[alsa-devel] [PATCH 00/12] ALSA: firewire-digi00x/dice: reserve/release isochronous resources in pcm.hw_params/hw_free callbacks

[Takashi Iwai]

On Tue, 11 Jun 2019 15:21:06 +0200,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> This patchset is a part of series of patches for all of drivers in
> ALSA firewire stack to reserve/release isochronous resources in
> pcm.hw_params/hw_free callbacks.
> 
> In current implementation, the resources are reserved at the same time
> to start packet streaming, and released at the same time to stop packet
> streaming. However, once allocated, the resources are available
> independent of lifetime of each of packet streaming.
> 
> The isochronous resources are the resources of IEEE 1394 bus. On the
> other side of view, it's a kind of resources of hardware to maintain
> the bus (isochronous resource manager). For this kind of reservation and
> release, hw_params and hw_free operations are suitable in ALSA PCM
> interface.
> 
> Ideally, the operation to reserve/release isochronous resource should
> be separated from the operation to start/stop packet streaming. However,
> IEEE 1394 bus has reset event. Once reset occurs, isochronous resource
> manager releases allocated resources. The resources should be
> reallocated by requesters themselves. For this reason, in this patchset,
> bus generation is checked before starting packet streaming. If
> generation is updated, reallocation is requested to isochronous
> resource manager, then packet streaming starts.
> 
> Takashi Sakamoto (12):
>   ALSA: firewire-digi00x: refactoring to move timing of registration for
>     isochronous channel
>   ALSA: firewire-digi00x: code refactoring to finish streaming session
>   ALSA: firewire-digi00x: simplify error path to begin streaming session
>   ALSA: firewire-digi00x: code refactoring to keep isochronous resources
>   ALSA: firewire-digi00x: reserve/release isochronous resources in
>     pcm.hw_params/hw_free callbacks
>   ALSA: firewire-digi00x: update isochronous resources when starting
>     packet streaming after bus-reset
>   ALSA: firewire-digi00x: code refactoring for pcm.hw_params/hw_free
>     callbacks
>   ALSA: dice: code refactoring to stop packet streaming
>   ALSA: dice: code refactoring to keep isochronous resources
>   ALSA: dice: reserve/release isochronous resources in
>     pcm.hw_params/hw_free callbacks
>   ALSA: dice: update isochronous resources when starting packet
>     streaming after bus-reset
>   ALSA: dice: code refactoring for pcm.hw_params/hw_free callbacks

Applied all twelve patches.  Thanks.


Takashi