Your Legion Go 2 hardware controls, together in the Steam overlay. Tune power, cooling and vibration, personalise lighting and buttons, manage charging, and check your display and Wi-Fi without leaving Gaming Mode.
Features · Requirements · Installation · Quick start · Modules · Desktop app · Troubleshooting · AI disclaimer
Legion Go 2 Companion combines nine hardware modules in one Decky plugin. Use the controls you need, hide the rest, and keep separate power and vibration settings for your games. Saved profiles keep working while the menu is closed. In Desktop Mode the same controls are also available as a native Desktop app.
| Module | What you can do |
|---|---|
| TDP | Choose a power preset or your own limits, adjust CPU Boost and CPU energy preference, and give games their own settings, also separately on battery and charger |
| Fan Control | Draw your own fan curve with touch or controller and see the measured fan speed and temperature |
| Vibration | Set handle vibration and touchpad feedback, also per game |
| Lighting | Set the stick-light effect, colour, brightness and speed, and switch the power-button light |
| Button mapping | Give the two extra buttons on the left controller your own actions |
| Gyro & touchpad | Choose which controller's gyro Steam uses, test the gyro and touchpad, and set when the detached controllers turn off |
| Controller firmware | Update the controllers and their receiver with Lenovo's firmware (experimental) |
| Battery | Limit charging to about 80% and see the console and both controller batteries |
| Display | Fix the HDR brightness games read |
| Wi-Fi | Prefer or require the faster 5/6 GHz bands |
| Requirement | Details |
|---|---|
| Device | Lenovo Legion Go 2 (best supported: 8ASP2 / 83N0); Legion Go and Legion Go S in early beta |
| System | SteamOS Stable with Decky Loader; Display needs SteamOS 3.9 or newer |
| Desktop app (optional) | Nothing extra: it uses the Qt 6.9+ that comes with SteamOS 3.8 and newer |
SteamOS 3.9 supports the Legion Go 2 screen natively; on older SteamOS, Display only offers its HDR brightness fix. Each page explains when a control is unavailable on your console.
The Legion Go 2 is fully supported. The Legion Go (83E1) and the Legion Go S (83L3, 83N6) are an early beta: Companion shows only what applies to the console it runs on, also in Manage Modules, but none of it has been tested on these consoles yet. A machine type that is not listed is placed by its product name and is never taken for a Legion Go 2; the types 83Q2 and 83Q3 are left out on purpose.
| Feature | Legion Go 2 | Legion Go | Legion Go S |
|---|---|---|---|
| TDP & CPU (Boost, EPP) | ✅ | ✅ ¹ | ✅ ¹ |
| Allow up to 50 W | ✅ | ➖ | |
| Separate battery presets | ✅ | ✅ ¹ | ✅ ¹ |
| Fan Control | ✅ / |
❌ | ❌ |
| Vibration | ✅ | ✅ ² | ✅ ⁴ ⁶ |
| Lighting (stick lights) | ✅ | ✅ ² | ✅ ⁶ |
| Power-button light | ✅ | ✅ ⁴ | ✅ ⁴ |
| Button mapping | ✅ | ➖ | ➖ |
| Gyro & touchpad | ✅ | ✅ ² | ➖ |
| Controller sleep | ✅ | ✅ ² ⁴ | ➖ |
| Battery protection | ✅ | ✅ ¹ | ✅ ¹ |
| Display | ✅ | ➖ | ➖ |
| Wi-Fi and band policy | ✅ | ✅ ¹ | ✅ ¹ |
| Controller firmware | ✅ / |
❌ | ❌ |
| Device report | ✅ | ✅ | ✅ |
| Desktop app | ✅ | ✅ | ✅ |
✅ supported ·
¹ When SteamOS offers what the feature needs: the firmware's power limits for TDP, the Long
Life charge mode for Battery, the MT7922 (mt7921e) Wi-Fi driver for the band policy.
² With the 2025 controller firmware. The Legion Go's controllers on older firmware have no Linux driver for these, so Companion hides them; update the controllers in Legion Space to unlock them.
³ ✅ on the Legion Go 2 (83N0);
⁴ Beta: not tested on this console yet.
⁵ The 50 W boosts go above the firmware's own limits and have not been tested on this console.
⁶ When SteamOS has the Legion Go S controller driver (hid-lenovo-go-s); without it Companion hides
the module.
Not supported yet on the Legion Go and Legion Go S: Fan Control, which needs EC data that has only been verified on the Legion Go 2, and controller firmware updates; on the Legion Go S also vibration modes, touchpad strength and the test buzz. Not needed there: Display (the other consoles use SteamOS's own display profiles); SteamOS handles the Legion Go's back buttons and the Legion Go S gyro natively; the Legion Go S needs no button mapping, and its firmware already allows more than 50 W. The power-button light uses the same firmware field as on the Legion Go 2, at the place each console's own BIOS describes, and stays hidden when the BIOS does not describe it exactly so.
Model compatibility and hardware checks
The main validation device is 8ASP2 / 83N0. Joystick RGB also supports 8AHP2 / 83N1
when the expected Lenovo controller and the complete hid-lenovo-go lighting interface are
present. An 8AHP2 owner confirmed RGB and sleep/wake recovery on SteamOS 3.9.1 Preview
(build 20260914.100). This covers controller RGB; not every feature has been verified on 8AHP2.
Fan Control and controller firmware require a Legion Go 2: 83N0 / Legion Go 8ASP2 or 83N1 / Legion Go 8AHP2 (Fan Control on the 83N1 is a beta: its BIOS describes the same EC fields, but the fan registers have not been tested on it, and it needs the 83N1's own RQCN BIOS line). The power-button light works on these and, as a beta, on the Legion Go (83E1) and the Legion Go S (83L3, 83N6). None of them depend on an exact BIOS or EC version:
- The power-button light checks that the BIOS's ACPI table still describes the light the same way (on each console the place its own BIOS uses), reads the light back after each change and puts it back if the change did not hold.
- Fan Control checks the EC fan interface's readings at every start. On its first start with a BIOS/EC version it has not seen (on an 83N1 always the first start) it also runs a one-time fan check: a short raise of the fan speed that Companion watches. If that check fails, Fan Control returns to firmware automatic, turns off and the page says why; turning it on again repeats the check.
Use only one fan controller at a time. Stop another EC fan-control tool and let it return control to firmware before enabling Companion's curve. Detected raw-port owners, an existing EC override or unknown ownership block activation; these checks cannot detect every non-cooperating EC writer.
- Install Decky Loader if you do not already have it.
- Download
LegionGo2Companion-<version>.zipfrom Releases. - Uninstall LeGoTDP, LeGo Vibe Control and LeGo2 Brightness Fix if you have them.
- In Gaming Mode, open Quick Access Menu → Decky → Settings → Developer.
- Choose Install Plugin from ZIP, select the archive, then open Legion Go 2 Companion in Decky.
No terminal commands are needed.
Important
Companion pauses all modules while LeGoTDP, LeGo Vibe Control or LeGo2 Brightness Fix is installed; disabling them is not enough. Uninstall them in Decky Settings, then restart Decky or the console.
Moving from the standalone plugins
Companion does not import settings from these plugins; set TDP, vibration and display again in Companion.
Check again confirms that a conflict is gone; a restart is still required. Renamed copies of those plugins still count. An unreadable manifest of an unrelated plugin is logged and does not pause Companion; failure to inspect the plugin directory itself still blocks controls.
Companion keeps its own settings when it is installed again or updated. After installation, check Manage Modules.
- Open About → Check for updates.
- Choose Download <version> and wait until the page shows the file in your Downloads folder.
- Install that ZIP through Decky Settings → Developer → Install Plugin from ZIP.
Downloading does not install the update. Decky removes the old version first, so Companion hands the hardware back for a moment; the new version applies your settings again when it starts, and an open Desktop app restarts in the new version. An update from 2.3.0 or older removes Companion's old display script by itself (see Display). The update from 2.2.x or older still loses the gyro source, battery protection, lighting control and Wi-Fi band policy once; set them again afterwards.
How updates are checked
Opening About alone does not contact GitHub. Only stable releases with a plugin ZIP are offered. Companion verifies the ZIP's version, size, SHA-256 digest and contents before it offers the file; if checking or downloading fails, the page shows the reason and you can try again. A failed download never replaces an existing ZIP.
Open Companion in Decky. Hardware Controls shows a short status for each module. Select a row to open its page and use ‹ All Controls to go back.
- Open Manage Modules and keep the modules you want to use.
- For game-specific power or vibration, start the game first. On TDP choose This game under Settings for <game>; on Vibration turn on Per-game profile.
- For custom cooling, open Fan Control, check the curve, save any edits, then turn on Enable Fan Control.
- Results appear as short notifications. If something fails, the reason stays under that control; Show details at the end of each page has the technical facts.
Your settings stay saved across reboots and come back after sleep. Fan Control resumes your curve after startup and sleep, but stays off after a detected fault until you turn it on again.
About the status summaries
The overview keeps the last received summaries when reopened. A note about old data means a fresh status could not be confirmed yet. Dropdown selections keep you on the current page. The screenshots in this guide are full 1920 × 1066 PNGs: click one to open it.
Turn a module off to stop its work, give its hardware back to the system and hide its page. Its settings are kept for when you turn it on again.
What each module restores when turned off
This differs from turning off a single setting: for example, Stick lights can stay off while lighting control stays active to keep them off after wake.
| Module | When turned off |
|---|---|
| TDP | Restores the platform profile, CPU Boost and EPP found before Companion first changed them; without them, Balanced, Boost on and balance_performance |
| Fan Control | Returns the fan to firmware automatic. Curves, assignments and units are kept; turning the module on again does not start the curve |
| Vibration | Restores the vibration settings found before Companion first changed them, otherwise the driver defaults; on the Legion Go S the values Companion set stay, as they cannot be read |
| Lighting, Button mapping, Gyro & touchpad, Battery | Restores the previous state for controls Companion still manages |
| Wi-Fi | Restores the configuration Companion changed; Wi-Fi may briefly reconnect |
| Display | Restores the original EDID copy, so games read the panel's own values again |
If cleanup cannot finish, the module stays blocked and offers Retry <module> cleanup. A module that could not start offers Retry <module> start. Unfinished cleanup is retried on startup.
Turn on Enable TDP control, then pick a preset. The line under the switch shows what runs now (Global or the game, the preset, the power limit and the live APU power).
| Preset | Sustained | Slow boost | Fast boost |
|---|---|---|---|
| Silent | 8 W | 15 W | 20 W |
| Balanced | 16 W | 25 W | 30 W |
| Performance | 20 W | 32 W | 35 W |
| Maximum | 35 W | 37 W | 45 W |
- A preset applies and saves as soon as you press it.
- Custom opens sliders for your own limits; press Apply to use them.
- Settings for <game> (while a game runs) chooses Global, This game, or This game + charger for different settings on battery and on charger.
- CPU Boost turns turbo frequencies on or off. CPU energy preference leans towards CPU speed (left) or leaves more power for the GPU (right).
Warning
Allow up to 50 W (under More) raises the boost limits beyond Lenovo's normal range.
Sustained power stays at the firmware's limit (35 W on the Legion Go 2); the processor does not
accept more. The console gets hotter and louder and the battery drains faster. It downloads and verifies the ryzenadj
helper from GitHub the first time you turn it on, and keeps it across updates.
Custom limits, boosts and game profiles in detail
Sustained power (SPL) is the main limit; slow and fast boost (SPPT and FPPT) allow more power for slower and shorter bursts. These are APU limits, not the whole console's consumption.
Custom limits are a draft: the section title shows · unsaved until you press Apply (Apply for <game> or Apply for <game> on charger, depending on what you edit). Picking a preset drops an unsaved draft.
Separate boost limits (under More) is on by default and shows all three limits. Turn it off for one Sustained power slider: normally 5–35 W, with slow boost following at +10 W up to 37 W and fast boost at +15 W up to 45 W. The available range is checked against your firmware. Show details lists the limits now in effect.
With This game + charger, Edit settings for picks Battery or Charger; it starts on the power source in use now. The charger decides which settings run; editing the other one saves it for later. Choosing Global keeps the game's own settings unused; choose This game again to bring them back. Delete profile for <game> removes them after a confirmation. A game's own settings start as a copy of the global ones; older profiles without CPU settings use the global CPU choices until edited.
Newer kernels show CPU energy preference as a 0–100% slider in 10% steps; older kernels show named preferences, including System default when available. CPU changes apply and save at once for the settings chosen above.
Separate battery presets (under More, off by default) makes Silent, Balanced and Performance use the lower limits the firmware sets on battery, and their usual values on the charger; Maximum and Custom are unchanged. Off, the presets use the charger values on battery too.
Turning Allow up to 50 W off lowers saved boosts above the standard limits. If the helper is unavailable, the normal range and your profiles stay available; use Retry helper download when offered. If status or a profile could not load, use Retry status or Retry profile.
Fan Control starts with the Balanced curve and stays off until you turn it on.
- Check the curve, adjust it if you like and press Save global curve.
- Turn on Enable Fan Control. Turn it off at any time to return to the fan's automatic mode.
The graph has 8 points from 0 to 100°C. Drag a point, or focus the graph and use the controller:
| Control | Action |
|---|---|
| A | Start editing points |
| LB / RB | Select the previous / next point |
| D-pad left / right | Change the temperature by 1°C |
| D-pad up / down | Change the speed by the selected step |
| B | Finish editing |
Starting curve offers Silent, Balanced and Aggressive as starting points to edit. Full screen curve editor gives you more room.
Curve rules, readings and units
Move the first seven points freely; the last stays at 100°C and only its speed changes, never below 2000 RPM. At 100°C the fan runs at full speed whatever the curve says. Temperatures stay in order and speeds can only stay equal or rise with temperature; the editor stops a point from crossing its neighbours. Positive speeds below 1500 RPM are skipped; 0 RPM requests a real stop.
Speed edit step starts at 100 RPM. Discard changes returns to the saved curve. Unsaved drafts are kept while you switch curves or open the full-screen editor; save them before leaving the page. Saving while Fan Control is off does not start it; when it is on, saving the active curve updates the fan at once. Templates are Companion's starting points, not Lenovo firmware profiles.
The page shows the measured fan speed, separately from the requested curve, also in automatic mode. APU means the higher of CPU Tctl and GPU edge. Missing or stale readings show a dash. Show fan speed as percentage (in Settings) changes the unit everywhere; 100% means 4800 RPM, the tested ceiling.
Different curves per TDP preset
The global curve is used unless Settings → Assign curves to TDP presets is on. Turn it on to choose Global, Silent, Balanced, Performance, Maximum or Custom in Curve, edit points and use Assign curve to <preset>. Selecting a row only chooses what you edit. An unassigned preset uses the global curve; Use global curve for <preset> removes an assignment. Assignments follow Companion's TDP presets, including those chosen by game and charger profiles, not SteamOS's own Performance profiles. Turning assignments off keeps saved curves and uses only the global curve.
What happens on sleep, restarts and errors
Once enabled, your curve keeps running across Gaming and Desktop Mode. Sleep, shutdown and plugin restarts briefly return the fan to automatic; the page shows Starting your curve… or Paused, resuming automatically until the curve is active again.
A short internal error (a slow sensor read or a momentary EC access error) restarts the controller up to three times in ten minutes before Fan Control turns itself off with the reason. Hardware evidence, such as a stalled fan, another program's fan override or a failed readback, turns it off at once. If the page says Another app controls the fan, Returning fan to automatic… or Turned off after an error, see Troubleshooting. The technical background is in Fan Control internals.
Set Vibration strength for both handles (Off, Low, Medium, High) and a Vibration mode pattern (for example FPS, Racing, Standard, SPG or RPG). Touchpad vibration and Touchpad strength are separate. Test vibration plays a short buzz. On the Legion Go S (beta) only Vibration strength and Touchpad vibration are offered; the controller cannot report them, so the page shows what Companion set. Companion sends that controller only the settings you change here, so the values from Legion Space stay for the others.
Changes save automatically. With a game running, Per-game profile gives that game its own settings; they apply whenever the game starts.
More vibration options
- Reset to defaults resets the selected global or game profile.
- Show details shows the controller driver and its endpoints.
- Retry settings reloads the settings after a load failure.
The available modes come from the controller driver. Saved vibration settings are reapplied after controller reconnection and wake.
Turn on Enable lighting control, switch Stick lights on or off and choose an Effect:
| Effect | Controls |
|---|---|
| Solid | Hue, saturation and brightness |
| Breathing | Hue, saturation, brightness and speed |
| Color cycle | Brightness and speed |
| Rainbow | Brightness and speed |
Changes save automatically and come back after startup and wake. Power button light switches the light in the power button (beta on the Legion Go and Legion Go S). Restore original lighting returns the lights to how they were before Companion.
Lighting details
The dot in the Hue description shows the chosen colour. The controller runs the animations itself. Saved settings, including lights off, are reapplied when the controller becomes available. The power-button light needs the BIOS to describe the light as explained in Requirements. Restore original lighting also ends Companion's lighting control.
Turn on Enable button mapping, then choose actions for the left controller's Desktop button (upper extra button) and Page button (lower extra button): Steam menus, the on-screen keyboard, screenshots, window switching, navigation keys, F1–F12 or Disabled.
Default restores a button's original action and Restore defaults restores both.
How mappings are applied
Actions are saved and applied through SteamOS's own InputPlumber service. Turning mapping off restores the mappings Companion still manages and keeps unrelated mappings and changes made elsewhere.
Choose the Gyro source: Left controller, Right controller, Both controllers or System default. The gyros are in the removable handles; Both averages them.
Start controller test shows live gyro and touchpad readings for 30 seconds, from the controllers and as Steam receives them, so you can see whether input reaches Steam. A game still needs gyro or touchpad assignments in its Steam Input layout.
Controller sleep → Turn off after sets how long the detached controllers wait without use before they turn themselves off: Never, 5, 10, 15, 30, 45 or 60 minutes, the same for both (the choices Legion Space offers). Until you pick one, Companion changes nothing and shows Controller default. Every two minutes, and after a wake or a reconnect, it sets the time again only on a controller that reports another one, so a controller that was asleep when you chose gets it after it wakes. The section appears only when both controllers have the timer. Turning the module off leaves the controllers at their current time.
Gyro and test details
Selecting a controller turns on its gyro reporting and routes its motion through InputPlumber. Until the route is confirmed, the description says Not confirmed yet…; Show details shows the current route. System default restores the previous settings Companion still manages. If an interrupted change is reported, use Restore previous controller settings before making another change.
The test only reads existing reports: it does not turn on sensors, calibrate the console or configure games. Stop test ends it early; it also stops when the page is hidden. Zero readings and missing reports are shown separately. Raw values are diagnostic counts, not degrees per second.
At the end of the Gyro & touchpad page (its own menu entry when that module is off), one button walks you through Check for updates, Download and Install. Companion asks Lenovo's update service for the newest left controller, right controller and receiver firmware and installs every newer part in one go.
Important
Connect the charger (on battery, Install needs at least 30% charge), keep both controllers attached and do not put the console to sleep. Check, Download and Install need both controllers attached, and Install refuses a controller below 30% battery. It can take up to about five minutes and the controllers may disconnect briefly. This is the only Companion feature that could damage the hardware, and it has been tested only by reinstalling the firmware already installed, so the panel and the Desktop app show a red risk notice above the buttons until the next real update has been verified.
How firmware updates work
Companion asks Lenovo's Legion Space update service for the current firmware, downloads and verifies every image with Lenovo's signing key, and installs the newer ones (left, right, then receiver) with SteamOS's own fwupd tool. Its own controller features pause during the install, and the new versions are checked afterwards. Only versions newer than the installed ones are offered. If an update fails, check again and retry, or use Legion Space on Windows. Details: CONTROLLER_FIRMWARE.md.
The first row shows the console battery, charging status and both controllers. Battery protection limits charging to about 80% using Lenovo's Long Life mode.
Battery details
The percentage is fixed by the firmware. If the battery is already above it, protection does not discharge it. Turning protection off restores the previous normal charging mode, including Fast when it was active. Restore previous charging mode (under Show details) returns the original state and stops Companion managing it; if a change was interrupted, the page asks you to use it first. Until the battery confirms a change, the switch says Waiting for the battery to confirm…. A fresh install leaves the charging mode alone until you choose. Detached controllers are labelled, with their last reported level when available.
Fix HDR brightness in games corrects the brightness information (EDID) that games read, so HDR games use the panel's real values instead of a 1499-nit placeholder. Restart a game that was already running. It changes gamescope's copy of the EDID, never the panel firmware.
SteamOS 3.9 and newer drives the Legion Go 2 screen itself (PQ/gamma, HDR switching and the brightness slider). On older SteamOS the page asks you to update; the HDR fix still works there.
Display details
Companion 2.3.0 and older offered their own display modes (PQ, Gamma 2.2, Hybrid), Setup and
brightness forwarding for SteamOS 3.8. They are gone. Each start removes the display script
those versions installed (~/.config/gamescope/scripts/lenovo.legiongo2.oled.lua, only when it
is exactly Companion's), so SteamOS's own profile is used. A script of your own that Setup kept
as lenovo.legiongo2.oled.lua.backup is put back on SteamOS 3.8 and left alone on 3.9, where it
would override SteamOS. A Gaming Mode that was already running keeps the old script until it
restarts.
The first row shows your network, band and channel. Pick a policy in Band:
| Option | What it does |
|---|---|
| Automatic | SteamOS chooses the band |
| Prefer 5/6 GHz | Favours the faster bands, keeps 2.4 GHz as a fallback |
| Only 5/6 GHz | Never uses 2.4 GHz; asks first, because you can lose Wi-Fi away from a 5/6 GHz router |
| Only 6 GHz | Connects only to 6 GHz; asks first. Needs SteamOS 3.9 or newer |
If you lose Wi-Fi with a strict option, choose Automatic or Prefer 5/6 GHz again.
Wi-Fi details by backend
The options depend on SteamOS's Wi-Fi backend (iwd or WPA supplicant, shown under
Show details) and need the Legion Go's MT7922 adapter (mt7921e driver).
| Backend | Option | Behaviour |
|---|---|---|
| iwd | Band: Prefer 5/6 GHz | Favours higher bands while keeping 2.4 GHz available |
| iwd | Band: Only 5/6 GHz | Excludes 2.4 GHz; can leave Wi-Fi disconnected outside higher-band coverage |
| iwd with Prefer, or WPA with Automatic | Reconnect to 5/6 GHz | A one-time attempt to connect to a detected higher-band access point |
| WPA with Automatic | Connect to 6 GHz once | Connects to a detected 6 GHz access point, then returns to normal roaming |
| WPA with Automatic | Band: Only 6 GHz | Limits the saved network to 6 GHz; needs NetworkManager 1.58 or newer |
Automatic restores the band settings Companion changed. A saved policy is not proof of the current connection; check the live band. With Prefer 5/6 GHz on iwd, Companion also looks for higher-band access points and moves the connection automatically. WPA uses SteamOS's normal roaming; its manual actions are one-time attempts.
If the first attempt of Only 5/6 GHz connects to no higher band, the previous policy comes back automatically. Manual reconnect actions briefly interrupt Wi-Fi. If SteamOS switches backend, a saved iwd preference stays visible but unused under WPA; choose Automatic to clear it. Companion never switches the backend or runs another Wi-Fi manager.
About shows the installed version, author and license, and checks for updates as described in Updating. Save device report is described in Reporting a problem on Legion Go / Go S (beta).
In Desktop Mode, Legion Go Companion is in the application menu. It has the same modules and settings as the Decky panel, laid out for a mouse and a wide window, and both always show the same state.
- When Desktop Mode starts, the app waits in the system tray; click the icon to open it.
- The TDP page lists every game that has its own settings, by name. Edit changes a game's settings even when it isn't running; Delete removes them.
- About → View logs shows recent events and can export them for a bug report.
Desktop app details
The app talks to the running Decky plugin. If Decky is not running, the app pauses its controls and offers Check Decky and, when the service is stopped, Start Decky. Turning off Show tray icon in the app's settings also stops the start in the tray. Editing a saved game profile never changes the settings running now; they apply when that game starts. Uninstalling the plugin closes the app and removes its menu and autostart entries; updating the plugin restarts it in the new version. Logs are described in LOGGING.md.
| What you see | What to do |
|---|---|
| All modules paused | Uninstall LeGoTDP, LeGo Vibe Control and LeGo2 Brightness Fix, then restart Decky or the console. |
| A module is missing | Check Manage Modules: a disabled module is hidden; a failed start or cleanup has a retry button there. |
| A control is unavailable | Read the reason on the page; some controls need system drivers or a specific model. |
| Fan Control is not available | Check your model in Requirements. |
| Another app controls the fan | Stop the other fan tool and let it return the fan to automatic. |
| Fan Control turned off after an error | Read the reason, let recovery finish, check your curve, then turn it on again. |
| Turned off: the BIOS/EC version changed how the fan is controlled | The check after a firmware update failed. Turn Fan Control on again to repeat it; if it keeps failing, report it with your BIOS and EC versions. |
| My curve is saved but the fan is on Automatic | Saving does not turn Fan Control on. Turn on Enable Fan Control. |
| A curve point will not move further | Temperatures stay in order and speeds cannot drop between points; the last point stays at 100°C and at least 2000 RPM. |
| The gyro test works but the game does not react | Check that game's Steam Input layout. |
| The controllers stopped working, often after sleep | Companion restarts SteamOS's InputPlumber by itself when it has lost the controllers (at most once per 10 minutes, and three times until Decky or the console restarts); if they still do not respond, restart the console. |
| Battery stays above 80% with protection on | Normal: protection stops charging, it does not discharge the battery. |
| Battery: the charging mode cannot be read | The firmware has fast charging and battery protection on together. Use Reset charging mode to Standard on the Battery page. |
| A game still reads old HDR values | Turn on Fix HDR brightness in games and restart the game. |
| Wi-Fi stays on 2.4 GHz | Check the live band; use Reconnect to 5/6 GHz when offered. A setting cannot create a missing 5/6 GHz network. |
| No Wi-Fi with Only 5/6 GHz or Only 6 GHz | Choose Automatic or Prefer 5/6 GHz. |
| Update check or download failed | Read the error and retry, or download the ZIP from Releases and install it manually. |
| The Desktop app says Qt is missing or too old | Use the Decky panel; the app needs SteamOS 3.8 or newer. |
More troubleshooting
| What you see | What to do |
|---|---|
| A preference is saved but not confirmed | Check the current state and the error; wait for recovery or use the offered retry. An unavailable reading is not treated as on or off. |
| 50 W is paused | Keep using the normal range. Connect to the internet and use Retry helper download; your profiles are kept. |
| Returning fan to automatic… | Let it finish. Keep custom control off if recovery cannot be confirmed. |
| Fan Control reports a watchdog connection failure | This is communication between local processes; the fan still returns to automatic. Include the reason and, before rebooting, the output of sudo cat /run/legiongo2companion-fan/last-fault.json (if it exists) in a report. |
| Fan RPM or APU shows a dash | The reading is unavailable or stale. Another program reading the EC can prevent a safe read. A dash does not mean the fan stopped. |
| Recovery required, settings damaged or cleanup incomplete | Keep the saved settings and backups; follow the page's reason and retry button. Deleting them can remove what is needed to restore your previous state. |
| A plugin conflict persists | Renamed copies of the old plugins still count; keep backups outside Decky's plugin folder. If the plugin folder cannot be read, restore access to it. |
| The plugin folder was deleted by hand and the display or Wi-Fi still acts as if Companion were set | Install Companion again and uninstall it in Decky Settings; uninstalling restores what it changed. By hand: remove the BandModifier2_4GHz line from [Rank] in /etc/iwd/main.conf (iwd backend only), then restart the console. |
Reporting a problem: include the plugin version, SteamOS version, console model, what the page says, when it happened and what you did, plus the logs from About → View logs in the Desktop app or as described in LOGGING.md. CHANGELOG.md lists the changes in each version.
Companion has not been tested on the Legion Go, the Legion Go S or the Legion Go 2 Z2 (83N1) yet, so reports from these consoles help most.
- In Decky open Companion → About → Save device report (Desktop app: About → View logs
→ Save device report). A file
LegionGoCompanion-device-report-<date>-<time>.txtappears on your Desktop. - Open a Beta report, say what works and what does not, and attach the file.
The report is made on the console, without internet, and only reads. It lists the model and firmware versions (DMI, BIOS and EC, firmware attributes, battery, controllers and their drivers, sensors, the display's maker and model, the Wi-Fi adapter and its bands, fwupd devices), the SteamOS, kernel, InputPlumber and fwupd versions, Companion's module status, and how many warnings and errors Companion logged in the last 24 hours. It also holds read-only firmware tables (DSDT) and EC readings, which help add Fan Control and the power-button light on more consoles: the BIOS's ACPI table (DSDT, compressed, with a one-line command to restore it), and on a Legion Go console the EC memory the DSDT describes, read as memory without sending the EC any command, with fields that can hold a serial number blanked. With the Fan module on (Legion Go 2) the report reads no EC memory and shows Fan Control's own last readings instead. It contains no serial numbers, MAC addresses, network names, user names or log text. Open it in a text editor to check it before you send it.
Hardware interfaces, recovery and background work
Companion coordinates independent hardware modules through Decky. Each module manages its own settings and verifies the interface it uses.
| Area | System interface |
|---|---|
| TDP | Lenovo WMI in the firmware range; verified ryzenadj helper for Allow up to 50 W |
| Fan Control | Restricted EC access on the 83N0 model, checked by behaviour; k10temp and amdgpu temperatures plus EC tachometer feedback |
| CPU Boost / EPP | Kernel CPU policy controls under sysfs |
| Package power | RAPL energy counters |
| Haptics / joystick RGB | hid-lenovo-go sysfs controls |
| Button mappings | InputPlumber's D-Bus profile API |
| Controller gyro | Lenovo IMU bypass controls and InputPlumber D-Bus event filters |
| Passive diagnostics | Read-only copies of native and virtual controller HID reports during an explicit test |
| Battery protection | The kernel battery charge_types attribute |
| Display | X properties and gamescope's published EDID copy |
| Wi-Fi | NetworkManager with the active iwd or WPA supplicant backend |
The HDR fix drops the DisplayID 2.0 block from gamescope's published EDID copy: DXVK's
libdisplay-info rejects the whole EDID because of it, and DXVK never reads that block. The
original bytes are kept root-only in /var/lib/legiongo2companion/ and put back when the fix is
turned off or Companion is uninstalled. The SteamOS 3.9 notice comes from the presence of
/usr/share/gamescope/scripts/00-gamescope/displays/lenovo.legiongo2.oled.lua; its contents are
not read.
Settings use atomic replacement and backup/recovery handling. Failed changes retain restoration information; controls pause if settings cannot be recovered. Restoration only changes state still owned by Companion, preserving conflicting external changes. TDP/CPU and Vibration capture the system's own values before their first change and restore them on withdrawal; installs from before 2.2 without captured values fall back to the defaults listed under Manage Modules. Interrupted cleanup is also retried during uninstall when Companion is not paused by a plugin conflict.
Background profile and recovery checks continue with Quick Access closed. RGB and remapping normally check once per minute, with five-second checks during the first 30 seconds after startup or wake; matching state avoids another write or profile reload. Battery and gyro also recover after startup and wake and check for drift. RGB retries a temporarily missing controller during wake recovery. InputPlumber restarts trigger earlier recovery checks, with backoff after failures.
Page refreshes pause while Quick Access is hidden. Diagnostic readers close outside a test; controller battery sampling is a short read with a 15-second cache. RGB animations run in firmware, and slider edits are grouped while a control is moving. Vibration discards superseded queued values for the same field and profile while keeping the final accepted edit. Actual overhead depends on enabled modules and the system build.
Conflict detection checks plugin folders and manifests, including renamed copies. It blocks requests and stops workers when a conflict appears; a restart is required after removal. WiFi Optimizer and HueSync are not part of that check.
The update downloader accepts stable release plugin ZIPs with a SHA-256 digest. It checks version, size, digest and archive contents before completing the download. Source archives and development branches are not used as fallback downloads.
EC access, temperature readings and recovery
Fan Control uses an independently implemented, restricted EC register interface on the validated hardware. The positive target range is 1500–4800 RPM; unsupported positive values below 1500 snap to stop or the running minimum. Custom zero uses a distinct EC stop request; a zero override releases control to firmware. Firmware automatic can also naturally stop a cool fan.
The EC interface is checked by behaviour, not by version. Every session start first reads all
of the registers Companion uses twice, without writing. The readings must be stable and
plausible, and an override must be absent or released. On a BIOS/EC version pair that Companion
has not checked yet, the first session sets 3000 RPM (4800 RPM if the fan already runs at
2200 RPM or more). The target must read back exactly, and the tachometer must come within 15% of
it in two consecutive samples within 15 seconds. Release must then read firmware automatic three
times. The check never lowers the fan speed, and the backup watchdog runs throughout. The
checked pair is remembered in a root-only file outside Decky's settings folder
(/var/lib/legiongo2companion-fan/fan_firmware.json), so later sessions skip this check. It is
a hardware fact, so uninstalling leaves it in place. A failed check is not remembered: Fan
Control turns off with the reason, and enabling it again repeats the check.
4800 RPM is an observed operating plateau on the tested unit, not a manufacturer motor rating or a guarantee for every console. Bounded trials through a 5200 RPM target produced no useful increase. The editor's finer target steps do not imply one-RPM motor accuracy. Starting from stop requests the curve's positive speed directly, without an artificial 4000 RPM kick; insufficient tach feedback causes withdrawal rather than repeated hidden boosts.
Control and the displayed APU value use max(CPU Tctl, GPU edge) from k10temp and amdgpu. The tested system exposes no Tdie or verified separate whole-package sensor. The EC temperature is supplementary telemetry with an unproven physical sensor identity; its difference from Tctl/GPU edge is not a fault. Invalid or slow sensor reads still withdraw control. A live tachometer reading is never replaced by the requested RPM.
A separate controller process and an independent recovery process supervise fresh sensors, progress and ownership. Cooling rises quickly and falls more slowly to limit oscillation. Custom control follows the curve up to 100°C; there, the controller and backup can enforce full speed without the normal ramp. This policy is tested with model inputs, not by heating the console to 100°C. Native thermal protections remain in place.
Disable, unload, SIGTERM, faults and normal sleep withdraw custom control and verify firmware automatic. Both fan processes hold their own login1 delay inhibitor during sleep preparation. Session endings are classified: sleep, shutdown and plugin restarts pause and then re-arm the saved curve with a fresh controller; transient software or timing errors retry at most three times in ten minutes; hardware evidence is a fault that saves Fan Control off with its reason. Every start repeats all checks (platform, ownership, both sensors, EC plausibility, backup readiness, sleep inhibitor, curve). The controller runs the curve from its own sensors, so a busy or detached Decky frontend does not end the session. Detected conflicting owners or unverifiable ownership block activation; a foreign raw-port reader can also block telemetry without proving an active fan override. A leftover EC override with no live owner, for example after both fan processes were killed, is released to firmware automatic when the next session starts.
Recovery requires a functioning kernel and EC transport. Recovery after a whole-system hang and a firmware-enforced lease have not been established. Userspace locks cannot exclude firmware/SMM or every non-cooperating EC writer. Do not run another fan or EC control tool alongside Companion's custom controller.
With custom control off, there are no fan workers or sleep inhibitors and no background EC polling. Visible fan views request bounded passive readings; hiding them stops new requests. Active control uses its own telemetry independently of the menu.
Saved fan settings use the format Fan Control shipped with in 2.1.0; any other format is refused and custom control stays off until the curve is reviewed. Optional TDP assignments remain dormant until explicitly enabled. Saving uses a revision check so an old editor cannot overwrite newer settings.
See SOURCE.md for protocol provenance and the limits of the hardware evidence.
Build, test and package from source
The Desktop app is written in C++17 and Qt Quick/QML and ships in the plugin ZIP. It links SteamOS's system Qt (6.9 or newer) instead of bundling Qt, and calls the same Python backend as the Decky panel over an authenticated loopback connection. See the Desktop app notes for its architecture, lifecycle, build and tests.
Requires Node.js 24, Git and tar (the packager writes the ZIP itself). Backend tests
require Python 3.10+. The native Desktop build additionally requires CMake, Ninja, a C++17 compiler and
a Qt 6.9 SDK.
npm ci
npm run typecheck # frontend types
npm run test:frontend # frontend regression suites
npm test # Python backend tests
npm run build # compile and validate the frontend
python scripts/build-native.py --qt /path/to/Qt/6.9.1/gcc_64 --build /tmp/companion-native --test --bundle dist/desktop
npm run test:desktop # native API/source contract; Qt tests run in the command above
npm run package # create LegionGo2Companion-<version>.zip and its .sha256Build before packaging: package uses the existing frontend build and the native app in
dist/desktop from the command above (npm run build keeps dist/desktop). Tracked files come
from the committed HEAD, so the same commit and build give a byte-identical ZIP. Install the result through Decky; a source checkout with
node_modules is not an installation package.
GitHub Actions runs the backend tests on Linux/Python 3.10 and 3.14 and Windows/Python 3.13, plus frontend tests, build and package validation on Node.js 24 LTS. The native app is built against Qt 6.9.1 and its tests run again on the newest Qt 6. Linux-specific checks skip on Windows. Hardware calls are mocked; device testing is still required for startup, wake, game transitions and native Steam UI behaviour. CI does not publish releases.
The archive includes frontend source/build inputs, license notices and bundled pyudev source.
RyzenAdj is downloaded separately and verified against its pinned hash before every use. It is
kept in /var/lib/legiongo2companion-tdp/, outside Decky's plugin folder, so updates keep it;
uninstalling leaves it there. A Wi-Fi band change keeps a short rollback journal in
/var/lib/legiongo2companion-wifi/ until the change has finished; the empty folder stays after
uninstalling. See
SOURCE.md for rebuilding and NOTICE for component provenance.
- Andrii Dmytrenko (@Antti) - 8AHP2 / 83N1 joystick RGB support and owner testing in PR #2
- Ally Vibe Control by piyush-tyagi-13, with original per-game profile work by M4ttiA - inherited MIT-licensed vibration code
- HueSync by honjow and Steam Deck Homebrew - reference for the lighting interface and Go 2 sysfs controls
- Rodpad/LeGo2-Fan-Control - published fan protocol/register facts used by Companion's independent implementation; no reference implementation was copied or adapted
- Armada Control - fan-editor UX reference; Companion's editor is independently designed and implemented, with no Armada code incorporated. See SOURCE.md
- RyzenAdj, pyudev, InputPlumber and Decky Loader - the supporting tools and interfaces
Component licenses are recorded in NOTICE; implementation and hardware-reference provenance are described in SOURCE.md.
BSD 3-Clause - see LICENSE. Inherited vibration code retains its MIT notice, and HueSync attribution is preserved in LICENSE.HUESYNC. Third-party terms and source information are listed in NOTICE and SOURCE.md.
This project was built with substantial help from AI coding assistants. Most of the code, tests and documentation were written by AI agents (first OpenAI Codex, later Anthropic's Claude Code) working under my direction: I defined what each feature should do, made the design and safety decisions, reviewed the results and chose what was released.
The AI was used to:
- write and refactor the Python backend, the Decky panel and the native Desktop app;
- build the automated test suites (about 1,300 tests run on Linux and Windows for every change);
- audit the code for bugs, security issues and wasted work, with every finding checked by independent review passes and, where possible, reproduced before it was fixed;
- research hardware interfaces and write this documentation.
Nothing here is untested AI output. I tested the plugin continuously on my own Legion Go 2 throughout development: in Gaming and Desktop Mode, across sleep, restarts, plugin updates and reinstalls, with games and HDR content, on SteamOS Stable (with a compatibility check on the Beta), and with supervised controller firmware installs. Hardware-facing features (fan control, power limits, display, firmware) were held back until they behaved correctly on the real device, and safety rules such as releasing the fan to firmware control on any failure were kept as hard requirements.
Even so, Companion controls power, cooling and firmware on your console. It is provided as is, without warranty (see License); use it at your own risk.