====== fourier — multi-layer V4L2 hardware-decode unlock for mainline ARM Wayland ======

A patch campaign that started as a single Chromium V4L2 dispatch unlock and
expanded — every time a layer was patched, the next layer's bug surfaced —
into **4 sibling patch series + 1 kernel RFC + 3 upstream submission drafts**
that together make hardware video decode actually work on mainline-Linux Wayland on
Rockchip + Mali-class ARM hardware.

  * Public face: [[https://github.com/marfrit/fourier|github.com/marfrit/fourier]] — sibling subdirs ''chromium-fourier/'', ''qt6-base-fourier/'', ''kwin-fourier/'', ''docs/'', ''tools/''
  * Local Arch packaging + investigation notes: [[https://git.reauktion.de/marfrit/marfrit-packages|gitea/marfrit-packages]] under ''arch/{chromium,qt6-base,kwin,firefox}-fourier/'', ''kernel/vb2-dma-resv-rfc/'', ''upstream-submissions/''
  * Reference target: **ohm** (PineTab2 / RK3566 / Mali-G52 / panfrost / mainline 6.19.10 / KDE Plasma 6.6.4 Wayland)

===== Status — paused 2026-04-30 =====

Project paused pending the GL/EGL pipeline campaign baseline. The browser-side ship-gate (1080p30 YouTube ≤ 30 % CPU, no drops) is gated on the Mali-side EGLImage import cost being addressed; running browser measurements before that lands produces known-failing results that contaminate the 8-phase loop.

Freeze-state record: [[fourier:phase5_2026-04-30|Phase 5 review handover, 2026-04-30]].

Live tasks that continue independently:
  * **chromium-fourier build** — finish the build + publish; package ships, measurement deferred.
  * **vb2 dma_resv RFC v2** — kernel-side, separate cadence.

Re-entry condition: GL fix campaign surfaces something useful that changes the GL-consumer baseline.

===== Status snapshot — 2026-04-30 =====

^ Series ^ Patches ^ State ^ Validated where ^ Notes ^
| **chromium-fourier** | 4 | end-to-end smooth playback | ohm | bbb_1080p30_h264.mp4: ~81 % chrome CPU vs ~131 % pre-patch baseline (~3.8× reduction) |
| **qt6-base-fourier** | 3 | shipped + upstream-targetable | ohm + fresnel | pure spec-correctness GLES3 fix; zero ''GL_INVALID_VALUE'' in journal post-relogin |
| **kwin-fourier** | 1 shipped (0001-skip-wait) | shipped, MR 9157 closed | ohm | reverted to 0001 after MR review found 0002 technically wrong; goes no-op once vb2-dma-resv RFC lands |
| **vb2-dma-resv RFC** | 3 sent 2026-04-29 | v1 reviewed (Nicolas + Christian); v2 sketch backlogged | — | not a NACK; attach point moves to ''device_run'', opt-in flag added, lockdep annotated for v2 |
| **firefox-fourier 150.0.1** | 4 | partial — gates 1+4 verified, 2+3 corrected today, rebuild pending | fresnel | root cause identified via ''MOZ_LOG'': must probe by ''h264_v4l2request'' codec name first |
| **upstream submission drafts** | 3 | written, awaiting validation gates | — | bugreports.qt.io, invent.kde.org MR, linux-media RFC |

===== Sub-pages =====

  * [[fourier:chromium_fourier|chromium-fourier — what we get + the rug-pull on Brave]] (2026-04-26 capture; predates the 4-patch end-to-end win)
  * [[fourier:patch_series|Patch series — the four sibling series in detail]]
  * [[fourier:vb2_dma_resv_rfc|vb2-dma-resv kernel RFC — the architectural correction]]
  * [[fourier:hosts|Per-host status — ohm / fresnel / boltzmann / CT220 / ampere]]
  * [[fourier:journey|Journey — chronological discovery (chromium → qt6 → kwin → vb2)]]
  * [[fourier:upstream_submissions|Upstream submission drafts — Qt, KDE, linux-media]]

===== Sources =====

==== Public ====

  * [[https://github.com/marfrit/fourier|github.com/marfrit/fourier]]
    * ''chromium-fourier/'' — 4 patches
    * ''qt6-base-fourier/'' — 3 patches
    * ''kwin-fourier/'' — 2 patches
    * ''docs/dmabuf-zero-copy.md'' — panfrost ''external_only'' finding + cascade
    * ''tools/'' — capture / measurement helpers

==== Local (gitea/marfrit-packages) ====

  * ''arch/chromium-fourier/'' — PKGBUILD + patches + ''NEXT.md'' campaign chronology + ''KWIN_PIVOT.md'' discovery story
  * ''arch/qt6-base-fourier/''
  * ''arch/kwin-fourier/''
  * ''arch/firefox-fourier/''
  * ''kernel/vb2-dma-resv-rfc/'' — 3-patch kernel RFC
  * ''upstream-submissions/qt6-base-fourier/qt-bug-report.md''
  * ''upstream-submissions/kwin-fourier/kde-mr-body.md''
  * ''upstream-submissions/vb2-dma-resv/lkml-submission-notes.md''

----

//Page index created 2026-04-28 from a fourier-campaign sync. The
''chromium-fourier'' sub-page predates the end-to-end win and reflects the
state on 2026-04-26; the ''[[fourier:patch_series|patch_series]]'' page
carries the current 4-patch shape.//