
+			 i+1);
+		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+				  scarlett_ctl_enum_resume, 0x34,
+				  0x00, i, USB_MIXER_S16, 1, mx,
+				  &info->opt_master, &elem);
+		if (err < 0)
+			return err;
+	}
+
+	/* val_len == 1 needed here */
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
+			  scarlett_ctl_enum_resume, 0x28, 0x01, 0,
+			  USB_MIXER_U8, 1, "Sample Clock Source",
+			  &opt_clock, &elem);
+	if (err < 0)
+		return err;
+
+	/* val_len == 1 and UAC2_CS_MEM */
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_sync, NULL, 0x3c, 0x00, 2,
+			  USB_MIXER_U8, 1, "Sample Clock Sync Status",
+			  &opt_sync, &elem);
+	if (err < 0)
+		return err;
+
+	/* initialize sampling rate to 48000 */
+	err = snd_usb_ctl_msg(mixer->chip->dev,
+		usb_sndctrlpipe(mixer->chip->dev, 0), UAC2_CS_CUR,
+		USB_RECIP_INTERFACE | USB_TYPE_CLASS |
+		USB_DIR_OUT, 0x0100, snd_usb_ctrl_intf(mixer->chip) |
+		(0x29 << 8), sample_rate_buffer, 4);
+	if (err < 0)
+		return err;
+
+	return err;
+}
diff --git a/sound/usb/mixer_scarlett.h b/sound/usb/mixer_scarlett.h
new file mode 100644
index 00000000000..19c592ab033
--- /dev/null
+++ b/sound/usb/mixer_scarlett.h
@@ -0,0 +1,6 @@
+#ifndef __USB_MIXER_SCARLETT_H
+#define __USB_MIXER_SCARLETT_H
+
+int snd_scarlett_controls_create(struct usb_mixer_interface *mixer);
+
+#endif /* __USB_MIXER_SCARLETT_H */
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index c62a1659106..0d8aba5fe1a 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -482,6 +482,11 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 	/* set interface */
 	if (subs->interface != fmt->iface ||
 	    subs->altset_idx != fmt->altset_idx) {
+
+		err = snd_usb_select_mode_quirk(subs, fmt);
+		if (err < 0)
+			return -EIO;
+
 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
 		if (err < 0) {
 			dev_err(&dev->dev,
diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index c657752a420..73d2ba47cc3 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -2667,57 +2667,6 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 		.type = QUIRK_MIDI_NOVATION
 	}
 },
-{
-	/*
-	 * Focusrite Scarlett 18i6
-	 *
-	 * Avoid mixer creation, which otherwise fails because some of
-	 * the interface descriptor subtypes for interface 0 are
-	 * unknown.  That should be fixed or worked-around but this at
-	 * least allows the device to be used successfully with a DAW
-	 * and an external mixer.  See comments below about other
-	 * ignored interfaces.
-	 */
-	USB_DEVICE(0x1235, 0x8004),
-	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {
-		.vendor_name = "Focusrite",
-		.product_name = "Scarlett 18i6",
-		.ifnum = QUIRK_ANY_INTERFACE,
-		.type = QUIRK_COMPOSITE,
-		.data = & (const struct snd_usb_audio_quirk[]) {
-			{
-				/* InterfaceSubClass 1 (Control Device) */
-				.ifnum = 0,
-				.type = QUIRK_IGNORE_INTERFACE
-			},
-			{
-				.ifnum = 1,
-				.type = QUIRK_AUDIO_STANDARD_INTERFACE
-			},
-			{
-				.ifnum = 2,
-				.type = QUIRK_AUDIO_STANDARD_INTERFACE
-			},
-			{
-				/* InterfaceSubClass 1 (Control Device) */
-				.ifnum = 3,
-				.type = QUIRK_IGNORE_INTERFACE
-			},
-			{
-				.ifnum = 4,
-				.type = QUIRK_MIDI_STANDARD_INTERFACE
-			},
-			{
-				/* InterfaceSubClass 1 (Device Firmware Update) */
-				.ifnum = 5,
-				.type = QUIRK_IGNORE_INTERFACE
-			},
-			{
-				.ifnum = -1
-			}
-		}
-	}
-},
 
 /* Access Music devices */
 {
@@ -2944,7 +2893,7 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 		.data = (const struct snd_usb_audio_quirk[]){
 			{
 				.ifnum = 0,
-				.type = QUIRK_IGNORE_INTERFACE,
+				.type = QUIRK_AUDIO_STANDARD_MIXER,
 			},
 			{
 				.ifnum = 1,
@@ -2955,16 +2904,40 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 					.iface = 1,
 					.altsetting = 1,
 					.altset_idx = 1,
-					.attributes = UAC_EP_CS_ATTR_SAMPLE_RATE,
+					.attributes = 0x4,
 					.endpoint = 0x02,
-					.ep_attr = 0x01,
-					.rates = SNDRV_PCM_RATE_44100 |
-						 SNDRV_PCM_RATE_48000,
-					.rate_min = 44100,
+					.ep_attr = USB_ENDPOINT_XFER_ISOC |
+						USB_ENDPOINT_SYNC_SYNC,
+					.maxpacksize = 0x130,
+					.rates = SNDRV_PCM_RATE_48000,
+					.rate_min = 48000,
 					.rate_max = 48000,
-					.nr_rates = 2,
+					.nr_rates = 1,
 					.rate_table = (unsigned int[]) {
-						44100, 48000
+						48000
+					}
+				}
+			},
+			{
+				.ifnum = 1,
+				.type = QUIRK_AUDIO_FIXED_ENDPOINT,
+				.data = &(const struct audioformat) {
+					.formats = SNDRV_PCM_FMTBIT_S24_3BE,
+					.channels = 2,
+					.iface = 1,
+					.altsetting = 1,
+					.altset_idx = 1,
+					.attributes = 0x4,
+					.endpoint = 0x81,
+					.ep_attr = USB_ENDPOINT_XFER_ISOC |
+						USB_ENDPOINT_SYNC_ASYNC,
+					.maxpacksize = 0x130,
+					.rates = SNDRV_PCM_RATE_48000,
+					.rate_min = 48000,
+					.rate_max = 48000,
+					.nr_rates = 1,
+					.rate_table = (unsigned int[]) {
+						48000
 					}
 				}
 			},
@@ -2972,7 +2945,6 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 				.ifnum = -1
 			}
 		}
-
 	}
 },
 
@@ -3203,6 +3175,46 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 
 {
 	/*
+	 * ZOOM R16/24 in audio interface mode.
+	 * Mixer descriptors are garbage, further quirks will be needed
+	 * to make any of it functional, thus disabled for now.
+	 * Playback stream appears to start and run fine but no sound
+	 * is produced, so also disabled for now.
+	 */
+	USB_DEVICE(0x1686, 0x00dd),
+	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {
+		.ifnum = QUIRK_ANY_INTERFACE,
+		.type = QUIRK_COMPOSITE,
+		.data = (const struct snd_usb_audio_quirk[]) {
+			{
+				/* Mixer */
+				.ifnum = 0,
+				.type = QUIRK_IGNORE_INTERFACE,
+			},
+			{
+				/* Playback  */
+				.ifnum = 1,
+				.type = QUIRK_IGNORE_INTERFACE,
+			},
+			{
+				/* Capture */
+				.ifnum = 2,
+				.type = QUIRK_AUDIO_STANDARD_INTERFACE,
+			},
+			{
+				/* Midi */
+				.ifnum = 3,
+				.type = QUIRK_MIDI_STANDARD_INTERFACE
+			},
+			{
+				.ifnum = -1
+			},
+		}
+	}
+},
+
+{
+	/*
 	 * Some USB MIDI devices don't have an audio control interface,
 	 * so we have to grab MIDI streaming interfaces here.
 	 */
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 60dfe0d2877..4dbfb3d18ee 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -43,12 +43,13 @@
 static int create_composite_quirk(struct snd_usb_audio *chip,
 				  struct usb_interface *iface,
 				  struct usb_driver *driver,
-				  const struct snd_usb_audio_quirk *quirk)
+				  const struct snd_usb_audio_quirk *quirk_comp)
 {
 	int probed_ifnum = get_iface_desc(iface->altsetting)->bInterfaceNumber;
+	const struct snd_usb_audio_quirk *quirk;
 	int err;
 
-	for (quirk = quirk->data; quirk->ifnum >= 0; ++quirk) {
+	for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) {
 		iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
 		if (!iface)
 			continue;
@@ -58,9 +59,17 @@ static int create_composite_quirk(struct snd_usb_audio *chip,
 		err = snd_usb_create_quirk(chip, iface, driver, quirk);
 		if (err < 0)
 			return err;
-		if (quirk->ifnum != probed_ifnum)
+	}
+
+	for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) {
+		iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
+		if (!iface)
+			continue;
+		if (quirk->ifnum != probed_ifnum &&
+		    !usb_interface_claimed(iface))
 			usb_driver_claim_interface(driver, iface, (void *)-1L);
 	}
+
 	return 0;
 }
 
@@ -1102,6 +1111,44 @@ void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
 	}
 }
 
+
+/* Marantz/Denon USB DACs need a vendor cmd to switch
+ * between PCM and native DSD mode
+ */
+int snd_usb_select_mode_quirk(struct snd_usb_substream *subs,
+			      struct audioformat *fmt)
+{
+	struct usb_device *dev = subs->dev;
+	int err;
+
+	switch (subs->stream->chip->usb_id) {
+	case USB_ID(0x154e, 0x3005): /* Marantz HD-DAC1 */
+	case USB_ID(0x154e, 0x3006): /* Marantz SA-14S1 */
+
+		/* First switch to alt set 0, otherwise the mode switch cmd
+		 * will not be accepted by the DAC
+		 */
+		err = usb_set_interface(dev, fmt->iface, 0);
+		if (err < 0)
+			return err;
+
+		mdelay(20); /* Delay needed after setting the interface */
+
+		switch (fmt->altsetting) {
+		case 2: /* DSD mode requested */
+		case 1: /* PCM mode requested */
+			err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0,
+					      USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+					      fmt->altsetting - 1, 1, NULL, 0);
+			if (err < 0)
+				return err;
+			break;
+		}
+		mdelay(20);
+	}
+	return 0;
+}
+
 void snd_usb_endpoint_start_quirk(struct snd_usb_endpoint *ep)
 {
 	/*
@@ -1160,6 +1207,14 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 			break;
 		}
 	}
+
+	/* Zoom R16/24 needs a tiny delay here, otherwise requests like
+	 * get/set frequency return as failed despite actually succeeding.
+	 */
+	if ((le16_to_cpu(dev->descriptor.idVendor) == 0x1686) &&
+	    (le16_to_cpu(dev->descriptor.idProduct) == 0x00dd) &&
+	    (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS)
+		mdelay(1);
 }
 
 /*
@@ -1204,5 +1259,16 @@ u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
 		break;
 	}
 
+	/* Denon/Marantz devices with USB DAC functionality */
+	switch (chip->usb_id) {
+	case USB_ID(0x154e, 0x3005): /* Marantz HD-DAC1 */
+	case USB_ID(0x154e, 0x3006): /* Marantz SA-14S1 */
+		if (fp->altsetting == 2)
+			return SNDRV_PCM_FMTBIT_DSD_U32_BE;
+		break;
+	default:
+		break;
+	}
+
 	return 0;
 }
diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
index 665e972a1b4..1b862386577 100644
--- a/sound/usb/quirks.h
+++ b/sound/usb/quirks.h
@@ -31,6 +31,9 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 			   __u8 request, __u8 requesttype, __u16 value,
 			   __u16 index, void *data, __u16 size);
 
+int snd_usb_select_mode_quirk(struct snd_usb_substream *subs,
+			      struct audioformat *fmt);
+
 u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
 					struct audioformat *fp,
 					unsigned int sample_bytes);
diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c
index a63330dd140..61d5dc2a342 100644
--- a/sound/usb/usx2y/usbusx2yaudio.c
+++ b/sound/usb/usx2y/usbusx2yaudio.c
@@ -272,13 +272,8 @@ static void usX2Y_clients_stop(struct usX2Ydev *usX2Y)
 	for (s = 0; s < 4; s++) {
 		struct snd_usX2Y_substream *subs = usX2Y->subs[s];
 		if (subs) {
-			if (atomic_read(&subs->state) >= state_PRERUNNING) {
-				unsigned long flags;
-
-				snd_pcm_stream_lock_irqsave(subs->pcm_substream, flags);
-				snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
-				snd_pcm_stream_unlock_irqrestore(subs->pcm_substream, flags);
-			}
+			if (atomic_read(&subs->state) >= state_PRERUNNING)
+				snd_pcm_stop_xrun(subs->pcm_substream);
 			for (u = 0; u < NRURBS; u++) {
 				struct urb *urb = subs->urb[u];
 				if (NULL != urb)