marfrit/libva-multiplanar
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Iteration 3 close — F GREEN, A reproduced + diagnosed for iter4

Browse Source 
Phase 1 locked F (Firefox RDD sandbox verify-by-patch) and A (frame-11
EINVAL diagnose) running in parallel on a single firefox-fourier build.

Track F: GREEN. Patched Firefox 150.0.1 (firefox-fourier, pkgrel=1.1)
launches on ohm WITHOUT MOZ_DISABLE_RDD_SANDBOX=1 and engages our
libva-v4l2-request backend end-to-end. Three patches needed (Phase 2
identified one and deferred two):
  - Broker policy (SandboxBrokerPolicyFactory.cpp): allow /dev/media*,
    extend cap-filter to admit stateless decoders that lack M2M caps.
  - Seccomp policy (SandboxFilter.cpp): allow ioctl magic byte '|'
    for <linux/media.h> request-API ioctls.
  - Driver (media.c): replace select() with poll() — Mozilla's RDD
    seccomp common policy admits poll/ppoll/epoll_* but not
    select/pselect6. Driver-side fix preferred; smaller surface,
    portable across sandbox policies, and poll() is the modern API.

Track A: REPRODUCES + DIAGNOSED. Frame-11 EINVAL fires deterministically
on a single-slice P-frame (slice_type=0, frame_num=5, post-IDR) — the
exact iter1/iter2 carryover signature, confirming it isn't environmental.
Y2 instrumentation (in v4l2_ioctl_controls) now logs num_controls /
error_idx / per-control id+size on EINVAL. Sizes match kernel UAPI;
error_idx == num_controls is the kernel's "all bad / no specific control"
sentinel — it's a request-level rejection, not a single-field violation.
Fix is iter4's lock; rig + Y2 in place for fast iter4 turnaround.

Build infrastructure introduced: firefox-fourier LXD container on
boltzmann (RK3588 aarch64, persistent, ssh -J boltzmann
builder@firefox-fourier). Upstream Arch x86_64 wasi packages installed
to work around 4-year-stale ALARM versions. PGO generation crashes at
exit (LXC has no display); obj/dist/ tarball used as the deployable
artifact instead of the pacman package.

Phase 6 surprises captured in phase6_iter3_findings.md: malformed
first-cut patch (descriptive vs numeric hunk headers), --enable-v4l2
isn't a Mozilla 150 flag (auto-set on aarch64+GTK), Mozilla 2025 PGP
key rotation, ALARM-stale wasi, onnxruntime missing in ALARM, and the
"no tricks" lesson (revert workarounds first when redirected).

Carries to iter4 substrate: Track A fix is the natural lock; mpv
libplacebo --vo=gpu segfault stays as separate iter4 candidate.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Markus Fritsche
2026-05-05 12:56:34 +00:00
parent c555040b24
commit f91469abe3
11 changed files with 1086 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files
README.md
+55 -6
View File
@@ -24,12 +24,20 @@ The chromium-fourier verdict's load-bearing claim is "multi-planar libva is the
## Process
Eight-plus-one phase loop per [`feedback_dev_process.md`](../../.claude/projects/-home-mfritsche-src/memory/feedback_dev_process.md). Phase 0 is locked in [`phase0_findings.md`](phase0_findings.md) — read that next. The fork's prior `STUDY.md` content was migrated into `phase0_findings.md` and the file in the fork is now a pointer (recover from commit `e0acc33` if historic content needed).
Eight-plus-one phase loop per [`feedback_dev_process.md`](../../.claude/projects/-home-mfritsche-src/memory/feedback_dev_process.md). Phase 0 of each iteration is locked in `phase0_findings*.md` — read the latest iteration's substrate next.
Phase 5 (second-model review via DokuWiki) and Phase 8 (memory entry) follow the predecessor cadence — invoke the Plan subagent with `model: sonnet` for the open-consultation review pattern (cf. `fourier_attribution` reviewer response).
Phase 5 (second-model review) and Phase 8 (iteration close + memory entry) follow the predecessor cadence — invoke the sonnet subagent for the review pattern.
Per the [`feedback_replicate_baseline_first.md`](../../.claude/projects/-home-mfritsche-src-kwin-overlay-subsurface/memory/feedback_replicate_baseline_first.md) lesson: any binding cell in this campaign anchors to in-session-acquired data. The migrated STUDY.md material and ohm_gl_fix patch-correctness audits are reference history, not threshold sources.
## Iteration history
| Iter | Status | Locked question | Outcome |
|---|---|---|---|
| 1 | Closed 2026-05-04 | "Does multi-planar libva-v4l2-request decode H.264 to NV12 dmabufs on hantro for any consumer?" | YES. vaapi-copy + Firefox-with-sandbox-bypass + vainfo all engage hantro. Documented bugs: surface-export DMA-BUF lifecycle race, multi-resolution session corruption, Mesa WSI 64-pitch alignment. See `phase8_iteration1_close.md`. |
| 2 | Closed 2026-05-04 | "Harden the iter1 deliverable: fix the three known bugs without regressing scope." | DONE. Fix 1 (resolution-change format-cache invalidation), Fix 2 (DRM_FORMAT_MOD_INVALID conditional for non-64 pitch), Fix 3 (decoupled `cap_pool` with LRU recycling for DMA-BUF lifecycle). mpv vaapi DMA-BUF playback "smooth" per operator inspection. See `phase8_iteration2_close.md`. |
| 3 | Closed 2026-05-05 | "F+A: verify the Firefox RDD sandbox hypothesis by patched-binary, while resolving the carryover frame-11 EINVAL on the same rig." | F GREEN — patched Firefox decodes through libva without `MOZ_DISABLE_RDD_SANDBOX=1` (broker policy + seccomp ioctl `'\|'` allow + driver `select() → poll()` migration). A REPRODUCED — frame-11 EINVAL fires deterministically on a single-slice P-frame, Y2 instrumentation logs the failing controls. Track A's fix deferred to iter4. See `phase8_iteration3_close.md`. |
## Predecessor work that this campaign builds on
State (carry-over) — fork content, file:line pointers, contract analyses:
@@ -101,12 +109,53 @@ The campaign repo and the fork repo are **separate git repositories** — campai
Operator-facing repo URL TBD: probably `git.reauktion.de/marfrit/libva-multiplanar` once the campaign produces something worth pushing. The fork is already at `git.reauktion.de/marfrit/libva-v4l2-request-fourier`.
## File map (will grow)
## File map
Iteration 1 (closed):
| File | What it is |
|---|---|
| `phase0_findings.md` | iter1 substrate: locked research question, locked scope, predecessor state, source-read references |
| `phase0_evidence/` | iter1 inventory + baseline anchor |
| `phase4_iter2_plan.md` | (mis-named — actually iter1 Phase 4) diff against FFmpeg + hantro kernel source identifying the bug fixed in iter1 |
| `phase5_review_2026-05-04.md` | iter1 sonnet review |
| `phase6_findings.md` | iter1 Phase 6: hantro decodes real H.264 pixels |
| `phase7_findings.md` | iter1 Phase 7 verification: vaapi-copy works, surface-export bug surfaces |
| `phase8_iteration1_close.md` | iter1 close |
| `diff_against_ffmpeg.md` | Cross-reference of fork divergence vs FFmpeg's V4L2 request-API code |
Iteration 2 (closed):
| File | What it is |
|---|---|
| `phase0_findings_iter2.md` | iter2 substrate |
| `phase2_iter2_analysis.md` | iter2 situation analysis |
| `phase5_review_iter2_2026-05-04.md` | iter2 sonnet review (3 architecture blockers + REQBUFS gap) |
| `phase8_iteration2_close.md` | iter2 close (Fix 1 + Fix 2 + Fix 3 landed) |
Iteration 3 (in progress):
| File | What it is |
|---|---|
| `phase0_findings_iter3.md` | iter3 substrate. **Read this for current iteration state.** |
| `phase2_iter3_situation.md` | Mozilla sandbox source verbatim (broker policy + cap filter) |
| `phase3_iter3_baseline.md` | Pre-patch baseline anchor (ohm offline; iter2-close evidence anchored) |
| `phase4_iter3_plan.md` | Patch authorship + PKGBUILD overlay + Track A diagnostic plan |
| `phase5_iter3_review.md` | iter3 Phase 5 sonnet review (Y1 patch idiom fix, Y2 driver error_idx instrumentation, B-slice bug) |
| `phase6_iter3_findings.md` | iter3 Phase 6 build-side surprises (proper unified-diff, no `--enable-v4l2`, GPG rotation, ALARM-stale wasi cluster, onnxruntime gap) |
| `firefox-fourier/` | Patch + PKGBUILD overlay artifacts for the boltzmann LXD container build |
| `firefox-fourier/0001-rdd-allow-stateless-v4l2-request-api.patch` | The Firefox RDD sandbox patch (allows /dev/media\*; cap-filter widened for stateless decoders) |
| `firefox-fourier/PKGBUILD-overlay.md` | PKGBUILD overlay strategy — verified working sequence |
| `firefox-fourier/bootstrap.sh` | Reproducible bootstrap script (run as `builder` inside the firefox-fourier LXD) |
Always-current:
| File | What it is |
|---|---|
| `README.md` | This file |
| `phase0_findings.md` | **Read this next.** Locked research question, locked scope, predecessor state-vs-data discipline, Phase 0 inventory work-to-do, source-read references |
| `worklist.md` | Phase-by-phase task list (filled in as phases land) |
| `phase0_evidence/` | Phase 0 inventory + in-session baseline anchor (created when first run lands) |
| `libva-v4l2-request-fourier/` | The fork (separate repo: `marfrit/libva-v4l2-request-fourier`) |
| `references/` | External docs: kernel source excerpts, Mozilla bugzilla notes |
## Build infrastructure
iter3 introduced a remote build host: `firefox-fourier` LXD container on `boltzmann` (RK3588 aarch64, 8 cores, 24 GB RAM, NVMe `/build`). Provisioned by the `his` agent, accessed as `ssh -J boltzmann builder@firefox-fourier`. Used to compile Firefox 150.0.1 with the iter3 sandbox patch ("firefox-fourier" build).