--- a/ath/if_ath.c
+++ b/ath/if_ath.c
@@ -1014,9 +1014,7 @@ ath_attach(u_int16_t devid, struct net_d
 	 */
 	sc->sc_hasveol = ath_hal_hasveol(ah);
 
-	/* Interference mitigation/ambient noise immunity (ANI).
-	 * In modes other than HAL_M_STA, it causes receive sensitivity
-	 * problems for OFDM. */
+	/* Interference mitigation/ambient noise immunity (ANI). */
 	sc->sc_hasintmit = ath_hal_hasintmit(ah);
 
 	/* get mac address from hardware */
@@ -1144,6 +1142,11 @@ ath_attach(u_int16_t devid, struct net_d
 	sc->sc_rp_lasttsf	= 0;
 	sc->sc_last_tsf		= 0;
 
+	/* set all 3 to auto */
+	sc->sc_intmit = -1;
+	sc->sc_noise_immunity = -1;
+	sc->sc_ofdm_weak_det = -1;
+
 	return 0;
 bad3:
 	ieee80211_ifdetach(ic);
@@ -2428,6 +2431,43 @@ ath_chan2flags(struct ieee80211_channel 
 	return flags;
 }
 
+static int ath_setintmit(struct ath_softc *sc)
+{
+	struct ath_hal *ah = sc->sc_ah;
+	int ret;
+	int val;
+
+	if (!sc->sc_hasintmit)
+		return 0;
+
+	switch(sc->sc_intmit) {
+		case -1:
+			if (sc->sc_opmode != IEEE80211_M_MONITOR)
+				val = 1;
+			else
+				val = 0;
+			break;
+		case 0: /* disabled */
+		case 1: /* enabled */
+			val = sc->sc_intmit;
+			break;
+		default:
+			return 0;
+	}
+	ret = ath_hal_setintmit(ah, val);
+	if (val)
+		goto done;
+
+	/* manual settings */
+	if ((sc->sc_noise_immunity >= 0) && (sc->sc_noise_immunity <= 5))
+		ath_hal_setcapability(ah, HAL_CAP_INTMIT, 2, sc->sc_noise_immunity, NULL);
+	if ((sc->sc_ofdm_weak_det == 0) || (sc->sc_ofdm_weak_det == 1))
+		ath_hal_setcapability(ah, HAL_CAP_INTMIT, 3, sc->sc_ofdm_weak_det, NULL);
+
+done:
+	return ret;
+}
+
 /*
  * Context: process context
  */
@@ -2493,8 +2533,7 @@ ath_init(struct net_device *dev)
 	if (sc->sc_softled)
 		ath_hal_gpioCfgOutput(ah, sc->sc_ledpin);
 
-	if ((sc->sc_opmode != HAL_M_STA) && sc->sc_hasintmit)
-		ath_hal_setintmit(ah, 0);
+	ath_setintmit(sc);
 
 	/*
 	 * This is needed only to setup initial state
@@ -2530,7 +2569,7 @@ ath_init(struct net_device *dev)
 	 * Enable MIB interrupts when there are hardware phy counters.
 	 * Note we only do this (at the moment) for station mode.
 	 */
-	if (sc->sc_needmib && ic->ic_opmode == IEEE80211_M_STA)
+	if (sc->sc_needmib && ath_hal_getintmit(ah, NULL))
 		sc->sc_imask |= HAL_INT_MIB;
 	ath_hal_intrset(ah, sc->sc_imask);
 
@@ -2787,9 +2826,7 @@ ath_reset(struct net_device *dev)
 		EPRINTF(sc, "Unable to reset hardware: '%s' (HAL status %u)\n",
 			ath_get_hal_status_desc(status), status);
 
-	if ((sc->sc_opmode != HAL_M_STA) && sc->sc_hasintmit)
-		ath_hal_setintmit(ah, 0);
-
+	ath_setintmit(sc);
 	ath_update_txpow(sc);		/* update tx power state */
 	ath_radar_update(sc);
 	ath_setdefantenna(sc, sc->sc_defant);
@@ -4174,6 +4211,8 @@ ath_calcrxfilter(struct ath_softc *sc)
 	if (sc->sc_nmonvaps > 0)
 		rfilt |= (HAL_RX_FILTER_CONTROL | HAL_RX_FILTER_BEACON |
 			  HAL_RX_FILTER_PROBEREQ | HAL_RX_FILTER_PROM);
+	if (sc->sc_hasintmit && !sc->sc_needmib && ath_hal_getintmit(ah, NULL))
+		rfilt |= HAL_RX_FILTER_PHYERR;
 	if (sc->sc_curchan.privFlags & CHANNEL_DFS)
 		rfilt |= (HAL_RX_FILTER_PHYERR | HAL_RX_FILTER_PHYRADAR);
 	return rfilt;
@@ -6526,9 +6565,6 @@ process_rx_again:
 			rs->rs_rssi = 0;
 
 		len = rs->rs_datalen;
-		/* DMA sync. dies spectacularly if len == 0 */
-		if (len == 0)
-			goto rx_next;
 
 		if (rs->rs_more) {
 			/*
@@ -8876,9 +8912,7 @@ ath_chan_set(struct ath_softc *sc, struc
 		if (sc->sc_softled)
 			ath_hal_gpioCfgOutput(ah, sc->sc_ledpin);
 
-		if ((sc->sc_opmode != HAL_M_STA) && sc->sc_hasintmit)
-			ath_hal_setintmit(ah, 0);
-
+		ath_setintmit(sc);
 		sc->sc_curchan = hchan;
 		ath_update_txpow(sc);		/* update tx power state */
 		ath_radar_update(sc);
@@ -10655,9 +10689,54 @@ enum {
 	ATH_RP_IGNORED 		= 24,
 	ATH_RADAR_IGNORED       = 25,
 	ATH_MAXVAPS  		= 26,
+	ATH_INTMIT			= 27,
+	ATH_NOISE_IMMUNITY	= 28,
+	ATH_OFDM_WEAK_DET	= 29
 };
 
 static int
+ath_sysctl_set_intmit(struct ath_softc *sc, long ctl, u_int val)
+{
+	int ret;
+
+	switch(ctl) {
+	case ATH_INTMIT:
+		sc->sc_intmit = val;
+		break;
+	case ATH_NOISE_IMMUNITY:
+		sc->sc_noise_immunity = val;
+		break;
+	case ATH_OFDM_WEAK_DET:
+		sc->sc_ofdm_weak_det = val;
+		break;
+	default:
+		return -EINVAL;
+	}
+	ret = ath_setintmit(sc);
+	ath_calcrxfilter(sc);
+	return ret;
+}
+
+static int
+ath_sysctl_get_intmit(struct ath_softc *sc, long ctl, u_int *val)
+{
+	struct ath_hal *ah = sc->sc_ah;
+
+	switch(ctl) {
+	case ATH_INTMIT:
+		*val = (ath_hal_getcapability(ah, HAL_CAP_INTMIT, 1, NULL) == HAL_OK);
+		break;
+	case ATH_NOISE_IMMUNITY:
+		return ath_hal_getcapability(ah, HAL_CAP_INTMIT, 2, val);
+	case ATH_OFDM_WEAK_DET:
+		return ath_hal_getcapability(ah, HAL_CAP_INTMIT, 3, val);
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int
 ATH_SYSCTL_DECL(ath_sysctl_halparam, ctl, write, filp, buffer, lenp, ppos)
 {
 	struct ath_softc *sc = ctl->extra1;
@@ -10843,6 +10922,11 @@ ATH_SYSCTL_DECL(ath_sysctl_halparam, ctl
 			case ATH_RADAR_IGNORED:
 				sc->sc_radar_ignored = val;
 				break;
+			case ATH_INTMIT:
+			case ATH_NOISE_IMMUNITY:
+			case ATH_OFDM_WEAK_DET:
+				ret = ath_sysctl_set_intmit(sc, (long)ctl->extra2, val);
+				break;
 			default:
 				ret = -EINVAL;
 				break;
@@ -10909,6 +10993,11 @@ ATH_SYSCTL_DECL(ath_sysctl_halparam, ctl
 		case ATH_RADAR_IGNORED:
 			val = sc->sc_radar_ignored;
 			break;
+		case ATH_INTMIT:
+		case ATH_NOISE_IMMUNITY:
+		case ATH_OFDM_WEAK_DET:
+			ret = ath_sysctl_get_intmit(sc, (long)ctl->extra2, &val);
+			break;
 		default:
 			ret = -EINVAL;
 			break;
@@ -11086,6 +11175,24 @@ static const ctl_table ath_sysctl_templa
 	  .proc_handler = ath_sysctl_halparam,
 	  .extra2	= (void *)ATH_RADAR_IGNORED,
 	},
+	{ .ctl_name	= CTL_AUTO,
+	  .procname     = "intmit",
+	  .mode         = 0644,
+	  .proc_handler = ath_sysctl_halparam,
+	  .extra2	= (void *)ATH_INTMIT,
+	},
+	{ .ctl_name	= CTL_AUTO,
+	  .procname     = "noise_immunity",
+	  .mode         = 0644,
+	  .proc_handler = ath_sysctl_halparam,
+	  .extra2	= (void *)ATH_NOISE_IMMUNITY,
+	},
+	{ .ctl_name	= CTL_AUTO,
+	  .procname     = "ofdm_weak_det",
+	  .mode         = 0644,
+	  .proc_handler = ath_sysctl_halparam,
+	  .extra2	= (void *)ATH_OFDM_WEAK_DET,
+	},
 	{ 0 }
 };
 
--- a/ath/if_athvar.h
+++ b/ath/if_athvar.h
@@ -693,6 +693,10 @@ struct ath_softc {
 	unsigned int sc_txcont_power; /* Continuous transmit power in 0.5dBm units */
 	unsigned int sc_txcont_rate;  /* Continuous transmit rate in Mbps */
 
+	int8_t sc_intmit; /* Interference mitigation enabled, -1 = auto, based on mode, 0/1 = off/on */
+	int8_t sc_noise_immunity; /* Noise immunity level, 0-4, -1 == auto) */
+	int8_t sc_ofdm_weak_det; /* OFDM weak frames detection, -1 == auto */
+
 	/* rate tables */
 	const HAL_RATE_TABLE *sc_rates[IEEE80211_MODE_MAX];
 	const HAL_RATE_TABLE *sc_currates;	/* current rate table */
--- a/ath/if_ath_hal.h
+++ b/ath/if_ath_hal.h
@@ -67,14 +67,14 @@ static inline HAL_POWER_MODE ath_hal_get
 
 static inline HAL_BOOL ath_hal_getdiagstate(struct ath_hal *ah, int request,
 					    const void *args, u_int32_t argsize,
-					    void **result,
+					    void *result,
 					    u_int32_t *resultsize)
 {
 	HAL_BOOL ret;
 	ATH_HAL_LOCK_IRQ(ah->ah_sc);
 	ath_hal_set_function(__func__);
 	ret =
-	    ah->ah_getDiagState(ah, request, args, argsize, *result,
+	    ah->ah_getDiagState(ah, request, args, argsize, result,
 				resultsize);
 	ath_hal_set_function(NULL);
 	ATH_HAL_UNLOCK_IRQ(ah->ah_sc);
