ath9k: Resync beacons properly

After a chip reset, the beacon timers have to re-programmed
correctly for a station in associated state. Use the PS flags
to ensure that this is done after a TSF sync happens, otherwise
the driver ends up using incorrect values for TBTT/DTIM in
powersave mode.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -210,6 +210,7 @@ static bool ath_complete_reset(struct ath_softc *sc, bool start)
 {
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_common *common = ath9k_hw_common(ah);
+	unsigned long flags;
 
 	if (ath_startrecv(sc) != 0) {
 		ath_err(common, "Unable to restart recv logic\n");
@@ -224,9 +225,18 @@ static bool ath_complete_reset(struct ath_softc *sc, bool start)
 	ath9k_hw_enable_interrupts(ah);
 
 	if (!(sc->hw->conf.flags & IEEE80211_CONF_OFFCHANNEL) && start) {
-		if (test_bit(SC_OP_BEACONS, &sc->sc_flags))
+		if (!test_bit(SC_OP_BEACONS, &sc->sc_flags))
+			goto work;
+
 		ath_set_beacon(sc);
 
+		if (ah->opmode == NL80211_IFTYPE_STATION &&
+		    test_bit(SC_OP_PRIM_STA_VIF, &sc->sc_flags)) {
+			spin_lock_irqsave(&sc->sc_pm_lock, flags);
+			sc->ps_flags |= PS_BEACON_SYNC | PS_WAIT_FOR_BEACON;
+			spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
+		}
+	work:
 		ath_restart_work(sc);
 	}