ALSA: firewire-lib: move parameter for pcm frame multiplier from context payload processing layer

The current implementation delegates the task to calculate the number of
processed PCM frames into the context payload processing layer. It looks
good as long as frame calculation is done for a single purpose.
Nevertheless, another purpose, the computation of extra delay for the
runtime of PCM substream, requires frame calculation, too.

This commit refactors the current implementation so that the packet stream
processing layer is responsible for the calculation of PCM frame, too. The
member is moved to stream structure for multiplier between data block
count and PCM frame count.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230110134933.322794-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-am824.c

@@ -36,8 +36,6 @@ struct amdtp_am824 {
 
 	u8 pcm_positions[AM824_MAX_CHANNELS_FOR_PCM];
 	u8 midi_position;
-
-	unsigned int frame_multiplier;
 };
 
 /**
@@ -59,8 +57,8 @@ int amdtp_am824_set_parameters(struct amdtp_stream *s, unsigned int rate,
 {
 	struct amdtp_am824 *p = s->protocol;
 	unsigned int midi_channels;
-	unsigned int i;
-	int err;
+	unsigned int pcm_frame_multiplier;
+	int i, err;
 
 	if (amdtp_stream_running(s))
 		return -EINVAL;
@@ -77,8 +75,18 @@ int amdtp_am824_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	    WARN_ON(midi_channels > AM824_MAX_CHANNELS_FOR_MIDI))
 		return -EINVAL;
 
-	err = amdtp_stream_set_parameters(s, rate,
-					  pcm_channels + midi_channels);
+	/*
+	 * In IEC 61883-6, one data block represents one event. In ALSA, one
+	 * event equals to one PCM frame. But Dice has a quirk at higher
+	 * sampling rate to transfer two PCM frames in one data block.
+	 */
+	if (double_pcm_frames)
+		pcm_frame_multiplier = 2;
+	else
+		pcm_frame_multiplier = 1;
+
+	err = amdtp_stream_set_parameters(s, rate, pcm_channels + midi_channels,
+					  pcm_frame_multiplier);
 	if (err < 0)
 		return err;
 
@@ -88,16 +96,6 @@ int amdtp_am824_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	p->pcm_channels = pcm_channels;
 	p->midi_ports = midi_ports;
 
-	/*
-	 * In IEC 61883-6, one data block represents one event. In ALSA, one
-	 * event equals to one PCM frame. But Dice has a quirk at higher
-	 * sampling rate to transfer two PCM frames in one data block.
-	 */
-	if (double_pcm_frames)
-		p->frame_multiplier = 2;
-	else
-		p->frame_multiplier = 1;
-
 	/* init the position map for PCM and MIDI channels */
 	for (i = 0; i < pcm_channels; i++)
 		p->pcm_positions[i] = i;
@@ -361,7 +359,7 @@ static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
 
 		if (pcm) {
 			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
-			pcm_frames += data_blocks * p->frame_multiplier;
+			pcm_frames += data_blocks * s->pcm_frame_multiplier;
 		} else {
 			write_pcm_silence(s, buf, data_blocks);
 		}
@@ -392,7 +390,7 @@ static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
 
 		if (pcm) {
 			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
-			pcm_frames += data_blocks * p->frame_multiplier;
+			pcm_frames += data_blocks * s->pcm_frame_multiplier;
 		}
 
 		if (p->midi_ports) {

sound/firewire/amdtp-stream.c

@@ -271,12 +271,14 @@ EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
  * @s: the AMDTP stream to configure
  * @rate: the sample rate
  * @data_block_quadlets: the size of a data block in quadlet unit
+ * @pcm_frame_multiplier: the multiplier to compute the number of PCM frames by the number of AMDTP
+ *			  events.
  *
  * The parameters must be set before the stream is started, and must not be
  * changed while the stream is running.
  */
 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
-				unsigned int data_block_quadlets)
+				unsigned int data_block_quadlets, unsigned int pcm_frame_multiplier)
 {
 	unsigned int sfc;
 
@@ -298,6 +300,8 @@ int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	if (s->flags & CIP_BLOCKING)
 		s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
 
+	s->pcm_frame_multiplier = pcm_frame_multiplier;
+
 	return 0;
 }
 EXPORT_SYMBOL(amdtp_stream_set_parameters);
@@ -1032,16 +1036,25 @@ static inline void cancel_stream(struct amdtp_stream *s)
 }
 
 static void process_ctx_payloads(struct amdtp_stream *s,
-				 const struct pkt_desc *descs,
+				 const struct pkt_desc *desc,
 				 unsigned int count)
 {
 	struct snd_pcm_substream *pcm;
-	unsigned int pcm_frames;
+	int i;
 
 	pcm = READ_ONCE(s->pcm);
-	pcm_frames = s->process_ctx_payloads(s, descs, count, pcm);
-	if (pcm)
-		update_pcm_pointers(s, pcm, pcm_frames);
+	(void)s->process_ctx_payloads(s, desc, count, pcm);
+
+	if (pcm) {
+		unsigned int data_block_count = 0;
+
+		for (i = 0; i < count; ++i) {
+			data_block_count += desc->data_blocks;
+			desc = amdtp_stream_next_packet_desc(s, desc);
+		}
+
+		update_pcm_pointers(s, pcm, data_block_count * s->pcm_frame_multiplier);
+	}
 }
 
 static void process_rx_packets(struct fw_iso_context *context, u32 tstamp, size_t header_length,

sound/firewire/amdtp-stream.h

@@ -190,6 +190,7 @@ struct amdtp_stream {
 	struct snd_pcm_substream *pcm;
 	snd_pcm_uframes_t pcm_buffer_pointer;
 	unsigned int pcm_period_pointer;
+	unsigned int pcm_frame_multiplier;
 
 	// To start processing content of packets at the same cycle in several contexts for
 	// each direction.
@@ -216,7 +217,7 @@ int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
 void amdtp_stream_destroy(struct amdtp_stream *s);
 
 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
-				unsigned int data_block_quadlets);
+				unsigned int data_block_quadlets, unsigned int pcm_frame_multiplier);
 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
 
 void amdtp_stream_update(struct amdtp_stream *s);

sound/firewire/digi00x/amdtp-dot.c

@@ -123,7 +123,7 @@ int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	 * A first data channel is for MIDI messages, the rest is Multi Bit
 	 * Linear Audio data channel.
 	 */
-	err = amdtp_stream_set_parameters(s, rate, pcm_channels + 1);
+	err = amdtp_stream_set_parameters(s, rate, pcm_channels + 1, 1);
 	if (err < 0)
 		return err;
 

sound/firewire/fireface/amdtp-ff.c

@@ -24,7 +24,7 @@ int amdtp_ff_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	p->pcm_channels = pcm_channels;
 	data_channels = pcm_channels;
 
-	return amdtp_stream_set_parameters(s, rate, data_channels);
+	return amdtp_stream_set_parameters(s, rate, data_channels, 1);
 }
 
 static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,

sound/firewire/motu/amdtp-motu.c

@@ -73,7 +73,7 @@ int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	data_chunks = formats->msg_chunks + pcm_chunks;
 	data_block_quadlets = 1 + DIV_ROUND_UP(data_chunks * 3, 4);
 
-	err = amdtp_stream_set_parameters(s, rate, data_block_quadlets);
+	err = amdtp_stream_set_parameters(s, rate, data_block_quadlets, 1);
 	if (err < 0)
 		return err;
 

sound/firewire/tascam/amdtp-tascam.c

@@ -29,7 +29,7 @@ int amdtp_tscm_set_parameters(struct amdtp_stream *s, unsigned int rate)
 	if (s->direction == AMDTP_IN_STREAM)
 		data_channels += 2;
 
-	return amdtp_stream_set_parameters(s, rate, data_channels);
+	return amdtp_stream_set_parameters(s, rate, data_channels, 1);
 }
 
 static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,