rtw88: recover rates of rate adaptive mechanism

Some APs like CMW270 only support one phyrate and the function
rtw_update_rate_mask could disable that rate. To fix such problem, we
restore the rate mask if we find that the rate_mask is empty.
Signed-off-by: NChien-Hsun Liao <ben.liao@realtek.com>
Signed-off-by: NKuan-Chung Chen <damon.chen@realtek.com>
Signed-off-by: NPing-Ke Shih <pkshih@realtek.com>
Signed-off-by: NKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220208082427.42433-2-pkshih@realtek.com

drivers/net/wireless/realtek/rtw88/main.c

@@ -1020,37 +1020,52 @@ static u8 get_rate_id(u8 wireless_set, enum rtw_bandwidth bw_mode, u8 tx_num)
 #define RA_MASK_VHT_RATES	(RA_MASK_VHT_RATES_1SS | \
 				 RA_MASK_VHT_RATES_2SS | \
 				 RA_MASK_VHT_RATES_3SS)
+#define RA_MASK_CCK_IN_BG	0x00005
 #define RA_MASK_CCK_IN_HT	0x00005
 #define RA_MASK_CCK_IN_VHT	0x00005
 #define RA_MASK_OFDM_IN_VHT	0x00010
 #define RA_MASK_OFDM_IN_HT_2G	0x00010
 #define RA_MASK_OFDM_IN_HT_5G	0x00030
 
-static u64 rtw_update_rate_mask(struct rtw_dev *rtwdev,
-				struct rtw_sta_info *si,
-				u64 ra_mask, bool is_vht_enable,
-				u8 wireless_set)
+static u64 rtw_rate_mask_rssi(struct rtw_sta_info *si, u8 wireless_set)
+{
+	u8 rssi_level = si->rssi_level;
+
+	if (wireless_set == WIRELESS_CCK)
+		return 0xffffffffffffffffULL;
+
+	if (rssi_level == 0)
+		return 0xffffffffffffffffULL;
+	else if (rssi_level == 1)
+		return 0xfffffffffffffff0ULL;
+	else if (rssi_level == 2)
+		return 0xffffffffffffefe0ULL;
+	else if (rssi_level == 3)
+		return 0xffffffffffffcfc0ULL;
+	else if (rssi_level == 4)
+		return 0xffffffffffff8f80ULL;
+	else
+		return 0xffffffffffff0f00ULL;
+}
+
+static u64 rtw_rate_mask_recover(u64 ra_mask, u64 ra_mask_bak)
+{
+	if ((ra_mask & ~(RA_MASK_CCK_RATES | RA_MASK_OFDM_RATES)) == 0)
+		ra_mask |= (ra_mask_bak & ~(RA_MASK_CCK_RATES | RA_MASK_OFDM_RATES));
+
+	if (ra_mask == 0)
+		ra_mask |= (ra_mask_bak & (RA_MASK_CCK_RATES | RA_MASK_OFDM_RATES));
+
+	return ra_mask;
+}
+
+static u64 rtw_rate_mask_cfg(struct rtw_dev *rtwdev, struct rtw_sta_info *si,
+			     u64 ra_mask, bool is_vht_enable)
 {
 	struct rtw_hal *hal = &rtwdev->hal;
 	const struct cfg80211_bitrate_mask *mask = si->mask;
 	u64 cfg_mask = GENMASK_ULL(63, 0);
-	u8 rssi_level, band;
-
-	if (wireless_set != WIRELESS_CCK) {
-		rssi_level = si->rssi_level;
-		if (rssi_level == 0)
-			ra_mask &= 0xffffffffffffffffULL;
-		else if (rssi_level == 1)
-			ra_mask &= 0xfffffffffffffff0ULL;
-		else if (rssi_level == 2)
-			ra_mask &= 0xffffffffffffefe0ULL;
-		else if (rssi_level == 3)
-			ra_mask &= 0xffffffffffffcfc0ULL;
-		else if (rssi_level == 4)
-			ra_mask &= 0xffffffffffff8f80ULL;
-		else if (rssi_level >= 5)
-			ra_mask &= 0xffffffffffff0f00ULL;
-	}
+	u8 band;
 
 	if (!si->use_cfg_mask)
 		return ra_mask;
@@ -1100,6 +1115,7 @@ void rtw_update_sta_info(struct rtw_dev *rtwdev, struct rtw_sta_info *si)
 	u8 ldpc_en = 0;
 	u8 tx_num = 1;
 	u64 ra_mask = 0;
+	u64 ra_mask_bak = 0;
 	bool is_vht_enable = false;
 	bool is_support_sgi = false;
 
@@ -1124,6 +1140,7 @@ void rtw_update_sta_info(struct rtw_dev *rtwdev, struct rtw_sta_info *si)
 
 	if (hal->current_band_type == RTW_BAND_5G) {
 		ra_mask |= (u64)sta->supp_rates[NL80211_BAND_5GHZ] << 4;
+		ra_mask_bak = ra_mask;
 		if (sta->vht_cap.vht_supported) {
 			ra_mask &= RA_MASK_VHT_RATES | RA_MASK_OFDM_IN_VHT;
 			wireless_set = WIRELESS_OFDM | WIRELESS_VHT;
@@ -1136,6 +1153,7 @@ void rtw_update_sta_info(struct rtw_dev *rtwdev, struct rtw_sta_info *si)
 		dm_info->rrsr_val_init = RRSR_INIT_5G;
 	} else if (hal->current_band_type == RTW_BAND_2G) {
 		ra_mask |= sta->supp_rates[NL80211_BAND_2GHZ];
+		ra_mask_bak = ra_mask;
 		if (sta->vht_cap.vht_supported) {
 			ra_mask &= RA_MASK_VHT_RATES | RA_MASK_CCK_IN_VHT |
 				   RA_MASK_OFDM_IN_VHT;
@@ -1149,11 +1167,13 @@ void rtw_update_sta_info(struct rtw_dev *rtwdev, struct rtw_sta_info *si)
 		} else if (sta->supp_rates[0] <= 0xf) {
 			wireless_set = WIRELESS_CCK;
 		} else {
+			ra_mask &= RA_MASK_OFDM_RATES | RA_MASK_CCK_IN_BG;
 			wireless_set = WIRELESS_CCK | WIRELESS_OFDM;
 		}
 		dm_info->rrsr_val_init = RRSR_INIT_2G;
 	} else {
 		rtw_err(rtwdev, "Unknown band type\n");
+		ra_mask_bak = ra_mask;
 		wireless_set = 0;
 	}
 
@@ -1185,8 +1205,9 @@ void rtw_update_sta_info(struct rtw_dev *rtwdev, struct rtw_sta_info *si)
 
 	rate_id = get_rate_id(wireless_set, bw_mode, tx_num);
 
-	ra_mask = rtw_update_rate_mask(rtwdev, si, ra_mask, is_vht_enable,
-				       wireless_set);
+	ra_mask &= rtw_rate_mask_rssi(si, wireless_set);
+	ra_mask = rtw_rate_mask_recover(ra_mask, ra_mask_bak);
+	ra_mask = rtw_rate_mask_cfg(rtwdev, si, ra_mask, is_vht_enable);
 
 	si->bw_mode = bw_mode;
 	si->stbc_en = stbc_en;