Follow-up ftrace measurement (post-reboot, 3-min 4MB/s capture):
- workqueue_execute_start: 5,643/sec ← dominates
- wsm_cmd_send: only 13/sec (host-to-chip command path NOT the hotspot)
- lock contention: 50/sec (modest)
The throughput floor is set by per-SDIO-transaction workqueue dispatch
overhead. Surgical patches B5-1/B5-2/B5-3 from the prior Phase 4 plan
all targeted the wrong layer; deferring those until an architectural
restructuring map is produced.
Promoting the Sonnet architect review from "backlog" to
"blocking on Bug #5" — the next step is a restructuring assessment,
not another patch.
claude-noether
594f73c6b4