# Power Management

veilor-os ships a 3-mode power profile system backed by `tuned`.

## Profiles

| Profile | Governor | EPP | Boost | ASUS TTP | Use |
|---------|----------|-----|-------|----------|-----|
| `veilor-powersave` | powersave | power | off | 2 (silent) | max battery |
| `veilor-balanced` | powersave | balance_performance | on | 1 (mid) | on the go |
| `veilor-performance` | performance | performance | on | 0 (full) | plugged in |

`ASUS TTP` (throttle_thermal_policy) only applies to ASUS laptops with
`asus-nb-wmi`. On other hardware those writes are silently skipped.

## Switching

```bash
veilor-power save     # max battery   (aliases: powersave, s)
veilor-power mid      # balanced      (aliases: balanced, b)
veilor-power perf     # performance   (aliases: performance, p)
veilor-power          # status: profile, governor, EPP, boost, freq
```

`veilor-power` calls `tuned-adm` via a NOPASSWD sudoers drop-in
locked to `veilor-*` profiles only (`/etc/sudoers.d/veilor-power`).

## Auto-switch on AC plug/unplug

`/etc/udev/rules.d/90-veilor-ac-switch.rules`:

```
SUBSYSTEM=="power_supply", ATTR{online}=="0", RUN+="/usr/bin/tuned-adm profile veilor-powersave"
SUBSYSTEM=="power_supply", ATTR{online}=="1", RUN+="/usr/bin/tuned-adm profile veilor-performance"
```

Override anytime with `veilor-power mid`.

## Battery longevity

`/etc/udev/rules.d/91-veilor-battery-threshold.rules` caps charge at
80% on supported hardware. Adjust by editing the rule or:

```bash
echo 100 | sudo tee /sys/class/power_supply/BAT0/charge_control_end_threshold
```

## What each profile actually does

`/etc/tuned/profiles/veilor-<profile>/script.sh` writes:

- `/sys/devices/system/cpu/cpufreq/boost`
- `/sys/devices/platform/asus-nb-wmi/throttle_thermal_policy` (ASUS only)
- `/sys/bus/pci/devices/*/power/control` (NVMe autosuspend)
- `/sys/class/drm/card*/device/power_dpm_force_performance_level` (AMD iGPU)
- `usb_autosuspend` enable/disable

All writes are guarded with `[ -w ... ]` so non-applicable hardware
silently no-ops.

## Persistence

`tuned.service` starts at boot and loads the last active profile from
`/var/lib/tuned/save.conf`. No GRUB params needed.

## Caveat: `platform_profile` vs `throttle_thermal_policy`

On some ASUS laptops the `platform_profile` sysfs key maps to TTP in
non-obvious order (e.g. `quiet`→TTP2, `balanced`→TTP0,
`performance`→TTP1). veilor profiles write TTP directly and never
touch `platform_profile` to avoid the second-write override race.