I am running Ubuntu 12.04 on a Lenovo Thinkpad T530. When I insert my headphones, the volume jumps to 100%, even if it was set lower before I inserted them (and also was lower the last time I used the headphones). If I then lower the volume and remove the headphones, the volume jumps to 100% again.
The only exception is that if the volume is muted, it stays muted when I insert or remove the headphones.
Any suggestions for what might be causing this?
lspci shows this audio device: 00:1b.0 Audio device: Intel Corporation Panther Point High Definition Audio Controller (rev 04)