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ALSA: bebob: keep duplex streams always to keep internal multiplexer properly

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Behringer FCA610 transmits packets with periodic noisy PCM samples
when receiving no streams, and generates a bit noisy sound.

ALSA BeBoB driver is programmed to establish both in/out connections
when starting streaming, then transfers packets as userspace applications
requested. This means that there's a case that one of incoming/outgoing
streams is running, to save CPU and bandwidth usage. Although, it's natural
to start transferring packets in both direction.

This commit makes this driver to keeps duplex streams always.

Tested-by: Kim Tore Jensen <kim@incendio.no>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto
2015-06-14 12:49:36 +09:00
committed by Takashi Iwai
parent c4d860a0d2
commit 8d1c2694e4
4 changed files with 16 additions and 27 deletions
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24
sound/firewire/bebob/bebob_stream.c
View File

@@ -574,7 +574,6 @@ int snd_bebob_stream_start_duplex(struct snd_bebob *bebob, unsigned int rate)
{
struct snd_bebob_rate_spec *rate_spec = bebob->spec->rate;
struct amdtp_stream *master, *slave;
atomic_t *slave_substreams;
enum cip_flags sync_mode;
unsigned int curr_rate;
bool updated = false;
@@ -599,8 +598,7 @@ int snd_bebob_stream_start_duplex(struct snd_bebob *bebob, unsigned int rate)
mutex_lock(&bebob->mutex);
/* Need no substreams */
if (atomic_read(&bebob->playback_substreams) == 0 &&
atomic_read(&bebob->capture_substreams) == 0)
if (atomic_read(&bebob->substreams_counter) == 0)
goto end;
err = get_sync_mode(bebob, &sync_mode);
@@ -609,11 +607,9 @@ int snd_bebob_stream_start_duplex(struct snd_bebob *bebob, unsigned int rate)
if (sync_mode == CIP_SYNC_TO_DEVICE) {
master = &bebob->tx_stream;
slave = &bebob->rx_stream;
slave_substreams = &bebob->playback_substreams;
} else {
master = &bebob->rx_stream;
slave = &bebob->tx_stream;
slave_substreams = &bebob->capture_substreams;
}
/*
@@ -714,7 +710,7 @@ int snd_bebob_stream_start_duplex(struct snd_bebob *bebob, unsigned int rate)
}
/* start slave if needed */
if (atomic_read(slave_substreams) > 0 && !amdtp_stream_running(slave)) {
if (!amdtp_stream_running(slave)) {
err = start_stream(bebob, slave, rate);
if (err < 0) {
dev_err(&bebob->unit->device,
@@ -740,31 +736,25 @@ end:
void snd_bebob_stream_stop_duplex(struct snd_bebob *bebob)
{
struct amdtp_stream *master, *slave;
atomic_t *master_substreams, *slave_substreams;
if (bebob->master == &bebob->rx_stream) {
slave = &bebob->tx_stream;
master = &bebob->rx_stream;
slave_substreams = &bebob->capture_substreams;
master_substreams = &bebob->playback_substreams;
} else {
slave = &bebob->rx_stream;
master = &bebob->tx_stream;
slave_substreams = &bebob->playback_substreams;
master_substreams = &bebob->capture_substreams;
}
mutex_lock(&bebob->mutex);
if (atomic_read(slave_substreams) == 0) {
if (atomic_read(&bebob->substreams_counter) == 0) {
amdtp_stream_pcm_abort(master);
amdtp_stream_stop(master);
amdtp_stream_pcm_abort(slave);
amdtp_stream_stop(slave);
if (atomic_read(master_substreams) == 0) {
amdtp_stream_pcm_abort(master);
amdtp_stream_stop(master);
break_both_connections(bebob);
}
break_both_connections(bebob);
}
mutex_unlock(&bebob->mutex);