Meta-iter1 was a scoping iteration — deliverable is the campaign
umbrella + sub-iter ledger, not a code change. Phases 2-8 are
either rolled into Phase 0+1 (situation, plan) or deliberately N/A
(no meta-level measurements or verification beyond 'issues filed +
ledger exists').
Phase 5 review is the documented deviation from 'reviews are never
skippable': justified because Phase 0's prior-art survey +
verification against kernel source IS the review-equivalent rigor
(per feedback_review_empirical_over_theoretical), and there's no
separate Phase 4 plan to review beyond the ledger. iter2 + iter3
each get a full Phase 5 review on their own.
No new memory entry — lessons fall under existing
feedback_dev_process (Phase 1 loopback when scoping was wrong) and
feedback_characterize_before_change (meta-iter1 = scope + ledger
extends naturally).
Next: start iter2 Phase 0 (HEVC backend extension via
V4L2_CID_STATELESS_HEVC_EXT_SPS_ST_RPS / _LT_RPS).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Operator picked option 2: meta-campaign coordinating an HEVC backend
iteration (iter2 against libva-v4l2-request-fourier#3) and a VP9
kernel iteration (iter3 against kernel-agent#12) as parallel children
under one umbrella.
Iteration order: HEVC first because (a) smaller blast radius / faster
feedback loop, (b) the survey's mechanism reconstruction is a
hypothesis not yet test-verified — cheapest way to confirm is a
minimal backend patch, (c) VP9 has unresolved upstream-tree selection
that benefits from absorbing iter2 findings first. Operator may
overrule for parallel execution.
Meta-success: iter2 + iter3 both close with HEVC + VP9 added to
ampere-fourier Phase 3 instrumentation (C1-C6 against per-codec
floors); no regression to iter1 3-codec baseline; patches in right
repos (libva for HEVC, kernel-agent experiment branch for VP9, NOT
linux-ampere-fourier baseline per operator policy).
Falsifiers: iter2 patch doesn't fix HEVC -> re-open kernel-agent#11
with new evidence; iter3 tree doesn't rebase cleanly -> pick another;
Phase 7 regression to iter1 baseline -> Phase 5 review missed shared-
code interaction.
iter1 of the meta-campaign is mostly Phase 0+1+8: scoping + ledger +
close. Real engineering happens inside iter2 and iter3.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Phase 0 ran the operator-mandated upstream prior-art survey FIRST,
before any source-read or hypothesis. Headline finding: the HEVC
OOPS is fundamentally re-scoped from 'kernel bug' to 'userspace UAPI
gap' against the new 7.0 controls
V4L2_CID_STATELESS_HEVC_EXT_SPS_ST_RPS / _LT_RPS.
Survey + verification:
- Casanova/Collabora v8 series merged in Linux 7.0 added the two
new V4L2 controls for VDPU381 HEVC; backend 7ac934e (June pre-iter38)
predates the UAPI and grep returns zero hits for these CIDs.
- ampere linux-api-headers is still 6.19-1, doesn't define the
constants — the backend literally cannot reference them without a
headers bump.
- ampere kernel source rkvdec-hevc-common.c:500-509 looks up the new
CIDs; if backend never set them, rkvdec_hevc_prepare_hw_st_rps
reads invalid memory via memcmp — exactly the __pi_memcmp OOPS
symptom.
VP9 still kernel-side per the v4 cover ('This patch only adds support
for H264 and H265 in both variants'). Multiple competing out-of-tree
starting trees: Sarma's android tree (working but Android-flavored),
dongioia/rock5bplus-rkvdec2 (mainline-style claims), Kwiboo (no VP9
on RK3588 yet). RKVDEC2 separate-driver path is dead — future VP9
extends the existing rkvdec driver's VDPU381 variant_ops.
Five open questions tabled for Phase 1 — most important being campaign
re-scope (HEVC moves to backend campaign; this stays VP9 kernel-only
OR becomes a meta-campaign coordinating both).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Sister to ampere-fourier (userspace consumer) and fresnel-fourier
(RK3399 peer). Tracks the 2 kernel-side blockers from ampere-fourier
iter1: HEVC OOPS in rkvdec_hevc_prepare_hw_st_rps (kernel-agent#11)
and VP9 enablement on VDPU381/383 (kernel-agent#12). AV1 stays
userspace (libva-v4l2-request-fourier#2), not in this campaign.
Process notes: Phase 0 includes a non-optional upstream prior-art
survey (linux-rockchip / linux-media / linux-mm / Kwiboo / Bootlin)
before any code; per operator policy, patches go to kernel-agent
experiment branches, NOT into the linux-ampere-fourier baseline
package.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
marfrit