ALSA: firewire-lib: unify packet handler for IT context

The handlers for packet with CIP and without CIP include common codes.
This commit unifies them and remove an member for pointer to callback
function from data structure.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream.c

@@ -496,26 +496,38 @@ static int handle_out_packet(struct amdtp_stream *s, unsigned int cycle,
 {
 	unsigned int syt;
 	unsigned int data_blocks;
-	unsigned int pcm_frames;
 	unsigned int payload_length;
+	__be32 *cip_header;
+	unsigned int pcm_frames;
 	struct snd_pcm_substream *pcm;
 
 	syt = calculate_syt(s, cycle);
 	data_blocks = calculate_data_blocks(s, syt);
-	pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
+
+	payload_length = data_blocks * sizeof(__be32) * s->data_block_quadlets;
+	if (!(s->flags & CIP_NO_HEADER)) {
+		cip_header = buffer;
+		buffer += 2;
+		payload_length += 2 * sizeof(__be32);
+	} else {
+		cip_header = NULL;
+	}
+
+	pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt);
 
 	if (s->flags & CIP_DBC_IS_END_EVENT)
 		s->data_block_counter =
 				(s->data_block_counter + data_blocks) & 0xff;
 
-	generate_cip_header(s, buffer, syt);
+	if (cip_header)
+		generate_cip_header(s, cip_header, syt);
 
 	if (!(s->flags & CIP_DBC_IS_END_EVENT))
 		s->data_block_counter =
 				(s->data_block_counter + data_blocks) & 0xff;
-	payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
 
-	trace_amdtp_packet(s, cycle, buffer, payload_length, data_blocks, index);
+	trace_amdtp_packet(s, cycle, cip_header, payload_length, data_blocks,
+			   index);
 
 	if (queue_out_packet(s, payload_length) < 0)
 		return -EIO;
@@ -524,37 +536,6 @@ static int handle_out_packet(struct amdtp_stream *s, unsigned int cycle,
 	if (pcm && pcm_frames > 0)
 		update_pcm_pointers(s, pcm, pcm_frames);
 
-	/* No need to return the number of handled data blocks. */
-	return 0;
-}
-
-static int handle_out_packet_without_header(struct amdtp_stream *s,
-				unsigned int cycle, const __be32 *ctx_header,
-				__be32 *buffer, unsigned int index)
-{
-	unsigned int syt;
-	unsigned int data_blocks;
-	unsigned int pcm_frames;
-	unsigned int payload_length;
-	struct snd_pcm_substream *pcm;
-
-	syt = calculate_syt(s, cycle);
-	data_blocks = calculate_data_blocks(s, syt);
-	pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt);
-	s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
-
-	payload_length = data_blocks * 4 * s->data_block_quadlets;
-
-	trace_amdtp_packet(s, cycle, NULL, payload_length, data_blocks, index);
-
-	if (queue_out_packet(s, payload_length) < 0)
-		return -EIO;
-
-	pcm = READ_ONCE(s->pcm);
-	if (pcm && pcm_frames > 0)
-		update_pcm_pointers(s, pcm, pcm_frames);
-
-	/* No need to return the number of handled data blocks. */
 	return 0;
 }
 
@@ -766,7 +747,7 @@ static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
 		cycle = compute_it_cycle(*ctx_header);
 		buffer = s->buffer.packets[s->packet_index].buffer;
 
-		if (s->handle_packet(s, cycle, ctx_header, buffer, i) < 0) {
+		if (handle_out_packet(s, cycle, ctx_header, buffer, i) < 0) {
 			cancel_stream(s);
 			return;
 		}
@@ -837,10 +818,6 @@ static void amdtp_stream_first_callback(struct fw_iso_context *context,
 		cycle = compute_it_cycle(*ctx_header);
 
 		context->callback.sc = out_stream_callback;
-		if (s->flags & CIP_NO_HEADER)
-			s->handle_packet = handle_out_packet_without_header;
-		else
-			s->handle_packet = handle_out_packet;
 	}
 
 	s->start_cycle = cycle;

sound/firewire/amdtp-stream.h

@@ -108,9 +108,6 @@ struct amdtp_stream {
 	struct iso_packets_buffer buffer;
 	int packet_index;
 	int tag;
-	int (*handle_packet)(struct amdtp_stream *s, unsigned int cycle,
-			     const __be32 *ctx_header, __be32 *buffer,
-			     unsigned int index);
 	union {
 		struct {
 			unsigned int ctx_header_size;