ALSA: firewire-lib: refactoring to obsolete IT packet handler

As a result of heavy refactoring based on IT packet header, the packet
handler becomes simpler.

This commit merges the packet handler into function for IT context
callback. The logic to build IT packet header and tracepoints event is
split to a function.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream.c

@@ -485,54 +485,36 @@ static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2],
 			(syt & CIP_SYT_MASK));
 }
 
-static int handle_out_packet(struct amdtp_stream *s, unsigned int cycle,
-			     const __be32 *ctx_header, __be32 *buffer,
-			     unsigned int index)
+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 syt;
-	unsigned int data_blocks;
 	__be32 *cip_header;
-	unsigned int pcm_frames;
-	struct snd_pcm_substream *pcm;
-	struct {
-		struct fw_iso_packet params;
-		__be32 header[IT_PKT_HEADER_SIZE_CIP / sizeof(__be32)];
-	} template = { {0}, {0} };
 
-	syt = calculate_syt(s, cycle);
-	data_blocks = calculate_data_blocks(s, syt);
-	pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt);
-
-	if (s->flags & CIP_DBC_IS_END_EVENT)
+	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 *)template.params.header;
+		cip_header = (__be32 *)params->header;
 		generate_cip_header(s, cip_header, syt);
-		template.params.header_length = 2 * sizeof(__be32);
+		params->header_length = 2 * sizeof(__be32);
 	} else {
 		cip_header = NULL;
 	}
 
-	if (!(s->flags & CIP_DBC_IS_END_EVENT))
+	if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
 		s->data_block_counter =
 				(s->data_block_counter + data_blocks) & 0xff;
+	}
 
-	template.params.payload_length =
+	params->payload_length =
 			data_blocks * sizeof(__be32) * s->data_block_quadlets;
 
-	trace_amdtp_packet(s, cycle, cip_header, template.params.payload_length,
+	trace_amdtp_packet(s, cycle, cip_header, params->payload_length,
 			   data_blocks, index);
-
-	if (queue_out_packet(s, &template.params) < 0)
-		return -EIO;
-
-	pcm = READ_ONCE(s->pcm);
-	if (pcm && pcm_frames > 0)
-		update_pcm_pointers(s, pcm, pcm_frames);
-
-	return 0;
 }
 
 static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
@@ -741,16 +723,34 @@ static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
 
 	for (i = 0; i < packets; ++i) {
 		u32 cycle;
+		unsigned int syt;
+		unsigned int data_block;
 		__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_block = calculate_data_blocks(s, syt);
 		buffer = s->buffer.packets[s->packet_index].buffer;
+		pcm_frames = s->process_data_blocks(s, buffer, data_block, &syt);
 
-		if (handle_out_packet(s, cycle, ctx_header, buffer, i) < 0) {
+		build_it_pkt_header(s, cycle, &template.params, data_block, 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;
 	}