ALSA: fireface: perform sequence replay for media clock recovery
This commit takes ALSA fireface driver to perform sequence replay for media clock recovery. The protocol specific to RME Fireface series is not compliant to IEC 61883-1/6 since it has no CIP header, therefore presentation time is not used for media clock recovery. The sequence of the number of data blocks per packet is important. I note that the device skips an isochronous cycle corresponding to an empty packet or a NODATA packet in blocking transmission method of IEC 61883-1/6. For sequence replay, the cycle is handled as receiving an empty packet. Furthermore, it doesn't start packet transmission till receiving any packet. The sequence replay is tested with below models: * Fireface 400 * Fireface 800 * Fireface 802 I note that it is better to initialize Fireface 400 in advance by initialization transaction implemented in snd-fireface-ctl-service of snd-firewire-ctl-services project. You can see whether initialized or not by HOST LED on the device. Unless, the device often stops packet transmission even if session starts. I guess the sequence replay also works well with below models: * Fireface UFX * Fireface UCX Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20210531025103.17880-7-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>
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