Re: [PATCH] ASoC: core: Change device numbering

[Jaroslav Kysela <perex@xxxxxxxx>]

On 29. 01. 25 15:51, Amadeusz Sławiński wrote:
> On 1/29/2025 10:25 AM, Cezary Rojewski wrote:
> > On 2025-01-27 3:54 PM, Jaroslav Kysela wrote:
> > > On 27. 01. 25 15:45, Amadeusz Sławiński wrote:

...

> > > Also, a bit off-topic, but the driver name (hdaudioB?D?) for this
> > > particular driver should be corrected, too. It should be like 'hda-
> > > avs- dsp' or so. If I am not wrong, the SST driver name was 'hda-dsp'.
> >
> > We had a discussion or two within the team and yes, we do agree that a
> > more user-friendly pattern should be provided. Currently card names are
> > mostly based on machine board device (platform_device) name. There is no
> > strong technical argument for that - the development was/is simply
> > focused on bringing new functionality and we did not prioritize the card
> > naming.
> >
> > The task touches all interfaces though, not just HDA. We would like to
> > streamline or fix the naming for all the interfaces. This time we will
> > specifically request a review for that : )
>
> And we had yet another discussion today ;) Are there some guidelines
> upstream, about how cards should be named? Currently we need names for:
I am not aware of any documentation, but it should be user friendly and 
meaningful. I am talking about driver name not other UI parts, but they should 
be probably corrected, too.

The driver name is more related to the kernel module name and it should just 
identify the affected driver not runtime (like addressing). Runtime 
descriptors should be put to the components string.

> HDA, HDMI, DMIC & I2S cards. Here are examples from running systems:
> HDA:
> card 0: hdaudioB0D0 [hdaudioB0D0], device 1: HDAudio Analog (*) []
> HDMI:
> card 1: hdaudioB0D2 [hdaudioB0D2], device 1: HDMI 0 (*) []
> DMIC:
> card 2: avsdmic [avs_dmic], device 2: Digital Microphone (*) []
> I2S:
> card 3: avsrt274 [avs_rt274], device 1: Audio (*) []

You should probably show all card info strings ('cat /proc/asound/cards' or 
'alsactl info 0').

There are basically four strings:

1) driver name (used for alsa-lib / ucm configs)
2) card short name (for UI)
3) card long name (for UI)
4) card components (more precise driver/hw identification)

The components string can be printed using 'amixer -c 0 info' or 'alsactl info 
0' command.

I think that in your case, you just set the short name which is copied to the 
driver name in the ASoC core. The avs_dmic/avs_rt274 names seems fine, but 
only the hdaudioB?C? names are really mess (including card short name).

> Additionally is there a way to alias card name? We would like to still
> allow users to use current names, to keep backward compatibility at
> least for some time.

We don't have this possibility in the kernel API. For user space (alsa-lib, 
UCM) we can use symlinks. As I already suggested, it would be probably best to 
create CONFIG_XXXXX_OBSOLETE option which can be turned on by default with 
proper description and let distribution maintainers to turn it off when 
alsa-lib / UCM / whatever related configs are updated in the user space.

					Jaroslav

--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.