ALSA: firewire-lib: code refactoring for transfer delay

In later commit, transfer delay is used in both IR and IT contexts. This
commit refactors regardless of transfer delay.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210522013303.49596-7-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream.c

@@ -294,17 +294,11 @@ int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
 	s->syt_interval = amdtp_syt_intervals[sfc];
 
 	// default buffering in the device.
-	if (s->direction == AMDTP_OUT_STREAM) {
-		s->ctx_data.rx.transfer_delay =
-					TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
-
-		if (s->flags & CIP_BLOCKING) {
-			// additional buffering needed to adjust for no-data
-			// packets.
-			s->ctx_data.rx.transfer_delay +=
-				TICKS_PER_SECOND * s->syt_interval / rate;
-		}
-	}
+	s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
+
+	// additional buffering needed to adjust for no-data packets.
+	if (s->flags & CIP_BLOCKING)
+		s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
 
 	return 0;
 }
@@ -897,12 +891,10 @@ static void generate_pkt_descs(struct amdtp_stream *s, const __be32 *ctx_header,
 
 		desc->cycle = compute_ohci_it_cycle(*ctx_header, s->queue_size);
 
-		if (aware_syt && seq->syt_offset != CIP_SYT_NO_INFO) {
-			desc->syt = compute_syt(seq->syt_offset, desc->cycle,
-						s->ctx_data.rx.transfer_delay);
-		} else {
+		if (aware_syt && seq->syt_offset != CIP_SYT_NO_INFO)
+			desc->syt = compute_syt(seq->syt_offset, desc->cycle, s->transfer_delay);
+		else
 			desc->syt = CIP_SYT_NO_INFO;
-		}
 
 		desc->data_blocks = seq->data_blocks;
 

sound/firewire/amdtp-stream.h

@@ -140,15 +140,13 @@ struct amdtp_stream {
 			unsigned int dbc_interval;
 		} tx;
 		struct {
-			// To calculate CIP data blocks and tstamp.
-			unsigned int transfer_delay;
-
 			// To generate CIP header.
 			unsigned int fdf;
 
 			// To generate constant hardware IRQ.
 			unsigned int event_count;
 
+			// To calculate CIP data blocks and tstamp.
 			struct {
 				struct seq_desc *descs;
 				unsigned int size;
@@ -169,7 +167,8 @@ struct amdtp_stream {
 	unsigned int sph;
 	unsigned int fmt;
 
-	/* Internal flags. */
+	// Internal flags.
+	unsigned int transfer_delay;
 	enum cip_sfc sfc;
 	unsigned int syt_interval;