[PATCH mt76 v2 09/12] wifi: mt76: mt7996: fix MLD group index assignment

[Shayne Chen]

Fix extender mode and MBSS issues caused by incorrect assignment of the
MLD group and remap indices.

Fixes: ed01c310eca9 ("wifi: mt76: mt7996: Fix mt7996_mcu_bss_mld_tlv routine")
Signed-off-by: Shayne Chen <shayne.chen at mediatek.com>
Acked-by: Lorenzo Bianconi <lorenzo at kernel.org>
---
 .../net/wireless/mediatek/mt76/mt7996/main.c  | 58 +++++++++++++------
 1 file changed, 40 insertions(+), 18 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/main.c b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
index ef605e81cba9..66e22f5576f8 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
@@ -90,9 +90,11 @@ static void mt7996_stop(struct ieee80211_hw *hw, bool suspend)
 {
 }
 
-static inline int get_free_idx(u32 mask, u8 start, u8 end)
+static inline int get_free_idx(u64 mask, u8 start, u8 end)
 {
-	return ffs(~mask & GENMASK(end, start));
+	if (~mask & GENMASK_ULL(end, start))
+		return __ffs64(~mask & GENMASK_ULL(end, start)) + 1;
+	return 0;
 }
 
 static int get_omac_idx(enum nl80211_iftype type, u64 mask)
@@ -308,12 +310,6 @@ int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 	if (idx < 0)
 		return -ENOSPC;
 
-	if (!dev->mld_idx_mask) { /* first link in the group */
-		mvif->mld_group_idx = get_own_mld_idx(dev->mld_idx_mask, true);
-		mvif->mld_remap_idx = get_free_idx(dev->mld_remap_idx_mask,
-						   0, 15);
-	}
-
 	mld_idx = get_own_mld_idx(dev->mld_idx_mask, false);
 	if (mld_idx < 0)
 		return -ENOSPC;
@@ -331,10 +327,6 @@ int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 		return ret;
 
 	dev->mt76.vif_mask |= BIT_ULL(mlink->idx);
-	if (!dev->mld_idx_mask) {
-		dev->mld_idx_mask |= BIT_ULL(mvif->mld_group_idx);
-		dev->mld_remap_idx_mask |= BIT_ULL(mvif->mld_remap_idx);
-	}
 	dev->mld_idx_mask |= BIT_ULL(link->mld_idx);
 	phy->omac_mask |= BIT_ULL(mlink->omac_idx);
 
@@ -424,11 +416,6 @@ void mt7996_vif_link_remove(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 	dev->mt76.vif_mask &= ~BIT_ULL(mlink->idx);
 	dev->mld_idx_mask &= ~BIT_ULL(link->mld_idx);
 	phy->omac_mask &= ~BIT_ULL(mlink->omac_idx);
-	if (!(dev->mld_idx_mask & ~BIT_ULL(mvif->mld_group_idx))) {
-		/* last link */
-		dev->mld_idx_mask &= ~BIT_ULL(mvif->mld_group_idx);
-		dev->mld_remap_idx_mask &= ~BIT_ULL(mvif->mld_remap_idx);
-	}
 
 	spin_lock_bh(&dev->mt76.sta_poll_lock);
 	if (!list_empty(&msta_link->wcid.poll_list))
@@ -2228,7 +2215,42 @@ mt7996_change_vif_links(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			u16 old_links, u16 new_links,
 			struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS])
 {
-	return 0;
+	struct mt7996_dev *dev = mt7996_hw_dev(hw);
+	struct mt7996_vif *mvif = (struct mt7996_vif *)vif->drv_priv;
+	int ret = 0;
+
+	mutex_lock(&dev->mt76.mutex);
+
+	if (!old_links) {
+		int idx;
+
+		idx = get_own_mld_idx(dev->mld_idx_mask, true);
+		if (idx < 0) {
+			ret = -ENOSPC;
+			goto out;
+		}
+		mvif->mld_group_idx = idx;
+		dev->mld_idx_mask |= BIT_ULL(mvif->mld_group_idx);
+
+		idx = get_free_idx(dev->mld_remap_idx_mask, 0, 15) - 1;
+		if (idx < 0) {
+			ret = -ENOSPC;
+			goto out;
+		}
+		mvif->mld_remap_idx = idx;
+		dev->mld_remap_idx_mask |= BIT_ULL(mvif->mld_remap_idx);
+	}
+
+	if (new_links)
+		goto out;
+
+	dev->mld_idx_mask &= ~BIT_ULL(mvif->mld_group_idx);
+	dev->mld_remap_idx_mask &= ~BIT_ULL(mvif->mld_remap_idx);
+
+out:
+	mutex_unlock(&dev->mt76.mutex);
+
+	return ret;
 }
 
 static void
-- 
2.51.0