I have been trying to put a microphone into my combined headphone/mic port and saw a video on hdajackretask . However, the device is busy when I say to apply. I can install the boot-override file but I cannot apply.
In the video, all he did was shut down alsa-mixer and he got rid of that problem. I did not start any sound devices.
Update: I noticed that pulse audio is running and maybe this effects it. However, when I shut it down, it seems to pop back up. I cannot know what is starting it. I am not sure if this is the reason.