Markus Fritsche
b02baffca7
Amendments per Sonnet architect review round 1:
- A1: 0007 v2 rewritten — 7 per-codec run() insertion points,
matches hantro pattern (after preamble metadata copy, before HW kick).
Old v1 (in rkvdec_device_run) REJECTED — wrong structural placement.
- A2: panthor ww_mutex/dma_resv contention added as primary hypothesis H1.
Smoke test 1.9/2.x extended to exercise GPU compositor path.
- A3: CONFIG_LOCALVERSION=-lockdep so lockdep kernel uname differs from
vanilla — prevents modules_install overwriting working tree.
- A4: pstore/serial gate is now HARD (one-of required); pre-flight aborts
if neither serial nor ramoops is functional.
- A5: PROVE_RCU removed from initial config — boot latency risk pushes
past watchdog before lockdep prints. Add back only if first run clean.
0007-v2 patch attached: 8 hunks across rkvdec-{h264,hevc,vdpu381-h264,
vdpu381-hevc,vdpu383-h264,vdpu383-hevc,vp9}.c + rkvdec.c queue_init flag.
25 lines insertions.
Pending Phase 5 round 2 delta-review of v2 source + amended plan before
any execution.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
ampere-kernel-decoders
Kernel-side sibling campaign to ampere-fourier (which validated the userspace libva backend on RK3588 at iter1 close, 3 codecs working) and fresnel-fourier (the RK3399 peer). Focuses on the kernel-side enablement required to unblock the three codec blockers iter1 of ampere-fourier surfaced:
- HEVC kernel OOPS in
rkvdec_hevc_prepare_hw_st_rps(__pi_memcmpfault, cascades tov4l2_mem2memwedge). Tracked atmarfrit/kernel-agent#11 [ka:experiment]. - VP9 not exposed on RK3588 rkvdec — kernel doesn't register
V4L2_PIX_FMT_VP9_FRAMEon the VDPU381/383 variant_ops. Tracked atmarfrit/kernel-agent#12 [ka:experiment]. - (AV1 backend iter39 is userspace work, not in this campaign's scope; tracked at
marfrit/libva-v4l2-request-fourier#2.)
Topology
| Property | Value |
|---|---|
| Working tree (substrate kernel) | boltzmann:~/src/linux-rockchip branch linux-rk3588-marfrit |
| Board patches | boltzmann:~/src/misc_patches/genbook/kernel/000*.patch (6 board DTS/config patches; the ampere baseline package consumes these) |
| Experiment target host | ampere (CoolPi CM5 GenBook, RK3588) |
| Baseline kernel for regression-checks | linux-ampere-fourier 7.0rc3.kafr1-1 (vanilla torvalds v7.0-rc3 + genbook/kernel/000* only — NO codec patches) |
| Patch destination | kernel-agent experiment branches per issue; promoted to linux-ampere-fourier only via explicit operator decision per feedback_characterize_before_change (campaign-experiment patches stay OUT of baseline) |
| Build host | boltzmann (primary aarch64 builder per kernel-agent README) + ampere as fallback secondary |
| Patch landing pad | marfrit/kernel-agent/patches/{soc,driver}/... scope-tagged per kernel-agent's tree convention |
Scope (in flux until Phase 0 close)
In scope (iter1 candidate):
- HEVC OOPS fix — minimal-blast-radius candidate patch for
rkvdec_hevc_prepare_hw_st_rps, validated on ampere by re-runningampere-fourierPhase 3 with HEVC added. - Survey upstream prior art (linux-rockchip, linux-media, linux-mm, Kwiboo, Bootlin, Collabora) before writing any code — there may already be a fix in v7.0-rc4+ or in an out-of-tree branch.
Out of scope (likely iter2+):
- VP9 enablement (broader work — VDPU381/383 variant_ops surface, DTS bindings, potentially backend codec table updates). Separate iteration.
- Multi-core support for rkvdec/hantro (the "missing multi-core support, ignoring this instance" lines in dmesg). Upstream work; out of fleet-scope.
Explicitly NOT in scope:
- Codec patches on the baseline
linux-ampere-fourierpackage. Per operator policy 2026-05-16, ampere baseline stays clean mainline + board DTS. Codec enablement = kernel-agent experiment branches only.
Process
8(+1)-phase loop per feedback_dev_process.md, same as ampere-fourier / fresnel-fourier. Notable for this campaign:
- Phase 0 includes an upstream prior-art survey (linux-rockchip + linux-media + linux-mm + Kwiboo + Bootlin). This is non-optional — writing a kernel patch without first checking whether the fix already exists upstream is the wrong workflow. Memory
feedback_no_upstreamsays no PR/MR/RFC from us by default; that's about publishing, not consuming. Consume aggressively. - Phase 5 review uses the sonnet-architect subagent pattern (
Planwithmodel: sonnet), same as ampere-fourier. Memory rulefeedback_review_empirical_over_theoreticalapplies — test-compile reviewer-suggested struct/field mappings before adopting amendments. - Phase 6 implementation produces kernel patches in
~/src/linux-rockchipon boltzmann + accompanying kernel-agent experiment branch entries. No patches land inmarfrit-packages/arch/linux-ampere-fourier/directly. - Phase 7 verification re-runs
ampere-fourieriter1's Phase 3 scripts with HEVC added to the codec list. Predicted outcome anchors against ampere-fourier iter1's baseline numbers.
Predecessor work this campaign builds on
../ampere-fourier/iter1 — the baseline floor this campaign regresses against. Re-anchoring to ampere-fourier's N=3 FPS numbers + per-codec SSIM floors for any codec that flips from "blocked" to "validated."marfrit/kernel-agent— the experiment-branch home + issue tracker.marfrit/kernel-agent/issues/11— HEVC bug ticket with the OOPS trace + reproducer.marfrit/kernel-agent/issues/12— VP9 enablement ticket.- Memory
feedback_rkvdec_patch_reachability— VDPU381/383 vs RK3399 legacy path boundary. - Memory
feedback_characterize_before_change— campaign-process rule from ampere-fourier iter1.
Operator-facing repo URL
git.reauktion.de/marfrit/ampere-kernel-decoders — to be created at iter1 close if there's something publish-worthy (matches the fresnel-fourier / ampere-fourier convention). Local-only at ~/src/ampere-kernel-decoders/ on noether for now.