Headphones is not working in 15.04 Dell XPS 13

Question

After upgrading to 15.04 , my headphones don't work, how to fix it?

When I type command alsamixer , I see something strange:

Answer 1

I don't have the full solution, but I did get sound working through the headphone jack on my Haswell Dell XPS 13 with 16.04. I'll post what I've done here in case it's helpful to others.

I added these options to /etc/modprobe.d/alsa-base.conf. I'm not sure if they helped.

options snd-hda-intel model=dell-headset-multi 

# Intel Corporation Haswell-ULT HD Audio Controller 
options snd-hda-intel index=0 model=auto vid=8086 pid=0a0c 
# # Intel Corporation 8 Series HD Audio Controller 
options snd-hda-intel index=1 model=auto vid=8086 pid=9c20 

# Prefer PCH card over HDMI card 
options snd_hda_intel index=1,0

You may need to confirm that the "vid" and "pid" values are the same for your motherboard. I've currently lost my reference on how I looked those up.

Finally, I frequently have to open the terminal and run alsamixer, which is a CLI app for volume adjustments. Use the arrow keys to select the "Headphone" column. Press "M" to unmute it, if it says "M" at the bottom. Press the up arrow to turn the volume all the way up in the headphone column. Then use the arrow keys to move to the "Speaker" column. You probably want to turn it all the way down unless you want sound to come out of the speakers and the headphone jack.

As an experiment, with alsamixer open, which what happens to the volumes when you use the media keys or the system volume slider to adjust the volume. You might expect or hope that only the "master" volume is selected, but I see that the "speaker" volume goes up and down as well, while the "headphone" volume is not affected.

My understanding is that the remaining issue is that PulseAudio does not see the Headphone output as an option. For example, if you open the sound settings, you will see "Speakers" an output option, but not "Headphones". So the next step for really fixing this to figure out how to get PulseAudio to recognize Headphone output. In the meantime, it's necessary to reset the volumes via alsamixer after every time they are adjusted by PulseAudio (using the media keys or system volume slider).

UPDATE March 6th, 2017 Now I'm running the 4.8 kernel and I noticed an option in alsamixer that I didn't notice before: "Auto-Mute Mode". Setting this to "Enabled" causes the OS to automatically mute the laptop speakers when something is plugged into the headphone jack, which is probably what you want.