[alsa-devel] [RFC 00/10] Enable HDA Codec support on Intel Platforms (Series2)

[Takashi Iwai]

On Fri, 01 Dec 2017 10:13:58 +0100,
Rakesh Ughreja wrote:
> 
> Many Intel platforms (SKL,KBL) etc. in the market supports enahanced 
> audio capabilities which also includes DSP processing. This patch carry
> forwads the works that is done in the previous series to enable HD Audio
> codecs on such platforms.
> 
> This patch series adds ASoC HDA codec driver for Intel platforms. It is
> written by reusing the legacy HDA ALSA codec driver. Intention is to
> maximize the reuse and minimize the changes in the legacy HDA codec driver.
> 
> I would like to receive feedback before proceeding further on this
> direction.

First of all, I appreciate this kind of work finally happening, so
that ASoC HD-audio can go forward to a wider usage.  However...


> TODO:
> 
> - This series is tested on KBL based product (Dell XPS 13).
> - Basic playback is working with headset and speakers.
> - Capture operation is not tested.
> - More platforms and use cases coverage can be added once we have basic
>   agreement in terms of the overall approach.

One big thing that is unclear to me is what about the complex I/O
configuration although we provide only a single machine driver, and
what happens if the (legacy) codec driver allows the jack retasking.
I know that nowadays the number of jacks are reduced than before, but
still there will be desktop boxes with individual front and rear I/O
jacks.


> FIXME:
> - KConfig changes does not look right, but I could not think of any proper
>   way without making changes into legacy HDA codec driver. So need some
>   help on this topic.

And this is another big issue.  As long as you don't allow build both,
it never flies with distros, and it means no dramatic improvement of
the situation, either.

IOW, we have to make the codec driver working on both controller/bus
implementations, and it essentially means to rewrite the HD-audio
codec plumbing code.  Currently, it's a kind of half-baked state, and
we need to cast to unified form.


thanks,

Takashi