mt76: mt7615: fix/rewrite the dfs state handling logic

Copy the updated logic from mt7915 to to fix issues in handling DFS radar
detector states
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7615/init.c

@@ -552,7 +552,6 @@ void mt7615_init_device(struct mt7615_dev *dev)
 	dev->pm.stats.last_wake_event = jiffies;
 	dev->pm.stats.last_doze_event = jiffies;
 	mt7615_cap_dbdc_disable(dev);
-	dev->phy.dfs_state = -1;
 
 #ifdef CONFIG_NL80211_TESTMODE
 	dev->mt76.test_ops = &mt7615_testmode_ops;

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

@@ -2287,44 +2287,51 @@ mt7615_dfs_init_radar_specs(struct mt7615_phy *phy)
 
 int mt7615_dfs_init_radar_detector(struct mt7615_phy *phy)
 {
-	struct cfg80211_chan_def *chandef = &phy->mt76->chandef;
 	struct mt7615_dev *dev = phy->dev;
 	bool ext_phy = phy != &dev->phy;
+	enum mt76_dfs_state dfs_state, prev_state;
 	int err;
 
 	if (is_mt7663(&dev->mt76))
 		return 0;
 
-	if (dev->mt76.region == NL80211_DFS_UNSET) {
-		phy->dfs_state = -1;
-		if (phy->rdd_state)
-			goto stop;
+	prev_state = phy->mt76->dfs_state;
+	dfs_state = mt76_phy_dfs_state(phy->mt76);
 
+	if (prev_state == dfs_state)
 		return 0;
-	}
 
-	if (test_bit(MT76_SCANNING, &phy->mt76->state))
-		return 0;
-
-	if (phy->dfs_state == chandef->chan->dfs_state)
-		return 0;
+	if (prev_state == MT_DFS_STATE_UNKNOWN)
+		mt7615_dfs_stop_radar_detector(phy);
 
-	err = mt7615_dfs_init_radar_specs(phy);
-	if (err < 0) {
-		phy->dfs_state = -1;
+	if (dfs_state == MT_DFS_STATE_DISABLED)
 		goto stop;
-	}
 
-	phy->dfs_state = chandef->chan->dfs_state;
+	if (prev_state <= MT_DFS_STATE_DISABLED) {
+		err = mt7615_dfs_init_radar_specs(phy);
+		if (err < 0)
+			return err;
+
+		err = mt7615_dfs_start_radar_detector(phy);
+		if (err < 0)
+			return err;
 
-	if (chandef->chan->flags & IEEE80211_CHAN_RADAR) {
-		if (chandef->chan->dfs_state != NL80211_DFS_AVAILABLE)
-			return mt7615_dfs_start_radar_detector(phy);
+		phy->mt76->dfs_state = MT_DFS_STATE_CAC;
+	}
+
+	if (dfs_state == MT_DFS_STATE_CAC)
+		return 0;
 
-		return mt76_connac_mcu_rdd_cmd(&dev->mt76, RDD_CAC_END, ext_phy,
-					       MT_RX_SEL0, 0);
+	err = mt76_connac_mcu_rdd_cmd(&dev->mt76, RDD_CAC_END,
+				      ext_phy, MT_RX_SEL0, 0);
+	if (err < 0) {
+		phy->mt76->dfs_state = MT_DFS_STATE_UNKNOWN;
+		return err;
 	}
 
+	phy->mt76->dfs_state = MT_DFS_STATE_ACTIVE;
+	return 0;
+
 stop:
 	err = mt76_connac_mcu_rdd_cmd(&dev->mt76, RDD_NORMAL_START, ext_phy,
 				      MT_RX_SEL0, 0);
@@ -2332,6 +2339,8 @@ int mt7615_dfs_init_radar_detector(struct mt7615_phy *phy)
 		return err;
 
 	mt7615_dfs_stop_radar_detector(phy);
+	phy->mt76->dfs_state = MT_DFS_STATE_DISABLED;
+
 	return 0;
 }