AdapterCaps: hardware-ARQ capability flags (ack_responder_ok / tx_retry_limit_ok) from the measured matrix (#365)

docs/logging.md

@@ -77,7 +77,7 @@ Emitters: L = library, RX/TX/... = demo. Optional fields in [brackets];
 | ev | emitter | fields |
 |---|---|---|
 | `init.timing` | L (`src/InitTimer.h`) + demos | stage ("scope.stage", e.g. "demo.first_rx_frame", "txdemo.first_tx_submit"), ms |
-| `adapter.caps` | RX, TX, doctor, txpower (`examples/common/caps_event.h`) | supported, chip, names, chip_id "0x..", gen, variant, transport, tx_chains, rx_chains, n_ss, stbc, ldpc, sgi, bw_max, bw[] (MHz), txpwr_max, txpwr_step_qdb, txpwr_step_measured, txpwr_min_qdb, txpwr_max_qdb, txpwr_rate_diffs, txpwr_rate_diffs_hw, txpwr_rate_diffs_measured, tune_2g4[]\|null, tune_5g[]\|null, char_2g4[]\|null, char_5g[]\|null, ldpc_rx_ht, ldpc_rx_vht, ldpc_rx_flag, per_pkt_txpwr, narrowband, fastretune, he_er_su, per_chain_rssi |
+| `adapter.caps` | RX, TX, doctor, txpower (`examples/common/caps_event.h`) | supported, chip, names, chip_id "0x..", gen, variant, transport, tx_chains, rx_chains, n_ss, stbc, ldpc, sgi, bw_max, bw[] (MHz), txpwr_max, txpwr_step_qdb, txpwr_step_measured, txpwr_min_qdb, txpwr_max_qdb, txpwr_rate_diffs, txpwr_rate_diffs_hw, txpwr_rate_diffs_measured, tune_2g4[]\|null, tune_5g[]\|null, char_2g4[]\|null, char_5g[]\|null, ldpc_rx_ht, ldpc_rx_vht, ldpc_rx_flag, per_pkt_txpwr, narrowband, fastretune, ack_responder, tx_retry_limit, he_er_su, per_chain_rssi |
 | `debug.wreg` | L (`DEVOURER_LOG_WRITES`) | addr "0x0nnn", width, val "0x…" |
 | `hop.prof` | L (`DEVOURER_HOP_PROF`) | gen, ch, `<stage>_us`…, total_us |
 | `tx.fail` | L (send failure; regress.py keys on it) | {status, actual_len, timeout} or {rc, timeout} |

docs/scheduled-mac.md

@@ -208,6 +208,25 @@ its SIFS ACKs only land intermittently); **8821AU never closed the loop**
 (TX retries stayed pinned with it armed); the 8812BU responder was
 separately proven (`tests/ack_responder_check.sh`).
 
+The full responder matrix (six cells, ch36, MCS3 unicast; run with
+`DEVOURER_TX_RETRY_LIMIT` at its 0 default, so delivered% is the
+**single-shot** ACK rate and capability is the on-vs-off delta — pin a
+nonzero limit for absolute numbers):
+
+| responder | on | off | verdict |
+|---|---|---|---|
+| 8814AU | 79% | 0% | works |
+| 8812BU | 98% | 0% | works |
+| 8821AU | 0% | 0% | broken (third independent confirmation) |
+| 8812EU | 98% | 0% | works |
+| 8812CU | 69% | 0% | works |
+| 8852CU (Kestrel) | 0% | 0% | not implemented (SetAckResponder is J1/2/3-only) |
+
+Unmeasured for lack of plugged hardware: 8821CU / PCIe 8821CE (recipe-shared
+with the 8822B; their `AdapterCaps.ack_responder_ok` stays false-as-unmeasured
+until a cell runs). The `ack_responder_ok` / `tx_retry_limit_ok` caps flags
+carry this table per die.
+
 ### The contract
 
 1. **Per-frame delivery detection is GO on all three generations**: the OFF

examples/common/caps_event.h

@@ -81,6 +81,8 @@ inline void emit_adapter_caps(EventSink &sink, IRtlDevice *dev) {
       .f("per_pkt_txpwr_measured", c.per_pkt_txpwr_measured ? 1 : 0)
       .f("narrowband", c.narrowband_ok ? 1 : 0)
       .f("fastretune", c.fastretune_ok ? 1 : 0)
+      .f("ack_responder", c.ack_responder_ok ? 1 : 0)
+      .f("tx_retry_limit", c.tx_retry_limit_ok ? 1 : 0)
       .f("he_er_su", c.he_er_su_ok ? 1 : 0)
       .f("per_chain_rssi", c.per_chain_rssi ? 1 : 0)
       .f("hw_rx_tsf", c.hw_rx_timestamp ? 1 : 0)

src/AdapterCaps.h

@@ -159,6 +159,25 @@ struct AdapterCaps {
    * strong-link, close-range mode, the opposite of a range mode. */
   bool vht_2g4_ok = false;
 
+  /* --- hardware-ARQ capability (bench-derived truth table, on-air responder
+   * matrix + retry-knob A/B; the measured contract is docs/scheduled-mac.md).
+   * ack_responder_ok: SetAckResponder measurably closes a hardware-ARQ loop
+   * as the RESPONDER (SIFS ACKs that a soliciting TX's CCX reports confirm).
+   * Measured true: 8812A (works, degraded — intermittent SIFS ACKs), 8814A,
+   * 8822B, 8812C/8822C, 8812E/8822E (the 8811A rides the 8812 die path and
+   * inherits its row). Measured FALSE: the 8821A die — an armed 8821AU never
+   * closed the loop across three independent runs. False-as-unmeasured (the
+   * vht_2g4_ok reading: unmeasured, not incapable): the 8821C — it shares
+   * the recipe but no 8821CU/CE cell has run. FALSE on Kestrel:
+   * SetAckResponder is not implemented on the AX generation.
+   * tx_retry_limit_ok: DEVOURER_TX_RETRY_LIMIT drives hardware autonomous
+   * retransmission (measured 12/0/12 A/B: 8821AU, 8812BU, 8822CU). FALSE on
+   * the 8814A die (the vendor DATA_RETRY_LIMIT=0 carve-out is kept — knob
+   * inert), false-as-unmeasured on the 8821C, and FALSE on Kestrel (retry is
+   * firmware-level there). */
+  bool ack_responder_ok = false;
+  bool tx_retry_limit_ok = false;
+
   /* --- feature flags --- */
   /* Per-packet TX power: a per-frame power trim driven by radiotap
    * DBM_TX_POWER (dB delta vs the calibrated table / session base) or a

src/jaguar1/RtlJaguarDevice.cpp

@@ -1725,6 +1725,11 @@ devourer::AdapterCaps RtlJaguarDevice::GetAdapterCaps() {
     c.narrowband_ok = true;
   }
   c.fastretune_ok = true; /* phy_SwChnl8812_fast (8812/8821) + full-path fallback */
+  /* Hardware ARQ (truth table at the AdapterCaps declarations): the 8821A
+   * die never closes the responder loop; the 8814A die keeps the vendor
+   * retry carve-out (knob inert). */
+  c.ack_responder_ok = _eepromManager->version_id.ICType != CHIP_8821;
+  c.tx_retry_limit_ok = _eepromManager->version_id.ICType != CHIP_8814A;
   /* Per-packet TX power: 8814A only — its dword5 [30:28] descriptor LUT (the
    * 8822B TXPWR_OFSET position; vendor-defined, vendor-unused). measured
    * stays false until tests/txpkt_pwr_ofset_onair.sh proves it moves on-air

src/jaguar2/RtlJaguar2Device.cpp

@@ -1124,6 +1124,11 @@ devourer::AdapterCaps RtlJaguar2Device::GetAdapterCaps() {
    * RF18 re-latch edge after the re-clock (see the set_channel_bw narrowband
    * branch). */
   c.narrowband_ok = true;
+  /* Hardware ARQ (truth table at the AdapterCaps declarations): the 8822B
+   * die is measured on both counts; the 8821C shares the recipe but has no
+   * bench cell yet, so its flags stay false-as-unmeasured. */
+  c.ack_responder_ok = _variant == jaguar2::ChipVariant::C8822B;
+  c.tx_retry_limit_ok = _variant == jaguar2::ChipVariant::C8822B;
   c.hw_rx_timestamp = true;  /* FrameParserJaguar2 fills RxAtrib.tsfl */
   c.hw_beacon_txtsf = true;  /* StartBeacon: MAC inserts the egress TSF into beacons */
   c.xtal_cap_max = 0x3f; /* 6-bit AFE crystal-cap trim (0x24/0x28) */

src/jaguar3/RtlJaguar3Device.cpp

@@ -1527,6 +1527,10 @@ devourer::AdapterCaps RtlJaguar3Device::GetAdapterCaps() {
   c.tx_chains = 2; /* 8822C/8822E are 2T2R */
   c.rx_chains = 2;
   c.per_chain_rssi = true;
+  /* Hardware ARQ (truth table at the AdapterCaps declarations): both dies
+   * measured — responder matrix + retry-knob A/B + the arq_e2e ledgers. */
+  c.ack_responder_ok = true;
+  c.tx_retry_limit_ok = true;
   /* Per-packet TX power: the TXPWR_OFSET_TYPE bank selector + programmable
    * 0x1e70 offset banks (SetTxPacketPowerOffsetQdb / radiotap DBM_TX_POWER;
    * TxPktPwrBanks.h). Continuous in step_qdb units, ±63/-64 index travel, 2

src/kestrel/RtlKestrelDevice.cpp

@@ -783,6 +783,9 @@ devourer::AdapterCaps RtlKestrelDevice::GetAdapterCaps() {
   c.tx_chains = 2; /* 8852B/8852C are 2T2R */
   c.rx_chains = 2;
   c.per_chain_rssi = true; /* per-path RSSI from the PPDU-status physts header */
+  /* Hardware ARQ: SetAckResponder is not implemented on the AX generation
+   * (matrix-measured 0% closure) and retry is firmware-level here, so the
+   * DEVOURER_TX_RETRY_LIMIT knob is inert — both flags stay false. */
   c.bw_mask = devourer::bw_mask_for_generation(c.generation);
   if (_variant == kestrel::ChipVariant::C8852C)
     c.bw_mask |= devourer::kBw160; /* 8852C-only (vendor bw_sup BW_CAP_160M) */