alsa-project/alsa-lib issue #47 was edited 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.

``` $ amixer -c 1 controls numid=7,iface=CARD,name='Clock Source 18 Validity' numid=10,iface=CARD,name='Clock Source 19 Validity' numid=17,iface=CARD,name='Clock Source 22 Validity' numid=11,iface=CARD,name='IEC958 In - Output Jack' numid=18,iface=CARD,name='Keep Interface' numid=14,iface=CARD,name='Line - Input Jack' numid=12,iface=CARD,name='Mic - Input Jack' numid=8,iface=CARD,name='Speaker - Output Jack' numid=20,iface=MIXER,name='Master Playback Volume' numid=19,iface=MIXER,name='Master Playback Volume',device=1 numid=5,iface=MIXER,name='PCM Playback Switch' numid=9,iface=MIXER,name='PCM Playback Switch',index=1 numid=16,iface=MIXER,name='PCM Capture Source' numid=15,iface=MIXER,name='Line Capture Switch' numid=13,iface=MIXER,name='Mic Capture Switch' numid=6,iface=MIXER,name='Input Gain Pad Control' numid=4,iface=PCM,name='Capture Channel Map' numid=1,iface=PCM,name='Playback Channel Map' numid=2,iface=PCM,name='Playback Channel Map',device=1 numid=3,iface=PCM,name='Playback Channel Map',device=2 ``` `amixer -c scontrols` fails withe the same error as `alsamixer`.

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