🔊 iMac 2017 Linux Audio Fix — Cirrus Logic CS8409

🇬🇧 English · 🇪🇸 Español · Current version: 1.2.0 · Changelog

No sound on your 2017 iMac in Linux? This fixes the internal speakers, headphones and HDMI audio on the Apple iMac 2017 (iMac18,1 · iMac18,2 · iMac18,3).

It ships a patched driver based on davidjo/snd_hda_macbookpro, a universal menu-driven installer (Fedora, Ubuntu/Debian, Arch, openSUSE and NixOS), automatic DKMS builds so the fix survives kernel updates, a speakers / headphones mode switch, and a PipeWire / WirePlumber profile to use the internal speakers and HDMI at the same time.

git clone https://github.com/riqgonzalo/imac-2017-linux-audio-cs8409.git
cd imac-2017-linux-audio-cs8409
./instalar_audio_imac.sh        # choose option 1 (autodetect)

The scripts’ menus are in Spanish. This page explains every option in English.

🙏 Did it work for you (or not)? Tell us here with your model and distro. Every report helps other iMac owners.

Symptoms

Is this my machine?

Model Machine Tested
iMac18,1 iMac 21.5” (2017) ✅ Main test machine
iMac18,2 iMac 21.5” Retina 4K (2017) Expected (same audio hardware)
iMac18,3 iMac 27” Retina 5K (2017) Expected (same audio hardware)
MacBook Pro with CS8409 MacBook Pro 2016–2017 Supported by the original driver 
cat /sys/class/dmi/id/product_name                     # → iMac18,1 / iMac18,2 / iMac18,3
grep -m1 Codec /proc/asound/card*/codec#*              # → Codec: Cirrus Logic CS8409
grep -m1 "Subsystem Id" /proc/asound/card*/codec#*     # → 0x106b1000 / 0x106b0f00 / 0x106b0e00

If the codec is Cirrus Logic CS8409 and the subsystem starts with 0x106b, this is for you.

Why it happens

The iMac’s audio is split across several chips: the Cirrus Logic CS8409 HDA bridge, a CS42L83 codec for the headphone jack, and TI TAS5764x amplifiers driving the four internal speakers.

  1. The stock kernel can’t initialise Apple’s hardware. The mainline snd_hda_codec_cs8409 module supports Dell and Cirrus reference boards, not Apple’s start-up sequence, so the amplifiers never turn on.
  2. davidjo’s driver reimplements that sequence and works on MacBook Pros and several iMacs.
  3. But on the 2017 iMac the jack sensor is read inverted. The original driver calls cs42l83_tip_sense(codec, 1) for these iMacs, which gives a permanent false “headphones connected”: all audio goes to the headphone output and the internal speakers are muted.

What this driver changes

snd_hda_macbookpro_imac/ is davidjo’s driver with three changes (also available as a standalone patch: parches/imac-cs8409.patch):

  1. Jack sense no longer inverted on iMac18,x, so speakers and headphones switch correctly.
  2. New force_speakers module parameter to force the internal speakers if your jack sensor still misbehaves.
  3. install.cirrus.driver.sh finishes cleanly under DKMS, so the module rebuilds on every kernel update.

Requirements

The installer first checks that the machine really is a Mac with CS8409. On any other PC it warns that you could lose sound and only continues if you type CONTINUAR.

Installation

git clone https://github.com/riqgonzalo/imac-2017-linux-audio-cs8409.git
cd imac-2017-linux-audio-cs8409
./instalar_audio_imac.sh

Choose 1) Autodetectar e instalar automáticamente (autodetect and install). You’ll hear a test sound at the end. If the modules were in use, it offers to reboot. Don’t move the folder before installing.

Optional desktop shortcuts: ./crear_lanzadores.sh.

Installer menu

Option What it does
1 Autodetect Reads /etc/os-release and runs the RPM, DEB, Arch or Nix flow. Stops on immutable systems.
2 RPM dnf/zypper dependencies, DKMS build, config, dracut initramfs.
3 DEB apt-get dependencies, DKMS build, config, update-initramfs.
4 Arch pacman (picks linux-headers, -lts, -zen or -hardened), mkinitcpio -P.
5 NixOS Generates /etc/nixos/cs8409-audio.nix (experimental).
6 HDMI + speakers Only the PipeWire/WirePlumber profile.
7 Diagnostics Shows the loaded module, patch status, DKMS, jack state, PipeWire outputs; plays a test sound.
8 Uninstall Removes the DKMS module, guard service and all config, regenerates initramfs.
9 Exit  

Speakers / headphones mode (force_speakers)

./cambiar_modo_audio.sh     # 1) automatic detection   2) always internal speakers

By hand:

cat /sys/module/snd_hda_codec_cs8409/parameters/force_speakers
echo 1 | sudo tee /sys/module/snd_hda_codec_cs8409/parameters/force_speakers
echo "options snd_hda_codec_cs8409 force_speakers=1" | sudo tee /etc/modprobe.d/cs8409.conf

Kernel updates

Troubleshooting

lsmod | grep -E "cs8409|snd_hda_intel"
modinfo snd_hda_codec_cs8409 | grep -E "filename|parm"
dkms status
sudo dmesg | grep -iE "cs8409|cs42l83|tas57"
pactl list sinks short
Symptom Fix
modinfo points to kernel/sound/… (stock module) sudo depmod -a, reboot, check dkms status.
force_speakers not listed by modinfo The patched module isn’t loaded: reinstall with option 1.
dkms status empty or “added” Install headers for your exact kernel (uname -r) and reinstall.
Still says “Headphones” with nothing plugged in ./cambiar_modo_audio.sh → option 2.
“LA INSTALACIÓN NO SE COMPLETÓ” (install failed) Read /var/log/instalar_audio_imac.log.
“Key was rejected by service” Secure Boot: disable it or sign the module (MOK).
No “speakers + HDMI” profile systemctl --user restart pipewire wireplumber.

Known limitations

Full details (step-by-step install, files touched, NixOS, manual uninstall) are in the Spanish README.

Credits & license

Licensed under GPL-2.0. ⚠️ This modifies kernel modules and audio configuration. No warranty; use at your own risk.