ath9k: Fix wifi disconnection when collocated bt scan is active

As all bt packets are priority traffic during bt scan, wifi
will get disconnected when bt scan lasts for few seconds. Fix
this by allocating 10% of bt period time (4.5ms) to wifi fully.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 22 insertions, 8 deletions

diff --git a/drivers/net/wireless/ath/ath9k/gpio.c b/drivers/net/wireless/ath/ath9k/gpio.c
index e204bd2..deab8be 100644
--- a/drivers/net/wireless/ath/ath9k/gpio.c
+++ b/drivers/net/wireless/ath/ath9k/gpio.c
@@ -230,12 +230,17 @@ static void ath_detect_bt_priority(struct ath_softc *sc)
 
 	if (time_after(jiffies, btcoex->bt_priority_time +
 			msecs_to_jiffies(ATH_BT_PRIORITY_TIME_THRESHOLD))) {
-		if (btcoex->bt_priority_cnt >= ATH_BT_CNT_THRESHOLD) {
+		sc->sc_flags &= ~(SC_OP_BT_PRIORITY_DETECTED | SC_OP_BT_SCAN);
+		/* Detect if colocated bt started scanning */
+		if (btcoex->bt_priority_cnt >= ATH_BT_CNT_SCAN_THRESHOLD) {
+			ath_print(ath9k_hw_common(sc->sc_ah), ATH_DBG_BTCOEX,
+				  "BT scan detected");
+			sc->sc_flags |= (SC_OP_BT_SCAN |
+					 SC_OP_BT_PRIORITY_DETECTED);
+		} else if (btcoex->bt_priority_cnt >= ATH_BT_CNT_THRESHOLD) {
 			ath_print(ath9k_hw_common(sc->sc_ah), ATH_DBG_BTCOEX,
 				  "BT priority traffic detected");
 			sc->sc_flags |= SC_OP_BT_PRIORITY_DETECTED;
-		} else {
-			sc->sc_flags &= ~SC_OP_BT_PRIORITY_DETECTED;
 		}
 
 		btcoex->bt_priority_cnt = 0;
@@ -316,12 +321,17 @@ static void ath_btcoex_period_timer(unsigned long data)
 	struct ath_softc *sc = (struct ath_softc *) data;
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_btcoex *btcoex = &sc->btcoex;
+	u32 timer_period;
+	bool is_btscan;
 
 	ath_detect_bt_priority(sc);
 
+	is_btscan = sc->sc_flags & SC_OP_BT_SCAN;
+
 	spin_lock_bh(&btcoex->btcoex_lock);
 
-	ath9k_btcoex_bt_stomp(sc, btcoex->bt_stomp_type);
+	ath9k_btcoex_bt_stomp(sc, is_btscan ? ATH_BTCOEX_STOMP_ALL :
+			      btcoex->bt_stomp_type);
 
 	spin_unlock_bh(&btcoex->btcoex_lock);
 
@@ -329,11 +339,12 @@ static void ath_btcoex_period_timer(unsigned long data)
 		if (btcoex->hw_timer_enabled)
 			ath9k_gen_timer_stop(ah, btcoex->no_stomp_timer);
 
+		timer_period = is_btscan ? btcoex->btscan_no_stomp :
+					   btcoex->btcoex_no_stomp;
 		ath9k_gen_timer_start(ah,
 				      btcoex->no_stomp_timer,
 				      (ath9k_hw_gettsf32(ah) +
-				       btcoex->btcoex_no_stomp),
-				       btcoex->btcoex_no_stomp * 10);
+				       timer_period), timer_period * 10);
 		btcoex->hw_timer_enabled = true;
 	}
 
@@ -350,13 +361,14 @@ static void ath_btcoex_no_stomp_timer(void *arg)
 	struct ath_softc *sc = (struct ath_softc *)arg;
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_btcoex *btcoex = &sc->btcoex;
+	bool is_btscan = sc->sc_flags & SC_OP_BT_SCAN;
 
 	ath_print(ath9k_hw_common(ah), ATH_DBG_BTCOEX,
 		  "no stomp timer running \n");
 
 	spin_lock_bh(&btcoex->btcoex_lock);
 
-	if (btcoex->bt_stomp_type == ATH_BTCOEX_STOMP_LOW)
+	if (btcoex->bt_stomp_type == ATH_BTCOEX_STOMP_LOW || is_btscan)
 		ath9k_btcoex_bt_stomp(sc, ATH_BTCOEX_STOMP_NONE);
 	 else if (btcoex->bt_stomp_type == ATH_BTCOEX_STOMP_ALL)
 		ath9k_btcoex_bt_stomp(sc, ATH_BTCOEX_STOMP_LOW);
@@ -371,6 +383,8 @@ int ath_init_btcoex_timer(struct ath_softc *sc)
 	btcoex->btcoex_period = ATH_BTCOEX_DEF_BT_PERIOD * 1000;
 	btcoex->btcoex_no_stomp = (100 - ATH_BTCOEX_DEF_DUTY_CYCLE) *
 		btcoex->btcoex_period / 100;
+	btcoex->btscan_no_stomp = (100 - ATH_BTCOEX_BTSCAN_DUTY_CYCLE) *
+				   btcoex->btcoex_period / 100;
 
 	setup_timer(&btcoex->period_timer, ath_btcoex_period_timer,
 			(unsigned long) sc);
@@ -405,7 +419,7 @@ void ath9k_btcoex_timer_resume(struct ath_softc *sc)
 
 	btcoex->bt_priority_cnt = 0;
 	btcoex->bt_priority_time = jiffies;
-	sc->sc_flags &= ~SC_OP_BT_PRIORITY_DETECTED;
+	sc->sc_flags &= ~(SC_OP_BT_PRIORITY_DETECTED | SC_OP_BT_SCAN);
 
 	mod_timer(&btcoex->period_timer, jiffies);
 }