Using Ubuntu 14.04 When I plug external speakers into the pro docking station with my Thinkpad T440p in it I get no sound (internal speakers mute).
Plugging the same speakers into the headphone jack on the laptop works fine
The following solution I found several places online but it did not work after restarting my machine.
Added the line
options snd-hda-intel model=thinkpad
to the /etc/modprobe.d/alsa-base.conf
After that didn't work I upgraded to a newer kernel 3.14.1-031401-generic, that worked to enable HDMI sound but the sound on the docking station still does not work.