mt76: mt7915: reject duplicated twt flows

Reject twt flows with the same parameters to prevent some potential issues
causing by duplicated establishment.

Reviewed-by: Ryder Lee <ryder.lee@mediatek.com>
Reviewed-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt7915/mac.c

@@ -2690,6 +2690,34 @@ static int mt7915_mac_check_twt_req(struct ieee80211_twt_setup *twt)
 	return 0;
 }
 
+static bool
+mt7915_mac_twt_param_equal(struct mt7915_sta *msta,
+			   struct ieee80211_twt_params *twt_agrt)
+{
+	u16 type = le16_to_cpu(twt_agrt->req_type);
+	u8 exp;
+	int i;
+
+	exp = FIELD_GET(IEEE80211_TWT_REQTYPE_WAKE_INT_EXP, type);
+	for (i = 0; i < MT7915_MAX_STA_TWT_AGRT; i++) {
+		struct mt7915_twt_flow *f;
+
+		if (!(msta->twt.flowid_mask & BIT(i)))
+			continue;
+
+		f = &msta->twt.flow[i];
+		if (f->duration == twt_agrt->min_twt_dur &&
+		    f->mantissa == twt_agrt->mantissa &&
+		    f->exp == exp &&
+		    f->protection == !!(type & IEEE80211_TWT_REQTYPE_PROTECTION) &&
+		    f->flowtype == !!(type & IEEE80211_TWT_REQTYPE_FLOWTYPE) &&
+		    f->trigger == !!(type & IEEE80211_TWT_REQTYPE_TRIGGER))
+			return true;
+	}
+
+	return false;
+}
+
 void mt7915_mac_add_twt_setup(struct ieee80211_hw *hw,
 			      struct ieee80211_sta *sta,
 			      struct ieee80211_twt_setup *twt)
@@ -2723,6 +2751,9 @@ void mt7915_mac_add_twt_setup(struct ieee80211_hw *hw,
 	exp = FIELD_GET(IEEE80211_TWT_REQTYPE_WAKE_INT_EXP, req_type);
 	sta_setup_cmd = FIELD_GET(IEEE80211_TWT_REQTYPE_SETUP_CMD, req_type);
 
+	if (mt7915_mac_twt_param_equal(msta, twt_agrt))
+		goto unlock;
+
 	flow = &msta->twt.flow[flowid];
 	memset(flow, 0, sizeof(*flow));
 	INIT_LIST_HEAD(&flow->list);