diff options
Diffstat (limited to 'sound/firewire/bebob/bebob.c')
| -rw-r--r-- | sound/firewire/bebob/bebob.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/sound/firewire/bebob/bebob.c b/sound/firewire/bebob/bebob.c index 671179eaff1e..3e4e0756e3fe 100644 --- a/sound/firewire/bebob/bebob.c +++ b/sound/firewire/bebob/bebob.c @@ -300,6 +300,22 @@ error: 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); |