Permissions

ThinkUtils needs write access to system files for CPU, fan, and battery control. A one-time setup configures everything — no repeated password prompts.

Quick Setup

1. Install the polkit policy:

   sudo ./install-polkit.sh

2. Launch the app and click "Setup Permissions" when prompted

3. Enter your password once — done!

Optional: Completely Passwordless

For users in the sudo/wheel group who want zero password prompts:

./setup-passwordless.sh

How It Works

What Gets Configured

The one-time pkexec call does three things:

1. sysfs File Permissions

Sets chmod 666 on system files so your user can directly control:

File	Purpose
/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor	CPU governor
/sys/devices/system/cpu/intel_pstate/no_turbo	Turbo boost
/sys/devices/platform/thinkpad_hwmon/pwm1*	Fan PWM control
/sys/class/power_supply/BAT*/charge_*_threshold	Battery limits

WARNING

sysfs permissions reset on reboot. Re-run setup from the app if CPU/battery controls stop working. Fan control is unaffected (see below).

2. Fan Control Helper

Installs a restricted helper script at /usr/local/bin/thinkutils-fan-control that validates commands before writing to /proc/acpi/ibm/fan. This persists across reboots.

3. Polkit Rule

Installs a rule at /etc/polkit-1/rules.d/50-thinkutils.rules that allows the fan helper to run without a password dialog. This is important for the background fan curve task that checks temperature every 2 seconds.

Design Decisions

• Performance settings are NOT auto-applied on startup — avoids triggering a pkexec password prompt every launch
• Fan settings are only restored if the helper is already installed — avoids dialog spam from the background fan curve task
• Permission checks use Path::exists() on the helper binary only — the polkit rules directory is root-only

Troubleshooting

Problem	Solution
Setup dialog doesn't appear	Permissions may already be configured — try using the features
Setup fails	Ensure you're in the sudo group (groups | grep sudo)
Features broken after reboot	sysfs permissions reset on reboot — click Setup Permissions again
Fan control not working	Check if /proc/acpi/ibm/fan exists (ThinkPad-specific)