[Sound-open-firmware] Signed firmware availability for kbl/cnl

[Pierre-Louis Bossart]

>> Please note, there is no signed KBL release yet as the firmware and
>> driver still need some work to cater for the different FW boot flow on
>> KBL. I'm also not sure when/if KBL will be done since it's an older
>> platform and currently supported upstream using the closed FW.
> 
> The Asus MJ401TA has Intel m3-8100Y (Amber Lake) and this audio controller:
> 
> 00:1f.3 Multimedia audio controller [0401]: Intel Corporation Sunrise
> Point-LP HD Audio [8086:9d71] (rev 21)
>           Subsystem: ASUSTeK Computer Inc. Sunrise Point-LP HD Audio [1043:18b1]
> 
> The kernel tries to laod sof-kbl.ri and sof-kbl-nocodec.tplg for this product.
> 
> This product has a digital MIC that works fine under Windows. However
> this does not seem to be supported by the closed FW:
> 
>   snd_soc_skl 0000:00:1f.3: DSP detected with PCI
> class/subclass/prog-if info 0x040100
>   snd_soc_skl 0000:00:1f.3: enabling device (0000 -> 0002)
>   snd_soc_skl 0000:00:1f.3: undefined DMIC array_type 0xf
>   snd_soc_skl 0000:00:1f.3: bound 0000:00:02.0 (ops 0xffffffffad150080)
>   skl_hda_dsp_generic skl_hda_dsp_generic: Unsupported HDAudio/iDisp
> configuration found
>   skl_hda_dsp_generic: probe of skl_hda_dsp_generic failed with error -22

There is a known issue with the NHLT parsing where the 'VENDOR_DEFINED' 
case is not handled. there is an additional piece of information that 
needs to be read to find out the number of microphones. I had a patch 
before my Summer break but I haven't shared it. I don't even remember 
the branch name except that it contains 'nhlt'

> So I believe there is device support missing here. We would be happy
> to lend a product sample to Intel if that helps get this solved.

Even with this NHLT patch, you would still need a topology file to get 
the DMIC to work with HDaudio, and that unfortunately brings us back to 
square one.

I was indeed told a while ago that there was a limited number of 
KBL-based devices with DMIC, but mistakenly assumed we could avoid 
dealing with this configuration and Murphy's Law applied of course. 
we'll have to huddle with our Intel colleagues to figure this one out.