ath9k: perform ANI cycle in idle state

As of now the ANI cycle is executed only when the chip is awake.
On idle state case, the station wakes up from network sleep for
beacon reception. Since most of the time, ANI cycle is not syncing
with beacon wakeup, ANI cycle is ignored. Approx 5 mins once, the
calibration is performed. This could affect the connection stability
when the station is idle for long. Even though the OFDM and CCK phy
error rates are too high, ANI is unable to tune its immunity level
as quick enough due to rare execution.

Here the experiment shows that OFDM and CCK levels are at default
even on higher phy error rate.

listenTime=44 OFDM:3 errs=121977/s CCK:2 errs=440818/s ofdm_turn=1

This change ensures that ANI calibration will be exectued atleast
once for every 10 seconds. The below result shows improvements and
immunity levels are adopted quick enough.

listenTime=557 OFDM:4 errs=752/s CCK:4 errs=125/s ofdm_turn=0

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -437,6 +437,7 @@ void ath9k_set_beacon(struct ath_softc *sc);
 #define ATH_LONG_CALINTERVAL_INT  1000    /* 1000 ms */
 #define ATH_LONG_CALINTERVAL      30000   /* 30 seconds */
 #define ATH_RESTART_CALINTERVAL   1200000 /* 20 minutes */
+#define ATH_ANI_MAX_SKIP_COUNT  10
 
 #define ATH_PAPRD_TIMEOUT	100 /* msecs */
 #define ATH_PLL_WORK_INTERVAL   100
@@ -642,6 +643,7 @@ enum sc_op_flags {
 #define PS_WAIT_FOR_PSPOLL_DATA   BIT(2)
 #define PS_WAIT_FOR_TX_ACK        BIT(3)
 #define PS_BEACON_SYNC            BIT(4)
+#define PS_WAIT_FOR_ANI           BIT(5)
 
 struct ath_rate_table;
 

drivers/net/wireless/ath/ath9k/hw.h

@@ -834,6 +834,7 @@ struct ath_hw {
 	int coarse_low[5];
 	int firpwr[5];
 	enum ath9k_ani_cmd ani_function;
+	u32 ani_skip_count;
 
 #ifdef CONFIG_ATH9K_BTCOEX_SUPPORT
 	struct ath_btcoex_hw btcoex_hw;

drivers/net/wireless/ath/ath9k/link.c

@@ -350,8 +350,18 @@ void ath_ani_calibrate(unsigned long data)
 		ATH_AP_SHORT_CALINTERVAL : ATH_STA_SHORT_CALINTERVAL;
 
 	/* Only calibrate if awake */
-	if (sc->sc_ah->power_mode != ATH9K_PM_AWAKE)
+	if (sc->sc_ah->power_mode != ATH9K_PM_AWAKE) {
+		if (++ah->ani_skip_count >= ATH_ANI_MAX_SKIP_COUNT) {
+			spin_lock_irqsave(&sc->sc_pm_lock, flags);
+			sc->ps_flags |= PS_WAIT_FOR_ANI;
+			spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
+		}
 		goto set_timer;
+	}
+	ah->ani_skip_count = 0;
+	spin_lock_irqsave(&sc->sc_pm_lock, flags);
+	sc->ps_flags &= ~PS_WAIT_FOR_ANI;
+	spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
 
 	ath9k_ps_wakeup(sc);
 

drivers/net/wireless/ath/ath9k/main.c

@@ -131,7 +131,8 @@ void ath9k_ps_restore(struct ath_softc *sc)
 		   !(sc->ps_flags & (PS_WAIT_FOR_BEACON |
 				     PS_WAIT_FOR_CAB |
 				     PS_WAIT_FOR_PSPOLL_DATA |
-				     PS_WAIT_FOR_TX_ACK))) {
+				     PS_WAIT_FOR_TX_ACK |
+				     PS_WAIT_FOR_ANI))) {
 		mode = ATH9K_PM_NETWORK_SLEEP;
 		if (ath9k_hw_btcoex_is_enabled(sc->sc_ah))
 			ath9k_btcoex_stop_gen_timer(sc);