# Session: 2026-04-26 — Baseline Revert + Parked-Controlsd Mode

## Context

This session was driven by a regression: the steering wheel "feels like
it pulls right" during normal driving, with no clear smoking gun. The
suspicion was that one of the variable-FPS / standstill-throttling
changes (added to reduce parked-state fan noise and CPU load) bled into
on-road driving behavior in a hard-to-isolate way.

Strategy: revert all driving-relevant logic to a known-good baseline
captured in `/projects/openpilot/archive/clearpilot` (HEAD `980f0aa`,
July 2024), keep all of the ClearPilot UI/dashcam/telemetry/bench-mode
infrastructure intact on top, then attack the parked-fan-noise problem
fresh from a different angle that doesn't touch driving logic at all.

Three commits landed in this order on branch `clearpilot`:

| SHA | Title |
|---|---|
| `47321e3` | restore driving logic to pre-variable-fps baseline |
| `f7e602c` | controlsd: re-wire UI hooks on top of restored baseline |
| `887b9c9` | parked-controlsd mode: shut down heavy stack while ignition+park |

Pre-revert tip was `62a403d`. The on-device agent should treat
**`62a403d` as "the broken version"** when looking at history.

---

## Commit 1: `47321e3` — Baseline restore

Reverted the following files wholesale to their `980f0aa` archive copy:

- `selfdrive/controls/controlsd.py`
- `selfdrive/controls/lib/events.py`
- `selfdrive/controls/lib/longitudinal_planner.py`
- `selfdrive/modeld/modeld.py`
- `selfdrive/modeld/dmonitoringmodeld.py`
- `selfdrive/locationd/calibrationd.py`
- `selfdrive/locationd/paramsd.py`
- `selfdrive/locationd/torqued.py`
- `selfdrive/car/interfaces.py`
- `selfdrive/car/hyundai/carstate.py` (CAN-FD telemetry preserved as a
  commented block at the bottom of `update_canfd` — re-enable by
  uncommenting; the `tlog` import is also commented out).
- `selfdrive/monitoring/dmonitoringd.py`
- `selfdrive/frogpilot/controls/frogpilot_planner.py`
- `common/realtime.py`

### Intentionally NOT restored (kept as the post-`62a403d` version)

- `selfdrive/thermald/*` — fan/power tuning kept as-is.
- `selfdrive/car/hyundai/carcontroller.py` and `hyundaicanfd.py` —
  reviewed; the only delta vs baseline is hoisting the
  `no_lat_lane_change` Params read out of the 100Hz hot path
  (~5% carcontroller CPU) by passing the bit as an argument. This is
  a perf-only change with no behavioral effect outside lane changes.
- `cereal/services.py`, `cereal/custom.capnp` — additive only.
  `custom.capnp` adds `latRequested @3` and `noLatLaneChange @4` fields
  to `FrogPilotCarControl`; capnp tag numbers are append-only so this is
  safe to leave in even though baseline code doesn't write to them.
- `selfdrive/manager/*`, `common/params.cc` — heavy ClearPilot
  infrastructure (bench mode, log dir, dashcamd, gpsd, ClearPilot params).
- All `selfdrive/ui/`, `selfdrive/clearpilot/`, `system/clearpilot/`.

### Things removed by the restore (no longer in the tree)

- Standstill frame skipping in modeld (was: skip GPU inference 19/20
  frames at standstill, report 0 dropped frames to fool controlsd).
- Standstill frame skipping in dmonitoringmodeld.
- Model standby logic + `ModelStandby`/`ModelStandbyTs` reads in
  controlsd's comm-issue suppression path.
- Parked-cycle skip in `state_control()` (10Hz vs 100Hz when in Park).
- Calibrationd validity decoupling from `sm.all_checks()`.
- Post-engage 2s commIssue/location/params suppression window.
- Per-cycle carstate write-gating for `CarSpeedLimit`/`CarIsMetric` in
  carstate.py.
- The diff-based carstate telemetry calls (preserved commented out).

These were the candidates for the steering-pull regression. The on-device
agent should **not re-introduce any of these** without a deliberate plan
and a test session. The user's intent is to get baseline driving feel
confirmed first, then re-introduce optimizations one at a time and drive
each.

---

## Commit 2: `f7e602c` — UI hooks on top of baseline

Baseline `controlsd.py` doesn't have the UI plumbing the ClearPilot UI
expects. This commit re-adds only the things needed for the existing UI
to keep working — pure params-write plumbing, no actuator effect.

### Changes (all in `selfdrive/controls/controlsd.py`)

1. **Import `SpeedState`** from `openpilot.selfdrive.clearpilot.speed_logic`.
2. **`Controls.__init__`**:
   - `params_memory.put_bool("ScreenDisplayMode", 0)` →
     `params_memory.put_int("ScreenDisplayMode", 0)` (UI reads it as int).
   - Added `self.speed_state = SpeedState()`, `self.speed_state_frame = 0`,
     `self.was_driving_gear = False`.
3. **SubMaster** — added `gpsLocation` to the subscriber list, with
   `ignore_alive` / `ignore_avg_freq` / `ignore_valid` so missing GPS
   doesn't trigger commIssue.
4. **`clearpilot_state_control(...)`** rewritten from a simple 3-state
   cycle into the documented 5-state ScreenDisplayMode machine:
   - Auto-wake on park→drive edge if currently in screen-off (state 3).
   - LFA button transitions in drive: `0→4, 1→2, 2→3, 3→4, 4→2`.
   - LFA button transitions outside drive: any except 3 → 3, state 3 → 0.
   - Speed/cruise-warning overlay tick at ~2Hz (`speed_state.update(...)`)
     reading `gpsLocation`, `CarSpeedLimit` param, `self.is_metric`,
     `CS.cruiseState`. This is what writes
     `ClearpilotSpeedDisplay`/`ClearpilotSpeedLimitDisplay`/
     `ClearpilotCruiseWarning` for the UI overlay.
5. **Lane-change suppression sync** — at the existing baseline
   `clearpilot_disable_lat_on_lane_change` block (around line 687), in
   addition to the existing `params_memory.put_bool("no_lat_lane_change", ...)`,
   also set `self.frogpilot_variables.no_lat_lane_change = True/False`.
   This is required because the kept (post-`62a403d`) carcontroller
   reads off `frogpilot_variables`, not Params.

### What does NOT change

No edits to lateral or longitudinal control paths. No new actuator-side
behavior. The UI features (nightrider/screen-off/auto day-night, speed
overlay, cruise warning chime) get wired back up purely through param
writes.

---

## Commit 3: `887b9c9` — Parked-controlsd mode

Architectural fix for the original problem this whole session was
chasing: while ignition is on but the car is in Park, the entire onroad
stack (modeld, planner, control, locationd, calibrationd, paramsd,
torqued, dmonitoring*, soundd, loggerd) is running and burning CPU/fan
even though none of it is needed.

Solution: redefine "onroad" as **ignition AND not parked** instead of
just **ignition**. Reuse the existing `started`-based process gating in
manager. Add a tiny second controlsd variant that runs while parked,
just to keep CAN flowing so thermald can see when gear leaves Park.

### Files

#### NEW: `selfdrive/controls/controlsd_parked.py`

Minimal entry point. Roughly:

```python
def main():
    config_realtime_process(4, Priority.CTRL_HIGH)
    card = CarD()                  # blocks until first CAN, fingerprints car
    card.initialize()
    fv = _make_default_frogpilot_variables()  # safe False/0 SimpleNamespace
    while True:
        card.state_update(fv)      # publishes carState/carOutput/carParams
```

`CarD.state_update` blocks via `drain_sock_raw(wait_for_one=True)`, so
the loop is paced by CAN traffic — no extra sleep, no CPU spin.

The default `frogpilot_variables` sets these to safe values so
`CarInterfaceBase.update` doesn't `AttributeError`:
`conditional_experimental_mode`, `experimental_mode_via_distance`,
`traffic_mode`, `sport_plus`, `long_pitch`, `no_lat_lane_change` — all
False.

#### `selfdrive/thermald/thermald.py`

- `onroad_conditions` now also has `"not_parked"`. Initialized to
  `False` (assume parked at boot) so the heavy stack waits for carState
  to confirm gear has left Park before spinning up.
- New module-level loop variables: `is_parked = True`,
  `parked_since: float | None = None`, `PARKED_HYSTERESIS_S = 1.5`,
  `ignition_param_prev: bool | None = None`.
- New block right after the panda-disconnect check (around line 258 in
  current state) reads `sm['carState'].gearShifter`:
  - Gear == Park: latch `parked_since`, flip `is_parked = True` after
    1.5s of continuous Park (hysteresis).
  - Gear != Park: clear `parked_since`, `is_parked = False` immediately
    (no hysteresis going out).
  - Reverse is treated as **not parked** — driver is moving.
- `onroad_conditions["not_parked"] = not is_parked` every tick.
- New `IgnitionOn` Params write, edge-driven (only on change of
  `onroad_conditions["ignition"]`) so we don't hammer the persistent
  filesystem 2x/sec.

#### `selfdrive/manager/process_config.py`

- New predicate:
  ```python
  def parked_only(started, params, CP):
      return params.get_bool("IgnitionOn") and not started
  ```
- New process entry directly after the existing `controlsd` entry:
  ```python
  PythonProcess("controlsd_parked", "selfdrive.controls.controlsd_parked", parked_only),
  ```
- `controlsd` is unchanged (still `only_onroad`). Mutually exclusive
  with `parked_only` because `started` is the negation of the relevant
  condition.

#### `selfdrive/manager/manager.py`

- Single line in `manager_init()` seeding `IgnitionOn=False` so the
  predicate evaluates correctly before thermald's first tick.

#### `common/params.cc`

- New entry in the alphabetical I-block:
  ```cpp
  {"IgnitionOn", CLEAR_ON_MANAGER_START},
  ```
- Manager predicates can only see persistent Params (not pandaStates
  or `/dev/shm/params`), which is why thermald has to expose ignition
  this way.

### State machine summary

| Ignition | Gear        | Predicates true             | What runs                     |
|----------|-------------|-----------------------------|-------------------------------|
| off      | any         | none                        | always_run only (ui, thermald, pandad, deleter, …) |
| on       | Park (>1.5s)| parked_only                 | always_run + controlsd_parked |
| on       | not Park    | only_onroad (=> all `started`) | full onroad stack             |

The transition between rows 2 and 3 is purely manager process
swapping driven by predicate flips — no IPC handshake, no
self-termination. Thermald sees gear change, flips `not_parked`,
`should_start = all(onroad_conditions.values())` flips, manager kills
the wrong variant and spawns the right one on its next tick.

---

## What the on-device agent needs to know / debug

### Build prerequisites

A new param key was added (`IgnitionOn`), so the C++ params whitelist
needs a fresh build. Per `CLAUDE.md` "Adding New Params":

```bash
chown -R comma:comma /data/openpilot
rm -f /data/openpilot/prebuilt /data/openpilot/common/params.o /data/openpilot/common/libcommon.a
su - comma -c "bash /data/openpilot/build_only.sh"
```

`build_only.sh` already deletes `prebuilt` but **does not** delete
`params.o` / `libcommon.a` — verify those are gone before building or
the new key won't be picked up and `Params().put_bool("IgnitionOn", …)`
will throw `UnknownKeyName` in manager_init or thermald.

### How to verify the swap is working

```bash
# 1. Watch which controlsd variant is running
watch -n 1 'ps -ef | grep -E "controlsd(_parked)?" | grep -v grep'

# 2. Watch the gating signals
watch -n 1 'echo "IgnitionOn:"; cat /data/params/d/IgnitionOn 2>/dev/null; \
            echo; echo "deviceState.started:" ; \
            python3 -c "import cereal.messaging as m; \
              s=m.sub_sock(\"deviceState\", timeout=1000); \
              print(m.recv_one(s).deviceState.started)"'

# 3. Watch gear via carState
python3 -c "
import cereal.messaging as m
s = m.sub_sock('carState', timeout=2000)
while True:
    msg = m.recv_one(s)
    if msg: print(msg.carState.gearShifter)
"
```

Expected behavior:
- Ignition off: neither variant in `ps`. `IgnitionOn` is `0`/missing.
- Ignition on, in Park: `controlsd_parked` in `ps`, `controlsd` is not.
  `started` is False. After ~1.5s of confirmed Park, modeld and friends
  should have stopped.
- Shift to Drive: `controlsd_parked` disappears within ~500ms, full
  `controlsd` appears, all the onroad processes spin up. There will be
  a brief carState gap during the swap (~0.5–2s).

### What to suspect first if something breaks

1. **Manager crash on startup** with `UnknownKeyName: IgnitionOn`. Means
   `params.o`/`libcommon.a` weren't rebuilt. Delete them and rebuild.
2. **`controlsd_parked` keeps respawning / dying.** Check
   `/data/log2/current/controlsd_parked.log`. Most likely either:
   - `CarD.__init__` is hanging on `get_one_can` because pandad isn't
     up yet — should only matter on the very first boot.
   - A `frogpilot_variables` attribute we missed defaulting; add it to
     `_make_default_frogpilot_variables` in `controlsd_parked.py`.
3. **Full controlsd never spawns after shift to Drive.** Check
   `IgnitionOn` (should be `1`), check carState.gearShifter (should not
   be `park`/`unknown`), check thermald.log for `should_start` logic.
   Also check that `carState` is actually being published by
   `controlsd_parked`.
4. **Steering still pulls right.** The whole point of commit 1 is to
   rule out the variable-FPS work as the cause. If the symptom persists
   on baseline-restored driving logic, the suspect list shifts to:
   - Anything still on the kept side (carcontroller's
     `no_lat_lane_change` plumbing, thermald-related changes,
     custom.capnp additions).
   - Hardware: a calibration that drifted, an alignment issue, panda
     CAN bus issue, or torque tuning that was modified outside of these
     files.
   - The custom driving model selected (`Params("Model")`). Confirm
     which `.thneed`/`.onnx` is loaded — none of the model files
     themselves were changed in this session.
5. **Panda safety alerts during park transition.** If panda logs a
   "lost heartbeat" or drops to NOOUTPUT mode in the swap window, we
   need controlsd_parked to issue a no-op carcontrol heartbeat to keep
   panda happy. Not implemented in this session — flag for follow-up.

### Open follow-up items (NOT done in this session)

- **Cold-start latency on shift-from-Park.** Modeld load + calibration
  warmup may produce a noticeable gap before lateral/long are ready.
  Anticipatory wake on `CS.brakePressed && in_park` is the planned
  mitigation if needed.
- **Methodically reintroduce optimizations.** Once baseline driving
  feels right, the standstill optimizations (modeld 1fps, fan clamps,
  etc.) can come back one at a time, each with a drive test.
- **The CAN-FD telemetry block in `selfdrive/car/hyundai/carstate.py`**
  is preserved as a commented block at the bottom of `update_canfd()`.
  Re-enabling requires uncommenting + restoring the `tlog` import at
  the top of the file.

---

## Key file index for fast navigation

```
selfdrive/controls/controlsd.py                        # full controlsd, restored to baseline + UI hooks re-added
selfdrive/controls/controlsd_parked.py                 # NEW: parked-only CAN listener
selfdrive/controls/clearpilot_state_control            # in controlsd.py, ~line 1255 — 5-state ScreenDisplayMode + speed_state tick
selfdrive/thermald/thermald.py                         # gear-aware not_parked + IgnitionOn writer (~line 258)
selfdrive/manager/process_config.py                    # parked_only predicate + new entry
selfdrive/manager/manager.py                           # IgnitionOn seed in manager_init
common/params.cc                                       # IgnitionOn registered (CLEAR_ON_MANAGER_START)
selfdrive/car/card.py                                  # CarD class — used by both controlsd variants, unchanged
selfdrive/clearpilot/speed_logic.py                    # SpeedState class — unchanged, called from controlsd.clearpilot_state_control
selfdrive/car/hyundai/carstate.py                      # restored baseline + commented telemetry block at end of update_canfd
```

## Reproducing the diff per commit

```bash
git show 47321e3            # baseline restore
git show f7e602c            # UI hooks
git show 887b9c9            # parked mode
git diff 62a403d..887b9c9   # full session delta
```