ALSA: bebob: give up updating streams at bus reset handler

DM1000/DM1100/DM1500 chipsets transfer packets with discontinue value in
'dbc' field of CIP header. For ALSA bebob driver, this makes its bus-reset
handler meaningless, because the discontinuity is detected quite earlier
than executing the handler.

This commit gives up updating streams at the bus reset handler.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto 2016-02-20 16:18:59 +09:00 committed by Takashi Iwai
parent 4fd6c6c729
commit 3800e6f944
3 changed files with 16 additions and 20 deletions

View file

@ -300,6 +300,22 @@ bebob_probe(struct fw_unit *unit,
return err;
}
/*
* This driver doesn't update streams in bus reset handler.
*
* DM1000/ DM1100/DM1500 chipsets with BeBoB firmware transfer packets with
* discontinued counter at bus reset. This discontinuity is immediately
* detected in packet streaming layer, then it sets XRUN to PCM substream.
*
* ALSA PCM applications can know the XRUN by getting -EPIPE from PCM operation.
* Then, they can recover the PCM substream by executing ioctl(2) with
* SNDRV_PCM_IOCTL_PREPARE. 'struct snd_pcm_ops.prepare' is called and drivers
* restart packet streaming.
*
* The above processing may be executed before this bus-reset handler is
* executed. When this handler updates streams with current isochronous
* channels, the streams already have the current ones.
*/
static void
bebob_update(struct fw_unit *unit)
{
@ -310,10 +326,6 @@ bebob_update(struct fw_unit *unit)
fcp_bus_reset(bebob->unit);
mutex_lock(&bebob->mutex);
snd_bebob_stream_update_duplex(bebob);
mutex_unlock(&bebob->mutex);
if (bebob->deferred_registration) {
if (snd_card_register(bebob->card) < 0) {
snd_bebob_stream_destroy_duplex(bebob);

View file

@ -217,7 +217,6 @@ int snd_bebob_stream_discover(struct snd_bebob *bebob);
int snd_bebob_stream_init_duplex(struct snd_bebob *bebob);
int snd_bebob_stream_start_duplex(struct snd_bebob *bebob, unsigned int rate);
void snd_bebob_stream_stop_duplex(struct snd_bebob *bebob);
void snd_bebob_stream_update_duplex(struct snd_bebob *bebob);
void snd_bebob_stream_destroy_duplex(struct snd_bebob *bebob);
void snd_bebob_stream_lock_changed(struct snd_bebob *bebob);

View file

@ -746,21 +746,6 @@ void snd_bebob_stream_stop_duplex(struct snd_bebob *bebob)
}
}
void snd_bebob_stream_update_duplex(struct snd_bebob *bebob)
{
if ((cmp_connection_update(&bebob->in_conn) < 0) ||
(cmp_connection_update(&bebob->out_conn) < 0)) {
amdtp_stream_pcm_abort(&bebob->rx_stream);
amdtp_stream_pcm_abort(&bebob->tx_stream);
amdtp_stream_stop(&bebob->rx_stream);
amdtp_stream_stop(&bebob->tx_stream);
break_both_connections(bebob);
} else {
amdtp_stream_update(&bebob->rx_stream);
amdtp_stream_update(&bebob->tx_stream);
}
}
/*
* This function should be called before starting streams or after stopping
* streams.