volume control quirk for Tenx TP6911 Audio Headset

Question

On a fresh install of 2021-01-11-raspios-buster-armhf-lite with dmesg an older, cheap, generic "3D SOUND" USB audio stick for headphone and microphone is detected as

[  480.467295] usb 1-1: New USB device found, idVendor=1130, idProduct=f211, bcdDevice= 5.10
[  480.467325] usb 1-1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[  480.467343] usb 1-1: Product: USB  AUDIO
[  480.492827] input: USB  AUDIO   as /devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.3/0003:1130:F211.0001/input/input0
[  480.560665] hid-generic 0003:1130:F211.0001: input,hidraw0: USB HID v1.10 Device [USB  AUDIO  ] on usb-20980000.usb-1/input3
[  480.576573] input: USB  AUDIO   as /devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.4/0003:1130:F211.0002/input/input1
[  480.638871] hid-generic 0003:1130:F211.0002: input,hidraw1: USB HID v1.10 Device [USB  AUDIO  ] on usb-20980000.usb-1/input4
[  481.084360] usb 1-1: usbmixer: volume control quirk for Tenx TP6911 Audio Headset
[  481.084414] usb 1-1: usbmixer: volume control quirk for Tenx TP6911 Audio Headset
[  481.104015] usbcore: registered new interface driver snd-usb-audio

lsusb reports accordingly

Bus 001 Device 002: ID 1130:f211 Tenx Technology, Inc. TP6911 Audio Headset

With /etc/asound.conf

pcm.!default  {
 type hw card 1
}
ctl.!default {
 type hw card 1
}

it blasts noise with

~ $ speaker-test -c2

speaker-test 1.1.8

Playback device is default
Stream parameters are 48000Hz, S16_LE, 2 channels
Using 16 octaves of pink noise
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 96 to 262144
Period size range from 48 to 131072
Using max buffer size 262144
Periods = 4
was set period_size = 65536
was set buffer_size = 262144
 0 - Front Left
 1 - Front Right
^CTime per period = 4.096809

(left and right channels seem to be swapped).

Ouch, it's way too loud on my headphones.

But I seem unable to reduce the volume with alsamixer

lqqqqqqqqqqqqqqqqqqqqqqq AlsaMixer v1.1.8 qqqqqqqqqqqqqqqqqqqqqqqqk
x Card: USB  AUDIO                        F1:  Help               x
x Chip: USB Mixer                         F2:  System information x
x View: Playback                          F6:  Select sound card  x
x Item: PCM                               Esc: Exit               x
x                                                                 x
x                                                                 x
x                                                                 x
x                                                                 x
x                                                                 x
x                              lqqk                               x
x                              xOOx                               x
x                              mqqj                               x
x                           <  PCM   >                            x
x                                                                 x
x                                                                 x
x                                                                 x
x                                                                 x
x                                                                 x
mqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj

amixer reports

Simple mixer control 'PCM',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]
Simple mixer control 'Mic',0
  Capabilities: cswitch cswitch-joined
  Capture channels: Mono
  Mono: Capture [on]

Is this (related to) the "volume control quirk for Tenx TP6911 Audio Headset" (dmesg)? Where can I find any information on this quirk?

There's a proposed configuration using softvolhere (2013).

• https://duckduckgo.com/?q=Tenx+TP6911
• http://www.iamnota.net/doku.php?id=hw:tp6911
• http://www.tenx.com.tw/Quick_Search_list.aspx?Keyword=tp6911&SearchType=All
• http://www.tenx.com.tw/Files/Doc/266/DS-TP6911_V10.pdf
• http://www.tenx.com.tw/Files/APNotes/303/AP-TP6911_01EV10.pdf
• https://www.google.com/search?q=Tenx+TP6911+site:www.raspberrypi.org

Answer 1

Not a real solution (to get hardware volume control working in the ALSA mixer for this device), only additional info:

• from mnoit on https://www.raspberrypi.org/forums/viewtopic.php?t=50821#p410468

There is no control bar because there is no volume control. This is perfectly normal:UAC (USB Audio Class) does not define a way to implement a hardware control. Some high-end cards have specific extensions, or non-standard drivers, to get some. You can adjust PCM output in the software you use, or setup an alsa plugin ... [softvol]

On the other hand, the datasheet states

64-level volume control

So I'll give playing audio with software-volume control a go

• https://www.raspberrypi.org/documentation/usage/audio/

  The simplest way of playing audio is to use the OMXPlayer application

  • https://www.raspberrypi.org/documentation/raspbian/applications/omxplayer.md

Installing the hardware-accelerated player takes 600 MB (I'm using lite)

sudo apt install omxplayer

Get some audio

wget http://rpf.io/lamp3 -O example.mp3 --no-check-certificate

Play

omxplayer example.mp3
Only 16M of gpu_mem is configured. Try running "sudo raspi-config" and ensure that "memory_split" has a value of 64 or greater
have a nice day ;)

(I had reduced this via config.txt since I thought I would not be using the VideoCore. You'll want to select Performance/GPU Memory in raspi-config)

Try again

omxplayer example.mp3
Error: Unable to open font
Audio codec mp3float channels 1 samplerate 11025 bitspersample 16
Subtitle count: 0, state: off, index: 1, delay: 0
have a nice day ;)

Huh.

It's missing

sudo apt install -y fonts-freefont-ttf

Ok, the error goes away, but there's no audio. Oh:

Note that omxplayer doesn't use ALSA and so ignores the audio configuration set by raspi-config or amixer.

Let's try another 6 MB

sudo apt install mpg123

and then

mpg123 example.mp3

AHHH!

You may not want to use that sample. Or try this:

mpg123 -f 512 example.mp3
High Performance MPEG 1.0/2.0/2.5 Audio Player for Layers 1, 2 and 3
        version 1.25.10; written and copyright by Michael Hipp and others
        free software (LGPL) without any warranty but with best wishes


Terminal control enabled, press 'h' for listing of keys and functions.

Playing MPEG stream 1 of 1: example.mp3 ...

MPEG 2.5 L III cbr32 11025 mono

Title:   Sound Effects - Female Operatic La 1 - Opera singer sings La.
Artist:  Download Sound Effects - SoundDogs - AOS
Comment: Royalty Free Sound Effects - Sounddogs.com              Album:  http://www.Sounddogs.com
Year:    2008                                                    Genre:  SFX - Humans; Vocalizations

[0:03] Decoding of example.mp3 finished.

Audio reduced to 9 bits.