ath9k: disable beaconing before stopping beacon queue

Beaconing should be disabled before stopping beacon queue.
Not doing so could queue up beacons in hw that causes
failure to stop Tx DMA, due to pending frames in hw
and also unnecessary beacon tasklet schedule.

Signed-off-by: Rajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index ed6e7d6..a4bdfdb 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -143,7 +143,7 @@
 	avp = (void *)vif->drv_priv;
 	cabq = sc->beacon.cabq;
 
-	if (avp->av_bcbuf == NULL)
+	if ((avp->av_bcbuf == NULL) || !avp->is_bslot_active)
 		return NULL;
 
 	/* Release the old beacon first */
@@ -249,6 +249,7 @@
 			for (slot = 0; slot < ATH_BCBUF; slot++)
 				if (sc->beacon.bslot[slot] == NULL) {
 					avp->av_bslot = slot;
+					avp->is_bslot_active = false;
 
 					/* NB: keep looking for a double slot */
 					if (slot == 0 || !sc->beacon.bslot[slot-1])
@@ -315,6 +316,7 @@
 		ath_err(common, "dma_mapping_error on beacon alloc\n");
 		return -ENOMEM;
 	}
+	avp->is_bslot_active = true;
 
 	return 0;
 }
@@ -749,3 +751,36 @@
 
 	sc->sc_flags |= SC_OP_BEACONS;
 }
+
+void ath9k_set_beaconing_status(struct ath_softc *sc, bool status)
+{
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath_vif *avp;
+	int slot;
+	bool found = false;
+
+	ath9k_ps_wakeup(sc);
+	if (status) {
+		for (slot = 0; slot < ATH_BCBUF; slot++) {
+			if (sc->beacon.bslot[slot]) {
+				avp = (void *)sc->beacon.bslot[slot]->drv_priv;
+				if (avp->is_bslot_active) {
+					found = true;
+					break;
+				}
+			}
+		}
+		if (found) {
+			/* Re-enable beaconing */
+			ah->imask |= ATH9K_INT_SWBA;
+			ath9k_hw_set_interrupts(ah, ah->imask);
+		}
+	} else {
+		/* Disable SWBA interrupt */
+		ah->imask &= ~ATH9K_INT_SWBA;
+		ath9k_hw_set_interrupts(ah, ah->imask);
+		tasklet_kill(&sc->bcon_tasklet);
+		ath9k_hw_stoptxdma(ah, sc->beacon.beaconq);
+	}
+	ath9k_ps_restore(sc);
+}