wifi: rtw88: handle station mode concurrent scan with AP mode

This patch allows vifs sharing same hardware with the AP mode vif to
do scan, do note that this could lead to packet loss or disconnection
of the AP's clients. Since we don't have chanctx, update scan info
upon set channel so bandwidth changes won't go unnoticed and get
misconfigured after scan. Download beacon just before scan starts to
allow hardware to get proper content to do beaconing. Last, beacons
should only be transmitted in AP's operating channel. Turn related
beacon functions off while we're in other channels so the receiving
stations won't get confused.

Signed-off-by: Po-Hao Huang <phhuang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230414121323.18008-1-pkshih@realtek.com

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

@@ -2160,6 +2160,12 @@ int rtw_hw_scan_offload(struct rtw_dev *rtwdev, struct ieee80211_vif *vif,
 	}
 	rtw_fw_set_scan_offload(rtwdev, &cs_option, rtwvif, &chan_list);
 out:
+	if (rtwdev->ap_active) {
+		ret = rtw_download_beacon(rtwdev);
+		if (ret)
+			rtw_err(rtwdev, "HW scan download beacon failed\n");
+	}
+
 	return ret;
 }
 
@@ -2251,6 +2257,7 @@ void rtw_hw_scan_chan_switch(struct rtw_dev *rtwdev, struct sk_buff *skb)
 		if (rtw_is_op_chan(rtwdev, chan)) {
 			rtw_store_op_chan(rtwdev, false);
 			ieee80211_wake_queues(rtwdev->hw);
+			rtw_core_enable_beacon(rtwdev, true);
 		}
 	} else if (id == RTW_SCAN_NOTIFY_ID_PRESWITCH) {
 		if (IS_CH_5G_BAND(chan)) {
@@ -2269,8 +2276,10 @@ void rtw_hw_scan_chan_switch(struct rtw_dev *rtwdev, struct sk_buff *skb)
 		 * if next channel is non-op channel.
 		 */
 		if (!rtw_is_op_chan(rtwdev, chan) &&
-		    rtw_is_op_chan(rtwdev, hal->current_channel))
+		    rtw_is_op_chan(rtwdev, hal->current_channel)) {
+			rtw_core_enable_beacon(rtwdev, false);
 			ieee80211_stop_queues(rtwdev->hw);
+		}
 	}
 
 	rtw_dbg(rtwdev, RTW_DBG_HW_SCAN,

drivers/net/wireless/realtek/rtw88/mac80211.c

@@ -404,7 +404,7 @@ static void rtw_ops_bss_info_changed(struct ieee80211_hw *hw,
 	if (changed & BSS_CHANGED_BSSID) {
 		ether_addr_copy(rtwvif->bssid, conf->bssid);
 		config |= PORT_SET_BSSID;
-		if (is_zero_ether_addr(rtwvif->bssid))
+		if (!rtw_core_check_sta_active(rtwdev))
 			rtw_clear_op_chan(rtwdev);
 		else
 			rtw_store_op_chan(rtwdev, true);
@@ -452,6 +452,7 @@ static int rtw_ops_start_ap(struct ieee80211_hw *hw,
 
 	mutex_lock(&rtwdev->mutex);
 	rtwdev->ap_active = true;
+	rtw_store_op_chan(rtwdev, true);
 	chip->ops->phy_calibration(rtwdev);
 	mutex_unlock(&rtwdev->mutex);
 
@@ -466,6 +467,8 @@ static void rtw_ops_stop_ap(struct ieee80211_hw *hw,
 
 	mutex_lock(&rtwdev->mutex);
 	rtwdev->ap_active = false;
+	if (!rtw_core_check_sta_active(rtwdev))
+		rtw_clear_op_chan(rtwdev);
 	mutex_unlock(&rtwdev->mutex);
 }
 

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

@@ -830,6 +830,9 @@ void rtw_set_channel(struct rtw_dev *rtwdev)
 
 	rtw_update_channel(rtwdev, center_chan, primary_chan, band, bandwidth);
 
+	if (rtwdev->scan_info.op_chan)
+		rtw_store_op_chan(rtwdev, true);
+
 	chip->ops->set_channel(rtwdev, center_chan, bandwidth,
 			       hal->current_primary_channel_index);
 
@@ -2330,6 +2333,42 @@ void rtw_core_port_switch(struct rtw_dev *rtwdev, struct ieee80211_vif *vif)
 	rtw_iterate_vifs(rtwdev, rtw_port_switch_iter, &iter_data);
 }
 
+static void rtw_check_sta_active_iter(void *data, u8 *mac,
+				      struct ieee80211_vif *vif)
+{
+	struct rtw_vif *rtwvif = (struct rtw_vif *)vif->drv_priv;
+	bool *active = data;
+
+	if (*active)
+		return;
+
+	if (vif->type != NL80211_IFTYPE_STATION)
+		return;
+
+	if (vif->cfg.assoc || !is_zero_ether_addr(rtwvif->bssid))
+		*active = true;
+}
+
+bool rtw_core_check_sta_active(struct rtw_dev *rtwdev)
+{
+	bool sta_active = false;
+
+	rtw_iterate_vifs(rtwdev, rtw_check_sta_active_iter, &sta_active);
+
+	return rtwdev->ap_active || sta_active;
+}
+
+void rtw_core_enable_beacon(struct rtw_dev *rtwdev, bool enable)
+{
+	if (!rtwdev->ap_active)
+		return;
+
+	if (enable)
+		rtw_write32_set(rtwdev, REG_BCN_CTRL, BIT_EN_BCN_FUNCTION);
+	else
+		rtw_write32_clr(rtwdev, REG_BCN_CTRL, BIT_EN_BCN_FUNCTION);
+}
+
 MODULE_AUTHOR("Realtek Corporation");
 MODULE_DESCRIPTION("Realtek 802.11ac wireless core module");
 MODULE_LICENSE("Dual BSD/GPL");

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

@@ -2201,4 +2201,6 @@ void rtw_update_channel(struct rtw_dev *rtwdev, u8 center_channel,
 			u8 primary_channel, enum rtw_supported_band band,
 			enum rtw_bandwidth bandwidth);
 void rtw_core_port_switch(struct rtw_dev *rtwdev, struct ieee80211_vif *vif);
+bool rtw_core_check_sta_active(struct rtw_dev *rtwdev);
+void rtw_core_enable_beacon(struct rtw_dev *rtwdev, bool enable);
 #endif