[alsa-devel] Internal Mic Boost channel is unused

[Raymond Yau]

>
>  1) I have the following hardware (alsa-info attached).

Simple mixer control 'Input Source',0
Capabilities: cenum Items: 'Mic' 'Internal Mic' 'Mic 1'
Item0: 'Internal Mic'
Simple mixer control 'Input Source',1
Capabilities: cenum Items: 'Mic' 'Internal Mic' 'Mic 1'
Item0: 'Internal Mic'
Simple mixer control 'Input Source',2
Capabilities: cenum Items: 'Mic' 'Internal Mic' 'Mic 1'
Item0: 'Internal Mic'


using hda-emu

the driver always use selector 0x17 for the three input source controls

6 Input Source:0
ITEM: 0:Mic, 1:Mic 1, 2:Internal Mic, VAL: [Mic]
> set 6 2
send: NID=0x14, VERB=0x701(set_connect_sel), PARM=0x0
receive: 0x0
send: NID=0x17, VERB=0x701(set_connect_sel), PARM=0x3
receive: 0x0
> set 7 2
send: NID=0x15, VERB=0x701(set_connect_sel), PARM=0x0
receive: 0x0
send: NID=0x17, VERB=0x701(set_connect_sel), PARM=0x3
receive: 0x0
> set 8 2
send: NID=0x16, VERB=0x701(set_connect_sel), PARM=0x0
receive: 0x0
send: NID=0x17, VERB=0x701(set_connect_sel), PARM=0x3
receive: 0x0

It is a bug of the driver to create three input source select controls when
there are only two audio selectors 0x17 and 0x18 as node 0x23 is not one of
the input pins

The topology does not allow three different input sources with two selectors

 >  2) The internal microphone requires that the mic boost channel be
something other than 0 to function properly.

You have to find out whether node 0x1a or 0x1b can be used as the headset
jack (headphone with Mic using TRRS connector)

>  3) Changing what pulseaudio expects things to be labelled causes the
problem to go away. (via the attached patch to
/usr/share/pulseaudio/paths/analog-input-mic.conf).
>
>   From the discussion with David Henningsson (diwic on IRC). It seems
that pulse doesn't expect a Mic Boost channel to be used with internal
microphones. As such to fix this particular hardware, the driver would need
to make the internal mic boost be labelled "Internal Mic Boost" as opposed
to Mic Boost, which is then is used for both external and internal mics.
>

Node 0x14 [Audio Input] wcaps 0x100d1b: Stereo Amp-In R/L
Control: name="Capture Volume", index=0, device=0 ControlAmp: chs=3,
dir=In, idx=0, ofs=0
Control: name="Capture Switch", index=0, device=0 ControlAmp: chs=3,
dir=In, idx=0, ofs=0
Device: name="CX20588 Analog", type="Audio", device=0 Amp-In caps:
ofs=0x4a, nsteps=0x50, stepsize=0x03, mute=1
Amp-In vals: [0x50 0x50] [0x80 0x80] [0x80 0x80] [0x80 0x80]
Converter: stream=4, channel=0 SDI-Select: 0
PCM: rates [0x160]: 44100 48000 96000
bits [0xe]: 16 20 24
formats [0x1]: PCM
Power states: D0 D1 D2 D3 D3cold EPSS Power: setting=D0, actual=D0
Connection: 4
0x17* 0x18 0x23 0x24

Node 0x24 [Audio Mixer] wcaps 0x20050b: Stereo Amp-In
Amp-In caps: ofs=0x4a, nsteps=0x4a, stepsize=0x03, mute=1
Amp-In vals: [0x00 0x00] [0x00 0x00]
Power states: D0 D1 D2 D3 D3cold EPSS
Power: setting=D0, actual=D0
Connection: 2
0x10 0x11

BTW there seem to be an audio path from DAC to ADC throungh audio mixer
0x24, does this allow you to record the DAC playback directly ? Using
hda-analyzer to change the selection of  audio input node 0x14 and fix the
amps at node 0x24