After bus reset, isochronous resource manager releases all of allocated isochronous resources. The nodes to restart packet streaming should request reallocation of the resources.
However, between the bus-reset and invocation of 'struct fw_driver.update' handler, ALSA PCM application can detect this situation by XRUN because the target device cancelled to transmit packets once bus-reset occurs.
Due to the above mechanism, ALSA firewire-tascam driver just stops packet streaming in the update handler, thus pcm.prepare handler should request the reallocation.
This commit requests the reallocation in pcm.prepare callback when bus generation is changed.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/tascam/tascam-stream.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/sound/firewire/tascam/tascam-stream.c b/sound/firewire/tascam/tascam-stream.c index 18d554d46be5..be9dcc808188 100644 --- a/sound/firewire/tascam/tascam-stream.c +++ b/sound/firewire/tascam/tascam-stream.c @@ -321,7 +321,7 @@ int snd_tscm_stream_init_duplex(struct snd_tscm *tscm) return err; }
-/* At bus reset, streaming is stopped and some registers are clear. */ +// At bus reset, streaming is stopped and some registers are clear. void snd_tscm_stream_update_duplex(struct snd_tscm *tscm) { amdtp_stream_pcm_abort(&tscm->tx_stream); @@ -390,6 +390,7 @@ void snd_tscm_stream_release_duplex(struct snd_tscm *tscm)
int snd_tscm_stream_start_duplex(struct snd_tscm *tscm, unsigned int rate) { + unsigned int generation = tscm->rx_resources.generation; int err;
if (tscm->substreams_counter == 0) @@ -403,6 +404,16 @@ int snd_tscm_stream_start_duplex(struct snd_tscm *tscm, unsigned int rate) finish_session(tscm); }
+ if (generation != fw_parent_device(tscm->unit)->card->generation) { + err = fw_iso_resources_update(&tscm->tx_resources); + if (err < 0) + goto error; + + err = fw_iso_resources_update(&tscm->rx_resources); + if (err < 0) + goto error; + } + if (!amdtp_stream_running(&tscm->rx_stream)) { err = set_stream_formats(tscm, rate); if (err < 0)