# x11-session-research

> **Status: PHASE 0 — research question pending operator
> confirmation.** See [`phase0_findings.md`](phase0_findings.md)
> § "Research question (provisional)" for the candidate framing
> drafted from the predecessor campaign's close-out. Phase 1
> lock will not happen before the operator confirms or
> redirects.

Campaign to investigate X11 session behaviour on PineTab2
RK3568, in the context of the just-closed
[`kwin_overlay_subsurface`](../kwin_overlay_subsurface/)
campaign. Whether running an X11 (Xorg) session on the same
hardware would (a) reproduce the drop-inversion phenomenon
that motivated the predecessor, (b) bypass it entirely, or
(c) introduce a different set of constraints, is the most
likely campaign question — but this is a working assumption,
not a locked goal. See `phase0_findings.md`.

## Predecessor

This campaign exists because
[`../kwin_overlay_subsurface/`](../kwin_overlay_subsurface/)
closed 2026-05-03 without patch (`phase8_handover.md`). Its
diagnostic loop terminated at "Phase 0 cage = 0 post-warmup
drops floor not reproducible at N=3." The natural next move
across the design surface is to vary the display server (X11
instead of Wayland) on the same hardware and the same client
binary, but the operator has not yet confirmed that as the
campaign's specific question.

## Hardware target (provisional, same as predecessor)

ohm — PineTab2, Rockchip RK3568 (4× Cortex-A55, Mali-G52 MP2,
hantro G1/G2 VPU). Kernel `6.19.10-danctnix1-1-pinetab2`.
Mesa 26.0.5. Currently runs KDE Plasma 6.6.4 Wayland.

For an X11-session campaign, ohm needs an Xorg + Plasma X11 (or
similar X11 desktop) install path verified. As of 2026-05-03,
the only confirmed display path on ohm is
`startplasma-wayland`. **Whether Plasma X11, an alternate X11
desktop (XFCE, openbox, lightweight WM), or Plasma running
under a Wayland-Xorg shim is in scope is part of the research
question to be locked.**

## Carry-overs from predecessor (still active on ohm)

Per `kwin_overlay_subsurface/phase1_evidence/ohm_tooling_revert_log.md`:

- `qt6-base-fourier 1:6.11.0-3` installed.
- `kwin-fourier 1:6.6.4-3` installed.
- CPU governor pinned to `performance` (was `conservative`).
- Baloo permanently disabled
  (`Indexing-Enabled=false` in `~/.config/baloofilerc`).
- `drm-info 2.9.0-1` installed.

These were not reverted at the predecessor's close-out. This
campaign inherits them unless an explicit revert is part of
the design.

## Non-upstreaming default

Inherited from the predecessor and from `ohm_gl_fix`. Bug
reports + MRs are explicit operator-tasked decisions, not
background process steps.

## File map (will grow)

| File | What it is |
|---|---|
| `README.md` | This file. |
| `phase0_findings.md` | Substrate from the predecessor + the candidate research question. **Awaits operator confirmation/redirect on the question itself.** |
| `worklist.md` | Phase-by-phase task list. Phase 0 only as of campaign start. |