[alsa-devel] [RFC PATCH 0/6] ALSA/HDA: abort probe when DMICs are detected

[Hui Wang]

On 2019/5/25 上午12:12, Pierre-Louis Bossart wrote:
>
>
> On 5/24/19 10:45 AM, Daniel Drake wrote:
>> Thanks for the patches!
>>
>> On Fri, May 24, 2019 at 7:26 AM Pierre-Louis Bossart
>> <pierre-louis.bossart at linux.intel.com> wrote:
>>> I am not sure if it's a good idea to enable this by default, the
>>> experience of the first round showed it's risky to make assumptions on
>>> what BIOS vendors implemented.
>>
>> Can you clarify what you mean here, are you saying you don't want to
>> enable this new DMIC hardware support by default?
>
> No. What I am saying is that
> a) the legacy HDaudio driver does not support DMICs
> b) the decision to abort the HDaudio legacy driver probe should not be 
> the default, since it depends on BIOS information that may be wrong 
> and on which I have *zero* control.
>
> There are 4 cases really:
>
> 1. DMICs attached to PCH and BIOS/NHLT reports DMICS -> abort HDaudio 
> legacy probe
> 2. No DMICs attached to PCH and BIOS/NHLT does not report DMICs -> 
> continue probe and use HDAudio legacy.
> 3. DMICs attached to PCH and BIOS/NHLT does not report DMICs -> broken 
> config, we will need an option to abort the probe by force and ignore 
> the BIOS if you care about audio capture.
> 4. no DMICs attached to PCH and BIOS/NHLT reports DMICs -> broken 
> config, we need an option to ignore the BIOS and continue the probe.

Got it,  we will do a test on a couple of machines, let us see if we can 
meet 3 and 4 in reality.

>
> Does this help?
>