[alsa-devel] [PATCH 1/2 v2] ASoC: nau8825: non-clock jack detection for power saving at standby

[John Hsu]

On 5/19/2016 1:05 AM, Mark Brown wrote:
> On Mon, May 16, 2016 at 09:47:49AM +0800, John Hsu wrote:
>
>   
>> There is another patch is made by this patch.
>> [PATCH 2/2] ASoC: nau8825: cross talk suppression measurement function
>>     
>
> I'm confused about what's going on here...  if you're sending multiple
> patches that need to be grouped together you should always send them all
> together.  If you're not sending a group of patches then you shouldn't
> use numbering in the subject line.
>
>   

I understand. Thank you very much.

>> Besides, please help to review the following patch for the DC offset
>> issue. Thank you very much.
>> [PATCH] ASoC: nau8825: apply BIQ to reduce recording signal DC offset
>>     
>
> This is hard to review since it's quite complex and doing things that
> look like they might be using general purpose parts of the chip for
> specialist purposes.
>   

We find there is a DC offset issue when recording. For the issue, it
needs a HPF in ADC to reduce the offset, but no such hardware circuit.
Thus, the driver configures the biquard filter as HPF when headset
connected. It is a must setup for the codec. This patch sets the
coefficients A1, A2, B0, B1, and B3 in the biquad filter to make the
HPF funciton.