Issue #533 has been updated by Evgeny Zinoviev.
There's also a chance that some, for example, SMBIOS tables or something similar are not filled or filled incorrectly, and as a result, the thinkpad_acpi linux driver just doesn't recognize the device as valid and supported. So I'd look into this too. I'd check with the driver code, see what it looks for, and compared it to what coreboot provides. Maybe the driver just doesn't catch our thinkpads as thinkpads :)
---------------------------------------- Bug #533: T440p audio mute button and fan control not working https://ticket.coreboot.org/issues/533#change-1781
* Author: frantic from xboot * Status: New * Priority: Normal * Target version: master * Start date: 2024-03-07 * Affected versions: master * Affected hardware: Lenovo Thinkpad T440p * Affected OS: All Linux distributions ---------------------------------------- In recent coreboot versions, the audio mute button and fan control has stopped working. Whereas you use the same revision from Libreboot, it all works fine and smoothly. This leads me to suspect that someone changed someone without testing, which is real annoying. The audio mute button technically still functions, but the LED no longer turns on/off. Always just off. Fan control no longer works with Thinkfan. /proc/acpi/ibm/fan doesn't exist any more. I've tried "force loading" thinkpad_acpi, but it doesn't work.