Commit 73246fc4 authored by Takashi Sakamoto's avatar Takashi Sakamoto Committed by Takashi Iwai
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ALSA: firewire-lib: insert descriptor for skipped cycle 



This commit fulfils sequence descriptors for skipped cycle when
it's one cycle. This is preparation for future integration.

Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210518130048.146596-9-o-takashi@sakamocchi.jp


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 705794c5

sound/firewire/amdtp-stream.c

+24 −5
Original line number Diff line number Diff line
@@ -723,7 +723,8 @@ static inline u32 compute_ohci_it_cycle(const __be32 ctx_header_tstamp, 
static int generate_device_pkt_descs(struct amdtp_stream *s,

				     struct pkt_desc *descs,

				     const __be32 *ctx_header,

				     unsigned int packets)

				     unsigned int packets,

				     unsigned int *desc_count)

{

	unsigned int next_cycle = s->next_cycle;

	unsigned int dbc = s->data_block_counter;
@@ -732,8 +733,9 @@ static int generate_device_pkt_descs(struct amdtp_stream *s, 
	int i;

	int err;



	*desc_count = 0;

	for (i = 0; i < packets; ++i) {

		struct pkt_desc *desc = descs + i;

		struct pkt_desc *desc = descs + *desc_count;

		unsigned int cycle;

		bool lost;

		unsigned int data_blocks;
@@ -745,11 +747,25 @@ static int generate_device_pkt_descs(struct amdtp_stream *s, 
			if (s->flags & CIP_NO_HEADER) {

				// Fireface skips transmission just for an isoc cycle corresponding

				// to empty packet.

				unsigned int prev_cycle = next_cycle;



				next_cycle = increment_ohci_cycle_count(next_cycle, 1);

				lost = (next_cycle != cycle);

				if (!lost) {

					// Prepare a description for the skipped cycle for

					// sequence replay.

					desc->cycle = prev_cycle;

					desc->syt = 0;

					desc->data_blocks = 0;

					desc->data_block_counter = dbc;

					desc->ctx_payload = NULL;

					++desc;

					++(*desc_count);

				}

			} else if (s->flags & CIP_JUMBO_PAYLOAD) {

				// OXFW970 skips transmission for several isoc cycles during

				// asynchronous transaction.

				// asynchronous transaction. The sequence replay is impossible due

				// to the reason.

				unsigned int safe_cycle = increment_ohci_cycle_count(next_cycle,

								IR_JUMBO_PAYLOAD_MAX_SKIP_CYCLES);

				lost = (compare_ohci_cycle_count(safe_cycle, cycle) > 0);
@@ -776,6 +792,7 @@ static int generate_device_pkt_descs(struct amdtp_stream *s, 
			dbc = (dbc + desc->data_blocks) & 0xff;



		next_cycle = increment_ohci_cycle_count(next_cycle, 1);

		++(*desc_count);

		ctx_header += s->ctx_data.tx.ctx_header_size / sizeof(*ctx_header);

		packet_index = (packet_index + 1) % queue_size;

	}
@@ -927,6 +944,7 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, 
	struct amdtp_stream *s = private_data;

	__be32 *ctx_header = header;

	unsigned int packets;

	unsigned int desc_count;

	int i;

	int err;
@@ -936,14 +954,15 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, 
	// Calculate the number of packets in buffer and check XRUN.

	packets = header_length / s->ctx_data.tx.ctx_header_size;



	err = generate_device_pkt_descs(s, s->pkt_descs, ctx_header, packets);

	desc_count = 0;

	err = generate_device_pkt_descs(s, s->pkt_descs, ctx_header, packets, &desc_count);

	if (err < 0) {

		if (err != -EAGAIN) {

			cancel_stream(s);

			return;

		}

	} else {

		process_ctx_payloads(s, s->pkt_descs, packets);

		process_ctx_payloads(s, s->pkt_descs, desc_count);

	}



	for (i = 0; i < packets; ++i) {