wifi: rtw89: fix EHT 20MHz TX rate for non-AP STA

[ Upstream commit fe30a8a ]

The 4-octet EHT MCS/NSS subfield is only used for 20 MHz-only
non-AP STA. Correct the interpretation of this subfield to
prevent improper rate limitations.

Fixes: f1dfcee ("wifi: rtw89: Correct EHT TX rate on 20MHz connection")
Signed-off-by: Kuan-Chung Chen <[email protected]>
Signed-off-by: Ping-Ke Shih <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Sasha Levin <[email protected]>

Author: Kuan-Chung Chen

drivers/net/wireless/realtek/rtw89/phy.c

@@ -119,10 +119,12 @@ static u64 get_eht_mcs_ra_mask(u8 *max_nss, u8 start_mcs, u8 n_nss)
 	return mask;
 }
 
-static u64 get_eht_ra_mask(struct ieee80211_link_sta *link_sta)
+static u64 get_eht_ra_mask(struct rtw89_vif_link *rtwvif_link,
+			   struct ieee80211_link_sta *link_sta)
 {
-	struct ieee80211_sta_eht_cap *eht_cap = &link_sta->eht_cap;
+	struct ieee80211_vif *vif = rtwvif_link_to_vif(rtwvif_link);
 	struct ieee80211_eht_mcs_nss_supp_20mhz_only *mcs_nss_20mhz;
+	struct ieee80211_sta_eht_cap *eht_cap = &link_sta->eht_cap;
 	struct ieee80211_eht_mcs_nss_supp_bw *mcs_nss;
 	u8 *he_phy_cap = link_sta->he_cap.he_cap_elem.phy_cap_info;
 
@@ -136,8 +138,8 @@ static u64 get_eht_ra_mask(struct ieee80211_link_sta *link_sta)
 		/* MCS 9, 11, 13 */
 		return get_eht_mcs_ra_mask(mcs_nss->rx_tx_max_nss, 9, 3);
 	case IEEE80211_STA_RX_BW_20:
-		if (!(he_phy_cap[0] &
-		      IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_MASK_ALL)) {
+		if (vif->type == NL80211_IFTYPE_AP &&
+		    !(he_phy_cap[0] & IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_MASK_ALL)) {
 			mcs_nss_20mhz = &eht_cap->eht_mcs_nss_supp.only_20mhz;
 			/* MCS 7, 9, 11, 13 */
 			return get_eht_mcs_ra_mask(mcs_nss_20mhz->rx_tx_max_nss, 7, 4);
@@ -332,7 +334,7 @@ static void rtw89_phy_ra_sta_update(struct rtw89_dev *rtwdev,
 	/* Set the ra mask from sta's capability */
 	if (link_sta->eht_cap.has_eht) {
 		mode |= RTW89_RA_MODE_EHT;
-		ra_mask |= get_eht_ra_mask(link_sta);
+		ra_mask |= get_eht_ra_mask(rtwvif_link, link_sta);
 
 		if (rtwdev->hal.no_mcs_12_13)
 			high_rate_masks = rtw89_ra_mask_eht_mcs0_11;