Re: [PATCH 1/3] ASoC: SOF: Parse fw/tplg filename from DT

[Daniel Baluta]

On Thu, Jul 15, 2021 at 5:39 PM Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> On Thu, Jul 15, 2021 at 05:18:00PM +0300, Daniel Baluta wrote:
>
> > Introduce two DT properties in dsp node:
> >       * fw-filename, optional property giving the firmware filename
> >       (if this is missing fw filename is read from board description)
> >       * tplg-filename, mandatory giving the topology filename.
>
> These sound entirely like operating system configuration which I'd
> expect to be inferred from the machine identification.  What happens if
> a system has multiple options for firmware files, or if the OS ships the
> topology and firmware bundled up in a single image to avoid them getting
> out of sync?  What's the benefit of putting them in the DT?

We thought that if a system has multiple options for firmware files
we could use different Device Tree files. But indeed this doesn't scale.

It would be awkward to create a new dts just to change the firmware name.

Similarly for topology files. We might have:

- different audio scenarios (e.g different audio pipeline with
different components, e.g Post Processing Components, etc)
- different hardware attached to a board (e.g i.MX8 can have a
baseboard attached which brings in more codecs).

I think the best way to specify the audio firmware is via the board
description structure which is already
used to provide a default value for firmware file name.

Then for the topology used we could make that as a module parameter.

For us it is important to be able to use different topologies without
recompiling the kernel. So, far we just
used a simbolic link to the default topology file and change the
symbolic link to the desired topology and then reboot.