How to Fix Debian 11 Audio “Dummy Output” Problem on Lenovo X1 Carbon
TL;DR:
Unfortunately, you need to enable installation of non-free firmware / software on your system for this fix to work. To enable this, you need to edit your /etc/apt/sources.list file. Below is what mine looks like in its entirety. The important part is that each line ends with the string main contrib non-free .
deb http://deb.debian.org/debian/ bullseye main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye main contrib non-freedeb http://security.debian.org/debian-security bullseye-security main contrib non-free
deb-src http://security.debian.org/debian-security bullseye-security main contrib non-free# bullseye-updates, to get updates before a point release is made;
# see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports
deb http://deb.debian.org/debian/ bullseye-updates main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye-updates main contrib non-free
After enabling non-free firmware installation, run this command and reboot:
sudo apt update && sudo apt install -y firmware-sof-signedBackground Info
I recently got a new Lenovo X1 Thinkpad for my work laptop, and I excitedly installed Debian 11 onto it. I’d dealt with Debian on Intel-based laptops before, and I knew I’d need the firmware-iwlwifi package to get the Intel wireless card working. But, what I didn’t realize was that the audio would be broken by default.
When I opened my Gnome audio settings, I found that the only audio device available was called “Dummy Audio”, and my laptop wasn’t making any sound. A quick web search revealed I was not alone. I tried the steps outlined in this Debian-specific post and this Ubuntu post. The former focused on kernel module settings for ALSA, and the latter was about the Timidity package, which my system didn’t have. Neither solution ended up working for me.
Eventually I found a Debian User Forum post where someone suggested checking the dmesg logs, so I ran their command:
sudo dmesg | grep 'snd\|PCH\|audio\|firmware'Within the dmesg errors, I found an error log (now gone, so I can’t post it here) that led me to the firmware-sof-signed package. A simple installation of that package with sudo apt update && sudo apt install -y firmware-sof-signed followed by a reboot fixed my issue, and I didn’t have to tinker with any kernel module settings or other packages.
Hopefully this works for you. If not, keep tinkering until something works, and then write your own blog so others can benefit from your frustration and hard work!
