wifi: rtw89: pause/proceed MCC for ROC and HW scan

During (TDMA-based) MCC (multi-channel concurrency), the below two
cases might not have a good behavior on channel usage.
* ROC (remain on channel)
* HW scan
So, we tend to separate them from MCC.

The two cases would expect to operate the channel to which they want.
However, during MCC, channels are scheduled by FW MCC state mechanism.
So, channels cannot be controlled explicitly. To avoid the two cases
from operating wrong channels with chance, we pause MCC (essentially
stop FW MCC) once the two cases are coming. And then, we proceed MCC
again (essentially restart FW MCC) once the two cases finish.
Signed-off-by: Zong-Zhe Yang <kevin_yang@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/20230921003559.11588-3-pkshih@realtek.com

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

@@ -205,6 +205,7 @@ void rtw89_entity_init(struct rtw89_dev *rtwdev)
 {
 	struct rtw89_hal *hal = &rtwdev->hal;
 
+	hal->entity_pause = false;
 	bitmap_zero(hal->entity_map, NUM_OF_RTW89_SUB_ENTITY);
 	bitmap_zero(hal->changes, NUM_OF_RTW89_CHANCTX_CHANGES);
 	atomic_set(&hal->roc_entity_idx, RTW89_SUB_ENTITY_IDLE);
@@ -221,6 +222,8 @@ enum rtw89_entity_mode rtw89_entity_recalc(struct rtw89_dev *rtwdev)
 	u8 last;
 	u8 idx;
 
+	lockdep_assert_held(&rtwdev->mutex);
+
 	weight = bitmap_weight(hal->entity_map, NUM_OF_RTW89_SUB_ENTITY);
 	switch (weight) {
 	default:
@@ -255,6 +258,9 @@ enum rtw89_entity_mode rtw89_entity_recalc(struct rtw89_dev *rtwdev)
 		rtw89_assign_entity_chan(rtwdev, idx, &chan);
 	}
 
+	if (hal->entity_pause)
+		return rtw89_get_entity_mode(rtwdev);
+
 	rtw89_set_entity_mode(rtwdev, mode);
 	return mode;
 }
@@ -1736,6 +1742,11 @@ void rtw89_chanctx_work(struct work_struct *work)
 
 	mutex_lock(&rtwdev->mutex);
 
+	if (hal->entity_pause) {
+		mutex_unlock(&rtwdev->mutex);
+		return;
+	}
+
 	for (i = 0; i < NUM_OF_RTW89_CHANCTX_CHANGES; i++) {
 		if (test_and_clear_bit(i, hal->changes))
 			changed |= BIT(i);
@@ -1816,10 +1827,14 @@ void rtw89_queue_chanctx_work(struct rtw89_dev *rtwdev)
 
 void rtw89_chanctx_track(struct rtw89_dev *rtwdev)
 {
+	struct rtw89_hal *hal = &rtwdev->hal;
 	enum rtw89_entity_mode mode;
 
 	lockdep_assert_held(&rtwdev->mutex);
 
+	if (hal->entity_pause)
+		return;
+
 	mode = rtw89_get_entity_mode(rtwdev);
 	switch (mode) {
 	case RTW89_ENTITY_MODE_MCC:
@@ -1830,6 +1845,61 @@ void rtw89_chanctx_track(struct rtw89_dev *rtwdev)
 	}
 }
 
+void rtw89_chanctx_pause(struct rtw89_dev *rtwdev,
+			 enum rtw89_chanctx_pause_reasons rsn)
+{
+	struct rtw89_hal *hal = &rtwdev->hal;
+	enum rtw89_entity_mode mode;
+
+	lockdep_assert_held(&rtwdev->mutex);
+
+	if (hal->entity_pause)
+		return;
+
+	rtw89_debug(rtwdev, RTW89_DBG_CHAN, "chanctx pause (rsn: %d)\n", rsn);
+
+	mode = rtw89_get_entity_mode(rtwdev);
+	switch (mode) {
+	case RTW89_ENTITY_MODE_MCC:
+		rtw89_mcc_stop(rtwdev);
+		break;
+	default:
+		break;
+	}
+
+	hal->entity_pause = true;
+}
+
+void rtw89_chanctx_proceed(struct rtw89_dev *rtwdev)
+{
+	struct rtw89_hal *hal = &rtwdev->hal;
+	enum rtw89_entity_mode mode;
+	int ret;
+
+	lockdep_assert_held(&rtwdev->mutex);
+
+	if (!hal->entity_pause)
+		return;
+
+	rtw89_debug(rtwdev, RTW89_DBG_CHAN, "chanctx proceed\n");
+
+	hal->entity_pause = false;
+	rtw89_set_channel(rtwdev);
+
+	mode = rtw89_get_entity_mode(rtwdev);
+	switch (mode) {
+	case RTW89_ENTITY_MODE_MCC:
+		ret = rtw89_mcc_start(rtwdev);
+		if (ret)
+			rtw89_warn(rtwdev, "failed to start MCC: %d\n", ret);
+		break;
+	default:
+		break;
+	}
+
+	rtw89_queue_chanctx_work(rtwdev);
+}
+
 int rtw89_chanctx_ops_add(struct rtw89_dev *rtwdev,
 			  struct ieee80211_chanctx_conf *ctx)
 {

drivers/net/wireless/realtek/rtw89/chan.h

@@ -33,6 +33,11 @@
 
 #define NUM_OF_RTW89_MCC_ROLES 2
 
+enum rtw89_chanctx_pause_reasons {
+	RTW89_CHANCTX_PAUSE_REASON_HW_SCAN,
+	RTW89_CHANCTX_PAUSE_REASON_ROC,
+};
+
 static inline bool rtw89_get_entity_state(struct rtw89_dev *rtwdev)
 {
 	struct rtw89_hal *hal = &rtwdev->hal;
@@ -81,6 +86,9 @@ void rtw89_queue_chanctx_work(struct rtw89_dev *rtwdev);
 void rtw89_queue_chanctx_change(struct rtw89_dev *rtwdev,
 				enum rtw89_chanctx_changes change);
 void rtw89_chanctx_track(struct rtw89_dev *rtwdev);
+void rtw89_chanctx_pause(struct rtw89_dev *rtwdev,
+			 enum rtw89_chanctx_pause_reasons rsn);
+void rtw89_chanctx_proceed(struct rtw89_dev *rtwdev);
 int rtw89_chanctx_ops_add(struct rtw89_dev *rtwdev,
 			  struct ieee80211_chanctx_conf *ctx);
 void rtw89_chanctx_ops_remove(struct rtw89_dev *rtwdev,

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

@@ -2706,6 +2706,7 @@ void rtw89_roc_start(struct rtw89_dev *rtwdev, struct rtw89_vif *rtwvif)
 
 	rtw89_leave_ips_by_hwflags(rtwdev);
 	rtw89_leave_lps(rtwdev);
+	rtw89_chanctx_pause(rtwdev, RTW89_CHANCTX_PAUSE_REASON_ROC);
 
 	ret = rtw89_core_send_nullfunc(rtwdev, rtwvif, true, true);
 	if (ret)
@@ -2748,7 +2749,7 @@ void rtw89_roc_end(struct rtw89_dev *rtwdev, struct rtw89_vif *rtwvif)
 
 	roc->state = RTW89_ROC_IDLE;
 	rtw89_config_roc_chandef(rtwdev, rtwvif->sub_entity_idx, NULL);
-	rtw89_set_channel(rtwdev);
+	rtw89_chanctx_proceed(rtwdev);
 	ret = rtw89_core_send_nullfunc(rtwdev, rtwvif, true, false);
 	if (ret)
 		rtw89_debug(rtwdev, RTW89_DBG_TXRX,

drivers/net/wireless/realtek/rtw89/core.h

@@ -4018,6 +4018,7 @@ struct rtw89_hal {
 	struct cfg80211_chan_def roc_chandef;
 
 	bool entity_active;
+	bool entity_pause;
 	enum rtw89_entity_mode entity_mode;
 
 	u32 edcca_bak;

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

@@ -4011,6 +4011,8 @@ void rtw89_hw_scan_start(struct rtw89_dev *rtwdev, struct ieee80211_vif *vif,
 			   rtw89_mac_reg_by_idx(rtwdev, mac->rx_fltr, RTW89_MAC_0),
 			   B_AX_RX_FLTR_CFG_MASK,
 			   rx_fltr);
+
+	rtw89_chanctx_pause(rtwdev, RTW89_CHANCTX_PAUSE_REASON_HW_SCAN);
 }
 
 void rtw89_hw_scan_complete(struct rtw89_dev *rtwdev, struct ieee80211_vif *vif,
@@ -4042,7 +4044,7 @@ void rtw89_hw_scan_complete(struct rtw89_dev *rtwdev, struct ieee80211_vif *vif,
 	scan_info->last_chan_idx = 0;
 	scan_info->scanning_vif = NULL;
 
-	rtw89_set_channel(rtwdev);
+	rtw89_chanctx_proceed(rtwdev);
 }
 
 void rtw89_hw_scan_abort(struct rtw89_dev *rtwdev, struct ieee80211_vif *vif)