Commit c9f3ac2a authored by Takashi Sakamoto's avatar Takashi Sakamoto Committed by Takashi Iwai
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ALSA: firewire-lib: code refactoring for generation of data block sequence 



This commit dissolves sequence generator in terms of the number of data
blocks per packet.

Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210522013303.49596-6-o-takashi@sakamocchi.jp


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent c79b7158

sound/firewire/amdtp-stream.c

+40 −33
Original line number Diff line number Diff line
@@ -357,26 +357,41 @@ void amdtp_stream_pcm_prepare(struct amdtp_stream *s) 
}

EXPORT_SYMBOL(amdtp_stream_pcm_prepare);



static unsigned int calculate_data_blocks(unsigned int *data_block_state,

				bool is_blocking, bool is_no_info,

				unsigned int syt_interval, enum cip_sfc sfc)

static void pool_blocking_data_blocks(struct amdtp_stream *s, struct seq_desc *descs,

				      const unsigned int seq_size, unsigned int seq_tail,

				      unsigned int count)

{

	unsigned int data_blocks;

	const unsigned int syt_interval = s->syt_interval;

	int i;



	/* Blocking mode. */

	if (is_blocking) {

		/* This module generate empty packet for 'no data'. */

		if (is_no_info)

			data_blocks = 0;

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

		struct seq_desc *desc = descs + seq_tail;



		if (desc->syt_offset != CIP_SYT_NO_INFO)

			desc->data_blocks = syt_interval;

		else

			data_blocks = syt_interval;

	/* Non-blocking mode. */

	} else {

			desc->data_blocks = 0;



		seq_tail = (seq_tail + 1) % seq_size;

	}

}



static void pool_ideal_nonblocking_data_blocks(struct amdtp_stream *s, struct seq_desc *descs,

					       const unsigned int seq_size, unsigned int seq_tail,

					       unsigned int count)

{

	const enum cip_sfc sfc = s->sfc;

	unsigned int state = s->ctx_data.rx.data_block_state;

	int i;



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

		struct seq_desc *desc = descs + seq_tail;



		if (!cip_sfc_is_base_44100(sfc)) {

			// Sample_rate / 8000 is an integer, and precomputed.

			data_blocks = *data_block_state;

			desc->data_blocks = state;

		} else {

			unsigned int phase = *data_block_state;

			unsigned int phase = state;



		/*

		 * This calculates the number of data blocks per packet so that
@@ -388,18 +403,19 @@ static unsigned int calculate_data_blocks(unsigned int *data_block_state, 
		 */

			if (sfc == CIP_SFC_44100)

				/* 6 6 5 6 5 6 5 ... */

				data_blocks = 5 + ((phase & 1) ^

						   (phase == 0 || phase >= 40));

				desc->data_blocks = 5 + ((phase & 1) ^ (phase == 0 || phase >= 40));

			else

				/* 12 11 11 11 11 ... or 23 22 22 22 22 ... */

				data_blocks = 11 * (sfc >> 1) + (phase == 0);

				desc->data_blocks = 11 * (sfc >> 1) + (phase == 0);

			if (++phase >= (80 >> (sfc >> 1)))

				phase = 0;

			*data_block_state = phase;

			state = phase;

		}



		seq_tail = (seq_tail + 1) % seq_size;

	}



	return data_blocks;

	s->ctx_data.rx.data_block_state = state;

}



static unsigned int calculate_syt_offset(unsigned int *last_syt_offset,
@@ -467,24 +483,15 @@ static void pool_ideal_seq_descs(struct amdtp_stream *s, unsigned int count) 
	struct seq_desc *descs = s->ctx_data.rx.seq.descs;

	unsigned int seq_tail = s->ctx_data.rx.seq.tail;

	const unsigned int seq_size = s->ctx_data.rx.seq.size;

	const unsigned int syt_interval = s->syt_interval;

	const enum cip_sfc sfc = s->sfc;

	const bool is_blocking = !!(s->flags & CIP_BLOCKING);

	int i;



	pool_ideal_syt_offsets(s, descs, seq_size, seq_tail, count);



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

		struct seq_desc *desc = s->ctx_data.rx.seq.descs + seq_tail;



		desc->data_blocks = calculate_data_blocks(&s->ctx_data.rx.data_block_state,

				is_blocking, desc->syt_offset == CIP_SYT_NO_INFO,

				syt_interval, sfc);



		seq_tail = (seq_tail + 1) % seq_size;

	}

	if (s->flags & CIP_BLOCKING)

		pool_blocking_data_blocks(s, descs, seq_size, seq_tail, count);

	else

		pool_ideal_nonblocking_data_blocks(s, descs, seq_size, seq_tail, count);



	s->ctx_data.rx.seq.tail = seq_tail;

	s->ctx_data.rx.seq.tail = (seq_tail + count) % seq_size;

}



static void update_pcm_pointers(struct amdtp_stream *s,