The drm_info-during-playback probe under Wayland confirmed
KWin IS GL-compositing per frame: Plane 39 rotates triple-
buffered ABGR8888 framebuffers (FB IDs 60/61/66) during
playback. The earlier "0% kwin CPU = direct-scanout" reading
in a1_summary.md was a CPU-blind-spot artifact — Panfrost
shader work isn't visible to top or perf-on-userspace.
Corrigendum added to a1_summary.md preserving the original
text as the on-the-day record.
Worklist: A1 entry updated to point at both summaries.
The probe itself was invasive (drm_info every 3s perturbed
KWin's atomic-commit fast-path, kwin %CPU jumped 0->18 median
and 6 drops appeared) — usable diagnostically but cannot be
embedded in measurement reps.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
marfrit
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