Comment 9 for bug 893611

Same symptoms here, not sure if I should open a new report because I'm using a different dock.

OS: Ubuntu 12.04 amd64, 3.2.0-20
Hardware: Thinkpad X230 and Ultrabase Series 3

Plugging the headphone into the Thinkpad itself works, pulling it out has music coming from the Thinkpad's speakers, but plugging it into the Ultrabase correctly mutes the Thinkpad yet leads to no output (very slight static noises).

Adding the model=thinkpad line and rebooting doesn't change the situation. alsamixer offers two devices: HDA Intel PCH and ThinPad Console Audio Control. Changes on the former correspond to real audio changes, but the Console Audio Control only has one muted unchangeable "Console" mixer.