mt76: fix sending encrypted broadcast packets for secondary interfaces

For encryption to work properly, the BSS index needs to be initialized
for the WCID entry used for the interface.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mediatek/mt76/mt76x2.h

@@ -39,6 +39,9 @@
 
 #define MT_CALIBRATE_INTERVAL	HZ
 
+#define MT_MAX_VIFS		8
+#define MT_VIF_WCID(_n)		(254 - ((_n) & 7))
+
 #include "mt76.h"
 #include "mt76x2_regs.h"
 #include "mt76x2_mac.h"

drivers/net/wireless/mediatek/mt76/mt76x2_init.c

@@ -296,6 +296,9 @@ static int mt76x2_mac_reset(struct mt76x2_dev *dev, bool hard)
 	for (i = 0; i < 256; i++)
 		mt76x2_mac_wcid_setup(dev, i, 0, NULL);
 
+	for (i = 0; i < MT_MAX_VIFS; i++)
+		mt76x2_mac_wcid_setup(dev, MT_VIF_WCID(i), i, NULL);
+
 	for (i = 0; i < 16; i++)
 		for (k = 0; k < 4; k++)
 			mt76x2_mac_shared_key_setup(dev, i, k, NULL);

drivers/net/wireless/mediatek/mt76/mt76x2_main.c

@@ -104,7 +104,7 @@ mt76x2_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 		idx += 8;
 
 	mvif->idx = idx;
-	mvif->group_wcid.idx = 254 - idx;
+	mvif->group_wcid.idx = MT_VIF_WCID(idx);
 	mvif->group_wcid.hw_key_idx = -1;
 	mt76x2_txq_init(dev, vif->txq);