test0r
93f2aab656
The block-ack policy uses 4 int counters (ba_acc, ba_cnt, ba_acc_rx, ba_cnt_rx) bumped per data frame in the TX and RX hot paths under spin_lock_bh(&hw_priv->ba_lock). The lock was the heaviest per-frame synchronization cost remaining after Patch C v3 (which fixed the sdio_rx_work relay). Per the Opus structural critique (PR #8), this pattern matches mac80211 driver convention for per-frame statistics: atomic_t suffices, no lock needed. Field-by-field changes in struct bes2600_common: ba_acc, ba_cnt, ba_acc_rx, ba_cnt_rx: int -> atomic_t ba_armed: new atomic_t (timer-arm flag) ba_ena: bool -> atomic_t ba_lock: removed (spinlock_t deleted) ba_hist: int (single-writer = ba_timer) Producer hot path (txrx.c TX submit + RX receive): - atomic_add for the byte accumulator - atomic_inc for the frame counter - atomic_cmpxchg(&ba_armed, 0, 1) to claim the once-per-window mod_timer arm — at most ONE producer succeeds; race-free - no spin_lock_bh Consumer paths (sta.c bes2600_ba_timer, sta.c disconnect-reset, sta.c bes2600_ba_work, debug.c debugfs reader): - atomic_read snapshots all 4 counters into locals; the threshold predicate (acc/cnt >= THLD) tolerates approximate snapshots — the timer fires periodically, a single misclassification just delays the policy update by one tick - atomic_set zeroes the counters at end of timer-callback window; racing producer increments after the snapshot are lost (acceptable for stats; same approximation the original lock allowed under contention) - atomic_set(&ba_armed, 0) re-enables the next window's arm Followup-amenable simplification: ba_hist remains int because only the single ba_timer callback writes it; multiple writers would need to upgrade it too. This patch follows the cw1200-mainline-idiom established by Patch C v3 (structural fix, not bandaid). The cw1200 reference doesn't have a similar lock to compare; bes2600 inherited this from a later Bestechnic addition rather than the upstream tree.