[PATCH 0/3] ALSA: firewire: media clock recovery for syt-aware devices

[Takashi Iwai]

On Tue, 01 Jun 2021 10:17:50 +0200,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> In a commit f9e5ecdfc2c2 ("ALSA: firewire-lib: add replay target to cache
> sequence of packet"), I categorize devices supported by drivers in ALSA
> firewire stack in terms of the way to deliver effective sampling
> transfer frequency. This patchset is for the devices in group 2.
> 
> The devices are known to have problems when ALSA dice/bebob drivers
> handle. Many of them sometimes transfer packets with discontinued counter,
> corrupt at break of CMP connection, generates bus-reset voluntarily.
> 
> The devices interpret presentation time to decide playback timing. The
> drivers process presentation time expressed in syt field of CIP header for
> outgoing packets. Current implementation of the drivers processes the
> sequence of outgoing packet by computation according to nominal sampling
> transfer frequency, assisted by ALSA IEC 61883-1/6 packet streaming engine.
> However, the ideal sequence is not adequate to the devices, actually.
> 
> With this patchset, the drivers are going to replay the sequence of
> incoming packets for media clock recovery. For the detail of sequence
> replay, please refer to a commit 39c2649c71d8 ("ALSA: firewire-lib: replay
> sequence of incoming packets for outgoing packets").
> 
> Takashi Sakamoto (3):
>   ALSA: dice: wait just for NOTIFY_CLOCK_ACCEPTED after
>     GLOBAL_CLOCK_SELECT operation
>   ALSA: dice: perform sequence replay for media clock recovery
>   ALSA: bebob: perform sequence replay for media clock recovery

Applied all three patches now.  Thanks.


Takashi