Volume control broken

[bob2356]

A1543 EMC 3099 running Ubuntu 24 LTS, manual reinstall after updates.

Everything worked fine up to kernel 6.17.0-22-generic but volume control is broken since -23.
Using the volume function keys, there have been 16 increasing volume steps before.
Now, it's like 0% - 50% - 100% - 100% - 100% - ... and it's similarly using the volume settings' slider.
Alsamixer still shows 0% - 6% - 12% - ..., while 12% sounds like 100%.

[timmy31113]

I'm on an A1534 EMC 3099 running Arch Linux, kernel 7.0.9, and I now experience the same behavior.

Using KMix I have 20 volume steps, labeled in 5% increments all the way up to 100%. The keys still work, but the actual volume doesn't match the percentage anymore. I also tried to slowly move the volume slider with the mouse to visualize. This is the output recorded with a microphone:

[bob2356]

Smaller steps volume steps are availabe by pressing (fn +) shift + volume keys.
Still, about 10% is as loud as 100% before, and there's no more increase or distortion above that level.

[grasi4950]

On my macbook 12 2017 on Kubuntu 26.04 Kernel 7.0.0-15-generic
same behavior. Volume steps 1-10 work like 1-100.
So at 10% it reaches maximum and all above is as loud as 10%

[Chitou1]

This is an issue with the latest version of this driver. This is a fork of the previous version which does not have the issue.
https://github.com/juicecultus/macbook12-audio-driver
It fixed the issue for me.