Re: Re: [RFC] DPCM for Tegra

From: Sameer Pujar
Date: Wed May 06 2020 - 12:10:12 EST




On 5/6/2020 9:23 PM, Mark Brown wrote:
On Wed, May 06, 2020 at 04:47:09PM +0200, Jerome Brunet wrote:
On Wed 06 May 2020 at 16:12, Sameer Pujar <spujar@xxxxxxxxxx> wrote:
XBAR currently exports all routing widgets which can be used to
interconnect multiple components and thus implements Mux widgets. Fixing
the routing paths in driver would limit anyone to try a different
combination as per the need, unless driver is modified.
I did not mean that you should restrict the routing ability of your SoC,
quite the opposite actually.

You should just expose it correctly
Yes, it's going to be less effort in the long run if nothing else.

This is what below reference tried to achieve in the original series, where all Mux widgets and corresponding kcontrols were exposed.
[1] http://patchwork.ozlabs.org/project/linux-tegra/patch/1582180492-25297-6-git-send-email-spujar@xxxxxxxxxx/

However it has DAI declarations too, that was mainly because codec-to-codec links were used to connect multiple components. DT would expose all these links (please note that machine driver was not sent as part of the original series). May be with DPCM these additional DAIs can be avoided, but it comes with few challenges highlighted in this RFC patch.