bear24rw / alsa-utils Goto Github PK

So I'm just looking for a little direction here:

I have a raspberry pi zero w, using an adafruit mono i2s amp installed with the hifiberry i2s dac script, and some GPIO buttons set to trigger the commands ["amixer set PCM 5%-", "amixer set PCM 5%+"]. This works fine 60% of the time, however occaisionally when I start the pi it becomes stuck at full volume. Amixer begins to output "invalid command" instead of the normal status lines when given the very same input, and the alsamixer tui does not change volume either, the device shows up as PCM but the up and down buttons dont affect the volume level.

I looked in alsamixer.c and it looks like this output of 'invalid command' is caused by either sset_enum() or sset_channels() returning a negative integer, apparently meaning that check_flag within them is failing to be set, because none of the branches are being entered when these functions are run. I am new to programming and extremely new to reading other's code so I am getting a bit lost when tracking down the conditions that would cause this error. If you could help me understand what conditions are not being met when this error appears, that would help me alot.