[PATCH 0/8] ALSA: firewire-lib: check cycle continuity

Takashi Iwai tiwai at suse.de
Wed May 19 16:25:34 CEST 2021


On Tue, 18 May 2021 15:00:39 +0200,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> Current implementation of ALSA IEC 61883-1/6 packet streaming engine
> doesn't check whether received packets are exactly per isochronous
> cycle. This is required to process packets transferred from
> OXFW970-based devices and devices in RME Fireface series. However, the
> packet sequence with skipped cycle is inconvenient for media clock
> recovery.
> 
> This patchset takes the engine to check cycle continuity at processing
> packets, including code refactoring. For RME Fireface series, the skipped
> cycle is handled as receiving an empty packet. For OXFW970-based devices,
> the skipped cycles are acceptable but media clock recovery is hard.
> 
> Takashi Sakamoto (8):
>   ALSA: firewire-lib: code refactoring to refer the same frame count per
>     period in domain structure
>   ALSA: firewire-lib: handle the case that empty isochronous packet
>     payload for CIP
>   ALSA: firewire-lib: code refactoring for sequence descriptor'
>   ALSA: firewire-lib: code refactoring for helper function to compute
>     OHCI 1394 cycle
>   ALSA: firewire-lib: code refactoring for parser of IR context header
>   ALSA: firewire-lib: code refactoring for check of CIP header about
>     payload size
>   ALSA: firewire-lib: check cycle continuity
>   ALSA: firewire-lib: insert descriptor for skipped cycle

Applied all eight patches now.  Thanks.


Takashi


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