Hi all!
T420 + Ubuntu 24.04.2 LTS - I could write to /proc/acpi/ibm/fan
for fan control.
That worked.
T420 + Ubuntu 25.04 - Now I get:
====================================
% cat fan_2.sh
echo "level 2" > /proc/acpi/ibm/fan
% sudo ./fan_2.sh
./fan_2.sh: 1: echo: echo: I/O error
====================================
Known issue (after upgrading)?