Supersedes v2 (PR #10). cw1200 mining (~/src/linux-rockchip, 228
cw1200 commits) confirmed: upstream cw1200 has no sdio_rx_work
workqueue at all. IRQ handler bumps bh_rx + wakes bh_wq; bh thread
does the SDIO read inline via cw1200_bh_rx_helper. Single thread =
single writer for hw_bufs_used = no race by construction. Same int
hw_bufs_used as bes2600, never atomic_t'd in 16 years upstream.
v3 brings bes2600 into that shape:
- delete sdio_rx_work, self->rx_work, self->rx_queue,
self->rx_queue_lock, bes2600_sdio_pipe_read
- GPIO IRQ handler calls self->irq_handler directly (matches
cw1200_sdio_irq_handler shape)
- bes2600_bh_rx_helper's BES_SDIO_RX_MULTIPLE_ENABLE branch
replaced with inline SDIO read + extract_packets + per-skb
delivery via new bes2600_bh_handle_rx_skb()
- GPIO wake-flag bracketing moves into bh thread
§5 shared-state delta table (the v2 lesson, applied): zero fields
require new locking. hw_bufs_used / hw_bufs_used_vif / wsm_tx_pending
all stay single-writer-from-bh. v2's atomic_t prep is mooted.
§6 risk #6 is the open question for reviewer: bes2600's
__bes2600_irq_enable(1) call is commented out in the BH-loop done:
label with an asm volatile("nop") in its place. Either SDIO IRQ
is auto-managed (so commenting out is fine) or the current code
relies on sdio_rx_work being queued regardless of driver-side IRQ
flag. Block Phase 6 on this audit.
Patch F (PR #4 merged) is the new baseline. v3 will branch off
F-merged cleanups. Phase 7 N=3 stress ramp uses wired enu1 path
(192.168.88.80) for wedge-resilient telemetry collection.
