Re: [PATCH v3] virtio-snd: add virtio sound device specification

[Anton Yakovlev <anton.yakovlev@opensynergy.com>]

On 18.12.2019 17:54, Mark Brown wrote:
> On Wed, Dec 18, 2019 at 04:34:12PM +0100, Anton Yakovlev wrote:
> > On 18.12.2019 12:52, Gerd Hoffmann wrote:
>
> > > Well, the driver has to manage buffers, so I can't see how a driver is
> > > not interested in completion notifications.  If the driver isn't
> > > interested in keeping the latency low by using lots of small buffers it
> > > still needs to queue at least two (larger) buffers, so the device still
> > > has data to continue playback when it completed a buffer.  And the
> > > driver needs to know when the device is done with a buffer so it can
> > > either recycle the buffer or free the pages.
>
> > It seems that you have mixed up two different things: sending/completing a
> > request containing a buffer, and period notifications. They are not the same.
>
> What do you expect a period notification to be?  The default expecation
> would very much be that they're tied to what's going on with the
> buffers.

Elapsed period notification was initially proposed as an optional feature. But
then the discussion switched on to define the entire period-based operational
sequence built in protocol. Well, we can go this way and make periods not an
optional notification, but a full optional mode of operation. Then we can add
all the requirements that Gerd spoke of.


--
Anton Yakovlev
Senior Software Engineer

OpenSynergy GmbH
Rotherstr. 20, 10245 Berlin

Phone: +49 30 60 98 54 0
E-Mail: anton.yakovlev@opensynergy.com