No audio in DELL XPS 13 (Ubuntu 15.04)

Today I installed Ubuntu 15.04 (desktop edition, 64 bit) on a DELL XPS 13 (model 9343) notebook. Prior to installation, I upgraded the computer bios to A03. The kernel I am running is 3.19.0-15. I have no audio/sound. Here is some info:

cribari@darwin4:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: HDMI [HDA Intel HDMI], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: HDMI [HDA Intel HDMI], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: HDMI [HDA Intel HDMI], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0

EDIT: the additional info of the comment

$ lspci -nn | grep -i audio
00:03.0 Audio device [0403]: Intel Corporation Broadwell-U Audio Controller [8086:160c] (rev 09)
00:1b.0 Audio device [0403]: Intel Corporation Wildcat Point-LP High DefinitionAudio Controller [8086:9ca0] (rev 03)

The solution is here (thanks to Paul Wall).

First try to do 2 cold reboot in Ubuntu (cold reboot means that do need to shutdown and power up and not reboot!). If you still have no sound, try

sudo modprobe snd-soc-rt286

and then select the sound card in Systems Settings/Sound (for me, that worked).

If you want to have the module automatically load at start up, do

sudo nano /etc/modules

add this to the file

snd-soc-rt286

save and close it. Restart and your sound should be working without the need of sudo modprobe snd-soc-rt286. You will still need, however, to do a cold reboot after using Windows.