I have a problem with sound. I managed to solve it to some extent, but the problem keeps coming back. The question is how to make the solution permanent.
The problem is that speakers do not mute when headphones were plugged in - the sound is coming from both the speakers and headphones. This got broken quite a while ago with some updates.
I have seen some threads on that, advising to create a file /etc/modprobe.d/sound.conf with content
options snd-hda-intel model=auto
I also tried several other models but without success.
In the end I found a switch in alsamixer (Auto-Mute Mode). It was disabled, so I enabled it and the problem with speakers/headphones disappeared, Now the problem is that this option does not always stay enabled. Every now and again it switches itself to "disabled". This does not happen with every restart, but often enough to be annoying.
Is there a way to make Auto Mute permanently enabled? Or, perhaps, enable it automatically at boot, e.g. in rc.local ?
The sound card is HDA Intel, Realtek ALC269VB, but I get the same problem on a different computer as well (I do not remember the data of the other sound card). I use KDE.