How to fix headphone jack audio issue for Dell XPS Studio on Ubuntu 10.04

After installing Ubuntu and its derivatives on a Dell XPS Studio, both the headphone jacks are unusable. Plugging earphones into the jacks produces no sound, and the system still outputs the sound on the laptop's speaker.

The problem is related to alsa and can be fixed with these steps.

1. Launch terminal.
2. Open Alsa module configration file using your preferred text editor.

   $ sudo vi /etc/modprobe.d/alsa-base.conf

3. Add the following line at the end of the file.

   options snd-hda-intel model=dell-m6

4. Save the file and exit your text editor.
5. Restart your machine.

   $ sudo reboot