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| author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2021-06-02 10:34:06 +0900 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-06-02 08:59:46 +0200 |
| commit | f2ac3b839540ec9203debac034003d0663db1e18 (patch) | |
| tree | 6a7d36d3932a770e98fab800852d3b51cabf8baa /sound/firewire/motu/motu-stream.c | |
| parent | e50dfac81f733ec379f3b0c6025b5720cf6880df (diff) | |
ALSA: firewire-motu: sequence replay for source packet header
This commit takes ALSA firewire-motu driver to perform sequence replay for
media clock recovery.
Unlike the other types of device, the devices in MOTU FireWire series
require two levels of sequence replay; the sequence of the number of
data blocks per packet and the sequence of source packet header per data
block. The former is already cached by ALSA IEC 61883-1/6 packet streaming
engine and ready to be replayed. The latter is also cached by ALSA
firewire-motu driver itself with a previous patch. This commit takes
the driver to replay both of them from the caches.
The sequence replay is tested with below models:
* 828 mkII
* Traveler
* UltraLite
* 828 mk3 FireWire
* 828 mk3 Hybrid (except for high sampling transfer frequency
* UltraLite mk3 FireWire
* 4pre
* AudioExpress
Unfortunately, below models still don't generate better sound, requires
more work:
* 8pre
* 828 mk3 Hybrid at high sampling transfer frequency
As long as I know, MOTU protocol version 1 requires extra care of the
format of data block, thus below models are not supported yet in this
time:
* 828
* 896
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210602013406.26442-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire/motu/motu-stream.c')
| -rw-r--r-- | sound/firewire/motu/motu-stream.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/sound/firewire/motu/motu-stream.c b/sound/firewire/motu/motu-stream.c index 369002568b2d..43ff5be32b15 100644 --- a/sound/firewire/motu/motu-stream.c +++ b/sound/firewire/motu/motu-stream.c @@ -274,8 +274,13 @@ int snd_motu_stream_start_duplex(struct snd_motu *motu) motu->cache.tail = 0; motu->cache.tx_cycle_count = UINT_MAX; + motu->cache.head = 0; + motu->cache.rx_cycle_count = UINT_MAX; - err = amdtp_domain_start(&motu->domain, 0, false, false); + // NOTE: The device requires both of replay; the sequence of the number of data + // blocks per packet, and the sequence of source packet header per data block as + // presentation time. + err = amdtp_domain_start(&motu->domain, 0, true, false); if (err < 0) goto stop_streams; |