Merge branch 'topic/hda-dmic' into for-next

Pull HD-audio DMIC probe patchset from Pierre-Louis Bossart

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/aoa/codecs/onyx.c b/sound/aoa/codecs/onyx.c
index db917546..9827bee 100644
--- a/sound/aoa/codecs/onyx.c
+++ b/sound/aoa/codecs/onyx.c
@@ -71,8 +71,10 @@ static int onyx_read_register(struct onyx *onyx, u8 reg, u8 *value)
 		return 0;
 	}
 	v = i2c_smbus_read_byte_data(onyx->i2c, reg);
-	if (v < 0)
+	if (v < 0) {
+		*value = 0;
 		return -1;
+	}
 	*value = (u8)v;
 	onyx->cache[ONYX_REG_CONTROL-FIRSTREGISTER] = *value;
 	return 0;
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 860543a..12dd9b3 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -77,7 +77,7 @@ void snd_pcm_group_init(struct snd_pcm_group *group)
 	spin_lock_init(&group->lock);
 	mutex_init(&group->mutex);
 	INIT_LIST_HEAD(&group->substreams);
-	refcount_set(&group->refs, 0);
+	refcount_set(&group->refs, 1);
 }
 
 /* define group lock helpers */
@@ -1096,8 +1096,7 @@ static void snd_pcm_group_unref(struct snd_pcm_group *group,
 
 	if (!group)
 		return;
-	do_free = refcount_dec_and_test(&group->refs) &&
-		list_empty(&group->substreams);
+	do_free = refcount_dec_and_test(&group->refs);
 	snd_pcm_group_unlock(group, substream->pcm->nonatomic);
 	if (do_free)
 		kfree(group);
@@ -2020,6 +2019,7 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
 	snd_pcm_group_lock_irq(target_group, nonatomic);
 	snd_pcm_stream_lock(substream1);
 	snd_pcm_group_assign(substream1, target_group);
+	refcount_inc(&target_group->refs);
 	snd_pcm_stream_unlock(substream1);
 	snd_pcm_group_unlock_irq(target_group, nonatomic);
  _end:
@@ -2056,13 +2056,14 @@ static int snd_pcm_unlink(struct snd_pcm_substream *substream)
 	snd_pcm_group_lock_irq(group, nonatomic);
 
 	relink_to_local(substream);
+	refcount_dec(&group->refs);
 
 	/* detach the last stream, too */
 	if (list_is_singular(&group->substreams)) {
 		relink_to_local(list_first_entry(&group->substreams,
 						 struct snd_pcm_substream,
 						 link_list));
-		do_free = !refcount_read(&group->refs);
+		do_free = refcount_dec_and_test(&group->refs);
 	}
 
 	snd_pcm_group_unlock_irq(group, nonatomic);
diff --git a/sound/firewire/amdtp-am824.c b/sound/firewire/amdtp-am824.c
index fd5d6b8..67d735e 100644
--- a/sound/firewire/amdtp-am824.c
+++ b/sound/firewire/amdtp-am824.c
@@ -146,19 +146,24 @@ void amdtp_am824_set_midi_position(struct amdtp_stream *s,
 }
 EXPORT_SYMBOL_GPL(amdtp_am824_set_midi_position);
 
-static void write_pcm_s32(struct amdtp_stream *s,
-			  struct snd_pcm_substream *pcm,
-			  __be32 *buffer, unsigned int frames)
+static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			  __be32 *buffer, unsigned int frames,
+			  unsigned int pcm_frames)
 {
 	struct amdtp_am824 *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	const u32 *src;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	src = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	for (i = 0; i < frames; ++i) {
 		for (c = 0; c < channels; ++c) {
@@ -172,19 +177,24 @@ static void write_pcm_s32(struct amdtp_stream *s,
 	}
 }
 
-static void read_pcm_s32(struct amdtp_stream *s,
-			 struct snd_pcm_substream *pcm,
-			 __be32 *buffer, unsigned int frames)
+static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			 __be32 *buffer, unsigned int frames,
+			 unsigned int pcm_frames)
 {
 	struct amdtp_am824 *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	u32 *dst;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	dst  = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	for (i = 0; i < frames; ++i) {
 		for (c = 0; c < channels; ++c) {
@@ -284,7 +294,7 @@ static void midi_rate_use_one_byte(struct amdtp_stream *s, unsigned int port)
 }
 
 static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
-				unsigned int frames)
+			unsigned int frames, unsigned int data_block_counter)
 {
 	struct amdtp_am824 *p = s->protocol;
 	unsigned int f, port;
@@ -293,7 +303,7 @@ static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
 	for (f = 0; f < frames; f++) {
 		b = (u8 *)&buffer[p->midi_position];
 
-		port = (s->data_block_counter + f) % 8;
+		port = (data_block_counter + f) % 8;
 		if (f < MAX_MIDI_RX_BLOCKS &&
 		    midi_ratelimit_per_packet(s, port) &&
 		    p->midi[port] != NULL &&
@@ -311,16 +321,20 @@ static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
 	}
 }
 
-static void read_midi_messages(struct amdtp_stream *s,
-			       __be32 *buffer, unsigned int frames)
+static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
+			unsigned int frames, unsigned int data_block_counter)
 {
 	struct amdtp_am824 *p = s->protocol;
-	unsigned int f, port;
 	int len;
 	u8 *b;
+	int f;
 
 	for (f = 0; f < frames; f++) {
-		port = (8 - s->ctx_data.tx.first_dbc + s->data_block_counter + f) % 8;
+		unsigned int port = f;
+
+		if (!(s->flags & CIP_UNALIGHED_DBC))
+			port += data_block_counter;
+		port %= 8;
 		b = (u8 *)&buffer[p->midi_position];
 
 		len = b[0] - 0x80;
@@ -331,44 +345,61 @@ static void read_midi_messages(struct amdtp_stream *s,
 	}
 }
 
-static unsigned int process_rx_data_blocks(struct amdtp_stream *s, __be32 *buffer,
-					   unsigned int data_blocks, unsigned int *syt)
+static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
 	struct amdtp_am824 *p = s->protocol;
-	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
-	unsigned int pcm_frames;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	if (pcm) {
-		write_pcm_s32(s, pcm, buffer, data_blocks);
-		pcm_frames = data_blocks * p->frame_multiplier;
-	} else {
-		write_pcm_silence(s, buffer, data_blocks);
-		pcm_frames = 0;
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
+
+		if (pcm) {
+			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks * p->frame_multiplier;
+		} else {
+			write_pcm_silence(s, buf, data_blocks);
+		}
+
+		if (p->midi_ports) {
+			write_midi_messages(s, buf, data_blocks,
+					    desc->data_block_counter);
+		}
 	}
 
-	if (p->midi_ports)
-		write_midi_messages(s, buffer, data_blocks);
-
 	return pcm_frames;
 }
 
-static unsigned int process_tx_data_blocks(struct amdtp_stream *s, __be32 *buffer,
-					   unsigned int data_blocks, unsigned int *syt)
+static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
 	struct amdtp_am824 *p = s->protocol;
-	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
-	unsigned int pcm_frames;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	if (pcm) {
-		read_pcm_s32(s, pcm, buffer, data_blocks);
-		pcm_frames = data_blocks * p->frame_multiplier;
-	} else {
-		pcm_frames = 0;
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
+
+		if (pcm) {
+			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks * p->frame_multiplier;
+		}
+
+		if (p->midi_ports) {
+			read_midi_messages(s, buf, data_blocks,
+					   desc->data_block_counter);
+		}
 	}
 
-	if (p->midi_ports)
-		read_midi_messages(s, buffer, data_blocks);
-
 	return pcm_frames;
 }
 
@@ -383,15 +414,14 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s, __be32 *buffe
 int amdtp_am824_init(struct amdtp_stream *s, struct fw_unit *unit,
 		     enum amdtp_stream_direction dir, enum cip_flags flags)
 {
-	amdtp_stream_process_data_blocks_t process_data_blocks;
+	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
 
 	if (dir == AMDTP_IN_STREAM)
-		process_data_blocks = process_tx_data_blocks;
+		process_ctx_payloads = process_ir_ctx_payloads;
 	else
-		process_data_blocks = process_rx_data_blocks;
+		process_ctx_payloads = process_it_ctx_payloads;
 
 	return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM,
-				 process_data_blocks,
-				 sizeof(struct amdtp_am824));
+			process_ctx_payloads, sizeof(struct amdtp_am824));
 }
 EXPORT_SYMBOL_GPL(amdtp_am824_init);
diff --git a/sound/firewire/amdtp-stream-trace.h b/sound/firewire/amdtp-stream-trace.h
index 4adbbf7..16c7f66 100644
--- a/sound/firewire/amdtp-stream-trace.h
+++ b/sound/firewire/amdtp-stream-trace.h
@@ -14,8 +14,8 @@
 #include <linux/tracepoint.h>
 
 TRACE_EVENT(amdtp_packet,
-	TP_PROTO(const struct amdtp_stream *s, u32 cycles, const __be32 *cip_header, unsigned int payload_length, unsigned int data_blocks, unsigned int index),
-	TP_ARGS(s, cycles, cip_header, payload_length, data_blocks, index),
+	TP_PROTO(const struct amdtp_stream *s, u32 cycles, const __be32 *cip_header, unsigned int payload_length, unsigned int data_blocks, unsigned int data_block_counter, unsigned int index),
+	TP_ARGS(s, cycles, cip_header, payload_length, data_blocks, data_block_counter, index),
 	TP_STRUCT__entry(
 		__field(unsigned int, second)
 		__field(unsigned int, cycle)
@@ -47,7 +47,7 @@ TRACE_EVENT(amdtp_packet,
 		}
 		__entry->payload_quadlets = payload_length / sizeof(__be32);
 		__entry->data_blocks = data_blocks;
-		__entry->data_block_counter = s->data_block_counter,
+		__entry->data_block_counter = data_block_counter,
 		__entry->packet_index = s->packet_index;
 		__entry->irq = !!in_interrupt();
 		__entry->index = index;
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 4d71d74..369e75e 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -74,16 +74,16 @@ static void pcm_period_tasklet(unsigned long data);
  * @dir: the direction of stream
  * @flags: the packet transmission method to use
  * @fmt: the value of fmt field in CIP header
- * @process_data_blocks: callback handler to process data blocks
+ * @process_ctx_payloads: callback handler to process payloads of isoc context
  * @protocol_size: the size to allocate newly for protocol
  */
 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
 		      enum amdtp_stream_direction dir, enum cip_flags flags,
 		      unsigned int fmt,
-		      amdtp_stream_process_data_blocks_t process_data_blocks,
+		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
 		      unsigned int protocol_size)
 {
-	if (process_data_blocks == NULL)
+	if (process_ctx_payloads == NULL)
 		return -EINVAL;
 
 	s->protocol = kzalloc(protocol_size, GFP_KERNEL);
@@ -102,7 +102,10 @@ int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
 	s->callbacked = false;
 
 	s->fmt = fmt;
-	s->process_data_blocks = process_data_blocks;
+	s->process_ctx_payloads = process_ctx_payloads;
+
+	if (dir == AMDTP_OUT_STREAM)
+		s->ctx_data.rx.syt_override = -1;
 
 	return 0;
 }
@@ -473,12 +476,12 @@ static inline int queue_in_packet(struct amdtp_stream *s,
 }
 
 static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2],
-				unsigned int syt)
+			unsigned int data_block_counter, unsigned int syt)
 {
 	cip_header[0] = cpu_to_be32(READ_ONCE(s->source_node_id_field) |
 				(s->data_block_quadlets << CIP_DBS_SHIFT) |
 				((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) |
-				s->data_block_counter);
+				data_block_counter);
 	cip_header[1] = cpu_to_be32(CIP_EOH |
 			((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) |
 			((s->ctx_data.rx.fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) |
@@ -487,8 +490,9 @@ static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2],
 
 static void build_it_pkt_header(struct amdtp_stream *s, unsigned int cycle,
 				struct fw_iso_packet *params,
-				unsigned int data_blocks, unsigned int syt,
-				unsigned int index)
+				unsigned int data_blocks,
+				unsigned int data_block_counter,
+				unsigned int syt, unsigned int index)
 {
 	unsigned int payload_length;
 	__be32 *cip_header;
@@ -496,14 +500,9 @@ static void build_it_pkt_header(struct amdtp_stream *s, unsigned int cycle,
 	payload_length = data_blocks * sizeof(__be32) * s->data_block_quadlets;
 	params->payload_length = payload_length;
 
-	if (s->flags & CIP_DBC_IS_END_EVENT) {
-		s->data_block_counter =
-				(s->data_block_counter + data_blocks) & 0xff;
-	}
-
 	if (!(s->flags & CIP_NO_HEADER)) {
 		cip_header = (__be32 *)params->header;
-		generate_cip_header(s, cip_header, syt);
+		generate_cip_header(s, cip_header, data_block_counter, syt);
 		params->header_length = 2 * sizeof(__be32);
 		payload_length += params->header_length;
 	} else {
@@ -511,23 +510,19 @@ static void build_it_pkt_header(struct amdtp_stream *s, unsigned int cycle,
 	}
 
 	trace_amdtp_packet(s, cycle, cip_header, payload_length, data_blocks,
-			   index);
-
-	if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
-		s->data_block_counter =
-				(s->data_block_counter + data_blocks) & 0xff;
-	}
+			   data_block_counter, index);
 }
 
 static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
 			    unsigned int payload_length,
-			    unsigned int *data_blocks, unsigned int *dbc,
-			    unsigned int *syt)
+			    unsigned int *data_blocks,
+			    unsigned int *data_block_counter, unsigned int *syt)
 {
 	u32 cip_header[2];
 	unsigned int sph;
 	unsigned int fmt;
 	unsigned int fdf;
+	unsigned int dbc;
 	bool lost;
 
 	cip_header[0] = be32_to_cpu(buf[0]);
@@ -579,17 +574,16 @@ static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
 	}
 
 	/* Check data block counter continuity */
-	*dbc = cip_header[0] & CIP_DBC_MASK;
+	dbc = cip_header[0] & CIP_DBC_MASK;
 	if (*data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
-	    s->data_block_counter != UINT_MAX)
-		*dbc = s->data_block_counter;
+	    *data_block_counter != UINT_MAX)
+		dbc = *data_block_counter;
 
-	if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) &&
-	     *dbc == s->ctx_data.tx.first_dbc) ||
-	    s->data_block_counter == UINT_MAX) {
+	if ((dbc == 0x00 && (s->flags & CIP_SKIP_DBC_ZERO_CHECK)) ||
+	    *data_block_counter == UINT_MAX) {
 		lost = false;
 	} else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
-		lost = *dbc != s->data_block_counter;
+		lost = dbc != *data_block_counter;
 	} else {
 		unsigned int dbc_interval;
 
@@ -598,16 +592,18 @@ static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
 		else
 			dbc_interval = *data_blocks;
 
-		lost = *dbc != ((s->data_block_counter + dbc_interval) & 0xff);
+		lost = dbc != ((*data_block_counter + dbc_interval) & 0xff);
 	}
 
 	if (lost) {
 		dev_err(&s->unit->device,
 			"Detect discontinuity of CIP: %02X %02X\n",
-			s->data_block_counter, *dbc);
+			*data_block_counter, dbc);
 		return -EIO;
 	}
 
+	*data_block_counter = dbc;
+
 	*syt = cip_header[1] & CIP_SYT_MASK;
 
 	return 0;
@@ -616,10 +612,10 @@ static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
 static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
 			       const __be32 *ctx_header,
 			       unsigned int *payload_length,
-			       unsigned int *data_blocks, unsigned int *syt,
-			       unsigned int index)
+			       unsigned int *data_blocks,
+			       unsigned int *data_block_counter,
+			       unsigned int *syt, unsigned int index)
 {
-	unsigned int dbc;
 	const __be32 *cip_header;
 	int err;
 
@@ -635,7 +631,7 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
 	if (!(s->flags & CIP_NO_HEADER)) {
 		cip_header = ctx_header + 2;
 		err = check_cip_header(s, cip_header, *payload_length,
-				       data_blocks, &dbc, syt);
+				       data_blocks, data_block_counter, syt);
 		if (err < 0)
 			return err;
 	} else {
@@ -645,16 +641,12 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
 			       s->data_block_quadlets;
 		*syt = 0;
 
-		if (s->data_block_counter != UINT_MAX)
-			dbc = s->data_block_counter;
-		else
-			dbc = 0;
+		if (*data_block_counter == UINT_MAX)
+			*data_block_counter = 0;
 	}
 
-	s->data_block_counter = dbc;
-
 	trace_amdtp_packet(s, cycle, cip_header, *payload_length, *data_blocks,
-			   index);
+			   *data_block_counter, index);
 
 	return err;
 }
@@ -686,6 +678,80 @@ static inline u32 compute_it_cycle(const __be32 ctx_header_tstamp)
 	return increment_cycle_count(cycle, QUEUE_LENGTH);
 }
 
+static int generate_device_pkt_descs(struct amdtp_stream *s,
+				     struct pkt_desc *descs,
+				     const __be32 *ctx_header,
+				     unsigned int packets)
+{
+	unsigned int dbc = s->data_block_counter;
+	int i;
+	int err;
+
+	for (i = 0; i < packets; ++i) {
+		struct pkt_desc *desc = descs + i;
+		unsigned int index = (s->packet_index + i) % QUEUE_LENGTH;
+		unsigned int cycle;
+		unsigned int payload_length;
+		unsigned int data_blocks;
+		unsigned int syt;
+
+		cycle = compute_cycle_count(ctx_header[1]);
+
+		err = parse_ir_ctx_header(s, cycle, ctx_header, &payload_length,
+					  &data_blocks, &dbc, &syt, i);
+		if (err < 0)
+			return err;
+
+		desc->cycle = cycle;
+		desc->syt = syt;
+		desc->data_blocks = data_blocks;
+		desc->data_block_counter = dbc;
+		desc->ctx_payload = s->buffer.packets[index].buffer;
+
+		if (!(s->flags & CIP_DBC_IS_END_EVENT))
+			dbc = (dbc + desc->data_blocks) & 0xff;
+
+		ctx_header +=
+			s->ctx_data.tx.ctx_header_size / sizeof(*ctx_header);
+	}
+
+	s->data_block_counter = dbc;
+
+	return 0;
+}
+
+static void generate_ideal_pkt_descs(struct amdtp_stream *s,
+				     struct pkt_desc *descs,
+				     const __be32 *ctx_header,
+				     unsigned int packets)
+{
+	unsigned int dbc = s->data_block_counter;
+	int i;
+
+	for (i = 0; i < packets; ++i) {
+		struct pkt_desc *desc = descs + i;
+		unsigned int index = (s->packet_index + i) % QUEUE_LENGTH;
+
+		desc->cycle = compute_cycle_count(*ctx_header);
+		desc->syt = calculate_syt(s, desc->cycle);
+		desc->data_blocks = calculate_data_blocks(s, desc->syt);
+
+		if (s->flags & CIP_DBC_IS_END_EVENT)
+			dbc = (dbc + desc->data_blocks) & 0xff;
+
+		desc->data_block_counter = dbc;
+
+		if (!(s->flags & CIP_DBC_IS_END_EVENT))
+			dbc = (dbc + desc->data_blocks) & 0xff;
+
+		desc->ctx_payload = s->buffer.packets[index].buffer;
+
+		++ctx_header;
+	}
+
+	s->data_block_counter = dbc;
+}
+
 static inline void cancel_stream(struct amdtp_stream *s)
 {
 	s->packet_index = -1;
@@ -694,6 +760,19 @@ static inline void cancel_stream(struct amdtp_stream *s)
 	WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN);
 }
 
+static void process_ctx_payloads(struct amdtp_stream *s,
+				 const struct pkt_desc *descs,
+				 unsigned int packets)
+{
+	struct snd_pcm_substream *pcm;
+	unsigned int pcm_frames;
+
+	pcm = READ_ONCE(s->pcm);
+	pcm_frames = s->process_ctx_payloads(s, descs, packets, pcm);
+	if (pcm)
+		update_pcm_pointers(s, pcm, pcm_frames);
+}
+
 static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
 				size_t header_length, void *header,
 				void *private_data)
@@ -706,38 +785,31 @@ static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
 	if (s->packet_index < 0)
 		return;
 
+	generate_ideal_pkt_descs(s, s->pkt_descs, ctx_header, packets);
+
+	process_ctx_payloads(s, s->pkt_descs, packets);
+
 	for (i = 0; i < packets; ++i) {
-		u32 cycle;
+		const struct pkt_desc *desc = s->pkt_descs + i;
 		unsigned int syt;
-		unsigned int data_blocks;
-		__be32 *buffer;
-		unsigned int pcm_frames;
 		struct {
 			struct fw_iso_packet params;
 			__be32 header[IT_PKT_HEADER_SIZE_CIP / sizeof(__be32)];
 		} template = { {0}, {0} };
-		struct snd_pcm_substream *pcm;
 
-		cycle = compute_it_cycle(*ctx_header);
-		syt = calculate_syt(s, cycle);
-		data_blocks = calculate_data_blocks(s, syt);
-		buffer = s->buffer.packets[s->packet_index].buffer;
-		pcm_frames = s->process_data_blocks(s, buffer, data_blocks,
-						    &syt);
+		if (s->ctx_data.rx.syt_override < 0)
+			syt = desc->syt;
+		else
+			syt = s->ctx_data.rx.syt_override;
 
-		build_it_pkt_header(s, cycle, &template.params, data_blocks,
+		build_it_pkt_header(s, desc->cycle, &template.params,
+				    desc->data_blocks, desc->data_block_counter,
 				    syt, i);
 
 		if (queue_out_packet(s, &template.params) < 0) {
 			cancel_stream(s);
 			return;
 		}
-
-		pcm = READ_ONCE(s->pcm);
-		if (pcm && pcm_frames > 0)
-			update_pcm_pointers(s, pcm, pcm_frames);
-
-		++ctx_header;
 	}
 
 	fw_iso_context_queue_flush(s->context);
@@ -748,8 +820,10 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
 			       void *private_data)
 {
 	struct amdtp_stream *s = private_data;
-	unsigned int i, packets;
+	unsigned int packets;
 	__be32 *ctx_header = header;
+	int i;
+	int err;
 
 	if (s->packet_index < 0)
 		return;
@@ -757,48 +831,23 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
 	// The number of packets in buffer.
 	packets = header_length / s->ctx_data.tx.ctx_header_size;
 
-	for (i = 0; i < packets; i++) {
-		u32 cycle;
-		unsigned int payload_length;
-		unsigned int data_blocks;
-		unsigned int syt;
-		__be32 *buffer;
-		unsigned int pcm_frames = 0;
-		struct fw_iso_packet params = {0};
-		struct snd_pcm_substream *pcm;
-		int err;
-
-		cycle = compute_cycle_count(ctx_header[1]);
-		err = parse_ir_ctx_header(s, cycle, ctx_header, &payload_length,
-					  &data_blocks, &syt, i);
-		if (err < 0 && err != -EAGAIN)
-			break;
-
-		if (err >= 0) {
-			buffer = s->buffer.packets[s->packet_index].buffer;
-			pcm_frames = s->process_data_blocks(s, buffer,
-							    data_blocks, &syt);
-
-			if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
-				s->data_block_counter += data_blocks;
-				s->data_block_counter &= 0xff;
-			}
+	err = generate_device_pkt_descs(s, s->pkt_descs, ctx_header, packets);
+	if (err < 0) {
+		if (err != -EAGAIN) {
+			cancel_stream(s);
+			return;
 		}
-
-		if (queue_in_packet(s, &params) < 0)
-			break;
-
-		pcm = READ_ONCE(s->pcm);
-		if (pcm && pcm_frames > 0)
-			update_pcm_pointers(s, pcm, pcm_frames);
-
-		ctx_header += s->ctx_data.tx.ctx_header_size / sizeof(*ctx_header);
+	} else {
+		process_ctx_payloads(s, s->pkt_descs, packets);
 	}
 
-	/* Queueing error or detecting invalid payload. */
-	if (i < packets) {
-		cancel_stream(s);
-		return;
+	for (i = 0; i < packets; ++i) {
+		struct fw_iso_packet params = {0};
+
+		if (queue_in_packet(s, &params) < 0) {
+			cancel_stream(s);
+			return;
+		}
 	}
 
 	fw_iso_context_queue_flush(s->context);
@@ -932,6 +981,13 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 	else
 		s->tag = TAG_CIP;
 
+	s->pkt_descs = kcalloc(INTERRUPT_INTERVAL, sizeof(*s->pkt_descs),
+			       GFP_KERNEL);
+	if (!s->pkt_descs) {
+		err = -ENOMEM;
+		goto err_context;
+	}
+
 	s->packet_index = 0;
 	do {
 		struct fw_iso_packet params;
@@ -943,7 +999,7 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 			err = queue_out_packet(s, &params);
 		}
 		if (err < 0)
-			goto err_context;
+			goto err_pkt_descs;
 	} while (s->packet_index > 0);
 
 	/* NOTE: TAG1 matches CIP. This just affects in stream. */
@@ -954,12 +1010,13 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 	s->callbacked = false;
 	err = fw_iso_context_start(s->context, -1, 0, tag);
 	if (err < 0)
-		goto err_context;
+		goto err_pkt_descs;
 
 	mutex_unlock(&s->mutex);
 
 	return 0;
-
+err_pkt_descs:
+	kfree(s->pkt_descs);
 err_context:
 	fw_iso_context_destroy(s->context);
 	s->context = ERR_PTR(-1);
@@ -1055,6 +1112,7 @@ void amdtp_stream_stop(struct amdtp_stream *s)
 	fw_iso_context_destroy(s->context);
 	s->context = ERR_PTR(-1);
 	iso_packets_buffer_destroy(&s->buffer, s->unit);
+	kfree(s->pkt_descs);
 
 	s->callbacked = false;
 
diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h
index 3942894..50041fa 100644
--- a/sound/firewire/amdtp-stream.h
+++ b/sound/firewire/amdtp-stream.h
@@ -33,6 +33,8 @@
  * @CIP_HEADER_WITHOUT_EOH: Only for in-stream. CIP Header doesn't include
  *	valid EOH.
  * @CIP_NO_HEADERS: a lack of headers in packets
+ * @CIP_UNALIGHED_DBC: Only for in-stream. The value of dbc is not alighed to
+ *	the value of current SYT_INTERVAL; e.g. initial value is not zero.
  */
 enum cip_flags {
 	CIP_NONBLOCKING		= 0x00,
@@ -45,6 +47,7 @@ enum cip_flags {
 	CIP_JUMBO_PAYLOAD	= 0x40,
 	CIP_HEADER_WITHOUT_EOH	= 0x80,
 	CIP_NO_HEADER		= 0x100,
+	CIP_UNALIGHED_DBC	= 0x200,
 };
 
 /**
@@ -91,12 +94,20 @@ enum amdtp_stream_direction {
 	AMDTP_IN_STREAM
 };
 
+struct pkt_desc {
+	u32 cycle;
+	u32 syt;
+	unsigned int data_blocks;
+	unsigned int data_block_counter;
+	__be32 *ctx_payload;
+};
+
 struct amdtp_stream;
-typedef unsigned int (*amdtp_stream_process_data_blocks_t)(
+typedef unsigned int (*amdtp_stream_process_ctx_payloads_t)(
 						struct amdtp_stream *s,
-						__be32 *buffer,
-						unsigned int data_blocks,
-						unsigned int *syt);
+						const struct pkt_desc *desc,
+						unsigned int packets,
+						struct snd_pcm_substream *pcm);
 struct amdtp_stream {
 	struct fw_unit *unit;
 	enum cip_flags flags;
@@ -107,6 +118,7 @@ struct amdtp_stream {
 	struct fw_iso_context *context;
 	struct iso_packets_buffer buffer;
 	int packet_index;
+	struct pkt_desc *pkt_descs;
 	int tag;
 	union {
 		struct {
@@ -119,8 +131,6 @@ struct amdtp_stream {
 			// Fixed interval of dbc between previos/current
 			// packets.
 			unsigned int dbc_interval;
-			// Indicate the value of dbc field in a first packet.
-			unsigned int first_dbc;
 		} tx;
 		struct {
 			// To calculate CIP data blocks and tstamp.
@@ -131,6 +141,7 @@ struct amdtp_stream {
 
 			// To generate CIP header.
 			unsigned int fdf;
+			int syt_override;
 		} rx;
 	} ctx_data;
 
@@ -158,13 +169,13 @@ struct amdtp_stream {
 
 	/* For backends to process data blocks. */
 	void *protocol;
-	amdtp_stream_process_data_blocks_t process_data_blocks;
+	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
 };
 
 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
 		      enum amdtp_stream_direction dir, enum cip_flags flags,
 		      unsigned int fmt,
-		      amdtp_stream_process_data_blocks_t process_data_blocks,
+		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
 		      unsigned int protocol_size);
 void amdtp_stream_destroy(struct amdtp_stream *s);
 
diff --git a/sound/firewire/digi00x/amdtp-dot.c b/sound/firewire/digi00x/amdtp-dot.c
index 45ff73d..d613642 100644
--- a/sound/firewire/digi00x/amdtp-dot.c
+++ b/sound/firewire/digi00x/amdtp-dot.c
@@ -143,17 +143,23 @@ int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
 }
 
 static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
-			  __be32 *buffer, unsigned int frames)
+			  __be32 *buffer, unsigned int frames,
+			  unsigned int pcm_frames)
 {
 	struct amdtp_dot *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	const u32 *src;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	src = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	buffer++;
 	for (i = 0; i < frames; ++i) {
@@ -169,17 +175,23 @@ static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
 }
 
 static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
-			 __be32 *buffer, unsigned int frames)
+			 __be32 *buffer, unsigned int frames,
+			 unsigned int pcm_frames)
 {
 	struct amdtp_dot *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	u32 *dst;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	dst  = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	buffer++;
 	for (i = 0; i < frames; ++i) {
@@ -234,7 +246,7 @@ static inline void midi_use_bytes(struct amdtp_stream *s,
 }
 
 static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
-				unsigned int data_blocks)
+		unsigned int data_blocks, unsigned int data_block_counter)
 {
 	struct amdtp_dot *p = s->protocol;
 	unsigned int f, port;
@@ -242,7 +254,7 @@ static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
 	u8 *b;
 
 	for (f = 0; f < data_blocks; f++) {
-		port = (s->data_block_counter + f) % 8;
+		port = (data_block_counter + f) % 8;
 		b = (u8 *)&buffer[0];
 
 		len = 0;
@@ -329,66 +341,74 @@ void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port,
 		WRITE_ONCE(p->midi[port], midi);
 }
 
-static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
-					   __be32 *buffer,
-					   unsigned int data_blocks,
-					   unsigned int *syt)
+static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
-	struct snd_pcm_substream *pcm;
-	unsigned int pcm_frames;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	pcm = READ_ONCE(s->pcm);
-	if (pcm) {
-		read_pcm_s32(s, pcm, buffer, data_blocks);
-		pcm_frames = data_blocks;
-	} else {
-		pcm_frames = 0;
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
+
+		if (pcm) {
+			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		}
+
+		read_midi_messages(s, buf, data_blocks);
 	}
 
-	read_midi_messages(s, buffer, data_blocks);
-
 	return pcm_frames;
 }
 
-static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
-					   __be32 *buffer,
-					   unsigned int data_blocks,
-					   unsigned int *syt)
+static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
-	struct snd_pcm_substream *pcm;
-	unsigned int pcm_frames;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	pcm = READ_ONCE(s->pcm);
-	if (pcm) {
-		write_pcm_s32(s, pcm, buffer, data_blocks);
-		pcm_frames = data_blocks;
-	} else {
-		write_pcm_silence(s, buffer, data_blocks);
-		pcm_frames = 0;
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
+
+		if (pcm) {
+			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		} else {
+			write_pcm_silence(s, buf, data_blocks);
+		}
+
+		write_midi_messages(s, buf, data_blocks,
+				    desc->data_block_counter);
 	}
 
-	write_midi_messages(s, buffer, data_blocks);
-
 	return pcm_frames;
 }
 
 int amdtp_dot_init(struct amdtp_stream *s, struct fw_unit *unit,
 		 enum amdtp_stream_direction dir)
 {
-	amdtp_stream_process_data_blocks_t process_data_blocks;
+	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
 	enum cip_flags flags;
 
-	/* Use different mode between incoming/outgoing. */
+	// Use different mode between incoming/outgoing.
 	if (dir == AMDTP_IN_STREAM) {
 		flags = CIP_NONBLOCKING;
-		process_data_blocks = process_tx_data_blocks;
+		process_ctx_payloads = process_ir_ctx_payloads;
 	} else {
 		flags = CIP_BLOCKING;
-		process_data_blocks = process_rx_data_blocks;
+		process_ctx_payloads = process_it_ctx_payloads;
 	}
 
 	return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM,
-				 process_data_blocks, sizeof(struct amdtp_dot));
+				process_ctx_payloads, sizeof(struct amdtp_dot));
 }
 
 void amdtp_dot_reset(struct amdtp_stream *s)
diff --git a/sound/firewire/fireface/amdtp-ff.c b/sound/firewire/fireface/amdtp-ff.c
index 2938489..119c007 100644
--- a/sound/firewire/fireface/amdtp-ff.c
+++ b/sound/firewire/fireface/amdtp-ff.c
@@ -27,19 +27,24 @@ int amdtp_ff_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	return amdtp_stream_set_parameters(s, rate, data_channels);
 }
 
-static void write_pcm_s32(struct amdtp_stream *s,
-			  struct snd_pcm_substream *pcm,
-			  __le32 *buffer, unsigned int frames)
+static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			  __le32 *buffer, unsigned int frames,
+			  unsigned int pcm_frames)
 {
 	struct amdtp_ff *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	const u32 *src;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	src = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	for (i = 0; i < frames; ++i) {
 		for (c = 0; c < channels; ++c) {
@@ -52,19 +57,24 @@ static void write_pcm_s32(struct amdtp_stream *s,
 	}
 }
 
-static void read_pcm_s32(struct amdtp_stream *s,
-			 struct snd_pcm_substream *pcm,
-			 __le32 *buffer, unsigned int frames)
+static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			 __le32 *buffer, unsigned int frames,
+			 unsigned int pcm_frames)
 {
 	struct amdtp_ff *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	u32 *dst;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	dst  = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	for (i = 0; i < frames; ++i) {
 		for (c = 0; c < channels; ++c) {
@@ -102,38 +112,47 @@ int amdtp_ff_add_pcm_hw_constraints(struct amdtp_stream *s,
 	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
 }
 
-static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
-					   __be32 *buffer,
-					   unsigned int data_blocks,
-					   unsigned int *syt)
+static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
+					   const struct pkt_desc *descs,
+					   unsigned int packets,
+					   struct snd_pcm_substream *pcm)
 {
-	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
-	unsigned int pcm_frames;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	if (pcm) {
-		write_pcm_s32(s, pcm, (__le32 *)buffer, data_blocks);
-		pcm_frames = data_blocks;
-	} else {
-		write_pcm_silence(s, (__le32 *)buffer, data_blocks);
-		pcm_frames = 0;
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__le32 *buf = (__le32 *)desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
+
+		if (pcm) {
+			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		} else {
+			write_pcm_silence(s, buf, data_blocks);
+		}
 	}
 
 	return pcm_frames;
 }
 
-static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
-					   __be32 *buffer,
-					   unsigned int data_blocks,
-					   unsigned int *syt)
+static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
-	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
-	unsigned int pcm_frames;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	if (pcm) {
-		read_pcm_s32(s, pcm, (__le32 *)buffer, data_blocks);
-		pcm_frames = data_blocks;
-	} else {
-		pcm_frames = 0;
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__le32 *buf = (__le32 *)desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
+
+		if (pcm) {
+			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		}
 	}
 
 	return pcm_frames;
@@ -142,13 +161,13 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 int amdtp_ff_init(struct amdtp_stream *s, struct fw_unit *unit,
 		  enum amdtp_stream_direction dir)
 {
-	amdtp_stream_process_data_blocks_t process_data_blocks;
+	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
 
 	if (dir == AMDTP_IN_STREAM)
-		process_data_blocks = process_tx_data_blocks;
+		process_ctx_payloads = process_ir_ctx_payloads;
 	else
-		process_data_blocks = process_rx_data_blocks;
+		process_ctx_payloads = process_it_ctx_payloads;
 
 	return amdtp_stream_init(s, unit, dir, CIP_NO_HEADER, 0,
-				 process_data_blocks, sizeof(struct amdtp_ff));
+				 process_ctx_payloads, sizeof(struct amdtp_ff));
 }
diff --git a/sound/firewire/fireworks/fireworks_stream.c b/sound/firewire/fireworks/fireworks_stream.c
index e659a0b..385fc96 100644
--- a/sound/firewire/fireworks/fireworks_stream.c
+++ b/sound/firewire/fireworks/fireworks_stream.c
@@ -146,7 +146,7 @@ int snd_efw_stream_init_duplex(struct snd_efw *efw)
 	    (efw->firmware_version == 0x5070000 ||
 	     efw->firmware_version == 0x5070300 ||
 	     efw->firmware_version == 0x5080000))
-		efw->tx_stream.ctx_data.tx.first_dbc = 0x02;
+		efw->tx_stream.flags |= CIP_UNALIGHED_DBC;
 	/* AudioFire9 always reports wrong dbs. */
 	if (efw->is_af9)
 		efw->tx_stream.flags |= CIP_WRONG_DBS;
diff --git a/sound/firewire/motu/amdtp-motu.c b/sound/firewire/motu/amdtp-motu.c
index 7973ded..0fd36e4 100644
--- a/sound/firewire/motu/amdtp-motu.c
+++ b/sound/firewire/motu/amdtp-motu.c
@@ -117,19 +117,25 @@ int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	return 0;
 }
 
-static void read_pcm_s32(struct amdtp_stream *s,
-			 struct snd_pcm_runtime *runtime,
-			 __be32 *buffer, unsigned int data_blocks)
+static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			 __be32 *buffer, unsigned int data_blocks,
+			 unsigned int pcm_frames)
 {
 	struct amdtp_motu *p = s->protocol;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int channels = p->pcm_chunks;
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	u8 *byte;
 	u32 *dst;
+	int i, c;
 
-	channels = p->pcm_chunks;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	dst = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	for (i = 0; i < data_blocks; ++i) {
 		byte = (u8 *)buffer + p->pcm_byte_offset;
@@ -147,19 +153,25 @@ static void read_pcm_s32(struct amdtp_stream *s,
 	}
 }
 
-static void write_pcm_s32(struct amdtp_stream *s,
-			  struct snd_pcm_runtime *runtime,
-			  __be32 *buffer, unsigned int data_blocks)
+static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			  __be32 *buffer, unsigned int data_blocks,
+			  unsigned int pcm_frames)
 {
 	struct amdtp_motu *p = s->protocol;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int channels = p->pcm_chunks;
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	u8 *byte;
 	const u32 *src;
+	int i, c;
 
-	channels = p->pcm_chunks;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	src = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	for (i = 0; i < data_blocks; ++i) {
 		byte = (u8 *)buffer + p->pcm_byte_offset;
@@ -298,24 +310,52 @@ static void __maybe_unused copy_message(u64 *frames, __be32 *buffer,
 	}
 }
 
-static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
-				__be32 *buffer, unsigned int data_blocks,
-				unsigned int *syt)
+static void probe_tracepoints_events(struct amdtp_stream *s,
+				     const struct pkt_desc *descs,
+				     unsigned int packets)
+{
+	int i;
+
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
+
+		trace_data_block_sph(s, data_blocks, buf);
+		trace_data_block_message(s, data_blocks, buf);
+	}
+}
+
+static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
 	struct amdtp_motu *p = s->protocol;
-	struct snd_pcm_substream *pcm;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	trace_data_block_sph(s, data_blocks, buffer);
-	trace_data_block_message(s, data_blocks, buffer);
+	// For data block processing.
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
 
-	if (p->midi_ports)
-		read_midi_messages(s, buffer, data_blocks);
+		if (pcm) {
+			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		}
 
-	pcm = READ_ONCE(s->pcm);
-	if (data_blocks > 0 && pcm)
-		read_pcm_s32(s, pcm->runtime, buffer, data_blocks);
+		if (p->midi_ports)
+			read_midi_messages(s, buf, data_blocks);
+	}
 
-	return data_blocks;
+	// For tracepoints.
+	if (trace_data_block_sph_enabled() ||
+	    trace_data_block_message_enabled())
+		probe_tracepoints_events(s, descs, packets);
+
+	return pcm_frames;
 }
 
 static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
@@ -360,46 +400,55 @@ static void write_sph(struct amdtp_stream *s, __be32 *buffer,
 	}
 }
 
-static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
-				__be32 *buffer, unsigned int data_blocks,
-				unsigned int *syt)
+static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
-	struct amdtp_motu *p = (struct amdtp_motu *)s->protocol;
-	struct snd_pcm_substream *pcm;
+	struct amdtp_motu *p = s->protocol;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	/* Not used. */
-	*syt = 0xffff;
+	// For data block processing.
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
 
-	/* TODO: how to interact control messages between userspace? */
+		if (pcm) {
+			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		} else {
+			write_pcm_silence(s, buf, data_blocks);
+		}
 
-	if (p->midi_ports)
-		write_midi_messages(s, buffer, data_blocks);
+		if (p->midi_ports)
+			write_midi_messages(s, buf, data_blocks);
 
-	pcm = READ_ONCE(s->pcm);
-	if (pcm)
-		write_pcm_s32(s, pcm->runtime, buffer, data_blocks);
-	else
-		write_pcm_silence(s, buffer, data_blocks);
+		// TODO: how to interact control messages between userspace?
 
-	write_sph(s, buffer, data_blocks);
+		write_sph(s, buf, data_blocks);
+	}
 
-	trace_data_block_sph(s, data_blocks, buffer);
-	trace_data_block_message(s, data_blocks, buffer);
+	// For tracepoints.
+	if (trace_data_block_sph_enabled() ||
+	    trace_data_block_message_enabled())
+		probe_tracepoints_events(s, descs, packets);
 
-	return data_blocks;
+	return pcm_frames;
 }
 
 int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
 		    enum amdtp_stream_direction dir,
 		    const struct snd_motu_protocol *const protocol)
 {
-	amdtp_stream_process_data_blocks_t process_data_blocks;
+	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
 	int fmt = CIP_FMT_MOTU;
 	int flags = CIP_BLOCKING;
 	int err;
 
 	if (dir == AMDTP_IN_STREAM) {
-		process_data_blocks = process_tx_data_blocks;
+		process_ctx_payloads = process_ir_ctx_payloads;
 
 		/*
 		 * Units of version 3 transmits packets with invalid CIP header
@@ -418,17 +467,23 @@ int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
 				 CIP_SKIP_DBC_ZERO_CHECK;
 		}
 	} else {
-		process_data_blocks = process_rx_data_blocks;
+		process_ctx_payloads = process_it_ctx_payloads;
 		flags |= CIP_DBC_IS_END_EVENT;
 	}
 
-	err = amdtp_stream_init(s, unit, dir, flags, fmt, process_data_blocks,
+	err = amdtp_stream_init(s, unit, dir, flags, fmt, process_ctx_payloads,
 				sizeof(struct amdtp_motu));
 	if (err < 0)
 		return err;
 
 	s->sph = 1;
-	s->ctx_data.rx.fdf = MOTU_FDF_AM824;
+
+	if (dir == AMDTP_OUT_STREAM) {
+		// Use fixed value for FDF field.
+		s->ctx_data.rx.fdf = MOTU_FDF_AM824;
+		// Not used.
+		s->ctx_data.rx.syt_override = 0xffff;
+	}
 
 	return 0;
 }
diff --git a/sound/firewire/tascam/amdtp-tascam.c b/sound/firewire/tascam/amdtp-tascam.c
index 95fb10b..e80bb84 100644
--- a/sound/firewire/tascam/amdtp-tascam.c
+++ b/sound/firewire/tascam/amdtp-tascam.c
@@ -32,19 +32,24 @@ int amdtp_tscm_set_parameters(struct amdtp_stream *s, unsigned int rate)
 	return amdtp_stream_set_parameters(s, rate, data_channels);
 }
 
-static void write_pcm_s32(struct amdtp_stream *s,
-			  struct snd_pcm_substream *pcm,
-			  __be32 *buffer, unsigned int frames)
+static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			  __be32 *buffer, unsigned int frames,
+			  unsigned int pcm_frames)
 {
 	struct amdtp_tscm *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	const u32 *src;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	src = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	for (i = 0; i < frames; ++i) {
 		for (c = 0; c < channels; ++c) {
@@ -57,19 +62,24 @@ static void write_pcm_s32(struct amdtp_stream *s,
 	}
 }
 
-static void read_pcm_s32(struct amdtp_stream *s,
-			 struct snd_pcm_substream *pcm,
-			 __be32 *buffer, unsigned int frames)
+static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
+			 __be32 *buffer, unsigned int frames,
+			 unsigned int pcm_frames)
 {
 	struct amdtp_tscm *p = s->protocol;
+	unsigned int channels = p->pcm_channels;
 	struct snd_pcm_runtime *runtime = pcm->runtime;
-	unsigned int channels, remaining_frames, i, c;
+	unsigned int pcm_buffer_pointer;
+	int remaining_frames;
 	u32 *dst;
+	int i, c;
 
-	channels = p->pcm_channels;
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
+
 	dst  = (void *)runtime->dma_area +
-			frames_to_bytes(runtime, s->pcm_buffer_pointer);
-	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+				frames_to_bytes(runtime, pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
 
 	/* The first data channel is for event counter. */
 	buffer += 1;
@@ -165,65 +175,82 @@ static void read_status_messages(struct amdtp_stream *s,
 	}
 }
 
-static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
-					   __be32 *buffer,
-					   unsigned int data_blocks,
-					   unsigned int *syt)
+static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
-	struct snd_pcm_substream *pcm;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	pcm = READ_ONCE(s->pcm);
-	if (data_blocks > 0 && pcm)
-		read_pcm_s32(s, pcm, buffer, data_blocks);
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
 
-	read_status_messages(s, buffer, data_blocks);
+		if (pcm) {
+			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		}
 
-	return data_blocks;
+		read_status_messages(s, buf, data_blocks);
+	}
+
+	return pcm_frames;
 }
 
-static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
-					   __be32 *buffer,
-					   unsigned int data_blocks,
-					   unsigned int *syt)
+static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
+					    const struct pkt_desc *descs,
+					    unsigned int packets,
+					    struct snd_pcm_substream *pcm)
 {
-	struct snd_pcm_substream *pcm;
+	unsigned int pcm_frames = 0;
+	int i;
 
-	/* This field is not used. */
-	*syt = 0x0000;
+	for (i = 0; i < packets; ++i) {
+		const struct pkt_desc *desc = descs + i;
+		__be32 *buf = desc->ctx_payload;
+		unsigned int data_blocks = desc->data_blocks;
 
-	pcm = READ_ONCE(s->pcm);
-	if (pcm)
-		write_pcm_s32(s, pcm, buffer, data_blocks);
-	else
-		write_pcm_silence(s, buffer, data_blocks);
+		if (pcm) {
+			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
+			pcm_frames += data_blocks;
+		} else {
+			write_pcm_silence(s, buf, data_blocks);
+		}
+	}
 
-	return data_blocks;
+	return pcm_frames;
 }
 
 int amdtp_tscm_init(struct amdtp_stream *s, struct fw_unit *unit,
 		    enum amdtp_stream_direction dir, unsigned int pcm_channels)
 {
-	amdtp_stream_process_data_blocks_t process_data_blocks;
+	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
 	struct amdtp_tscm *p;
 	unsigned int fmt;
 	int err;
 
 	if (dir == AMDTP_IN_STREAM) {
 		fmt = AMDTP_FMT_TSCM_TX;
-		process_data_blocks = process_tx_data_blocks;
+		process_ctx_payloads = process_ir_ctx_payloads;
 	} else {
 		fmt = AMDTP_FMT_TSCM_RX;
-		process_data_blocks = process_rx_data_blocks;
+		process_ctx_payloads = process_it_ctx_payloads;
 	}
 
 	err = amdtp_stream_init(s, unit, dir,
-				CIP_NONBLOCKING | CIP_SKIP_DBC_ZERO_CHECK, fmt,
-				process_data_blocks, sizeof(struct amdtp_tscm));
+			CIP_NONBLOCKING | CIP_SKIP_DBC_ZERO_CHECK, fmt,
+			process_ctx_payloads, sizeof(struct amdtp_tscm));
 	if (err < 0)
 		return 0;
 
-	/* Use fixed value for FDF field. */
-	s->ctx_data.rx.fdf = 0x00;
+	if (dir == AMDTP_OUT_STREAM) {
+		// Use fixed value for FDF field.
+		s->ctx_data.rx.fdf = 0x00;
+		// Not used.
+		s->ctx_data.rx.syt_override = 0x0000;
+	}
 
 	/* This protocol uses fixed number of data channels for PCM samples. */
 	p = s->protocol;
diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index 3b01105..196bbc8 100644
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -447,6 +447,8 @@ static void azx_int_disable(struct hdac_bus *bus)
 	list_for_each_entry(azx_dev, &bus->stream_list, list)
 		snd_hdac_stream_updateb(azx_dev, SD_CTL, SD_INT_MASK, 0);
 
+	synchronize_irq(bus->irq);
+
 	/* disable SIE for all streams */
 	snd_hdac_chip_writeb(bus, INTCTL, 0);
 
diff --git a/sound/i2c/other/ak4xxx-adda.c b/sound/i2c/other/ak4xxx-adda.c
index 5f59316..7d15093 100644
--- a/sound/i2c/other/ak4xxx-adda.c
+++ b/sound/i2c/other/ak4xxx-adda.c
@@ -775,11 +775,12 @@ static int build_adc_controls(struct snd_akm4xxx *ak)
 				return err;
 
 			memset(&knew, 0, sizeof(knew));
-			knew.name = ak->adc_info[mixer_ch].selector_name;
-			if (!knew.name) {
+			if (!ak->adc_info ||
+				!ak->adc_info[mixer_ch].selector_name) {
 				knew.name = "Capture Channel";
 				knew.index = mixer_ch + ak->idx_offset * 2;
-			}
+			} else
+				knew.name = ak->adc_info[mixer_ch].selector_name;
 
 			knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 			knew.info = ak4xxx_capture_source_info;
diff --git a/sound/oss/dmasound/dmasound_atari.c b/sound/oss/dmasound/dmasound_atari.c
index 8365368..823ccfa 100644
--- a/sound/oss/dmasound/dmasound_atari.c
+++ b/sound/oss/dmasound/dmasound_atari.c
@@ -1432,25 +1432,25 @@ static int FalconMixerIoctl(u_int cmd, u_long arg)
 {
 	int data;
 	switch (cmd) {
-	    case SOUND_MIXER_READ_RECMASK:
+	case SOUND_MIXER_READ_RECMASK:
 		return IOCTL_OUT(arg, SOUND_MASK_MIC);
-	    case SOUND_MIXER_READ_DEVMASK:
+	case SOUND_MIXER_READ_DEVMASK:
 		return IOCTL_OUT(arg, SOUND_MASK_VOLUME | SOUND_MASK_MIC | SOUND_MASK_SPEAKER);
-	    case SOUND_MIXER_READ_STEREODEVS:
+	case SOUND_MIXER_READ_STEREODEVS:
 		return IOCTL_OUT(arg, SOUND_MASK_VOLUME | SOUND_MASK_MIC);
-	    case SOUND_MIXER_READ_VOLUME:
+	case SOUND_MIXER_READ_VOLUME:
 		return IOCTL_OUT(arg,
 			VOLUME_ATT_TO_VOXWARE(dmasound.volume_left) |
 			VOLUME_ATT_TO_VOXWARE(dmasound.volume_right) << 8);
-	    case SOUND_MIXER_READ_CAPS:
+	case SOUND_MIXER_READ_CAPS:
 		return IOCTL_OUT(arg, SOUND_CAP_EXCL_INPUT);
-	    case SOUND_MIXER_WRITE_MIC:
+	case SOUND_MIXER_WRITE_MIC:
 		IOCTL_IN(arg, data);
 		tt_dmasnd.input_gain =
 			RECLEVEL_VOXWARE_TO_GAIN(data & 0xff) << 4 |
 			RECLEVEL_VOXWARE_TO_GAIN(data >> 8 & 0xff);
-		/* fall thru, return set value */
-	    case SOUND_MIXER_READ_MIC:
+		/* fall through - return set value */
+	case SOUND_MIXER_READ_MIC:
 		return IOCTL_OUT(arg,
 			RECLEVEL_GAIN_TO_VOXWARE(tt_dmasnd.input_gain >> 4 & 0xf) |
 			RECLEVEL_GAIN_TO_VOXWARE(tt_dmasnd.input_gain & 0xf) << 8);
diff --git a/sound/pci/echoaudio/echoaudio.c b/sound/pci/echoaudio/echoaudio.c
index b612a53..ca91257 100644
--- a/sound/pci/echoaudio/echoaudio.c
+++ b/sound/pci/echoaudio/echoaudio.c
@@ -2189,11 +2189,10 @@ static int snd_echo_resume(struct device *dev)
 	u32 pipe_alloc_mask;
 	int err;
 
-	commpage_bak = kmalloc(sizeof(*commpage), GFP_KERNEL);
+	commpage = chip->comm_page;
+	commpage_bak = kmemdup(commpage, sizeof(*commpage), GFP_KERNEL);
 	if (commpage_bak == NULL)
 		return -ENOMEM;
-	commpage = chip->comm_page;
-	memcpy(commpage_bak, commpage, sizeof(*commpage));
 
 	err = init_hw(chip, chip->pci->device, chip->pci->subsystem_device);
 	if (err < 0) {
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index e30e86c..51f10ed 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -2942,7 +2942,7 @@ static int hda_codec_runtime_resume(struct device *dev)
 static int hda_codec_force_resume(struct device *dev)
 {
 	struct hda_codec *codec = dev_to_hda_codec(dev);
-	bool forced_resume = !codec->relaxed_resume;
+	bool forced_resume = !codec->relaxed_resume && codec->jacktbl.used;
 	int ret;
 
 	/* The get/put pair below enforces the runtime resume even if the
diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c
index c8d1b43..4b4cb0fd 100644
--- a/sound/pci/hda/hda_controller.c
+++ b/sound/pci/hda/hda_controller.c
@@ -864,10 +864,13 @@ static int azx_rirb_get_response(struct hdac_bus *bus, unsigned int addr,
 	 */
 	if (hbus->allow_bus_reset && !hbus->response_reset && !hbus->in_reset) {
 		hbus->response_reset = 1;
+		dev_err(chip->card->dev,
+			"No response from codec, resetting bus: last cmd=0x%08x\n",
+			bus->last_cmd[addr]);
 		return -EAGAIN; /* give a chance to retry */
 	}
 
-	dev_err(chip->card->dev,
+	dev_WARN(chip->card->dev,
 		"azx_get_response timeout, switching to single_cmd mode: last cmd=0x%08x\n",
 		bus->last_cmd[addr]);
 	chip->single_cmd = 1;
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index ae9c132..635d971 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1305,9 +1305,9 @@ static int azx_free(struct azx *chip)
 	}
 
 	if (bus->chip_init) {
+		azx_stop_chip(chip);
 		azx_clear_irq_pending(chip);
 		azx_stop_all_streams(chip);
-		azx_stop_chip(chip);
 	}
 
 	if (bus->irq >= 0)
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index bea7b09..2096993 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -18,6 +18,7 @@
 
 #include <linux/init.h>
 #include <linux/delay.h>
+#include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
@@ -119,6 +120,7 @@ struct hdmi_pcm {
 };
 
 struct hdmi_spec {
+	struct hda_codec *codec;
 	int num_cvts;
 	struct snd_array cvts; /* struct hdmi_spec_per_cvt */
 	hda_nid_t cvt_nids[4]; /* only for haswell fix */
@@ -163,9 +165,11 @@ struct hdmi_spec {
 	struct hda_multi_out multiout;
 	struct hda_pcm_stream pcm_playback;
 
-	/* i915/powerwell (Haswell+/Valleyview+) specific */
-	bool use_acomp_notifier; /* use i915 eld_notify callback for hotplug */
+	bool use_jack_detect; /* jack detection enabled */
+	bool use_acomp_notifier; /* use eld_notify callback for hotplug */
+	bool acomp_registered; /* audio component registered in this driver */
 	struct drm_audio_component_audio_ops drm_audio_ops;
+	int (*port2pin)(struct hda_codec *, int); /* reverse port/pin mapping */
 
 	struct hdac_chmap chmap;
 	hda_nid_t vendor_nid;
@@ -765,6 +769,10 @@ static void check_presence_and_report(struct hda_codec *codec, hda_nid_t nid,
 static void jack_callback(struct hda_codec *codec,
 			  struct hda_jack_callback *jack)
 {
+	/* stop polling when notification is enabled */
+	if (codec_has_acomp(codec))
+		return;
+
 	/* hda_jack don't support DP MST */
 	check_presence_and_report(codec, jack->nid, 0);
 }
@@ -823,6 +831,9 @@ static void hdmi_unsol_event(struct hda_codec *codec, unsigned int res)
 	int tag = res >> AC_UNSOL_RES_TAG_SHIFT;
 	int subtag = (res & AC_UNSOL_RES_SUBTAG) >> AC_UNSOL_RES_SUBTAG_SHIFT;
 
+	if (codec_has_acomp(codec))
+		return;
+
 	if (!snd_hda_jack_tbl_get_from_tag(codec, tag)) {
 		codec_dbg(codec, "Unexpected HDMI event tag 0x%x\n", tag);
 		return;
@@ -1421,7 +1432,7 @@ static void hdmi_pcm_reset_pin(struct hdmi_spec *spec,
 /* update per_pin ELD from the given new ELD;
  * setup info frame and notification accordingly
  */
-static void update_eld(struct hda_codec *codec,
+static bool update_eld(struct hda_codec *codec,
 		       struct hdmi_spec_per_pin *per_pin,
 		       struct hdmi_eld *eld)
 {
@@ -1452,18 +1463,22 @@ static void update_eld(struct hda_codec *codec,
 		snd_hdmi_show_eld(codec, &eld->info);
 
 	eld_changed = (pin_eld->eld_valid != eld->eld_valid);
-	if (eld->eld_valid && pin_eld->eld_valid)
+	eld_changed |= (pin_eld->monitor_present != eld->monitor_present);
+	if (!eld_changed && eld->eld_valid && pin_eld->eld_valid)
 		if (pin_eld->eld_size != eld->eld_size ||
 		    memcmp(pin_eld->eld_buffer, eld->eld_buffer,
 			   eld->eld_size) != 0)
 			eld_changed = true;
 
-	pin_eld->monitor_present = eld->monitor_present;
-	pin_eld->eld_valid = eld->eld_valid;
-	pin_eld->eld_size = eld->eld_size;
-	if (eld->eld_valid)
-		memcpy(pin_eld->eld_buffer, eld->eld_buffer, eld->eld_size);
-	pin_eld->info = eld->info;
+	if (eld_changed) {
+		pin_eld->monitor_present = eld->monitor_present;
+		pin_eld->eld_valid = eld->eld_valid;
+		pin_eld->eld_size = eld->eld_size;
+		if (eld->eld_valid)
+			memcpy(pin_eld->eld_buffer, eld->eld_buffer,
+			       eld->eld_size);
+		pin_eld->info = eld->info;
+	}
 
 	/*
 	 * Re-setup pin and infoframe. This is needed e.g. when
@@ -1481,6 +1496,7 @@ static void update_eld(struct hda_codec *codec,
 			       SNDRV_CTL_EVENT_MASK_VALUE |
 			       SNDRV_CTL_EVENT_MASK_INFO,
 			       &get_hdmi_pcm(spec, pcm_idx)->eld_ctl->id);
+	return eld_changed;
 }
 
 /* update ELD and jack state via HD-audio verbs */
@@ -1582,6 +1598,7 @@ static void sync_eld_via_acomp(struct hda_codec *codec,
 	struct hdmi_spec *spec = codec->spec;
 	struct hdmi_eld *eld = &spec->temp_eld;
 	struct snd_jack *jack = NULL;
+	bool changed;
 	int size;
 
 	mutex_lock(&per_pin->lock);
@@ -1608,15 +1625,13 @@ static void sync_eld_via_acomp(struct hda_codec *codec,
 	 * disconnected event. Jack must be fetched before update_eld()
 	 */
 	jack = pin_idx_to_jack(codec, per_pin);
-	update_eld(codec, per_pin, eld);
+	changed = update_eld(codec, per_pin, eld);
 	if (jack == NULL)
 		jack = pin_idx_to_jack(codec, per_pin);
-	if (jack == NULL)
-		goto unlock;
-	snd_jack_report(jack,
-			(eld->monitor_present && eld->eld_valid) ?
+	if (changed && jack)
+		snd_jack_report(jack,
+				(eld->monitor_present && eld->eld_valid) ?
 				SND_JACK_AVOUT : 0);
- unlock:
 	mutex_unlock(&per_pin->lock);
 }
 
@@ -1632,18 +1647,13 @@ static bool hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 			snd_hda_power_down_pm(codec);
 			return false;
 		}
-	}
-
-	if (codec_has_acomp(codec)) {
+		ret = hdmi_present_sense_via_verbs(per_pin, repoll);
+		snd_hda_power_down_pm(codec);
+	} else {
 		sync_eld_via_acomp(codec, per_pin);
 		ret = false; /* don't call snd_hda_jack_report_sync() */
-	} else {
-		ret = hdmi_present_sense_via_verbs(per_pin, repoll);
 	}
 
-	if (!codec_has_acomp(codec))
-		snd_hda_power_down_pm(codec);
-
 	return ret;
 }
 
@@ -2248,6 +2258,8 @@ static int generic_hdmi_init(struct hda_codec *codec)
 	struct hdmi_spec *spec = codec->spec;
 	int pin_idx;
 
+	mutex_lock(&spec->pcm_lock);
+	spec->use_jack_detect = !codec->jackpoll_interval;
 	for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) {
 		struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx);
 		hda_nid_t pin_nid = per_pin->pin_nid;
@@ -2255,11 +2267,15 @@ static int generic_hdmi_init(struct hda_codec *codec)
 
 		snd_hda_set_dev_select(codec, pin_nid, dev_id);
 		hdmi_init_pin(codec, pin_nid);
-		if (!codec_has_acomp(codec))
+		if (codec_has_acomp(codec))
+			continue;
+		if (spec->use_jack_detect)
+			snd_hda_jack_detect_enable(codec, pin_nid);
+		else
 			snd_hda_jack_detect_enable_callback(codec, pin_nid,
-				codec->jackpoll_interval > 0 ?
-				jack_callback : NULL);
+							    jack_callback);
 	}
+	mutex_unlock(&spec->pcm_lock);
 	return 0;
 }
 
@@ -2292,7 +2308,9 @@ static void generic_hdmi_free(struct hda_codec *codec)
 	struct hdmi_spec *spec = codec->spec;
 	int pin_idx, pcm_idx;
 
-	if (codec_has_acomp(codec)) {
+	if (spec->acomp_registered) {
+		snd_hdac_acomp_exit(&codec->bus->core);
+	} else if (codec_has_acomp(codec)) {
 		snd_hdac_acomp_register_notifier(&codec->bus->core, NULL);
 		codec->relaxed_resume = 0;
 	}
@@ -2360,6 +2378,7 @@ static int alloc_generic_hdmi(struct hda_codec *codec)
 	if (!spec)
 		return -ENOMEM;
 
+	spec->codec = codec;
 	spec->ops = generic_standard_hdmi_ops;
 	spec->dev_num = 1;	/* initialize to 1 */
 	mutex_init(&spec->pcm_lock);
@@ -2398,6 +2417,136 @@ static int patch_generic_hdmi(struct hda_codec *codec)
 }
 
 /*
+ * generic audio component binding
+ */
+
+/* turn on / off the unsol event jack detection dynamically */
+static void reprogram_jack_detect(struct hda_codec *codec, hda_nid_t nid,
+				  bool use_acomp)
+{
+	struct hda_jack_tbl *tbl;
+
+	tbl = snd_hda_jack_tbl_get(codec, nid);
+	if (tbl) {
+		/* clear unsol even if component notifier is used, or re-enable
+		 * if notifier is cleared
+		 */
+		unsigned int val = use_acomp ? 0 : (AC_USRSP_EN | tbl->tag);
+		snd_hda_codec_write_cache(codec, nid, 0,
+					  AC_VERB_SET_UNSOLICITED_ENABLE, val);
+	} else {
+		/* if no jack entry was defined beforehand, create a new one
+		 * at need (i.e. only when notifier is cleared)
+		 */
+		if (!use_acomp)
+			snd_hda_jack_detect_enable(codec, nid);
+	}
+}
+
+/* set up / clear component notifier dynamically */
+static void generic_acomp_notifier_set(struct drm_audio_component *acomp,
+				       bool use_acomp)
+{
+	struct hdmi_spec *spec;
+	int i;
+
+	spec = container_of(acomp->audio_ops, struct hdmi_spec, drm_audio_ops);
+	mutex_lock(&spec->pcm_lock);
+	spec->use_acomp_notifier = use_acomp;
+	spec->codec->relaxed_resume = use_acomp;
+	/* reprogram each jack detection logic depending on the notifier */
+	if (spec->use_jack_detect) {
+		for (i = 0; i < spec->num_pins; i++)
+			reprogram_jack_detect(spec->codec,
+					      get_pin(spec, i)->pin_nid,
+					      use_acomp);
+	}
+	mutex_unlock(&spec->pcm_lock);
+}
+
+/* enable / disable the notifier via master bind / unbind */
+static int generic_acomp_master_bind(struct device *dev,
+				     struct drm_audio_component *acomp)
+{
+	generic_acomp_notifier_set(acomp, true);
+	return 0;
+}
+
+static void generic_acomp_master_unbind(struct device *dev,
+					struct drm_audio_component *acomp)
+{
+	generic_acomp_notifier_set(acomp, false);
+}
+
+/* check whether both HD-audio and DRM PCI devices belong to the same bus */
+static int match_bound_vga(struct device *dev, int subtype, void *data)
+{
+	struct hdac_bus *bus = data;
+	struct pci_dev *pci, *master;
+
+	if (!dev_is_pci(dev) || !dev_is_pci(bus->dev))
+		return 0;
+	master = to_pci_dev(bus->dev);
+	pci = to_pci_dev(dev);
+	return master->bus == pci->bus;
+}
+
+/* audio component notifier for AMD/Nvidia HDMI codecs */
+static void generic_acomp_pin_eld_notify(void *audio_ptr, int port, int dev_id)
+{
+	struct hda_codec *codec = audio_ptr;
+	struct hdmi_spec *spec = codec->spec;
+	hda_nid_t pin_nid = spec->port2pin(codec, port);
+
+	if (!pin_nid)
+		return;
+	if (get_wcaps_type(get_wcaps(codec, pin_nid)) != AC_WID_PIN)
+		return;
+	/* skip notification during system suspend (but not in runtime PM);
+	 * the state will be updated at resume
+	 */
+	if (snd_power_get_state(codec->card) != SNDRV_CTL_POWER_D0)
+		return;
+	/* ditto during suspend/resume process itself */
+	if (snd_hdac_is_in_pm(&codec->core))
+		return;
+
+	check_presence_and_report(codec, pin_nid, dev_id);
+}
+
+/* set up the private drm_audio_ops from the template */
+static void setup_drm_audio_ops(struct hda_codec *codec,
+				const struct drm_audio_component_audio_ops *ops)
+{
+	struct hdmi_spec *spec = codec->spec;
+
+	spec->drm_audio_ops.audio_ptr = codec;
+	/* intel_audio_codec_enable() or intel_audio_codec_disable()
+	 * will call pin_eld_notify with using audio_ptr pointer
+	 * We need make sure audio_ptr is really setup
+	 */
+	wmb();
+	spec->drm_audio_ops.pin2port = ops->pin2port;
+	spec->drm_audio_ops.pin_eld_notify = ops->pin_eld_notify;
+	spec->drm_audio_ops.master_bind = ops->master_bind;
+	spec->drm_audio_ops.master_unbind = ops->master_unbind;
+}
+
+/* initialize the generic HDMI audio component */
+static void generic_acomp_init(struct hda_codec *codec,
+			       const struct drm_audio_component_audio_ops *ops,
+			       int (*port2pin)(struct hda_codec *, int))
+{
+	struct hdmi_spec *spec = codec->spec;
+
+	spec->port2pin = port2pin;
+	setup_drm_audio_ops(codec, ops);
+	if (!snd_hdac_acomp_init(&codec->bus->core, &spec->drm_audio_ops,
+				 match_bound_vga, 0))
+		spec->acomp_registered = true;
+}
+
+/*
  * Intel codec parsers and helpers
  */
 
@@ -2565,20 +2714,19 @@ static void intel_pin_eld_notify(void *audio_ptr, int port, int pipe)
 	check_presence_and_report(codec, pin_nid, dev_id);
 }
 
+static const struct drm_audio_component_audio_ops intel_audio_ops = {
+	.pin2port = intel_pin2port,
+	.pin_eld_notify = intel_pin_eld_notify,
+};
+
 /* register i915 component pin_eld_notify callback */
 static void register_i915_notifier(struct hda_codec *codec)
 {
 	struct hdmi_spec *spec = codec->spec;
 
 	spec->use_acomp_notifier = true;
-	spec->drm_audio_ops.audio_ptr = codec;
-	/* intel_audio_codec_enable() or intel_audio_codec_disable()
-	 * will call pin_eld_notify with using audio_ptr pointer
-	 * We need make sure audio_ptr is really setup
-	 */
-	wmb();
-	spec->drm_audio_ops.pin2port = intel_pin2port;
-	spec->drm_audio_ops.pin_eld_notify = intel_pin_eld_notify;
+	spec->port2pin = intel_port2pin;
+	setup_drm_audio_ops(codec, &intel_audio_ops);
 	snd_hdac_acomp_register_notifier(&codec->bus->core,
 					&spec->drm_audio_ops);
 	/* no need for forcible resume for jack check thanks to notifier */
@@ -2976,6 +3124,7 @@ static int patch_simple_hdmi(struct hda_codec *codec,
 	if (!spec)
 		return -ENOMEM;
 
+	spec->codec = codec;
 	codec->spec = spec;
 	hdmi_array_init(spec, 1);
 
@@ -3280,6 +3429,26 @@ static int nvhdmi_chmap_validate(struct hdac_chmap *chmap,
 	return 0;
 }
 
+/* map from pin NID to port; port is 0-based */
+/* for Nvidia: assume widget NID starting from 4, with step 1 (4, 5, 6, ...) */
+static int nvhdmi_pin2port(void *audio_ptr, int pin_nid)
+{
+	return pin_nid - 4;
+}
+
+/* reverse-map from port to pin NID: see above */
+static int nvhdmi_port2pin(struct hda_codec *codec, int port)
+{
+	return port + 4;
+}
+
+static const struct drm_audio_component_audio_ops nvhdmi_audio_ops = {
+	.pin2port = nvhdmi_pin2port,
+	.pin_eld_notify = generic_acomp_pin_eld_notify,
+	.master_bind = generic_acomp_master_bind,
+	.master_unbind = generic_acomp_master_unbind,
+};
+
 static int patch_nvhdmi(struct hda_codec *codec)
 {
 	struct hdmi_spec *spec;
@@ -3296,6 +3465,8 @@ static int patch_nvhdmi(struct hda_codec *codec)
 		nvhdmi_chmap_cea_alloc_validate_get_type;
 	spec->chmap.ops.chmap_validate = nvhdmi_chmap_validate;
 
+	generic_acomp_init(codec, &nvhdmi_audio_ops, nvhdmi_port2pin);
+
 	return 0;
 }
 
@@ -3783,6 +3954,26 @@ static int atihdmi_init(struct hda_codec *codec)
 	return 0;
 }
 
+/* map from pin NID to port; port is 0-based */
+/* for AMD: assume widget NID starting from 3, with step 2 (3, 5, 7, ...) */
+static int atihdmi_pin2port(void *audio_ptr, int pin_nid)
+{
+	return pin_nid / 2 - 1;
+}
+
+/* reverse-map from port to pin NID: see above */
+static int atihdmi_port2pin(struct hda_codec *codec, int port)
+{
+	return port * 2 + 3;
+}
+
+static const struct drm_audio_component_audio_ops atihdmi_audio_ops = {
+	.pin2port = atihdmi_pin2port,
+	.pin_eld_notify = generic_acomp_pin_eld_notify,
+	.master_bind = generic_acomp_master_bind,
+	.master_unbind = generic_acomp_master_unbind,
+};
+
 static int patch_atihdmi(struct hda_codec *codec)
 {
 	struct hdmi_spec *spec;
@@ -3831,6 +4022,8 @@ static int patch_atihdmi(struct hda_codec *codec)
 	 */
 	codec->link_down_at_suspend = 1;
 
+	generic_acomp_init(codec, &atihdmi_audio_ops, atihdmi_port2pin);
+
 	return 0;
 }
 
diff --git a/sound/sparc/dbri.c b/sound/sparc/dbri.c
index 0101131..6e065d4 100644
--- a/sound/sparc/dbri.c
+++ b/sound/sparc/dbri.c
@@ -580,12 +580,16 @@ static __u32 reverse_bytes(__u32 b, int len)
 	switch (len) {
 	case 32:
 		b = ((b & 0xffff0000) >> 16) | ((b & 0x0000ffff) << 16);
+		/* fall through */
 	case 16:
 		b = ((b & 0xff00ff00) >> 8) | ((b & 0x00ff00ff) << 8);
+		/* fall through */
 	case 8:
 		b = ((b & 0xf0f0f0f0) >> 4) | ((b & 0x0f0f0f0f) << 4);
+		/* fall through */
 	case 4:
 		b = ((b & 0xcccccccc) >> 2) | ((b & 0x33333333) << 2);
+		/* fall through */
 	case 2:
 		b = ((b & 0xaaaaaaaa) >> 1) | ((b & 0x55555555) << 1);
 	case 1:
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index e1ce257..f4b7384 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -11,6 +11,7 @@
 			mixer.o \
 			mixer_quirks.o \
 			mixer_scarlett.o \
+			mixer_scarlett_gen2.o \
 			mixer_us16x08.o \
 			pcm.o \
 			power.o \
diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c
index ab2ec89..b5a3f75 100644
--- a/sound/usb/line6/driver.c
+++ b/sound/usb/line6/driver.c
@@ -342,7 +342,7 @@ int line6_read_data(struct usb_line6 *line6, unsigned address, void *data,
 	if (address > 0xffff || datalen > 0xff)
 		return -EINVAL;
 
-	len = kmalloc(sizeof(*len), GFP_KERNEL);
+	len = kmalloc(1, GFP_KERNEL);
 	if (!len)
 		return -ENOMEM;
 
@@ -418,7 +418,7 @@ int line6_write_data(struct usb_line6 *line6, unsigned address, void *data,
 	if (address > 0xffff || datalen > 0xffff)
 		return -EINVAL;
 
-	status = kmalloc(sizeof(*status), GFP_KERNEL);
+	status = kmalloc(1, GFP_KERNEL);
 	if (!status)
 		return -ENOMEM;
 
diff --git a/sound/usb/line6/podhd.c b/sound/usb/line6/podhd.c
index f0662bd..27bf61c 100644
--- a/sound/usb/line6/podhd.c
+++ b/sound/usb/line6/podhd.c
@@ -368,7 +368,7 @@ static const struct line6_properties podhd_properties_table[] = {
 		.name = "POD HD500",
 		.capabilities	= LINE6_CAP_PCM
 				| LINE6_CAP_HWMON,
-		.altsetting = 1,
+		.altsetting = 0,
 		.ep_ctrl_r = 0x81,
 		.ep_ctrl_w = 0x01,
 		.ep_audio_r = 0x86,
diff --git a/sound/usb/line6/variax.c b/sound/usb/line6/variax.c
index 0d24c72c..ed158f0 100644
--- a/sound/usb/line6/variax.c
+++ b/sound/usb/line6/variax.c
@@ -244,5 +244,5 @@ static struct usb_driver variax_driver = {
 
 module_usb_driver(variax_driver);
 
-MODULE_DESCRIPTION("Vairax Workbench USB driver");
+MODULE_DESCRIPTION("Variax Workbench USB driver");
 MODULE_LICENSE("GPL");
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 7498b51..7b51ab4 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -3509,6 +3509,8 @@ void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer)
 		usb_kill_urb(mixer->urb);
 	if (mixer->rc_urb)
 		usb_kill_urb(mixer->rc_urb);
+	if (mixer->private_free)
+		mixer->private_free(mixer);
 	mixer->disconnected = true;
 }
 
@@ -3536,6 +3538,8 @@ static int snd_usb_mixer_activate(struct usb_mixer_interface *mixer)
 int snd_usb_mixer_suspend(struct usb_mixer_interface *mixer)
 {
 	snd_usb_mixer_inactivate(mixer);
+	if (mixer->private_suspend)
+		mixer->private_suspend(mixer);
 	return 0;
 }
 
diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 394cd91..37e1b23 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -28,6 +28,10 @@ struct usb_mixer_interface {
 	struct media_mixer_ctl *media_mixer_ctl;
 
 	bool disconnected;
+
+	void *private_data;
+	void (*private_free)(struct usb_mixer_interface *mixer);
+	void (*private_suspend)(struct usb_mixer_interface *mixer);
 };
 
 #define MAX_CHANNELS	16	/* max logical channels */
diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c
index 199fa15..70805c1 100644
--- a/sound/usb/mixer_quirks.c
+++ b/sound/usb/mixer_quirks.c
@@ -32,6 +32,7 @@
 #include "mixer.h"
 #include "mixer_quirks.h"
 #include "mixer_scarlett.h"
+#include "mixer_scarlett_gen2.h"
 #include "mixer_us16x08.h"
 #include "helper.h"
 
@@ -2258,6 +2259,12 @@ int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer)
 		err = snd_scarlett_controls_create(mixer);
 		break;
 
+	case USB_ID(0x1235, 0x8203): /* Focusrite Scarlett 6i6 2nd Gen */
+	case USB_ID(0x1235, 0x8204): /* Focusrite Scarlett 18i8 2nd Gen */
+	case USB_ID(0x1235, 0x8201): /* Focusrite Scarlett 18i20 2nd Gen */
+		err = snd_scarlett_gen2_controls_create(mixer);
+		break;
+
 	case USB_ID(0x041e, 0x323b): /* Creative Sound Blaster E1 */
 		err = snd_soundblaster_e1_switch_create(mixer);
 		break;
diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c
new file mode 100644
index 0000000..7d460b1f
--- /dev/null
+++ b/sound/usb/mixer_scarlett_gen2.c
@@ -0,0 +1,2075 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *   Focusrite Scarlett 6i6/18i8/18i20 Gen 2 Driver for ALSA
+ *
+ *   Copyright (c) 2018-2019 by Geoffrey D. Bennett <g at b4.vu>
+ *
+ *   Based on the Scarlett (Gen 1) 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>
+ */
+
+/* Mixer Interface for the Focusrite Scarlett 6i6/18i8/18i20 Gen 2 audio
+ * interface. Based on the Gen 1 driver and rewritten.
+ */
+
+/* The protocol was reverse engineered by looking at the communication
+ * between Focusrite Control 2.3.4 and the Focusrite(R) Scarlett 18i20
+ * (firmware 1083) using usbmon in July-August 2018.
+ *
+ * Scarlett 18i8 support added in April 2019.
+ *
+ * Scarlett 6i6 support added in June 2019 (thanks to Martin Wittmann
+ * for providing usbmon output and testing).
+ *
+ * This ALSA mixer gives access to:
+ *  - input, output, mixer-matrix muxes
+ *  - 18x10 mixer-matrix gain stages
+ *  - gain/volume controls
+ *  - level meters
+ *  - line/inst level and pad controls
+ *
+ * <ditaa>
+ *    /--------------\    18chn            20chn     /--------------\
+ *    | Hardware  in +--+------\    /-------------+--+ ALSA PCM out |
+ *    \--------------/  |      |    |             |  \--------------/
+ *                      |      |    |    /-----\  |
+ *                      |      |    |    |     |  |
+ *                      |      v    v    v     |  |
+ *                      |   +---------------+  |  |
+ *                      |    \ Matrix  Mux /   |  |
+ *                      |     +-----+-----+    |  |
+ *                      |           |          |  |
+ *                      |           |18chn     |  |
+ *                      |           |          |  |
+ *                      |           |     10chn|  |
+ *                      |           v          |  |
+ *                      |     +------------+   |  |
+ *                      |     | Mixer      |   |  |
+ *                      |     |     Matrix |   |  |
+ *                      |     |            |   |  |
+ *                      |     | 18x10 Gain |   |  |
+ *                      |     |   stages   |   |  |
+ *                      |     +-----+------+   |  |
+ *                      |           |          |  |
+ *                      |18chn      |10chn     |  |20chn
+ *                      |           |          |  |
+ *                      |           +----------/  |
+ *                      |           |             |
+ *                      v           v             v
+ *                      ===========================
+ *               +---------------+       +--—------------+
+ *                \ Output  Mux /         \ Capture Mux /
+ *                 +---+---+---+           +-----+-----+
+ *                     |   |                     |
+ *                10chn|   |                     |18chn
+ *                     |   |                     |
+ *  /--------------\   |   |                     |   /--------------\
+ *  | S/PDIF, ADAT |<--/   |10chn                \-->| ALSA PCM in  |
+ *  | Hardware out |       |                         \--------------/
+ *  \--------------/       |
+ *                         v
+ *                  +-------------+    Software gain per channel.
+ *                  | Master Gain |<-- 18i20 only: Switch per channel
+ *                  +------+------+    to select HW or SW gain control.
+ *                         |
+ *                         |10chn
+ *  /--------------\       |
+ *  | Analogue     |<------/
+ *  | Hardware out |
+ *  \--------------/
+ * </ditaa>
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/moduleparam.h>
+
+#include <sound/control.h>
+#include <sound/tlv.h>
+
+#include "usbaudio.h"
+#include "mixer.h"
+#include "helper.h"
+
+#include "mixer_scarlett_gen2.h"
+
+/* device_setup value to enable */
+#define SCARLETT2_ENABLE 0x01
+
+/* some gui mixers can't handle negative ctl values */
+#define SCARLETT2_VOLUME_BIAS 127
+
+/* mixer range from -80dB to +6dB in 0.5dB steps */
+#define SCARLETT2_MIXER_MIN_DB -80
+#define SCARLETT2_MIXER_BIAS (-SCARLETT2_MIXER_MIN_DB * 2)
+#define SCARLETT2_MIXER_MAX_DB 6
+#define SCARLETT2_MIXER_MAX_VALUE \
+	((SCARLETT2_MIXER_MAX_DB - SCARLETT2_MIXER_MIN_DB) * 2)
+
+/* map from (dB + 80) * 2 to mixer value
+ * for dB in 0 .. 172: int(8192 * pow(10, ((dB - 160) / 2 / 20)))
+ */
+static const u16 scarlett2_mixer_values[173] = {
+	0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
+	2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 8, 8,
+	9, 9, 10, 10, 11, 12, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
+	23, 24, 25, 27, 29, 30, 32, 34, 36, 38, 41, 43, 46, 48, 51,
+	54, 57, 61, 65, 68, 73, 77, 81, 86, 91, 97, 103, 109, 115,
+	122, 129, 137, 145, 154, 163, 173, 183, 194, 205, 217, 230,
+	244, 259, 274, 290, 307, 326, 345, 365, 387, 410, 434, 460,
+	487, 516, 547, 579, 614, 650, 689, 730, 773, 819, 867, 919,
+	973, 1031, 1092, 1157, 1225, 1298, 1375, 1456, 1543, 1634,
+	1731, 1833, 1942, 2057, 2179, 2308, 2445, 2590, 2744, 2906,
+	3078, 3261, 3454, 3659, 3876, 4105, 4349, 4606, 4879, 5168,
+	5475, 5799, 6143, 6507, 6892, 7301, 7733, 8192, 8677, 9191,
+	9736, 10313, 10924, 11571, 12257, 12983, 13752, 14567, 15430,
+	16345
+};
+
+/* Maximum number of analogue outputs */
+#define SCARLETT2_ANALOGUE_MAX 10
+
+/* Maximum number of level and pad switches */
+#define SCARLETT2_LEVEL_SWITCH_MAX 2
+#define SCARLETT2_PAD_SWITCH_MAX 4
+
+/* Maximum number of inputs to the mixer */
+#define SCARLETT2_INPUT_MIX_MAX 18
+
+/* Maximum number of outputs from the mixer */
+#define SCARLETT2_OUTPUT_MIX_MAX 10
+
+/* Maximum size of the data in the USB mux assignment message:
+ * 18 inputs, 20 outputs, 18 matrix inputs, 8 spare
+ */
+#define SCARLETT2_MUX_MAX 64
+
+/* Number of meters:
+ * 18 inputs, 20 outputs, 18 matrix inputs
+ */
+#define SCARLETT2_NUM_METERS 56
+
+/* Hardware port types:
+ * - None (no input to mux)
+ * - Analogue I/O
+ * - S/PDIF I/O
+ * - ADAT I/O
+ * - Mixer I/O
+ * - PCM I/O
+ */
+enum {
+	SCARLETT2_PORT_TYPE_NONE = 0,
+	SCARLETT2_PORT_TYPE_ANALOGUE = 1,
+	SCARLETT2_PORT_TYPE_SPDIF = 2,
+	SCARLETT2_PORT_TYPE_ADAT = 3,
+	SCARLETT2_PORT_TYPE_MIX = 4,
+	SCARLETT2_PORT_TYPE_PCM = 5,
+	SCARLETT2_PORT_TYPE_COUNT = 6,
+};
+
+/* Count of total I/O and number available at each sample rate */
+enum {
+	SCARLETT2_PORT_IN = 0,
+	SCARLETT2_PORT_OUT = 1,
+	SCARLETT2_PORT_OUT_44 = 2,
+	SCARLETT2_PORT_OUT_88 = 3,
+	SCARLETT2_PORT_OUT_176 = 4,
+	SCARLETT2_PORT_DIRECTIONS = 5,
+};
+
+/* Hardware buttons on the 18i20 */
+#define SCARLETT2_BUTTON_MAX 2
+
+static const char *const scarlett2_button_names[SCARLETT2_BUTTON_MAX] = {
+	"Mute", "Dim"
+};
+
+/* Description of each hardware port type:
+ * - id: hardware ID for this port type
+ * - num: number of sources/destinations of this port type
+ * - src_descr: printf format string for mux input selections
+ * - src_num_offset: added to channel number for the fprintf
+ * - dst_descr: printf format string for mixer controls
+ */
+struct scarlett2_ports {
+	u16 id;
+	int num[SCARLETT2_PORT_DIRECTIONS];
+	const char * const src_descr;
+	int src_num_offset;
+	const char * const dst_descr;
+};
+
+struct scarlett2_device_info {
+	u8 line_out_hw_vol; /* line out hw volume is sw controlled */
+	u8 button_count; /* number of buttons */
+	u8 level_input_count; /* inputs with level selectable */
+	u8 pad_input_count; /* inputs with pad selectable */
+	const char * const line_out_descrs[SCARLETT2_ANALOGUE_MAX];
+	struct scarlett2_ports ports[SCARLETT2_PORT_TYPE_COUNT];
+};
+
+struct scarlett2_mixer_data {
+	struct usb_mixer_interface *mixer;
+	struct mutex usb_mutex; /* prevent sending concurrent USB requests */
+	struct mutex data_mutex; /* lock access to this data */
+	struct delayed_work work;
+	const struct scarlett2_device_info *info;
+	int num_mux_srcs;
+	u16 scarlett2_seq;
+	u8 vol_updated;
+	u8 master_vol;
+	u8 vol[SCARLETT2_ANALOGUE_MAX];
+	u8 vol_sw_hw_switch[SCARLETT2_ANALOGUE_MAX];
+	u8 level_switch[SCARLETT2_LEVEL_SWITCH_MAX];
+	u8 pad_switch[SCARLETT2_PAD_SWITCH_MAX];
+	u8 buttons[SCARLETT2_BUTTON_MAX];
+	struct snd_kcontrol *master_vol_ctl;
+	struct snd_kcontrol *vol_ctls[SCARLETT2_ANALOGUE_MAX];
+	struct snd_kcontrol *button_ctls[SCARLETT2_BUTTON_MAX];
+	u8 mux[SCARLETT2_MUX_MAX];
+	u8 mix[SCARLETT2_INPUT_MIX_MAX * SCARLETT2_OUTPUT_MIX_MAX];
+};
+
+/*** Model-specific data ***/
+
+static const struct scarlett2_device_info s6i6_gen2_info = {
+	/* The first two analogue inputs can be switched between line
+	 * and instrument levels.
+	 */
+	.level_input_count = 2,
+
+	/* The first two analogue inputs have an optional pad. */
+	.pad_input_count = 2,
+
+	.line_out_descrs = {
+		"Monitor L",
+		"Monitor R",
+		"Headphones L",
+		"Headphones R",
+	},
+
+	.ports = {
+		{
+			.id = 0x000,
+			.num = { 1, 0, 8, 8, 8 },
+			.src_descr = "Off",
+			.src_num_offset = 0,
+		},
+		{
+			.id = 0x080,
+			.num = { 4, 4, 4, 4, 4 },
+			.src_descr = "Analogue %d",
+			.src_num_offset = 1,
+			.dst_descr = "Analogue Output %02d Playback"
+		},
+		{
+			.id = 0x180,
+			.num = { 2, 2, 2, 2, 2 },
+			.src_descr = "S/PDIF %d",
+			.src_num_offset = 1,
+			.dst_descr = "S/PDIF Output %d Playback"
+		},
+		{
+			.id = 0x300,
+			.num = { 10, 18, 18, 18, 18 },
+			.src_descr = "Mix %c",
+			.src_num_offset = 65,
+			.dst_descr = "Mixer Input %02d Capture"
+		},
+		{
+			.id = 0x600,
+			.num = { 6, 6, 6, 6, 6 },
+			.src_descr = "PCM %d",
+			.src_num_offset = 1,
+			.dst_descr = "PCM %02d Capture"
+		},
+	},
+};
+
+static const struct scarlett2_device_info s18i8_gen2_info = {
+	/* The first two analogue inputs can be switched between line
+	 * and instrument levels.
+	 */
+	.level_input_count = 2,
+
+	/* The first four analogue inputs have an optional pad. */
+	.pad_input_count = 4,
+
+	.line_out_descrs = {
+		"Monitor L",
+		"Monitor R",
+		"Headphones 1 L",
+		"Headphones 1 R",
+		"Headphones 2 L",
+		"Headphones 2 R",
+	},
+
+	.ports = {
+		{
+			.id = 0x000,
+			.num = { 1, 0, 8, 8, 4 },
+			.src_descr = "Off",
+			.src_num_offset = 0,
+		},
+		{
+			.id = 0x080,
+			.num = { 8, 6, 6, 6, 6 },
+			.src_descr = "Analogue %d",
+			.src_num_offset = 1,
+			.dst_descr = "Analogue Output %02d Playback"
+		},
+		{
+			/* S/PDIF outputs aren't available at 192KHz
+			 * but are included in the USB mux I/O
+			 * assignment message anyway
+			 */
+			.id = 0x180,
+			.num = { 2, 2, 2, 2, 2 },
+			.src_descr = "S/PDIF %d",
+			.src_num_offset = 1,
+			.dst_descr = "S/PDIF Output %d Playback"
+		},
+		{
+			.id = 0x200,
+			.num = { 8, 0, 0, 0, 0 },
+			.src_descr = "ADAT %d",
+			.src_num_offset = 1,
+		},
+		{
+			.id = 0x300,
+			.num = { 10, 18, 18, 18, 18 },
+			.src_descr = "Mix %c",
+			.src_num_offset = 65,
+			.dst_descr = "Mixer Input %02d Capture"
+		},
+		{
+			.id = 0x600,
+			.num = { 20, 18, 18, 14, 10 },
+			.src_descr = "PCM %d",
+			.src_num_offset = 1,
+			.dst_descr = "PCM %02d Capture"
+		},
+	},
+};
+
+static const struct scarlett2_device_info s18i20_gen2_info = {
+	/* The analogue line outputs on the 18i20 can be switched
+	 * between software and hardware volume control
+	 */
+	.line_out_hw_vol = 1,
+
+	/* Mute and dim buttons */
+	.button_count = 2,
+
+	.line_out_descrs = {
+		"Monitor L",
+		"Monitor R",
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		"Headphones 1 L",
+		"Headphones 1 R",
+		"Headphones 2 L",
+		"Headphones 2 R",
+	},
+
+	.ports = {
+		{
+			.id = 0x000,
+			.num = { 1, 0, 8, 8, 6 },
+			.src_descr = "Off",
+			.src_num_offset = 0,
+		},
+		{
+			.id = 0x080,
+			.num = { 8, 10, 10, 10, 10 },
+			.src_descr = "Analogue %d",
+			.src_num_offset = 1,
+			.dst_descr = "Analogue Output %02d Playback"
+		},
+		{
+			/* S/PDIF outputs aren't available at 192KHz
+			 * but are included in the USB mux I/O
+			 * assignment message anyway
+			 */
+			.id = 0x180,
+			.num = { 2, 2, 2, 2, 2 },
+			.src_descr = "S/PDIF %d",
+			.src_num_offset = 1,
+			.dst_descr = "S/PDIF Output %d Playback"
+		},
+		{
+			.id = 0x200,
+			.num = { 8, 8, 8, 4, 0 },
+			.src_descr = "ADAT %d",
+			.src_num_offset = 1,
+			.dst_descr = "ADAT Output %d Playback"
+		},
+		{
+			.id = 0x300,
+			.num = { 10, 18, 18, 18, 18 },
+			.src_descr = "Mix %c",
+			.src_num_offset = 65,
+			.dst_descr = "Mixer Input %02d Capture"
+		},
+		{
+			.id = 0x600,
+			.num = { 20, 18, 18, 14, 10 },
+			.src_descr = "PCM %d",
+			.src_num_offset = 1,
+			.dst_descr = "PCM %02d Capture"
+		},
+	},
+};
+
+/* get the starting port index number for a given port type/direction */
+static int scarlett2_get_port_start_num(const struct scarlett2_ports *ports,
+					int direction, int port_type)
+{
+	int i, num = 0;
+
+	for (i = 0; i < port_type; i++)
+		num += ports[i].num[direction];
+
+	return num;
+}
+
+/*** USB Interactions ***/
+
+/* Vendor-Specific Interface, Endpoint, MaxPacketSize, Interval */
+#define SCARLETT2_USB_VENDOR_SPECIFIC_INTERFACE 5
+#define SCARLETT2_USB_INTERRUPT_ENDPOINT 4
+#define SCARLETT2_USB_INTERRUPT_MAX_DATA 64
+#define SCARLETT2_USB_INTERRUPT_INTERVAL 3
+
+/* Interrupt flags for volume and mute/dim button changes */
+#define SCARLETT2_USB_INTERRUPT_VOL_CHANGE 0x400000
+#define SCARLETT2_USB_INTERRUPT_BUTTON_CHANGE 0x200000
+
+/* Commands for sending/receiving requests/responses */
+#define SCARLETT2_USB_VENDOR_SPECIFIC_CMD_REQ 2
+#define SCARLETT2_USB_VENDOR_SPECIFIC_CMD_RESP 3
+
+#define SCARLETT2_USB_INIT_SEQ 0x00000000
+#define SCARLETT2_USB_GET_METER_LEVELS 0x00001001
+#define SCARLETT2_USB_SET_MIX 0x00002002
+#define SCARLETT2_USB_SET_MUX 0x00003002
+#define SCARLETT2_USB_GET_DATA 0x00800000
+#define SCARLETT2_USB_SET_DATA 0x00800001
+#define SCARLETT2_USB_DATA_CMD 0x00800002
+#define SCARLETT2_USB_CONFIG_SAVE 6
+
+#define SCARLETT2_USB_VOLUME_STATUS_OFFSET 0x31
+#define SCARLETT2_USB_METER_LEVELS_GET_MAGIC 1
+
+/* volume status is read together (matches scarlett2_config_items[]) */
+struct scarlett2_usb_volume_status {
+	/* mute & dim buttons */
+	u8 buttons[SCARLETT2_BUTTON_MAX];
+
+	u8 pad1;
+
+	/* software volume setting */
+	s16 sw_vol[SCARLETT2_ANALOGUE_MAX];
+
+	/* actual volume of output inc. dim (-18dB) */
+	s16 hw_vol[SCARLETT2_ANALOGUE_MAX];
+
+	u8 pad2[SCARLETT2_ANALOGUE_MAX];
+
+	/* sw (0) or hw (1) controlled */
+	u8 sw_hw_switch[SCARLETT2_ANALOGUE_MAX];
+
+	u8 pad3[6];
+
+	/* front panel volume knob */
+	s16 master_vol;
+} __packed;
+
+/* Configuration parameters that can be read and written */
+enum {
+	SCARLETT2_CONFIG_BUTTONS = 0,
+	SCARLETT2_CONFIG_LINE_OUT_VOLUME = 1,
+	SCARLETT2_CONFIG_SW_HW_SWITCH = 2,
+	SCARLETT2_CONFIG_LEVEL_SWITCH = 3,
+	SCARLETT2_CONFIG_PAD_SWITCH = 4,
+	SCARLETT2_CONFIG_COUNT = 5
+};
+
+/* Location, size, and activation command number for the configuration
+ * parameters
+ */
+struct scarlett2_config {
+	u8 offset;
+	u8 size;
+	u8 activate;
+};
+
+static const struct scarlett2_config
+		scarlett2_config_items[SCARLETT2_CONFIG_COUNT] = {
+	/* Mute/Dim Buttons */
+	{
+		.offset = 0x31,
+		.size = 1,
+		.activate = 2
+	},
+
+	/* Line Out Volume */
+	{
+		.offset = 0x34,
+		.size = 2,
+		.activate = 1
+	},
+
+	/* SW/HW Volume Switch */
+	{
+		.offset = 0x66,
+		.size = 1,
+		.activate = 3
+	},
+
+	/* Level Switch */
+	{
+		.offset = 0x7c,
+		.size = 1,
+		.activate = 7
+	},
+
+	/* Pad Switch */
+	{
+		.offset = 0x84,
+		.size = 1,
+		.activate = 8
+	}
+};
+
+/* proprietary request/response format */
+struct scarlett2_usb_packet {
+	u32 cmd;
+	u16 size;
+	u16 seq;
+	u32 error;
+	u32 pad;
+	u8 data[];
+};
+
+#define SCARLETT2_USB_PACKET_LEN (sizeof(struct scarlett2_usb_packet))
+
+static void scarlett2_fill_request_header(struct scarlett2_mixer_data *private,
+					  struct scarlett2_usb_packet *req,
+					  u32 cmd, u16 req_size)
+{
+	/* sequence must go up by 1 for each request */
+	u16 seq = private->scarlett2_seq++;
+
+	req->cmd = cpu_to_le32(cmd);
+	req->size = cpu_to_le16(req_size);
+	req->seq = cpu_to_le16(seq);
+	req->error = 0;
+	req->pad = 0;
+}
+
+/* Send a proprietary format request to the Scarlett interface */
+static int scarlett2_usb(
+	struct usb_mixer_interface *mixer, u32 cmd,
+	void *req_data, u16 req_size, void *resp_data, u16 resp_size)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	u16 req_buf_size = sizeof(struct scarlett2_usb_packet) + req_size;
+	u16 resp_buf_size = sizeof(struct scarlett2_usb_packet) + resp_size;
+	struct scarlett2_usb_packet *req = NULL, *resp = NULL;
+	int err = 0;
+
+	req = kmalloc(req_buf_size, GFP_KERNEL);
+	if (!req) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	resp = kmalloc(resp_buf_size, GFP_KERNEL);
+	if (!resp) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	mutex_lock(&private->usb_mutex);
+
+	/* build request message and send it */
+
+	scarlett2_fill_request_header(private, req, cmd, req_size);
+
+	if (req_size)
+		memcpy(req->data, req_data, req_size);
+
+	err = snd_usb_ctl_msg(mixer->chip->dev,
+			usb_sndctrlpipe(mixer->chip->dev, 0),
+			SCARLETT2_USB_VENDOR_SPECIFIC_CMD_REQ,
+			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
+			0,
+			SCARLETT2_USB_VENDOR_SPECIFIC_INTERFACE,
+			req,
+			req_buf_size);
+
+	if (err != req_buf_size) {
+		usb_audio_err(
+			mixer->chip,
+			"Scarlett Gen 2 USB request result cmd %x was %d\n",
+			cmd, err);
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	/* send a second message to get the response */
+
+	err = snd_usb_ctl_msg(mixer->chip->dev,
+			usb_sndctrlpipe(mixer->chip->dev, 0),
+			SCARLETT2_USB_VENDOR_SPECIFIC_CMD_RESP,
+			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
+			0,
+			SCARLETT2_USB_VENDOR_SPECIFIC_INTERFACE,
+			resp,
+			resp_buf_size);
+
+	/* validate the response */
+
+	if (err != resp_buf_size) {
+		usb_audio_err(
+			mixer->chip,
+			"Scarlett Gen 2 USB response result cmd %x was %d\n",
+			cmd, err);
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	if (resp->cmd != req->cmd ||
+	    resp->seq != req->seq ||
+	    resp_size != le16_to_cpu(resp->size) ||
+	    resp->error ||
+	    resp->pad) {
+		usb_audio_err(
+			mixer->chip,
+			"Scarlett Gen 2 USB invalid response; "
+			   "cmd tx/rx %d/%d seq %d/%d size %d/%d "
+			   "error %d pad %d\n",
+			le16_to_cpu(req->cmd), le16_to_cpu(resp->cmd),
+			le16_to_cpu(req->seq), le16_to_cpu(resp->seq),
+			resp_size, le16_to_cpu(resp->size),
+			le16_to_cpu(resp->error),
+			le16_to_cpu(resp->pad));
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	if (resp_size > 0)
+		memcpy(resp_data, resp->data, resp_size);
+
+unlock:
+	mutex_unlock(&private->usb_mutex);
+error:
+	kfree(req);
+	kfree(resp);
+	return err;
+}
+
+/* Send SCARLETT2_USB_DATA_CMD SCARLETT2_USB_CONFIG_SAVE */
+static void scarlett2_config_save(struct usb_mixer_interface *mixer)
+{
+	u32 req = cpu_to_le32(SCARLETT2_USB_CONFIG_SAVE);
+
+	scarlett2_usb(mixer, SCARLETT2_USB_DATA_CMD,
+		      &req, sizeof(u32),
+		      NULL, 0);
+}
+
+/* Delayed work to save config */
+static void scarlett2_config_save_work(struct work_struct *work)
+{
+	struct scarlett2_mixer_data *private =
+		container_of(work, struct scarlett2_mixer_data, work.work);
+
+	scarlett2_config_save(private->mixer);
+}
+
+/* Send a USB message to set a configuration parameter (volume level,
+ * sw/hw volume switch, line/inst level switch, or pad switch)
+ */
+static int scarlett2_usb_set_config(
+	struct usb_mixer_interface *mixer,
+	int config_item_num, int index, int value)
+{
+	const struct scarlett2_config config_item =
+	       scarlett2_config_items[config_item_num];
+	struct {
+		u32 offset;
+		u32 bytes;
+		s32 value;
+	} __packed req;
+	u32 req2;
+	int err;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	/* Cancel any pending NVRAM save */
+	cancel_delayed_work_sync(&private->work);
+
+	/* Send the configuration parameter data */
+	req.offset = cpu_to_le32(config_item.offset + index * config_item.size);
+	req.bytes = cpu_to_le32(config_item.size);
+	req.value = cpu_to_le32(value);
+	err = scarlett2_usb(mixer, SCARLETT2_USB_SET_DATA,
+			    &req, sizeof(u32) * 2 + config_item.size,
+			    NULL, 0);
+	if (err < 0)
+		return err;
+
+	/* Activate the change */
+	req2 = cpu_to_le32(config_item.activate);
+	err = scarlett2_usb(mixer, SCARLETT2_USB_DATA_CMD,
+			    &req2, sizeof(req2), NULL, 0);
+	if (err < 0)
+		return err;
+
+	/* Schedule the change to be written to NVRAM */
+	schedule_delayed_work(&private->work, msecs_to_jiffies(2000));
+
+	return 0;
+}
+
+/* Send a USB message to get data; result placed in *buf */
+static int scarlett2_usb_get(
+	struct usb_mixer_interface *mixer,
+	int offset, void *buf, int size)
+{
+	struct {
+		u32 offset;
+		u32 size;
+	} __packed req;
+
+	req.offset = cpu_to_le32(offset);
+	req.size = cpu_to_le32(size);
+	return scarlett2_usb(mixer, SCARLETT2_USB_GET_DATA,
+			     &req, sizeof(req), buf, size);
+}
+
+/* Send a USB message to get configuration parameters; result placed in *buf */
+static int scarlett2_usb_get_config(
+	struct usb_mixer_interface *mixer,
+	int config_item_num, int count, void *buf)
+{
+	const struct scarlett2_config config_item =
+	       scarlett2_config_items[config_item_num];
+	int size = config_item.size * count;
+
+	return scarlett2_usb_get(mixer, config_item.offset, buf, size);
+}
+
+/* Send a USB message to get volume status; result placed in *buf */
+static int scarlett2_usb_get_volume_status(
+	struct usb_mixer_interface *mixer,
+	struct scarlett2_usb_volume_status *buf)
+{
+	return scarlett2_usb_get(mixer, SCARLETT2_USB_VOLUME_STATUS_OFFSET,
+				 buf, sizeof(*buf));
+}
+
+/* Send a USB message to set the volumes for all inputs of one mix
+ * (values obtained from private->mix[])
+ */
+static int scarlett2_usb_set_mix(struct usb_mixer_interface *mixer,
+				     int mix_num)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_device_info *info = private->info;
+
+	struct {
+		u16 mix_num;
+		u16 data[SCARLETT2_INPUT_MIX_MAX];
+	} __packed req;
+
+	int i, j;
+	int num_mixer_in =
+		info->ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_OUT];
+
+	req.mix_num = cpu_to_le16(mix_num);
+
+	for (i = 0, j = mix_num * num_mixer_in; i < num_mixer_in; i++, j++)
+		req.data[i] = cpu_to_le16(
+			scarlett2_mixer_values[private->mix[j]]
+		);
+
+	return scarlett2_usb(mixer, SCARLETT2_USB_SET_MIX,
+			     &req, (num_mixer_in + 1) * sizeof(u16),
+			     NULL, 0);
+}
+
+/* Convert a port number index (per info->ports) to a hardware ID */
+static u32 scarlett2_mux_src_num_to_id(const struct scarlett2_ports *ports,
+				       int num)
+{
+	int port_type;
+
+	for (port_type = 0;
+	     port_type < SCARLETT2_PORT_TYPE_COUNT;
+	     port_type++) {
+		if (num < ports[port_type].num[SCARLETT2_PORT_IN])
+			return ports[port_type].id | num;
+		num -= ports[port_type].num[SCARLETT2_PORT_IN];
+	}
+
+	/* Oops */
+	return 0;
+}
+
+/* Send USB messages to set mux inputs */
+static int scarlett2_usb_set_mux(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_device_info *info = private->info;
+	const struct scarlett2_ports *ports = info->ports;
+	int rate, port_dir_rate;
+
+	static const int assignment_order[SCARLETT2_PORT_TYPE_COUNT] = {
+		SCARLETT2_PORT_TYPE_PCM,
+		SCARLETT2_PORT_TYPE_ANALOGUE,
+		SCARLETT2_PORT_TYPE_SPDIF,
+		SCARLETT2_PORT_TYPE_ADAT,
+		SCARLETT2_PORT_TYPE_MIX,
+		SCARLETT2_PORT_TYPE_NONE,
+	};
+
+	struct {
+		u16 pad;
+		u16 num;
+		u32 data[SCARLETT2_MUX_MAX];
+	} __packed req;
+
+	req.pad = 0;
+
+	/* mux settings for each rate */
+	for (rate = 0, port_dir_rate = SCARLETT2_PORT_OUT_44;
+	     port_dir_rate <= SCARLETT2_PORT_OUT_176;
+	     rate++, port_dir_rate++) {
+		int order_num, i, err;
+
+		req.num = cpu_to_le16(rate);
+
+		for (order_num = 0, i = 0;
+		     order_num < SCARLETT2_PORT_TYPE_COUNT;
+		     order_num++) {
+			int port_type = assignment_order[order_num];
+			int j = scarlett2_get_port_start_num(ports,
+							     SCARLETT2_PORT_OUT,
+							     port_type);
+			int port_id = ports[port_type].id;
+			int channel;
+
+			for (channel = 0;
+			     channel < ports[port_type].num[port_dir_rate];
+			     channel++, i++, j++)
+				/* lower 12 bits for the destination and
+				 * next 12 bits for the source
+				 */
+				req.data[i] = !port_id
+					? 0
+					: cpu_to_le32(
+						port_id |
+						channel |
+						scarlett2_mux_src_num_to_id(
+							ports, private->mux[j]
+						) << 12
+					  );
+
+			/* skip private->mux[j] entries not output */
+			j += ports[port_type].num[SCARLETT2_PORT_OUT] -
+			     ports[port_type].num[port_dir_rate];
+		}
+
+		err = scarlett2_usb(mixer, SCARLETT2_USB_SET_MUX,
+				    &req, (i + 1) * sizeof(u32),
+				    NULL, 0);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/* Send USB message to get meter levels */
+static int scarlett2_usb_get_meter_levels(struct usb_mixer_interface *mixer,
+					  u16 *levels)
+{
+	struct {
+		u16 pad;
+		u16 num_meters;
+		u32 magic;
+	} __packed req;
+	u32 resp[SCARLETT2_NUM_METERS];
+	int i, err;
+
+	req.pad = 0;
+	req.num_meters = cpu_to_le16(SCARLETT2_NUM_METERS);
+	req.magic = cpu_to_le32(SCARLETT2_USB_METER_LEVELS_GET_MAGIC);
+	err = scarlett2_usb(mixer, SCARLETT2_USB_GET_METER_LEVELS,
+			    &req, sizeof(req), resp, sizeof(resp));
+	if (err < 0)
+		return err;
+
+	/* copy, convert to u16 */
+	for (i = 0; i < SCARLETT2_NUM_METERS; i++)
+		levels[i] = resp[i];
+
+	return 0;
+}
+
+/*** Control Functions ***/
+
+/* helper function to create a new control */
+static int scarlett2_add_new_ctl(struct usb_mixer_interface *mixer,
+				 const struct snd_kcontrol_new *ncontrol,
+				 int index, int channels, const char *name,
+				 struct snd_kcontrol **kctl_return)
+{
+	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->control = index;
+	elem->head.id = index;
+	elem->channels = channels;
+
+	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 (kctl_return)
+		*kctl_return = kctl;
+
+	return 0;
+}
+
+/*** Analogue Line Out Volume Controls ***/
+
+/* Update hardware volume controls after receiving notification that
+ * they have changed
+ */
+static int scarlett2_update_volumes(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_ports *ports = private->info->ports;
+	struct scarlett2_usb_volume_status volume_status;
+	int num_line_out =
+		ports[SCARLETT2_PORT_TYPE_ANALOGUE].num[SCARLETT2_PORT_OUT];
+	int err, i;
+
+	private->vol_updated = 0;
+
+	err = scarlett2_usb_get_volume_status(mixer, &volume_status);
+	if (err < 0)
+		return err;
+
+	private->master_vol = clamp(
+		volume_status.master_vol + SCARLETT2_VOLUME_BIAS,
+		0, SCARLETT2_VOLUME_BIAS);
+
+	for (i = 0; i < num_line_out; i++) {
+		if (private->vol_sw_hw_switch[i])
+			private->vol[i] = private->master_vol;
+	}
+
+	for (i = 0; i < private->info->button_count; i++)
+		private->buttons[i] = !!volume_status.buttons[i];
+
+	return 0;
+}
+
+static int scarlett2_volume_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 = SCARLETT2_VOLUME_BIAS;
+	uinfo->value.integer.step = 1;
+	return 0;
+}
+
+static int scarlett2_master_volume_ctl_get(struct snd_kcontrol *kctl,
+					   struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	if (private->vol_updated) {
+		mutex_lock(&private->data_mutex);
+		scarlett2_update_volumes(mixer);
+		mutex_unlock(&private->data_mutex);
+	}
+
+	ucontrol->value.integer.value[0] = private->master_vol;
+	return 0;
+}
+
+static int scarlett2_volume_ctl_get(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	int index = elem->control;
+
+	if (private->vol_updated) {
+		mutex_lock(&private->data_mutex);
+		scarlett2_update_volumes(mixer);
+		mutex_unlock(&private->data_mutex);
+	}
+
+	ucontrol->value.integer.value[0] = private->vol[index];
+	return 0;
+}
+
+static int scarlett2_volume_ctl_put(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	int index = elem->control;
+	int oval, val, err = 0;
+
+	mutex_lock(&private->data_mutex);
+
+	oval = private->vol[index];
+	val = ucontrol->value.integer.value[0];
+
+	if (oval == val)
+		goto unlock;
+
+	private->vol[index] = val;
+	err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_LINE_OUT_VOLUME,
+				       index, val - SCARLETT2_VOLUME_BIAS);
+	if (err == 0)
+		err = 1;
+
+unlock:
+	mutex_unlock(&private->data_mutex);
+	return err;
+}
+
+static const DECLARE_TLV_DB_MINMAX(
+	db_scale_scarlett2_gain, -SCARLETT2_VOLUME_BIAS * 100, 0
+);
+
+static const struct snd_kcontrol_new scarlett2_master_volume_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.name = "",
+	.info = scarlett2_volume_ctl_info,
+	.get  = scarlett2_master_volume_ctl_get,
+	.private_value = 0, /* max value */
+	.tlv = { .p = db_scale_scarlett2_gain }
+};
+
+static const struct snd_kcontrol_new scarlett2_line_out_volume_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.name = "",
+	.info = scarlett2_volume_ctl_info,
+	.get  = scarlett2_volume_ctl_get,
+	.put  = scarlett2_volume_ctl_put,
+	.private_value = 0, /* max value */
+	.tlv = { .p = db_scale_scarlett2_gain }
+};
+
+/*** HW/SW Volume Switch Controls ***/
+
+static int scarlett2_sw_hw_enum_ctl_info(struct snd_kcontrol *kctl,
+					 struct snd_ctl_elem_info *uinfo)
+{
+	static const char *const values[2] = {
+		"SW", "HW"
+	};
+
+	return snd_ctl_enum_info(uinfo, 1, 2, values);
+}
+
+static int scarlett2_sw_hw_enum_ctl_get(struct snd_kcontrol *kctl,
+					struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett2_mixer_data *private = elem->head.mixer->private_data;
+
+	ucontrol->value.enumerated.item[0] =
+		private->vol_sw_hw_switch[elem->control];
+	return 0;
+}
+
+static int scarlett2_sw_hw_enum_ctl_put(struct snd_kcontrol *kctl,
+					struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	int index = elem->control;
+	int oval, val, err = 0;
+
+	mutex_lock(&private->data_mutex);
+
+	oval = private->vol_sw_hw_switch[index];
+	val = !!ucontrol->value.integer.value[0];
+
+	if (oval == val)
+		goto unlock;
+
+	private->vol_sw_hw_switch[index] = val;
+
+	/* Change access mode to RO (hardware controlled volume)
+	 * or RW (software controlled volume)
+	 */
+	if (val)
+		private->vol_ctls[index]->vd[0].access &=
+			~SNDRV_CTL_ELEM_ACCESS_WRITE;
+	else
+		private->vol_ctls[index]->vd[0].access |=
+			SNDRV_CTL_ELEM_ACCESS_WRITE;
+
+	/* Reset volume to master volume */
+	private->vol[index] = private->master_vol;
+
+	/* Set SW volume to current HW volume */
+	err = scarlett2_usb_set_config(
+		mixer, SCARLETT2_CONFIG_LINE_OUT_VOLUME,
+		index, private->master_vol - SCARLETT2_VOLUME_BIAS);
+	if (err < 0)
+		goto unlock;
+
+	/* Notify of RO/RW change */
+	snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_INFO,
+		       &private->vol_ctls[index]->id);
+
+	/* Send SW/HW switch change to the device */
+	err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_SW_HW_SWITCH,
+				       index, val);
+
+unlock:
+	mutex_unlock(&private->data_mutex);
+	return err;
+}
+
+static const struct snd_kcontrol_new scarlett2_sw_hw_enum_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett2_sw_hw_enum_ctl_info,
+	.get  = scarlett2_sw_hw_enum_ctl_get,
+	.put  = scarlett2_sw_hw_enum_ctl_put,
+};
+
+/*** Line Level/Instrument Level Switch Controls ***/
+
+static int scarlett2_level_enum_ctl_info(struct snd_kcontrol *kctl,
+					 struct snd_ctl_elem_info *uinfo)
+{
+	static const char *const values[2] = {
+		"Line", "Inst"
+	};
+
+	return snd_ctl_enum_info(uinfo, 1, 2, values);
+}
+
+static int scarlett2_level_enum_ctl_get(struct snd_kcontrol *kctl,
+					struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett2_mixer_data *private = elem->head.mixer->private_data;
+
+	ucontrol->value.enumerated.item[0] =
+		private->level_switch[elem->control];
+	return 0;
+}
+
+static int scarlett2_level_enum_ctl_put(struct snd_kcontrol *kctl,
+					struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	int index = elem->control;
+	int oval, val, err = 0;
+
+	mutex_lock(&private->data_mutex);
+
+	oval = private->level_switch[index];
+	val = !!ucontrol->value.integer.value[0];
+
+	if (oval == val)
+		goto unlock;
+
+	private->level_switch[index] = val;
+
+	/* Send switch change to the device */
+	err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_LEVEL_SWITCH,
+				       index, val);
+
+unlock:
+	mutex_unlock(&private->data_mutex);
+	return err;
+}
+
+static const struct snd_kcontrol_new scarlett2_level_enum_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett2_level_enum_ctl_info,
+	.get  = scarlett2_level_enum_ctl_get,
+	.put  = scarlett2_level_enum_ctl_put,
+};
+
+/*** Pad Switch Controls ***/
+
+static int scarlett2_pad_ctl_get(struct snd_kcontrol *kctl,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett2_mixer_data *private = elem->head.mixer->private_data;
+
+	ucontrol->value.enumerated.item[0] =
+		private->pad_switch[elem->control];
+	return 0;
+}
+
+static int scarlett2_pad_ctl_put(struct snd_kcontrol *kctl,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	int index = elem->control;
+	int oval, val, err = 0;
+
+	mutex_lock(&private->data_mutex);
+
+	oval = private->pad_switch[index];
+	val = !!ucontrol->value.integer.value[0];
+
+	if (oval == val)
+		goto unlock;
+
+	private->pad_switch[index] = val;
+
+	/* Send switch change to the device */
+	err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_PAD_SWITCH,
+				       index, val);
+
+unlock:
+	mutex_unlock(&private->data_mutex);
+	return err;
+}
+
+static const struct snd_kcontrol_new scarlett2_pad_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = snd_ctl_boolean_mono_info,
+	.get  = scarlett2_pad_ctl_get,
+	.put  = scarlett2_pad_ctl_put,
+};
+
+/*** Mute/Dim Controls ***/
+
+static int scarlett2_button_ctl_get(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	if (private->vol_updated) {
+		mutex_lock(&private->data_mutex);
+		scarlett2_update_volumes(mixer);
+		mutex_unlock(&private->data_mutex);
+	}
+
+	ucontrol->value.enumerated.item[0] = private->buttons[elem->control];
+	return 0;
+}
+
+static int scarlett2_button_ctl_put(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	int index = elem->control;
+	int oval, val, err = 0;
+
+	mutex_lock(&private->data_mutex);
+
+	oval = private->buttons[index];
+	val = !!ucontrol->value.integer.value[0];
+
+	if (oval == val)
+		goto unlock;
+
+	private->buttons[index] = val;
+
+	/* Send switch change to the device */
+	err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_BUTTONS,
+				       index, val);
+
+unlock:
+	mutex_unlock(&private->data_mutex);
+	return err;
+}
+
+static const struct snd_kcontrol_new scarlett2_button_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = snd_ctl_boolean_mono_info,
+	.get  = scarlett2_button_ctl_get,
+	.put  = scarlett2_button_ctl_put
+};
+
+/*** Create the analogue output controls ***/
+
+static int scarlett2_add_line_out_ctls(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_device_info *info = private->info;
+	const struct scarlett2_ports *ports = info->ports;
+	int num_line_out =
+		ports[SCARLETT2_PORT_TYPE_ANALOGUE].num[SCARLETT2_PORT_OUT];
+	int err, i;
+	char s[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+
+	/* Add R/O HW volume control */
+	if (info->line_out_hw_vol) {
+		snprintf(s, sizeof(s), "Master HW Playback Volume");
+		err = scarlett2_add_new_ctl(mixer,
+					    &scarlett2_master_volume_ctl,
+					    0, 1, s, &private->master_vol_ctl);
+		if (err < 0)
+			return err;
+	}
+
+	/* Add volume controls */
+	for (i = 0; i < num_line_out; i++) {
+
+		/* Fader */
+		if (info->line_out_descrs[i])
+			snprintf(s, sizeof(s),
+				 "Line %02d (%s) Playback Volume",
+				 i + 1, info->line_out_descrs[i]);
+		else
+			snprintf(s, sizeof(s),
+				 "Line %02d Playback Volume",
+				 i + 1);
+		err = scarlett2_add_new_ctl(mixer,
+					    &scarlett2_line_out_volume_ctl,
+					    i, 1, s, &private->vol_ctls[i]);
+		if (err < 0)
+			return err;
+
+		/* Make the fader read-only if the SW/HW switch is set to HW */
+		if (private->vol_sw_hw_switch[i])
+			private->vol_ctls[i]->vd[0].access &=
+				~SNDRV_CTL_ELEM_ACCESS_WRITE;
+
+		/* SW/HW Switch */
+		if (info->line_out_hw_vol) {
+			snprintf(s, sizeof(s),
+				 "Line Out %02d Volume Control Playback Enum",
+				 i + 1);
+			err = scarlett2_add_new_ctl(mixer,
+						    &scarlett2_sw_hw_enum_ctl,
+						    i, 1, s, NULL);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	/* Add HW button controls */
+	for (i = 0; i < private->info->button_count; i++) {
+		err = scarlett2_add_new_ctl(mixer, &scarlett2_button_ctl,
+					    i, 1, scarlett2_button_names[i],
+					    &private->button_ctls[i]);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/*** Create the analogue input controls ***/
+
+static int scarlett2_add_line_in_ctls(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_device_info *info = private->info;
+	int err, i;
+	char s[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+
+	/* Add input level (line/inst) controls */
+	for (i = 0; i < info->level_input_count; i++) {
+		snprintf(s, sizeof(s), "Line In %d Level Capture Enum", i + 1);
+		err = scarlett2_add_new_ctl(mixer, &scarlett2_level_enum_ctl,
+					    i, 1, s, NULL);
+		if (err < 0)
+			return err;
+	}
+
+	/* Add input pad controls */
+	for (i = 0; i < info->pad_input_count; i++) {
+		snprintf(s, sizeof(s), "Line In %d Pad Capture Switch", i + 1);
+		err = scarlett2_add_new_ctl(mixer, &scarlett2_pad_ctl,
+					    i, 1, s, NULL);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/*** Mixer Volume Controls ***/
+
+static int scarlett2_mixer_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 = SCARLETT2_MIXER_MAX_VALUE;
+	uinfo->value.integer.step = 1;
+	return 0;
+}
+
+static int scarlett2_mixer_ctl_get(struct snd_kcontrol *kctl,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett2_mixer_data *private = elem->head.mixer->private_data;
+
+	ucontrol->value.integer.value[0] = private->mix[elem->control];
+	return 0;
+}
+
+static int scarlett2_mixer_ctl_put(struct snd_kcontrol *kctl,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_device_info *info = private->info;
+	const struct scarlett2_ports *ports = info->ports;
+	int oval, val, num_mixer_in, mix_num, err = 0;
+
+	mutex_lock(&private->data_mutex);
+
+	oval = private->mix[elem->control];
+	val = ucontrol->value.integer.value[0];
+	num_mixer_in = ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_OUT];
+	mix_num = elem->control / num_mixer_in;
+
+	if (oval == val)
+		goto unlock;
+
+	private->mix[elem->control] = val;
+	err = scarlett2_usb_set_mix(mixer, mix_num);
+	if (err == 0)
+		err = 1;
+
+unlock:
+	mutex_unlock(&private->data_mutex);
+	return err;
+}
+
+static const DECLARE_TLV_DB_MINMAX(
+	db_scale_scarlett2_mixer,
+	SCARLETT2_MIXER_MIN_DB * 100,
+	SCARLETT2_MIXER_MAX_DB * 100
+);
+
+static const struct snd_kcontrol_new scarlett2_mixer_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.name = "",
+	.info = scarlett2_mixer_ctl_info,
+	.get  = scarlett2_mixer_ctl_get,
+	.put  = scarlett2_mixer_ctl_put,
+	.private_value = SCARLETT2_MIXER_MAX_DB, /* max value */
+	.tlv = { .p = db_scale_scarlett2_mixer }
+};
+
+static int scarlett2_add_mixer_ctls(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_ports *ports = private->info->ports;
+	int err, i, j;
+	int index;
+	char s[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+
+	int num_inputs = ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_OUT];
+	int num_outputs = ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_IN];
+
+	for (i = 0, index = 0; i < num_outputs; i++) {
+		for (j = 0; j < num_inputs; j++, index++) {
+			snprintf(s, sizeof(s),
+				 "Mix %c Input %02d Playback Volume",
+				 'A' + i, j + 1);
+			err = scarlett2_add_new_ctl(mixer, &scarlett2_mixer_ctl,
+						    index, 1, s, NULL);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+/*** Mux Source Selection Controls ***/
+
+static int scarlett2_mux_src_enum_ctl_info(struct snd_kcontrol *kctl,
+					   struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett2_mixer_data *private = elem->head.mixer->private_data;
+	const struct scarlett2_ports *ports = private->info->ports;
+	unsigned int item = uinfo->value.enumerated.item;
+	int items = private->num_mux_srcs;
+	int port_type;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
+	uinfo->count = elem->channels;
+	uinfo->value.enumerated.items = items;
+
+	if (item >= items)
+		item = uinfo->value.enumerated.item = items - 1;
+
+	for (port_type = 0;
+	     port_type < SCARLETT2_PORT_TYPE_COUNT;
+	     port_type++) {
+		if (item < ports[port_type].num[SCARLETT2_PORT_IN]) {
+			sprintf(uinfo->value.enumerated.name,
+				ports[port_type].src_descr,
+				item + ports[port_type].src_num_offset);
+			return 0;
+		}
+		item -= ports[port_type].num[SCARLETT2_PORT_IN];
+	}
+
+	return -EINVAL;
+}
+
+static int scarlett2_mux_src_enum_ctl_get(struct snd_kcontrol *kctl,
+					  struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett2_mixer_data *private = elem->head.mixer->private_data;
+
+	ucontrol->value.enumerated.item[0] = private->mux[elem->control];
+	return 0;
+}
+
+static int scarlett2_mux_src_enum_ctl_put(struct snd_kcontrol *kctl,
+					  struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct usb_mixer_interface *mixer = elem->head.mixer;
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	int index = elem->control;
+	int oval, val, err = 0;
+
+	mutex_lock(&private->data_mutex);
+
+	oval = private->mux[index];
+	val = clamp(ucontrol->value.integer.value[0],
+		    0L, private->num_mux_srcs - 1L);
+
+	if (oval == val)
+		goto unlock;
+
+	private->mux[index] = val;
+	err = scarlett2_usb_set_mux(mixer);
+	if (err == 0)
+		err = 1;
+
+unlock:
+	mutex_unlock(&private->data_mutex);
+	return err;
+}
+
+static const struct snd_kcontrol_new scarlett2_mux_src_enum_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett2_mux_src_enum_ctl_info,
+	.get  = scarlett2_mux_src_enum_ctl_get,
+	.put  = scarlett2_mux_src_enum_ctl_put,
+};
+
+static int scarlett2_add_mux_enums(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_ports *ports = private->info->ports;
+	int port_type, channel, i;
+
+	for (i = 0, port_type = 0;
+	     port_type < SCARLETT2_PORT_TYPE_COUNT;
+	     port_type++) {
+		for (channel = 0;
+		     channel < ports[port_type].num[SCARLETT2_PORT_OUT];
+		     channel++, i++) {
+			int err;
+			char s[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+			const char *const descr = ports[port_type].dst_descr;
+
+			snprintf(s, sizeof(s) - 5, descr, channel + 1);
+			strcat(s, " Enum");
+
+			err = scarlett2_add_new_ctl(mixer,
+						    &scarlett2_mux_src_enum_ctl,
+						    i, 1, s, NULL);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+/*** Meter Controls ***/
+
+static int scarlett2_meter_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 = 4095;
+	uinfo->value.integer.step = 1;
+	return 0;
+}
+
+static int scarlett2_meter_ctl_get(struct snd_kcontrol *kctl,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	u16 meter_levels[SCARLETT2_NUM_METERS];
+	int i, err;
+
+	err = scarlett2_usb_get_meter_levels(elem->head.mixer, meter_levels);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < elem->channels; i++)
+		ucontrol->value.integer.value[i] = meter_levels[i];
+
+	return 0;
+}
+
+static const struct snd_kcontrol_new scarlett2_meter_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_PCM,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+	.name = "",
+	.info = scarlett2_meter_ctl_info,
+	.get  = scarlett2_meter_ctl_get
+};
+
+static int scarlett2_add_meter_ctl(struct usb_mixer_interface *mixer)
+{
+	return scarlett2_add_new_ctl(mixer, &scarlett2_meter_ctl,
+				     0, SCARLETT2_NUM_METERS,
+				     "Level Meter", NULL);
+}
+
+/*** Cleanup/Suspend Callbacks ***/
+
+static void scarlett2_private_free(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	cancel_delayed_work_sync(&private->work);
+	kfree(private);
+	mixer->private_data = NULL;
+}
+
+static void scarlett2_private_suspend(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+
+	if (cancel_delayed_work_sync(&private->work))
+		scarlett2_config_save(private->mixer);
+}
+
+/*** Initialisation ***/
+
+static int scarlett2_count_mux_srcs(const struct scarlett2_ports *ports)
+{
+	int port_type, count = 0;
+
+	for (port_type = 0;
+	     port_type < SCARLETT2_PORT_TYPE_COUNT;
+	     port_type++)
+		count += ports[port_type].num[SCARLETT2_PORT_IN];
+
+	return count;
+}
+
+/* Default routing connects PCM outputs and inputs to Analogue,
+ * S/PDIF, then ADAT
+ */
+static void scarlett2_init_routing(u8 *mux,
+				   const struct scarlett2_ports *ports)
+{
+	int i, input_num, input_count, port_type;
+	int output_num, output_count, port_type_connect_num;
+
+	static const int connect_order[] = {
+		SCARLETT2_PORT_TYPE_ANALOGUE,
+		SCARLETT2_PORT_TYPE_SPDIF,
+		SCARLETT2_PORT_TYPE_ADAT,
+		-1
+	};
+
+	/* Assign PCM inputs (routing outputs) */
+	output_num = scarlett2_get_port_start_num(ports,
+						  SCARLETT2_PORT_OUT,
+						  SCARLETT2_PORT_TYPE_PCM);
+	output_count = ports[SCARLETT2_PORT_TYPE_PCM].num[SCARLETT2_PORT_OUT];
+
+	for (port_type = connect_order[port_type_connect_num = 0];
+	     port_type >= 0;
+	     port_type = connect_order[++port_type_connect_num]) {
+		input_num = scarlett2_get_port_start_num(
+			ports, SCARLETT2_PORT_IN, port_type);
+		input_count = ports[port_type].num[SCARLETT2_PORT_IN];
+		for (i = 0;
+		     i < input_count && output_count;
+		     i++, output_count--)
+			mux[output_num++] = input_num++;
+	}
+
+	/* Assign PCM outputs (routing inputs) */
+	input_num = scarlett2_get_port_start_num(ports,
+						 SCARLETT2_PORT_IN,
+						 SCARLETT2_PORT_TYPE_PCM);
+	input_count = ports[SCARLETT2_PORT_TYPE_PCM].num[SCARLETT2_PORT_IN];
+
+	for (port_type = connect_order[port_type_connect_num = 0];
+	     port_type >= 0;
+	     port_type = connect_order[++port_type_connect_num]) {
+		output_num = scarlett2_get_port_start_num(
+			ports, SCARLETT2_PORT_OUT, port_type);
+		output_count = ports[port_type].num[SCARLETT2_PORT_OUT];
+		for (i = 0;
+		     i < output_count && input_count;
+		     i++, input_count--)
+			mux[output_num++] = input_num++;
+	}
+}
+
+/* Initialise private data, routing, sequence number */
+static int scarlett2_init_private(struct usb_mixer_interface *mixer,
+				  const struct scarlett2_device_info *info)
+{
+	struct scarlett2_mixer_data *private =
+		kzalloc(sizeof(struct scarlett2_mixer_data), GFP_KERNEL);
+
+	if (!private)
+		return -ENOMEM;
+
+	mutex_init(&private->usb_mutex);
+	mutex_init(&private->data_mutex);
+	INIT_DELAYED_WORK(&private->work, scarlett2_config_save_work);
+	private->info = info;
+	private->num_mux_srcs = scarlett2_count_mux_srcs(info->ports);
+	private->scarlett2_seq = 0;
+	private->mixer = mixer;
+	mixer->private_data = private;
+	mixer->private_free = scarlett2_private_free;
+	mixer->private_suspend = scarlett2_private_suspend;
+
+	/* Setup default routing */
+	scarlett2_init_routing(private->mux, info->ports);
+
+	/* Initialise the sequence number used for the proprietary commands */
+	return scarlett2_usb(mixer, SCARLETT2_USB_INIT_SEQ, NULL, 0, NULL, 0);
+}
+
+/* Read line-in config and line-out volume settings on start */
+static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_device_info *info = private->info;
+	const struct scarlett2_ports *ports = info->ports;
+	int num_line_out =
+		ports[SCARLETT2_PORT_TYPE_ANALOGUE].num[SCARLETT2_PORT_OUT];
+	u8 level_switches[SCARLETT2_LEVEL_SWITCH_MAX];
+	u8 pad_switches[SCARLETT2_PAD_SWITCH_MAX];
+	struct scarlett2_usb_volume_status volume_status;
+	int err, i;
+
+	if (info->level_input_count) {
+		err = scarlett2_usb_get_config(
+			mixer,
+			SCARLETT2_CONFIG_LEVEL_SWITCH,
+			info->level_input_count,
+			level_switches);
+		if (err < 0)
+			return err;
+		for (i = 0; i < info->level_input_count; i++)
+			private->level_switch[i] = level_switches[i];
+	}
+
+	if (info->pad_input_count) {
+		err = scarlett2_usb_get_config(
+			mixer,
+			SCARLETT2_CONFIG_PAD_SWITCH,
+			info->pad_input_count,
+			pad_switches);
+		if (err < 0)
+			return err;
+		for (i = 0; i < info->pad_input_count; i++)
+			private->pad_switch[i] = pad_switches[i];
+	}
+
+	err = scarlett2_usb_get_volume_status(mixer, &volume_status);
+	if (err < 0)
+		return err;
+
+	private->master_vol = clamp(
+		volume_status.master_vol + SCARLETT2_VOLUME_BIAS,
+		0, SCARLETT2_VOLUME_BIAS);
+
+	for (i = 0; i < num_line_out; i++) {
+		int volume;
+
+		private->vol_sw_hw_switch[i] =
+			info->line_out_hw_vol
+				&& volume_status.sw_hw_switch[i];
+
+		volume = private->vol_sw_hw_switch[i]
+			   ? volume_status.master_vol
+			   : volume_status.sw_vol[i];
+		volume = clamp(volume + SCARLETT2_VOLUME_BIAS,
+			       0, SCARLETT2_VOLUME_BIAS);
+		private->vol[i] = volume;
+	}
+
+	for (i = 0; i < info->button_count; i++)
+		private->buttons[i] = !!volume_status.buttons[i];
+
+	return 0;
+}
+
+/* Notify on volume change */
+static void scarlett2_mixer_interrupt_vol_change(
+	struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_ports *ports = private->info->ports;
+	int num_line_out =
+		ports[SCARLETT2_PORT_TYPE_ANALOGUE].num[SCARLETT2_PORT_OUT];
+	int i;
+
+	private->vol_updated = 1;
+
+	snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
+		       &private->master_vol_ctl->id);
+
+	for (i = 0; i < num_line_out; i++) {
+		if (!private->vol_sw_hw_switch[i])
+			continue;
+		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
+			       &private->vol_ctls[i]->id);
+	}
+}
+
+/* Notify on button change */
+static void scarlett2_mixer_interrupt_button_change(
+	struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	int i;
+
+	private->vol_updated = 1;
+
+	for (i = 0; i < private->info->button_count; i++)
+		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
+			       &private->button_ctls[i]->id);
+}
+
+/* Interrupt callback */
+static void scarlett2_mixer_interrupt(struct urb *urb)
+{
+	struct usb_mixer_interface *mixer = urb->context;
+	int len = urb->actual_length;
+	int ustatus = urb->status;
+	u32 data;
+
+	if (ustatus != 0)
+		goto requeue;
+
+	if (len == 8) {
+		data = le32_to_cpu(*(u32 *)urb->transfer_buffer);
+		if (data & SCARLETT2_USB_INTERRUPT_VOL_CHANGE)
+			scarlett2_mixer_interrupt_vol_change(mixer);
+		if (data & SCARLETT2_USB_INTERRUPT_BUTTON_CHANGE)
+			scarlett2_mixer_interrupt_button_change(mixer);
+	} else {
+		usb_audio_err(mixer->chip,
+			      "scarlett mixer interrupt length %d\n", len);
+	}
+
+requeue:
+	if (ustatus != -ENOENT &&
+	    ustatus != -ECONNRESET &&
+	    ustatus != -ESHUTDOWN) {
+		urb->dev = mixer->chip->dev;
+		usb_submit_urb(urb, GFP_ATOMIC);
+	}
+}
+
+static int scarlett2_mixer_status_create(struct usb_mixer_interface *mixer)
+{
+	struct usb_device *dev = mixer->chip->dev;
+	unsigned int pipe = usb_rcvintpipe(dev,
+					   SCARLETT2_USB_INTERRUPT_ENDPOINT);
+	void *transfer_buffer;
+
+	if (mixer->urb) {
+		usb_audio_err(mixer->chip,
+			      "%s: mixer urb already in use!\n", __func__);
+		return 0;
+	}
+
+	if (snd_usb_pipe_sanity_check(dev, pipe))
+		return -EINVAL;
+
+	mixer->urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!mixer->urb)
+		return -ENOMEM;
+
+	transfer_buffer = kmalloc(SCARLETT2_USB_INTERRUPT_MAX_DATA, GFP_KERNEL);
+	if (!transfer_buffer)
+		return -ENOMEM;
+
+	usb_fill_int_urb(mixer->urb, dev, pipe,
+			 transfer_buffer, SCARLETT2_USB_INTERRUPT_MAX_DATA,
+			 scarlett2_mixer_interrupt, mixer,
+			 SCARLETT2_USB_INTERRUPT_INTERVAL);
+
+	return usb_submit_urb(mixer->urb, GFP_KERNEL);
+}
+
+/* Entry point */
+int snd_scarlett_gen2_controls_create(struct usb_mixer_interface *mixer)
+{
+	const struct scarlett2_device_info *info;
+	int err;
+
+	/* only use UAC_VERSION_2 */
+	if (!mixer->protocol)
+		return 0;
+
+	switch (mixer->chip->usb_id) {
+	case USB_ID(0x1235, 0x8203):
+		info = &s6i6_gen2_info;
+		break;
+	case USB_ID(0x1235, 0x8204):
+		info = &s18i8_gen2_info;
+		break;
+	case USB_ID(0x1235, 0x8201):
+		info = &s18i20_gen2_info;
+		break;
+	default: /* device not (yet) supported */
+		return -EINVAL;
+	}
+
+	if (!(mixer->chip->setup & SCARLETT2_ENABLE)) {
+		usb_audio_err(mixer->chip,
+			"Focusrite Scarlett Gen 2 Mixer Driver disabled; "
+			"use options snd_usb_audio device_setup=1 "
+			"to enable and report any issues to g@b4.vu");
+		return 0;
+	}
+
+	/* Initialise private data, routing, sequence number */
+	err = scarlett2_init_private(mixer, info);
+	if (err < 0)
+		return err;
+
+	/* Read volume levels and controls from the interface */
+	err = scarlett2_read_configs(mixer);
+	if (err < 0)
+		return err;
+
+	/* Create the analogue output controls */
+	err = scarlett2_add_line_out_ctls(mixer);
+	if (err < 0)
+		return err;
+
+	/* Create the analogue input controls */
+	err = scarlett2_add_line_in_ctls(mixer);
+	if (err < 0)
+		return err;
+
+	/* Create the input, output, and mixer mux input selections */
+	err = scarlett2_add_mux_enums(mixer);
+	if (err < 0)
+		return err;
+
+	/* Create the matrix mixer controls */
+	err = scarlett2_add_mixer_ctls(mixer);
+	if (err < 0)
+		return err;
+
+	/* Create the level meter controls */
+	err = scarlett2_add_meter_ctl(mixer);
+	if (err < 0)
+		return err;
+
+	/* Set up the interrupt polling if there are hardware buttons */
+	if (info->button_count) {
+		err = scarlett2_mixer_status_create(mixer);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
diff --git a/sound/usb/mixer_scarlett_gen2.h b/sound/usb/mixer_scarlett_gen2.h
new file mode 100644
index 0000000..52e1dad
--- /dev/null
+++ b/sound/usb/mixer_scarlett_gen2.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __USB_MIXER_SCARLETT_GEN2_H
+#define __USB_MIXER_SCARLETT_GEN2_H
+
+int snd_scarlett_gen2_controls_create(struct usb_mixer_interface *mixer);
+
+#endif /* __USB_MIXER_SCARLETT_GEN2_H */