Argthtjtr

I use windows 10 and Ubuntu 16.04 as dual boot. If I turn on my laptop and enter windows, the speakers are not even found and there is no audio. If I turn the laptop off, back on and disable audio in BIOS, then turn the computer off and back on and enable audio, I get audio on windows. The same happens with Ubuntu. The only difference is that it seems like the speaker is recognized on Ubuntu, but there is still no audio. Also, sometimes I have to repeat this process more than two times to get it working on linux. In some cases I get the headphone to work but not the speaker. I have a Dell XPS 15 9560 and this issue has been very frustrating. I have already tried to update the driver for windows and reinstall alsamixer on Ubuntu.

There are a few reported issues(here, here, here, etc.) of dual-booters having sound issues with their Dell XPS models, myself included. My issue was ultimately solved by upgrading my firmware and updating my kernel to a newer version. Although many of the resources provided don't match your model exactly, I think they're still valuable for troubleshooting purposes and don't cause your system any harm should they be executed properly(except perhaps for the advanced troubleshooting methods like kernel manipulation).

Below are some steps to try to resolve the issue. I'll provide lots of links and detail but since this is a potentially complicated issue, you should definitely do your own research along the way to make sure you have a decent understanding of all the steps you're taking should something go awry especially for steps 4 and 5 which are advanced in nature and could potentially harm your computer if you don't know what you're doing. After each step you can check your sound for results. If you're not seeing a permanent fix yet, try the following step.

1. 
   

   First you may want to try a couple shell commands to restart/reconfigure the higher levels of your audio stack. These include:

   
   
   
   
   
   • 
     

     Restarting pulseaudio, removing your home folder config files and rebooting:

     
     
     

     rm -r ~/.config/pulse/
pulseaudio -k && sudo alsa force-reload
sudo reboot

     
     
   
   
   • 
     Verifying all software on the linux sound stack is properly installed and that the correct module is loading. In the Ubuntu terminal, enter:
     sudo apt-get install alsa-base alsa-utils alsa-tools libasound2 libasound2-plugins pavucontrol pulseaudio dkms.
     Now enter sudo nano /etc/modprobe.d/alsa-base.conf. Go to the bottom of the file and enter: options snd-hda-intel model=generic, and then save and close the file(ctrl+x, y, enter with the nano text editor).
     Now restart alsa with: sudo alsa force-reload.
     Now try a rebooting with sudo reboot.
   
   
   
   



2. Try doing the Dell UEFI Hardware Checkup for a UEFI-level assessment of the Audio Codec(which refers to the piece of hardware on your motherboard that is responsible for audio processing). Directions screenshotted from Dell's website:
   If this tests fails to output any audio(it'll indicate when you should hear audio signals), that doesn't necessarily indicate hardware failure. It could also mean(as was the case for myself) that the UEFI/BIOS hasn't properly detected the Audio Codec. This can happen regardless of whether or not the device drivers are at the latest version.



3. Let's assume that this is a hardware detection issue and try an upgrade to the latest version of the machine's firmware(UEFI/BIOS) which is what I did. Overall, this is a good, necessary practice that a user should be doing regularly(these updates are not automated). The last update was Oct. 23 2018, version 1.12.1. For now the easiest way to do this would be to obtain an upgrade executable file from Dell directly and boot to it. That file is found here. Once obtained, there are a few pathways available to allow you to boot to it. Generally you can either do this from Windows or from Ubuntu. After completing the update, you'll want to fully power-cycle the machine twice(shut down instead of reboot). For me, it took a few cold boots before I was getting consistent audio device detection again.


4. If you're cold booted a few times and you're still getting no sound, you could look into a bug reported on launchpad(where Ubuntu bugs are detailed) regarding an xps 9343 sound issue in which the Audio Codec is loaded in HDA mode instead of I2S mode, causing sound issues. Although this bug describes an older version of the XPS, I think it may still be relevant to your machine. Users commenting in the bugs thread discussed upgrading to a newer stable kernel to resolve the issue. A separate site gives instructions on how to do this.


5. If the above hasn't produced results after a couple cold boots, you might try compiling the latest kernel yourself and modifying a kernel parameter to force I2S mode for the Audio Codec.

Best of luck!