[PATCH ath-next v5 4/9] wifi: ath11k: report tx airtime and enable airtime fairness

[Julius Bairaktaris]

mac80211 charges the airtime deficit only through
ieee80211_sta_register_airtime(), which ath11k never calls, so with
NL80211_EXT_FEATURE_AIRTIME_FAIRNESS alone every station stays in
credit. Register fes_duration_us from the PPDU stats, which ath11k
already adds to arsta->tx_duration, and set the bit. The TID comes from
the ack/BA status TLV, sent only for a PPDU that drew a response, then
from the completion or rate TLV, then BE. Each user of a downlink MU
PPDU is charged the whole duration, as arsta->tx_duration is; every PPDU
on this hardware had one user. mac80211 takes only
local->active_txq_lock[ac] inside the call, which runs under
ar->data_lock and ab->base_lock.

'iw station set <mac> airtime_weight' fails with -EOPNOTSUPP before this
patch and succeeds after it.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.9.0.1-02146-QCAHKSWPL_SILICONZ-1

Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Julius Bairaktaris <julius at bairaktaris.de>
---
 drivers/net/wireless/ath/ath11k/dp_rx.c | 17 +++++++++++++++++
 drivers/net/wireless/ath/ath11k/mac.c   |  2 ++
 2 files changed, 19 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 6d95f7b343a55..8b9df63966989 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -1382,6 +1382,7 @@ ath11k_update_per_peer_tx_stats(struct ath11k *ar,
 	u16 rate = 0, succ_pkts = 0;
 	u32 tx_duration = 0;
 	u8 tid = HTT_PPDU_STATS_NON_QOS_TID;
+	u8 airtime_tid;
 	bool is_ampdu = false;
 
 	if (!(usr_stats->tlv_flags & BIT(HTT_PPDU_STATS_TAG_USR_RATE)))
@@ -1490,6 +1491,22 @@ ath11k_update_per_peer_tx_stats(struct ath11k *ar,
 
 	arsta->txrate.bw = ath11k_mac_bw_to_mac80211_bw(bw);
 	arsta->tx_duration += tx_duration;
+
+	/* The ack/BA status TLV names the TID only for a PPDU that drew a
+	 * response; fall back to the completion and rate TLVs, then to BE.
+	 */
+	airtime_tid = tid;
+	if (airtime_tid >= IEEE80211_NUM_TIDS &&
+	    usr_stats->tlv_flags & BIT(HTT_PPDU_STATS_TAG_USR_COMPLTN_COMMON))
+		airtime_tid = usr_stats->cmpltn_cmn.tid_num;
+	if (airtime_tid >= IEEE80211_NUM_TIDS)
+		airtime_tid = user_rate->tid_num;
+	if (airtime_tid >= IEEE80211_NUM_TIDS)
+		airtime_tid = 0;
+
+	if (tx_duration)
+		ieee80211_sta_register_airtime(sta, airtime_tid, tx_duration, 0);
+
 	memcpy(&arsta->last_txrate, &arsta->txrate, sizeof(struct rate_info));
 
 	/* PPDU stats reported for mgmt packet doesn't have valid tx bytes.
diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 6f4462b7d3f15..eca16a151d068 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -10653,6 +10653,8 @@ static int __ath11k_mac_register(struct ath11k *ar)
 
 	wiphy_ext_feature_set(ar->hw->wiphy, NL80211_EXT_FEATURE_CQM_RSSI_LIST);
 	wiphy_ext_feature_set(ar->hw->wiphy, NL80211_EXT_FEATURE_AQL);
+	wiphy_ext_feature_set(ar->hw->wiphy,
+			      NL80211_EXT_FEATURE_AIRTIME_FAIRNESS);
 	wiphy_ext_feature_set(ar->hw->wiphy, NL80211_EXT_FEATURE_STA_TX_PWR);
 	if (test_bit(WMI_TLV_SERVICE_BSS_COLOR_OFFLOAD,
 		     ar->ab->wmi_ab.svc_map)) {
-- 
2.53.0