Re: More Generic Audio Graph Sound Card idea

From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
To: Sameer Pujar <spujar@nvidia.com>
Cc: sharadg@nvidia.com, Linux-ALSA <alsa-devel@alsa-project.org>,
	Mark Brown <broonie@kernel.org>,
	Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
	jonathanh@nvidia.com
Subject: Re: More Generic Audio Graph Sound Card idea
Date: 27 Aug 2020 10:18:04 +0900	[thread overview]
Message-ID: <871rjsx51e.wl-kuninori.morimoto.gx@renesas.com> (raw)
In-Reply-To: <f21353ca-5d47-afac-3451-f951eced36e2@nvidia.com>

Hi Sameer

> What you are suggesting is 'audio-graph-card2' is a new restructured
> version of 'audio-graph-card' with some additional customization
> available for specific users. Do you think updating existing
> 'audio-graph-card' itself, with necessary hooks, would be too
> complicated to handle?

It depends on how new driver was implemented.
If we need to keep current card, I will keep it as-is and do nothing anymore,
and has customize option at card2.
If we update current card, customize option will be added to it.

> From a brief overview, it may solve my issue in customizing few
> stuff. But I am not too sure if we want to go that way, because
> eventually we end up in writing a separate machine driver for Tegra
> (though there can be common stuff used from the generic graph
> card). The original idea was to use 'audio-graph-card' and people
> facing similar issues could use "-cc-" compatible.

The biggest issue on current audio-graph-card is that
DPCM feature is limited, and because of it, the link detection
is very tricky.
Your "-cc-" assumes all links are DPCM, but it is more limitation.
We want to have more flexible/generic detection.

> >                  dsp {
> >                          compatible = "audio-graph-card2-dsp";
> 
> Sorry I did not understand this. Do you intend to parse 'dsp'
> separately with some version of audio graph card? In my case 'dsp' is
> just a 'crossbar' and is registered as a component exposing all
> routes. However I have described links in the DT in a similar way
> where my 'crossbar' is exposing FEs and BEs like below.

This compatible is used just for indicating audio-graph DSP.
"audio-graph-card" will parse it if it was connected.
If you confuse it, just ignore for now.

Thank you for your help !!

Best regards
---
Kuninori Morimoto