alsa-project/alsa-lib issue #47 was opened from igrekster:

I have a PCIE Asus Sound Card (Asus Xonar AE) that uses USB interface: ``` Bus 003 Device 002: ID 0b05:180f ASUSTek Computer, Inc. ``` It's been working fine on earlier versions of kernel/alsa-lib but at some point the volume control stopped working (the playback still works fine):

``` $ alsamixer -c 1 ALSA lib /var/tmp/portage/media-libs/alsa-lib-1.2.2-r1/work/alsa-lib-1.2.2/src/mixer/simple_none.c:1544:(simple_add1) helem (MIXER,'Master Playback Volume',0,1,0) appears twice or more cannot load mixer controls: Invalid argument ``` This is on kernel 5.4.37/alsa 1.2.2. Unfortunately I cannot downgrade to the point when it was working to pinpoint the issue. I tried kernels 5.3.11 and alsa 1.1.8. I've tried building the latest alsa-lib, and it is still showing the error. I'm happy to try patches to alsa or kernel modules to help debug this.

A few more details:

[alsa-info.txt](https://github.com/alsa-project/alsa-lib/files/4569764/alsa-info.txt) [proc-asound.txt](https://github.com/alsa-project/alsa-lib/files/4569766/proc-asound.txt)

Issue URL : https://github.com/alsa-project/alsa-lib/issues/47 Repository URL: https://github.com/alsa-project/alsa-lib