ec_su_axb35 fan curve systemd service

This repository contains a small systemd oneshot service for loading the ec_su_axb35 kernel module and applying fan ramp-up/ramp-down curves from configuration files.

The Linux kernel module can be found here: https://github.com/cmetz/ec-su_axb35-linux

Files

• usr/local/bin/ec-su-axb35-fan-apply: root-run helper that loads the module and applies all fan configs.
• etc/systemd/system/ec-su-axb35-fan.service: systemd unit.
• etc/ec-su-axb35-fan.d/fan3.conf: example fan config.

Install

From this repository:

sudo install -Dm755 usr/local/bin/ec-su-axb35-fan-apply /usr/local/bin/ec-su-axb35-fan-apply
sudo install -Dm644 etc/systemd/system/ec-su-axb35-fan.service /etc/systemd/system/ec-su-axb35-fan.service
sudo install -Dm644 etc/ec-su-axb35-fan.d/fan3.conf /etc/ec-su-axb35-fan.d/fan3.conf
sudo systemctl daemon-reload
sudo systemctl enable --now ec-su-axb35-fan.service

To apply changes after editing a config:

sudo systemctl restart ec-su-axb35-fan.service

Config

Create one file per fan in /etc/ec-su-axb35-fan.d/*.conf:

FAN=fan3
SET_RAMPUP_CURVE=35,44,67,79,95
SET_RAMPDOWN_CURVE=30,40,62,75,91

• Each SET_* entry writes to the matching lowercase sysfs attribute.
• For example, SET_MODE=auto writes auto to /sys/class/ec_su_axb35/${FAN}/mode.
• Attributes are only written when the live sysfs value differs from the config value.
  • This avoids unnecessary ec_writes by the driver.
• Values whose key starts with SET_RAMP must be comma-separated numbers.
• SET_MODE, when used, must be one of auto, fixed, or curve.

For additional fans, add more .conf files with different FAN values.