wifi: mt76: mt7996: add sanity checks for background radar trigger

Check if background radar is enabled or not before manually triggering it,
and also add more checks in radar detected event.
Signed-off-by: StanleyYP Wang <StanleyYP.Wang@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c

@@ -225,6 +225,11 @@ mt7996_radar_trigger(void *data, u64 val)
 	if (val > MT_RX_SEL2)
 		return -EINVAL;
 
+	if (val == MT_RX_SEL2 && !dev->rdd2_phy) {
+		dev_err(dev->mt76.dev, "Background radar is not enabled\n");
+		return -EINVAL;
+	}
+
 	return mt7996_mcu_rdd_cmd(dev, RDD_RADAR_EMULATE,
 				  val, 0, 0);
 }

drivers/net/wireless/mediatek/mt76/mt7996/mcu.c

@@ -355,7 +355,10 @@ mt7996_mcu_rx_radar_detected(struct mt7996_dev *dev, struct sk_buff *skb)
 	if (r->band_idx >= ARRAY_SIZE(dev->mt76.phys))
 		return;
 
-	if (dev->rdd2_phy && r->band_idx == MT_RX_SEL2)
+	if (r->band_idx == MT_RX_SEL2 && !dev->rdd2_phy)
+		return;
+
+	if (r->band_idx == MT_RX_SEL2)
 		mphy = dev->rdd2_phy->mt76;
 	else
 		mphy = dev->mt76.phys[r->band_idx];