[PATCH 04/12] wifi: mt76: mt7996: fix incorrect interpretation of EHT MCS caps

[Shayne Chen]

From: Benjamin Lin <benjamin-jw.lin at mediatek.com>

The EHT MCS map subfield of 20 MHz-Only is not present in the EHT
capability of AP, so STA does not need to parse the subfield.
Moreover, AP should parse the subfield only if STA is 20 MHz-Only, which
can be confirmed by checking supported channel width in HE capability.

Fixes: 92aa2da9fa49 ("wifi: mt76: mt7996: enable EHT support in firmware")
Co-developed-by: Shayne Chen <shayne.chen at mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen at mediatek.com>
Signed-off-by: Benjamin Lin <benjamin-jw.lin at mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index 3c729b563edc..02d858fdc9fe 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
@@ -1240,6 +1240,9 @@ mt7996_mcu_sta_he_6g_tlv(struct sk_buff *skb, struct ieee80211_sta *sta)
 static void
 mt7996_mcu_sta_eht_tlv(struct sk_buff *skb, struct ieee80211_sta *sta)
 {
+	struct mt7996_sta *msta = (struct mt7996_sta *)sta->drv_priv;
+	struct ieee80211_vif *vif = container_of((void *)msta->vif,
+						 struct ieee80211_vif, drv_priv);
 	struct ieee80211_eht_mcs_nss_supp *mcs_map;
 	struct ieee80211_eht_cap_elem_fixed *elem;
 	struct sta_rec_eht *eht;
@@ -1259,8 +1262,17 @@ mt7996_mcu_sta_eht_tlv(struct sk_buff *skb, struct ieee80211_sta *sta)
 	eht->phy_cap = cpu_to_le64(*(u64 *)elem->phy_cap_info);
 	eht->phy_cap_ext = cpu_to_le64(elem->phy_cap_info[8]);
 
-	if (sta->deflink.bandwidth == IEEE80211_STA_RX_BW_20)
-		memcpy(eht->mcs_map_bw20, &mcs_map->only_20mhz, sizeof(eht->mcs_map_bw20));
+	if (vif->type != NL80211_IFTYPE_STATION &&
+	    (sta->deflink.he_cap.he_cap_elem.phy_cap_info[0] &
+	     (IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_IN_2G |
+	      IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_80MHZ_IN_5G |
+	      IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_160MHZ_IN_5G |
+	      IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_80PLUS80_MHZ_IN_5G)) == 0) {
+		memcpy(eht->mcs_map_bw20, &mcs_map->only_20mhz,
+		       sizeof(eht->mcs_map_bw20));
+		return;
+	}
+
 	memcpy(eht->mcs_map_bw80, &mcs_map->bw._80, sizeof(eht->mcs_map_bw80));
 	memcpy(eht->mcs_map_bw160, &mcs_map->bw._160, sizeof(eht->mcs_map_bw160));
 	memcpy(eht->mcs_map_bw320, &mcs_map->bw._320, sizeof(eht->mcs_map_bw320));
-- 
2.39.2