Ubuntu Version:
Ubuntu 24.04.4 LTS HWE
Kernel: 6.17.0-35-generic
Desktop Environment:
GNOME / PipeWire
Problem Description:
I would like to share an experimental test result and ask for feedback from other iMac18,3 users.
On an iMac 2017 Retina 5K (iMac18,3), I adapted and tested a CS8409 speaker patch for Ubuntu 24.04 HWE.
With the patched snd-hda-codec-cs8409.ko module, built-in speaker playback works through the normal Analog Stereo profile on my machine.
This is not a claim that built-in audio is fixed in stock Ubuntu. It is an experimental result from one iMac18,3.
Relevant System Information:
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Machine: iMac 2017 Retina 5K
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Model Identifier: iMac18,3
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Codec: Cirrus Logic CS8409
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Codec subsystem ID:
106b:1000 -
Audio path: CS8409 / CS42L83 / TAS576
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Audio server: PipeWire
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Tested kernel:
6.17.0-35-generic
What I have confirmed:
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Direct ALSA stereo playback
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PipeWire Analog Stereo playback
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Firefox / YouTube playback
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44.1 kHz and 48 kHz stereo playback
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Playback after reboot
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Playback recovery after stopping one video and starting another
I had also confirmed practical speaker playback earlier on Ubuntu 24.04 HWE kernel 6.17.0-20. The same patch approach was reproduced on 6.17.0-35.
What I have tried:
I replaced only the CS8409 codec module rather than the complete HDA stack.
The tested module was installed at:
/lib/modules/6.17.0-35-generic/updates/snd-hda-codec-cs8409.ko
For ordinary use, I keep the audio profile at:
output:analog-stereo+input:analog-stereo
Known limitations:
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Headphone switching is not supported yet
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Built-in microphone input is not supported yet
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External microphone input is not supported yet
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2.1 / 4.0 / Pro Audio profiles are not fully verified
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Switching away from Analog Stereo may produce noise or temporarily disturb desktop volume controls
The Ubuntu-specific patch, source information, checksum, and detailed test notes are available here:
https://github.com/network-garden-lab/imac18-3-cs8409-ubuntu-hwe-speaker-patch
A Japanese technical report is also available here:
https://qiita.com/network-garden-lab/items/47ad678534f0ee9ac47d
I would welcome reports from other iMac18,3 users, especially on different Ubuntu HWE kernels.