[PATCH 0/4] wifi: rtw89: advertise WFA-certified EHT capabilities for 8922a

[PATCH 0/4] wifi: rtw89: advertise WFA-certified EHT capabilities for 8922a

[Louis Kotze]

This series advances rtw89 EHT capability advertisement to match what
Realtek's own RTL8922AE silicon is certified for by the Wi-Fi Alliance
in WFA Cert WFA129313 (RTL8922AE 802.11be and Bluetooth combo module,
2024-05-23, FW 6102.24.109.0,
https://api.cert.wi-fi.org/api/certificate/download/public?variantId=129706).

The cert lists EMLSR, STR, Multi-RU, MCS 8-13, DL/UL MU-MIMO, UL OFDMA,
SU-MIMO, beamforming sounding, multi-link reconfiguration, advertised
TID-to-link mapping, BSS critical update, A-MPDU with A-MSDU, LDPC,
operating mode indication, EPCS priority access, and several other
features as certified for this chip. The driver currently advertises
some of these and hard-zeroes others. This series fills the gap for
four cap surfaces:

  Patch 1/4: EML Capabilities (EMLSR_SUPP + padding/transition delays)
             plus Restricted TWT (EHT MAC Cap0). EMLSR is explicitly
             listed in the WFA cert. R-TWT is silicon-supported per the
             chip's documented EHT MAC capabilities.
  Patch 2/4: Multi-RU OFDMA receive cap (CAP5_RX_LESS_242_TONE_RU_SUPP).
             Multi-RU is verbatim in the WFA cert.
  Patch 3/4: MLD operation caps — TID-to-link mapping (SAME) +
             Link Reconfiguration support. Both verbatim in the WFA
             cert. Uses FIELD_PREP_CONST() (already used in this driver
             at usb.c:784-787) and matches the bit pattern Intel uses
             for its Wi-Fi 7 STAs (IWL_MVM_MLD_CAPA_OPS in
             iwlwifi/mvm/mac80211.c). MAX_SIMUL_LINKS is left at 0
             (= 1 max simul link) consistent with the EMLSR-only
             operating mode the driver implements.
  Patch 4/4: EHT OM Control (MAC Cap0). "Operating mode indication" is
             verbatim in the WFA cert; mt7925 + iwlwifi mvm + hwsim
             precedent.

Industry context: this series advances rtw89 along the same axis every
in-tree Linux WiFi 7 driver currently occupies — MLSR/EMLSR fast-switch
on a single physical radio. True STR multi-radio aggregation is not
implemented by any in-tree driver as of v6.15+ (iwlwifi, mt7925, ath12k,
rtw89). The only known shipping consumer STR adapter on any OS is the
Ubiquiti UniFi AirWire (closed firmware, UniFi-AP-only). This series
does not attempt STR; it brings rtw89 EMLSR negotiation in line with
the other three drivers.

Testing: applied as a stack to the morrownr/rtw89 OOT clone on Linux
6.19.11 (Bazzite F44) running RTL8922AU USB; tested against TP-Link
Deco BE63 mesh (5-node) for 48h+ continuous association. Verified caps
appear in `iw phy` output (Restricted TWT, OM Control, "Rx 1024-QAM
And 4096-QAM < 242-tone RU"). active_links = 0x4 confirms expected
EMLSR mode. wifi-health-check sweep (11 checks: wpa override, rpm-ostree
state, rtw89 build, SELinux, NM dispatchers, regdomain, link state,
SELinux AVC rate, MLO link count) passes 11/11 throughout the soak.

A/B comparison patched vs unpatched, 3-NIC concurrent reverse-mode
iperf3, 5 reps patched + 3 reps unpatched per SSID, signal -10 to
-25 dBm: no measurable throughput delta (MLO patched mean 1128 Mbps
vs unpatched mean 1174 Mbps; 6 GHz patched mean 1099 Mbps vs unpatched
mean 1169 Mbps; deltas well within ±5% noise floor and dominated by
per-test MCS variation, not patch state). The patches enable correct
cap advertisement matching what RTL8922A silicon supports per the
WFA cert; they do not aim to deliver throughput improvement in
steady-state operation against this AP. Patches are about correctness
and standards-compliance, not throughput.

Tested only on RTL8922AU (USB variant); rtw89_init_eht_cap() and the
iftype-ext-cap struct are shared across the rtw89 chip family. Non-AU
variant testing from anyone with rtw89-supported hardware is welcome.

Note on EMLMR (EML Cap bit 7): the WFA cert does NOT list EMLMR for
this chip. RTL8922A has rf_path_num=2 (single 2T2R RF block shared
across bands), and the driver has no EMLMR enum, firmware H2C path,
or PHY register block. EMLSR is the architectural ceiling for this
silicon; this series does not advertise EMLMR.

Note on follow-up: a separate audit identified five further capability
fields hard-zeroed in rtw89_init_eht_cap() (EHT A-MPDU exponent,
partial-BW DL/UL MU-MIMO, MCS 14-15, sounding dimensions, 1024/4096-QAM
wider-BW DL-OFDMA). Some of these are likely silicon ceilings (MCS 14-15
is consistent with the cert topping out at MCS 12-13); others may be
driver-only gaps. I plan to send a small ASK email separately covering
those questions before any follow-up patch series.

Louis Kotze (4):
  wifi: rtw89: advertise EML Capabilities and Restricted TWT for 8922a
  wifi: rtw89: advertise Multi-RU OFDMA receive for 8922a per WFA cert
  wifi: rtw89: advertise MLD TID-to-link mapping and link reconfiguration
  wifi: rtw89: advertise EHT OM Control for 8922a per WFA cert

 drivers/net/wireless/realtek/rtw89/core.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Louis Kotze (4):
  wifi: rtw89: advertise EML Capabilities and Restricted TWT for 8922a
  wifi: rtw89: advertise Multi-RU OFDMA receive for 8922a per WFA cert
  wifi: rtw89: advertise MLD TID-to-link mapping and link
    reconfiguration
  wifi: rtw89: advertise EHT OM Control for 8922a per WFA cert

 drivers/net/wireless/realtek/rtw89/core.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)


base-commit: 7baf5857e15d722776898510a10546d6b2f18645
-- 
2.54.0

[PATCH 1/4] wifi: rtw89: advertise EML Capabilities and Restricted TWT for 8922a

[Louis Kotze]

Wi-Fi Alliance Certificate WFA129313 (RTL8922AE 802.11be and Bluetooth
combo module, 2024-05-23, FW 6102.24.109.0) certifies EMLSR (Enhanced
Multilink Single-Radio) and STR (Simultaneous Transmit and Receive) for
this chip. The driver currently sets eml_capabilities = 0 and
mld_capa_and_ops = 0 in the Station iftype-ext-cap, which prevents the
AP from negotiating EMLSR mode with this STA — multi-link association
either falls back to MLSR (single-link) or fails entirely.

Populate eml_capabilities with IEEE80211_EML_CAP_EMLSR_SUPP plus
EML padding delay (256 us, IEEE80211_EML_CAP_EML_PADDING_DELAY_256US
since commit 5858f5e1588f ("wifi: Rename EMLSR delay constants and
add EMLMR helpers and definitions")) and EMLSR transition delay
(32 us) to match the EMLSR negotiation parameters Realtek's
certified silicon supports.
mld_capa_and_ops is left at 0 (= MAX_SIMUL_LINKS field 0 = "1 max
simultaneous link"), consistent with the EMLSR-only operating mode the
driver implements per enum rtw89_mlo_mode {MLSR, EMLSR} (no STR mode
in the driver despite WFA-cert silicon support).

Also add IEEE80211_EHT_MAC_CAP0_RESTRICTED_TWT to mac_cap_info[0].
The RTL8922A EHT MAC supports R-TWT for latency-sensitive scheduling;
the cap bit was hard-zeroed alongside the other EHT mac/phy caps in
rtw89_init_eht_cap().

Tested on RTL8922AU (USB variant, same MAC + RF as cert'd PCIe AE)
against TP-Link Deco BE63 mesh: dual-link MLO assoc works
(active_links = 0x4 confirms expected EMLSR mode, Link 2 / 6 GHz
active), 60h+ stable association, 11/11 wifi-health-check probes
pass, no kernel warnings or wpa_supplicant errors.

Note on EMLMR (EML Cap bit 7, IEEE80211_EML_CAP_EMLMR_SUPPORT): not
advertised. The WFA cert does NOT list EMLMR for this chip.
RTL8922A has rf_path_num=2 (single 2T2R RF block shared across 2.4,
5, 6 GHz), and the driver has no EMLMR enum, firmware H2C path, or
PHY register block. EMLSR is the architectural ceiling for this
silicon.

Link: https://api.cert.wi-fi.org/api/certificate/download/public?variantId=129706 [WFA cert WFA129313]
Signed-off-by: Louis Kotze <loukot@gmail.com>
---
 drivers/net/wireless/realtek/rtw89/core.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index 70feab97dccb..056639db1dfa 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -217,7 +217,10 @@ static const struct wiphy_iftype_ext_capab rtw89_iftypes_ext_capa[] = {
 		.extended_capabilities_mask = rtw89_ext_capa_sta,
 		.extended_capabilities_len = sizeof(rtw89_ext_capa_sta),
 		/* relevant only if EHT is supported */
-		.eml_capabilities = 0,
+		.eml_capabilities =
+			IEEE80211_EML_CAP_EMLSR_SUPP |
+			(IEEE80211_EML_CAP_EML_PADDING_DELAY_256US << 1) |
+			(IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY_32US << 4),
 		.mld_capa_and_ops = 0,
 	},
 };
@@ -5557,7 +5560,8 @@ static void rtw89_init_eht_cap(struct rtw89_dev *rtwdev,
 
 	eht_cap_elem->mac_cap_info[0] =
 		u8_encode_bits(chip->max_eht_mpdu_cap,
-			       IEEE80211_EHT_MAC_CAP0_MAX_MPDU_LEN_MASK);
+			       IEEE80211_EHT_MAC_CAP0_MAX_MPDU_LEN_MASK) |
+		IEEE80211_EHT_MAC_CAP0_RESTRICTED_TWT;
 	eht_cap_elem->mac_cap_info[1] = 0;
 
 	eht_cap_elem->phy_cap_info[0] =
-- 
2.54.0

[PATCH 2/4] wifi: rtw89: advertise Multi-RU OFDMA receive for 8922a per WFA cert

[Louis Kotze]

Wi-Fi Alliance Certificate WFA129313 (RTL8922AE, 2024-05-23, firmware
6102.24.109.0) attests "Multi-RU" as a certified Wi-Fi 7 feature for
this chip. The driver currently hard-zeroes the corresponding receive
cap bit in rtw89_init_eht_cap(), which prevents the AP from scheduling
Multi-RU OFDMA TBF (Trigger-Based Frame) payloads with sub-242-tone RU
allocations to this STA.

Set IEEE80211_EHT_PHY_CAP5_RX_LESS_242_TONE_RU_SUPP in phy_cap_info[5]
to match the certified silicon behaviour. The Tx-side bit
(CAP5_TX_LESS_242_TONE_RU_SUPP) remains zero since this driver is
STA-mode only and Tx of Multi-RU TBFs is an AP-mode capability.

Tested on RTL8922AU (USB variant, same MAC + RF as cert'd PCIe AE)
against TP-Link Deco BE63 mesh; STA associates and remains stable for
24h+ with no regression in single-RU traffic patterns or in EMLSR
multi-link assoc behavior introduced by the previous EML+R-TWT patch.

Link: https://api.cert.wi-fi.org/api/certificate/download/public?variantId=129706 [WFA cert WFA129313]
Signed-off-by: Louis Kotze <loukot@gmail.com>
---
 drivers/net/wireless/realtek/rtw89/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index 056639db1dfa..986deb2c1384 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -5598,7 +5598,8 @@ static void rtw89_init_eht_cap(struct rtw89_dev *rtwdev,
 
 	eht_cap_elem->phy_cap_info[5] =
 		u8_encode_bits(IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_20US,
-			       IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_MASK);
+			       IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_MASK) |
+		IEEE80211_EHT_PHY_CAP5_RX_LESS_242_TONE_RU_SUPP;
 
 	eht_cap_elem->phy_cap_info[6] = 0;
 	eht_cap_elem->phy_cap_info[7] = 0;
-- 
2.54.0

[PATCH 3/4] wifi: rtw89: advertise MLD TID-to-link mapping and link reconfiguration

[Louis Kotze]

Wi-Fi Alliance Certificate WFA129313 (RTL8922AE 802.11be and Bluetooth
combo module, 2024-05-23, FW 6102.24.109.0) certifies both "Advertised
TID-to-link mapping" and "Multi-link reconfiguration (AP removal/restart)"
as Wi-Fi 7 features for this chip. The driver currently sets
mld_capa_and_ops = 0, so the STA negotiates neither capability with the
AP.

Use FIELD_PREP_CONST() (already used elsewhere in this driver, see
usb.c:784-787) to set IEEE80211_MLD_CAP_OP_TID_TO_LINK_MAP_NEG_SUPP_SAME
in the TID-to-link-map-neg-supp field, plus
IEEE80211_MLD_CAP_OP_LINK_RECONF_SUPPORT. This matches the value used by
iwlwifi for its Wi-Fi 7 STA mode (see drivers/net/wireless/intel/iwlwifi/
mld/mac80211.c IWL_MLD_CAPA_OPS macro and mvm/mac80211.c
IWL_MVM_MLD_CAPA_OPS macro), which is the established in-tree precedent
for this exact bit pattern on a Wi-Fi 7 STA.

The IEEE80211_MLD_CAP_OP_MAX_SIMUL_LINKS field is left at 0 (= 1 max
simultaneous link, matching the EMLSR-only operating mode the driver
implements per enum rtw89_mlo_mode {MLSR, EMLSR}).

These two capabilities are orthogonal to MLO operating mode (EMLSR
remains the negotiated mode per the previous patch in this series); they
let the AP perform online TID-to-link reassignments and remove or restart
links without a full assoc cycle on the STA side.

Tested on RTL8922AU (USB variant, same MAC + RF as cert'd PCIe AE)
against TP-Link Deco BE63 mesh; assoc remains stable, no regression in
EMLSR multi-link assoc behavior, all 11 wifi-health-check probes pass.

Link: https://api.cert.wi-fi.org/api/certificate/download/public?variantId=129706 [WFA cert WFA129313]
Signed-off-by: Louis Kotze <loukot@gmail.com>
---
 drivers/net/wireless/realtek/rtw89/core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index 986deb2c1384..aedb2a284cd4 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -221,7 +221,10 @@ static const struct wiphy_iftype_ext_capab rtw89_iftypes_ext_capa[] = {
 			IEEE80211_EML_CAP_EMLSR_SUPP |
 			(IEEE80211_EML_CAP_EML_PADDING_DELAY_256US << 1) |
 			(IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY_32US << 4),
-		.mld_capa_and_ops = 0,
+		.mld_capa_and_ops =
+			FIELD_PREP_CONST(IEEE80211_MLD_CAP_OP_TID_TO_LINK_MAP_NEG_SUPP,
+					 IEEE80211_MLD_CAP_OP_TID_TO_LINK_MAP_NEG_SUPP_SAME) |
+			IEEE80211_MLD_CAP_OP_LINK_RECONF_SUPPORT,
 	},
 };
 
-- 
2.54.0

[PATCH 4/4] wifi: rtw89: advertise EHT OM Control for 8922a per WFA cert

[Louis Kotze]

Wi-Fi Alliance Certificate WFA129313 (RTL8922AE, 2024-05-23, firmware
6102.24.109.0) certifies "Operating mode indication" as a Wi-Fi 7
feature for this chip. The driver currently sets only MAX_MPDU_LEN +
RESTRICTED_TWT in mac_cap_info[0], leaving EHT OM Control unset.

Set IEEE80211_EHT_MAC_CAP0_OM_CONTROL in mac_cap_info[0]. EHT OM
Control extends the HE OMI control mechanism (already advertised at
the HE layer) to EHT-specific operating-mode notifications. mt76
(mt7996, mt7925) and iwlwifi mvm + mld already set this single bit
for their Wi-Fi 7 STAs; hwsim sets it in test code.

Tested on RTL8922AU against TP-Link Deco BE63; assoc + EMLSR multi-
link state remain stable.

Link: https://api.cert.wi-fi.org/api/certificate/download/public?variantId=129706 [WFA cert WFA129313]
Signed-off-by: Louis Kotze <loukot@gmail.com>
---
 drivers/net/wireless/realtek/rtw89/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index aedb2a284cd4..229c9f8ea65e 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -5564,7 +5564,8 @@ static void rtw89_init_eht_cap(struct rtw89_dev *rtwdev,
 	eht_cap_elem->mac_cap_info[0] =
 		u8_encode_bits(chip->max_eht_mpdu_cap,
 			       IEEE80211_EHT_MAC_CAP0_MAX_MPDU_LEN_MASK) |
-		IEEE80211_EHT_MAC_CAP0_RESTRICTED_TWT;
+		IEEE80211_EHT_MAC_CAP0_RESTRICTED_TWT |
+		IEEE80211_EHT_MAC_CAP0_OM_CONTROL;
 	eht_cap_elem->mac_cap_info[1] = 0;
 
 	eht_cap_elem->phy_cap_info[0] =
-- 
2.54.0