ALSA: firewire-lib: set streaming error outside of packetization

In previous commit, error handling for incoming packet processing is
outside of packetization. This is nice for reading the codes.

This commit applies this idea for outgoing packet processing, too.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp.c

@@ -647,16 +647,13 @@ static inline int queue_in_packet(struct amdtp_stream *s)
 			    amdtp_stream_get_max_payload(s), false);
 }
 
-static void handle_out_packet(struct amdtp_stream *s, unsigned int data_blocks,
-			      unsigned int syt)
+static int handle_out_packet(struct amdtp_stream *s, unsigned int data_blocks,
+			     unsigned int syt)
 {
 	__be32 *buffer;
 	unsigned int payload_length;
 	struct snd_pcm_substream *pcm;
 
-	if (s->packet_index < 0)
-		return;
-
 	buffer = s->buffer.packets[s->packet_index].buffer;
 	buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
 				(s->data_block_quadlets << AMDTP_DBS_SHIFT) |
@@ -676,14 +673,14 @@ static void handle_out_packet(struct amdtp_stream *s, unsigned int data_blocks,
 	s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
 
 	payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
-	if (queue_out_packet(s, payload_length, false) < 0) {
-		s->packet_index = -1;
-		amdtp_stream_pcm_abort(s);
-		return;
-	}
+	if (queue_out_packet(s, payload_length, false) < 0)
+		return -EIO;
 
 	if (pcm)
 		update_pcm_pointers(s, pcm, data_blocks);
+
+	/* No need to return the number of handled data blocks. */
+	return 0;
 }
 
 static int handle_in_packet(struct amdtp_stream *s,
@@ -795,6 +792,9 @@ static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
 	unsigned int i, syt, packets = header_length / 4;
 	unsigned int data_blocks;
 
+	if (s->packet_index < 0)
+		return;
+
 	/*
 	 * Compute the cycle of the last queued packet.
 	 * (We need only the four lowest bits for the SYT, so we can ignore
@@ -806,8 +806,13 @@ static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
 		syt = calculate_syt(s, ++cycle);
 		data_blocks = calculate_data_blocks(s, syt);
 
-		handle_out_packet(s, data_blocks, syt);
+		if (handle_out_packet(s, data_blocks, syt) < 0) {
+			s->packet_index = -1;
+			amdtp_stream_pcm_abort(s);
+			return;
+		}
 	}
+
 	fw_iso_context_queue_flush(s->context);
 }
 
@@ -821,6 +826,9 @@ static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
 	unsigned int data_blocks;
 	__be32 *buffer, *headers = header;
 
+	if (s->packet_index < 0)
+		return;
+
 	/* The number of packets in buffer */
 	packets = header_length / IN_PACKET_HEADER_SIZE;
 
@@ -828,9 +836,6 @@ static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
 	max_payload_quadlets = amdtp_stream_get_max_payload(s) / 4;
 
 	for (p = 0; p < packets; p++) {
-		if (s->packet_index < 0)
-			break;
-
 		buffer = s->buffer.packets[s->packet_index].buffer;
 
 		/* The number of quadlets in this packet */
@@ -853,7 +858,11 @@ static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
 		/* Process sync slave stream */
 		if (s->sync_slave && s->sync_slave->callbacked) {
 			syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
-			handle_out_packet(s->sync_slave, data_blocks, syt);
+			if (handle_out_packet(s->sync_slave,
+					      data_blocks, syt) < 0) {
+				s->packet_index = -1;
+				break;
+			}
 		}
 	}