4 files changed, 182 insertions, 112 deletions

diff --git a/sound/firewire/fireface/amdtp-ff.c b/sound/firewire/fireface/amdtp-ff.c
index 2938489740b4..119c0076b17a 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;
+
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
 
-	channels = p->pcm_channels;
 	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;
+
+	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
+	pcm_buffer_pointer %= runtime->buffer_size;
 
-	channels = p->pcm_channels;
 	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;
-
-	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;
+	unsigned int pcm_frames = 0;
+	int i;
+
+	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;
-
-	if (pcm) {
-		read_pcm_s32(s, pcm, (__le32 *)buffer, data_blocks);
-		pcm_frames = data_blocks;
-	} else {
-		pcm_frames = 0;
+	unsigned int pcm_frames = 0;
+	int i;
+
+	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/fireface/ff-pcm.c b/sound/firewire/fireface/ff-pcm.c
index 9eab3ad283ce..f978cc2fed7d 100644
--- a/sound/firewire/fireface/ff-pcm.c
+++ b/sound/firewire/fireface/ff-pcm.c
@@ -139,6 +139,7 @@ static int pcm_init_hw_params(struct snd_ff *ff,
 static int pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_ff *ff = substream->private_data;
+	struct amdtp_domain *d = &ff->domain;
 	unsigned int rate;
 	enum snd_ff_clock_src src;
 	int i, err;
@@ -155,16 +156,21 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	if (err < 0)
 		goto release_lock;
 
+	mutex_lock(&ff->mutex);
+
+	// When source of clock is not internal or any stream is reserved for
+	// transmission of PCM frames, the available sampling rate is limited
+	// at current one.
 	if (src != SND_FF_CLOCK_SRC_INTERNAL) {
 		for (i = 0; i < CIP_SFC_COUNT; ++i) {
 			if (amdtp_rate_table[i] == rate)
 				break;
 		}
-		/*
-		 * The unit is configured at sampling frequency which packet
-		 * streaming engine can't support.
-		 */
+
+		// The unit is configured at sampling frequency which packet
+		// streaming engine can't support.
 		if (i >= CIP_SFC_COUNT) {
+			mutex_unlock(&ff->mutex);
 			err = -EIO;
 			goto release_lock;
 		}
@@ -172,14 +178,34 @@ static int pcm_open(struct snd_pcm_substream *substream)
 		substream->runtime->hw.rate_min = rate;
 		substream->runtime->hw.rate_max = rate;
 	} else {
-		if (amdtp_stream_pcm_running(&ff->rx_stream) ||
-		    amdtp_stream_pcm_running(&ff->tx_stream)) {
+		if (ff->substreams_counter > 0) {
+			unsigned int frames_per_period = d->events_per_period;
+			unsigned int frames_per_buffer = d->events_per_buffer;
+
 			rate = amdtp_rate_table[ff->rx_stream.sfc];
 			substream->runtime->hw.rate_min = rate;
 			substream->runtime->hw.rate_max = rate;
+
+			err = snd_pcm_hw_constraint_minmax(substream->runtime,
+					SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
+					frames_per_period, frames_per_period);
+			if (err < 0) {
+				mutex_unlock(&ff->mutex);
+				goto release_lock;
+			}
+
+			err = snd_pcm_hw_constraint_minmax(substream->runtime,
+					SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+					frames_per_buffer, frames_per_buffer);
+			if (err < 0) {
+				mutex_unlock(&ff->mutex);
+				goto release_lock;
+			}
 		}
 	}
 
+	mutex_unlock(&ff->mutex);
+
 	snd_pcm_set_sync(substream);
 
 	return 0;
@@ -202,24 +228,22 @@ static int pcm_hw_params(struct snd_pcm_substream *substream,
 			 struct snd_pcm_hw_params *hw_params)
 {
 	struct snd_ff *ff = substream->private_data;
-	int err;
-
-	err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
-					       params_buffer_bytes(hw_params));
-	if (err < 0)
-		return err;
+	int err = 0;
 
 	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 		unsigned int rate = params_rate(hw_params);
+		unsigned int frames_per_period = params_period_size(hw_params);
+		unsigned int frames_per_buffer = params_buffer_size(hw_params);
 
 		mutex_lock(&ff->mutex);
-		err = snd_ff_stream_reserve_duplex(ff, rate);
+		err = snd_ff_stream_reserve_duplex(ff, rate, frames_per_period,
+						   frames_per_buffer);
 		if (err >= 0)
 			++ff->substreams_counter;
 		mutex_unlock(&ff->mutex);
 	}
 
-	return 0;
+	return err;
 }
 
 static int pcm_hw_free(struct snd_pcm_substream *substream)
@@ -235,7 +259,7 @@ static int pcm_hw_free(struct snd_pcm_substream *substream)
 
 	mutex_unlock(&ff->mutex);
 
-	return snd_pcm_lib_free_vmalloc_buffer(substream);
+	return 0;
 }
 
 static int pcm_capture_prepare(struct snd_pcm_substream *substream)
@@ -312,28 +336,28 @@ static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
 {
 	struct snd_ff *ff = sbstrm->private_data;
 
-	return amdtp_stream_pcm_pointer(&ff->tx_stream);
+	return amdtp_domain_stream_pcm_pointer(&ff->domain, &ff->tx_stream);
 }
 
 static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
 {
 	struct snd_ff *ff = sbstrm->private_data;
 
-	return amdtp_stream_pcm_pointer(&ff->rx_stream);
+	return amdtp_domain_stream_pcm_pointer(&ff->domain, &ff->rx_stream);
 }
 
 static int pcm_capture_ack(struct snd_pcm_substream *substream)
 {
 	struct snd_ff *ff = substream->private_data;
 
-	return amdtp_stream_pcm_ack(&ff->tx_stream);
+	return amdtp_domain_stream_pcm_ack(&ff->domain, &ff->tx_stream);
 }
 
 static int pcm_playback_ack(struct snd_pcm_substream *substream)
 {
 	struct snd_ff *ff = substream->private_data;
 
-	return amdtp_stream_pcm_ack(&ff->rx_stream);
+	return amdtp_domain_stream_pcm_ack(&ff->domain, &ff->rx_stream);
 }
 
 int snd_ff_create_pcm_devices(struct snd_ff *ff)
@@ -341,26 +365,22 @@ int snd_ff_create_pcm_devices(struct snd_ff *ff)
 	static const struct snd_pcm_ops pcm_capture_ops = {
 		.open		= pcm_open,
 		.close		= pcm_close,
-		.ioctl		= snd_pcm_lib_ioctl,
 		.hw_params	= pcm_hw_params,
 		.hw_free	= pcm_hw_free,
 		.prepare	= pcm_capture_prepare,
 		.trigger	= pcm_capture_trigger,
 		.pointer	= pcm_capture_pointer,
 		.ack		= pcm_capture_ack,
-		.page		= snd_pcm_lib_get_vmalloc_page,
 	};
 	static const struct snd_pcm_ops pcm_playback_ops = {
 		.open		= pcm_open,
 		.close		= pcm_close,
-		.ioctl		= snd_pcm_lib_ioctl,
 		.hw_params	= pcm_hw_params,
 		.hw_free	= pcm_hw_free,
 		.prepare	= pcm_playback_prepare,
 		.trigger	= pcm_playback_trigger,
 		.pointer	= pcm_playback_pointer,
 		.ack		= pcm_playback_ack,
-		.page		= snd_pcm_lib_get_vmalloc_page,
 	};
 	struct snd_pcm *pcm;
 	int err;
@@ -374,6 +394,7 @@ int snd_ff_create_pcm_devices(struct snd_ff *ff)
 		 "%s PCM", ff->card->shortname);
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_playback_ops);
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &pcm_capture_ops);
+	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
 
 	return 0;
 }
diff --git a/sound/firewire/fireface/ff-stream.c b/sound/firewire/fireface/ff-stream.c
index 4208b8004d1a..63b79c4a5405 100644
--- a/sound/firewire/fireface/ff-stream.c
+++ b/sound/firewire/fireface/ff-stream.c
@@ -32,61 +32,65 @@ int snd_ff_stream_get_multiplier_mode(enum cip_sfc sfc,
 
 static inline void finish_session(struct snd_ff *ff)
 {
-	amdtp_stream_stop(&ff->tx_stream);
-	amdtp_stream_stop(&ff->rx_stream);
-
 	ff->spec->protocol->finish_session(ff);
 	ff->spec->protocol->switch_fetching_mode(ff, false);
 }
 
-static int init_stream(struct snd_ff *ff, enum amdtp_stream_direction dir)
+static int init_stream(struct snd_ff *ff, struct amdtp_stream *s)
 {
-	int err;
 	struct fw_iso_resources *resources;
-	struct amdtp_stream *stream;
+	enum amdtp_stream_direction dir;
+	int err;
 
-	if (dir == AMDTP_IN_STREAM) {
+	if (s == &ff->tx_stream) {
 		resources = &ff->tx_resources;
-		stream = &ff->tx_stream;
+		dir = AMDTP_IN_STREAM;
 	} else {
 		resources = &ff->rx_resources;
-		stream = &ff->rx_stream;
+		dir = AMDTP_OUT_STREAM;
 	}
 
 	err = fw_iso_resources_init(resources, ff->unit);
 	if (err < 0)
 		return err;
 
-	err = amdtp_ff_init(stream, ff->unit, dir);
+	err = amdtp_ff_init(s, ff->unit, dir);
 	if (err < 0)
 		fw_iso_resources_destroy(resources);
 
 	return err;
 }
 
-static void destroy_stream(struct snd_ff *ff, enum amdtp_stream_direction dir)
+static void destroy_stream(struct snd_ff *ff, struct amdtp_stream *s)
 {
-	if (dir == AMDTP_IN_STREAM) {
-		amdtp_stream_destroy(&ff->tx_stream);
+	amdtp_stream_destroy(s);
+
+	if (s == &ff->tx_stream)
 		fw_iso_resources_destroy(&ff->tx_resources);
-	} else {
-		amdtp_stream_destroy(&ff->rx_stream);
+	else
 		fw_iso_resources_destroy(&ff->rx_resources);
-	}
 }
 
 int snd_ff_stream_init_duplex(struct snd_ff *ff)
 {
 	int err;
 
-	err = init_stream(ff, AMDTP_OUT_STREAM);
+	err = init_stream(ff, &ff->rx_stream);
 	if (err < 0)
-		goto end;
+		return err;
+
+	err = init_stream(ff, &ff->tx_stream);
+	if (err < 0) {
+		destroy_stream(ff, &ff->rx_stream);
+		return err;
+	}
+
+	err = amdtp_domain_init(&ff->domain);
+	if (err < 0) {
+		destroy_stream(ff, &ff->rx_stream);
+		destroy_stream(ff, &ff->tx_stream);
+	}
 
-	err = init_stream(ff, AMDTP_IN_STREAM);
-	if (err < 0)
-		destroy_stream(ff, AMDTP_OUT_STREAM);
-end:
 	return err;
 }
 
@@ -96,11 +100,15 @@ end:
  */
 void snd_ff_stream_destroy_duplex(struct snd_ff *ff)
 {
-	destroy_stream(ff, AMDTP_IN_STREAM);
-	destroy_stream(ff, AMDTP_OUT_STREAM);
+	amdtp_domain_destroy(&ff->domain);
+
+	destroy_stream(ff, &ff->rx_stream);
+	destroy_stream(ff, &ff->tx_stream);
 }
 
-int snd_ff_stream_reserve_duplex(struct snd_ff *ff, unsigned int rate)
+int snd_ff_stream_reserve_duplex(struct snd_ff *ff, unsigned int rate,
+				 unsigned int frames_per_period,
+				 unsigned int frames_per_buffer)
 {
 	unsigned int curr_rate;
 	enum snd_ff_clock_src src;
@@ -114,6 +122,7 @@ int snd_ff_stream_reserve_duplex(struct snd_ff *ff, unsigned int rate)
 		enum snd_ff_stream_mode mode;
 		int i;
 
+		amdtp_domain_stop(&ff->domain);
 		finish_session(ff);
 
 		fw_iso_resources_free(&ff->tx_resources);
@@ -143,6 +152,14 @@ int snd_ff_stream_reserve_duplex(struct snd_ff *ff, unsigned int rate)
 		err = ff->spec->protocol->allocate_resources(ff, rate);
 		if (err < 0)
 			return err;
+
+		err = amdtp_domain_set_events_per_period(&ff->domain,
+					frames_per_period, frames_per_buffer);
+		if (err < 0) {
+			fw_iso_resources_free(&ff->tx_resources);
+			fw_iso_resources_free(&ff->rx_resources);
+			return err;
+		}
 	}
 
 	return 0;
@@ -156,51 +173,60 @@ int snd_ff_stream_start_duplex(struct snd_ff *ff, unsigned int rate)
 		return 0;
 
 	if (amdtp_streaming_error(&ff->tx_stream) ||
-	    amdtp_streaming_error(&ff->rx_stream))
+	    amdtp_streaming_error(&ff->rx_stream)) {
+		amdtp_domain_stop(&ff->domain);
 		finish_session(ff);
+	}
 
 	/*
 	 * Regardless of current source of clock signal, drivers transfer some
 	 * packets. Then, the device transfers packets.
 	 */
 	if (!amdtp_stream_running(&ff->rx_stream)) {
+		int spd = fw_parent_device(ff->unit)->max_speed;
+		unsigned int ir_delay_cycle;
+
 		err = ff->spec->protocol->begin_session(ff, rate);
 		if (err < 0)
 			goto error;
 
-		err = amdtp_stream_start(&ff->rx_stream,
-					 ff->rx_resources.channel,
-					 fw_parent_device(ff->unit)->max_speed);
+		err = amdtp_domain_add_stream(&ff->domain, &ff->rx_stream,
+					      ff->rx_resources.channel, spd);
 		if (err < 0)
 			goto error;
 
-		if (!amdtp_stream_wait_callback(&ff->rx_stream,
-						CALLBACK_TIMEOUT_MS)) {
-			err = -ETIMEDOUT;
-			goto error;
-		}
-
-		err = ff->spec->protocol->switch_fetching_mode(ff, true);
+		err = amdtp_domain_add_stream(&ff->domain, &ff->tx_stream,
+					      ff->tx_resources.channel, spd);
 		if (err < 0)
 			goto error;
-	}
 
-	if (!amdtp_stream_running(&ff->tx_stream)) {
-		err = amdtp_stream_start(&ff->tx_stream,
-					 ff->tx_resources.channel,
-					 fw_parent_device(ff->unit)->max_speed);
+		// The device postpones start of transmission mostly for several
+		// cycles after receiving packets firstly.
+		if (ff->spec->protocol == &snd_ff_protocol_ff800)
+			ir_delay_cycle = 800;	// = 100 msec
+		else
+			ir_delay_cycle = 16;	// = 2 msec
+
+		err = amdtp_domain_start(&ff->domain, ir_delay_cycle);
 		if (err < 0)
 			goto error;
 
-		if (!amdtp_stream_wait_callback(&ff->tx_stream,
+		if (!amdtp_stream_wait_callback(&ff->rx_stream,
+						CALLBACK_TIMEOUT_MS) ||
+		    !amdtp_stream_wait_callback(&ff->tx_stream,
 						CALLBACK_TIMEOUT_MS)) {
 			err = -ETIMEDOUT;
 			goto error;
 		}
+
+		err = ff->spec->protocol->switch_fetching_mode(ff, true);
+		if (err < 0)
+			goto error;
 	}
 
 	return 0;
 error:
+	amdtp_domain_stop(&ff->domain);
 	finish_session(ff);
 
 	return err;
@@ -209,6 +235,7 @@ error:
 void snd_ff_stream_stop_duplex(struct snd_ff *ff)
 {
 	if (ff->substreams_counter == 0) {
+		amdtp_domain_stop(&ff->domain);
 		finish_session(ff);
 
 		fw_iso_resources_free(&ff->tx_resources);
@@ -218,12 +245,11 @@ void snd_ff_stream_stop_duplex(struct snd_ff *ff)
 
 void snd_ff_stream_update_duplex(struct snd_ff *ff)
 {
+	amdtp_domain_stop(&ff->domain);
+
 	// The device discontinue to transfer packets.
 	amdtp_stream_pcm_abort(&ff->tx_stream);
-	amdtp_stream_stop(&ff->tx_stream);
-
 	amdtp_stream_pcm_abort(&ff->rx_stream);
-	amdtp_stream_stop(&ff->rx_stream);
 }
 
 void snd_ff_stream_lock_changed(struct snd_ff *ff)
diff --git a/sound/firewire/fireface/ff.h b/sound/firewire/fireface/ff.h
index 36dd0c75b9f7..dc7a20f75983 100644
--- a/sound/firewire/fireface/ff.h
+++ b/sound/firewire/fireface/ff.h
@@ -91,6 +91,8 @@ struct snd_ff {
 	int dev_lock_count;
 	bool dev_lock_changed;
 	wait_queue_head_t hwdep_wait;
+
+	struct amdtp_domain domain;
 };
 
 enum snd_ff_clock_src {
@@ -137,7 +139,9 @@ int snd_ff_stream_get_multiplier_mode(enum cip_sfc sfc,
 				      enum snd_ff_stream_mode *mode);
 int snd_ff_stream_init_duplex(struct snd_ff *ff);
 void snd_ff_stream_destroy_duplex(struct snd_ff *ff);
-int snd_ff_stream_reserve_duplex(struct snd_ff *ff, unsigned int rate);
+int snd_ff_stream_reserve_duplex(struct snd_ff *ff, unsigned int rate,
+				 unsigned int frames_per_period,
+				 unsigned int frames_per_buffer);
 int snd_ff_stream_start_duplex(struct snd_ff *ff, unsigned int rate);
 void snd_ff_stream_stop_duplex(struct snd_ff *ff);
 void snd_ff_stream_update_duplex(struct snd_ff *ff);