diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index d9d2119f0828..3560881d17ee 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -146,9 +146,11 @@ struct ieee80211_low_level_stats {
 /**
  * enum ieee80211_chanctx_change - change flag for channel context
  * @IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE: The channel type was changed
+ * @IEEE80211_CHANCTX_CHANGE_RX_CHAINS: The number of RX chains changed
  */
 enum ieee80211_chanctx_change {
 	IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE	= BIT(0),
+	IEEE80211_CHANCTX_CHANGE_RX_CHAINS	= BIT(1),
 };
 
 /**
@@ -159,6 +161,11 @@ enum ieee80211_chanctx_change {
  *
  * @channel: the channel to tune to
  * @channel_type: the channel (HT) type
+ * @rx_chains_static: The number of RX chains that must always be
+ *	active on the channel to receive MIMO transmissions
+ * @rx_chains_dynamic: The number of RX chains that must be enabled
+ *	after RTS/CTS handshake to receive SMPS MIMO transmissions;
+ *	this will always be >= @rx_chains_always.
  * @drv_priv: data area for driver use, will always be aligned to
  *	sizeof(void *), size is determined in hw information.
  */
@@ -166,6 +173,8 @@ struct ieee80211_chanctx_conf {
 	struct ieee80211_channel *channel;
 	enum nl80211_channel_type channel_type;
 
+	u8 rx_chains_static, rx_chains_dynamic;
+
 	u8 drv_priv[0] __attribute__((__aligned__(sizeof(void *))));
 };
 
@@ -820,6 +829,8 @@ enum ieee80211_conf_flags {
  * @IEEE80211_CONF_CHANGE_RETRY_LIMITS: retry limits changed
  * @IEEE80211_CONF_CHANGE_IDLE: Idle flag changed
  * @IEEE80211_CONF_CHANGE_SMPS: Spatial multiplexing powersave mode changed
+ *	Note that this is only valid if channel contexts are not used,
+ *	otherwise each channel context has the number of chains listed.
  */
 enum ieee80211_conf_changed {
 	IEEE80211_CONF_CHANGE_SMPS		= BIT(1),
@@ -885,7 +896,9 @@ enum ieee80211_smps_mode {
  *
  * @smps_mode: spatial multiplexing powersave mode; note that
  *	%IEEE80211_SMPS_STATIC is used when the device is not
- *	configured for an HT channel
+ *	configured for an HT channel.
+ *	Note that this is only valid if channel contexts are not used,
+ *	otherwise each channel context has the number of chains listed.
  */
 struct ieee80211_conf {
 	u32 flags;
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 09c90627fd19..03216b0408c7 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -884,6 +884,10 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	if (old)
 		return -EALREADY;
 
+	/* TODO: make hostapd tell us what it wants */
+	sdata->smps_mode = IEEE80211_SMPS_OFF;
+	sdata->needed_rx_chains = sdata->local->rx_chains;
+
 	err = ieee80211_vif_use_channel(sdata, params->channel,
 					params->channel_type,
 					IEEE80211_CHANCTX_SHARED);
@@ -1673,6 +1677,10 @@ static int ieee80211_join_mesh(struct wiphy *wiphy, struct net_device *dev,
 	if (err)
 		return err;
 
+	/* can mesh use other SMPS modes? */
+	sdata->smps_mode = IEEE80211_SMPS_OFF;
+	sdata->needed_rx_chains = sdata->local->rx_chains;
+
 	err = ieee80211_vif_use_channel(sdata, setup->channel,
 					setup->channel_type,
 					IEEE80211_CHANCTX_SHARED);
@@ -2052,13 +2060,12 @@ int __ieee80211_request_smps(struct ieee80211_sub_if_data *sdata,
 
 	/*
 	 * If not associated, or current association is not an HT
-	 * association, there's no need to send an action frame.
+	 * association, there's no need to do anything, just store
+	 * the new value until we associate.
 	 */
 	if (!sdata->u.mgd.associated ||
-	    sdata->vif.bss_conf.channel_type == NL80211_CHAN_NO_HT) {
-		ieee80211_recalc_smps(sdata->local);
+	    sdata->vif.bss_conf.channel_type == NL80211_CHAN_NO_HT)
 		return 0;
-	}
 
 	ap = sdata->u.mgd.associated->bssid;
 
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 41e1aa69f7aa..bfaa486d928c 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -118,6 +118,8 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
 
 	ctx->conf.channel = channel;
 	ctx->conf.channel_type = channel_type;
+	ctx->conf.rx_chains_static = 1;
+	ctx->conf.rx_chains_dynamic = 1;
 	ctx->mode = mode;
 
 	if (!local->use_chanctx) {
@@ -222,8 +224,10 @@ static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 
 	drv_unassign_vif_chanctx(local, sdata, ctx);
 
-	if (ctx->refcount > 0)
+	if (ctx->refcount > 0) {
 		ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
+		ieee80211_recalc_smps_chanctx(local, ctx);
+	}
 }
 
 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
@@ -246,6 +250,89 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 		ieee80211_free_chanctx(local, ctx);
 }
 
+void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
+				   struct ieee80211_chanctx *chanctx)
+{
+	struct ieee80211_sub_if_data *sdata;
+	u8 rx_chains_static, rx_chains_dynamic;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	rx_chains_static = 1;
+	rx_chains_dynamic = 1;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		u8 needed_static, needed_dynamic;
+
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
+						&chanctx->conf)
+			continue;
+
+		switch (sdata->vif.type) {
+		case NL80211_IFTYPE_P2P_DEVICE:
+			continue;
+		case NL80211_IFTYPE_STATION:
+			if (!sdata->u.mgd.associated)
+				continue;
+			break;
+		case NL80211_IFTYPE_AP_VLAN:
+			continue;
+		case NL80211_IFTYPE_AP:
+		case NL80211_IFTYPE_ADHOC:
+		case NL80211_IFTYPE_WDS:
+		case NL80211_IFTYPE_MESH_POINT:
+			break;
+		default:
+			WARN_ON_ONCE(1);
+		}
+
+		switch (sdata->smps_mode) {
+		default:
+			WARN_ONCE(1, "Invalid SMPS mode %d\n",
+				  sdata->smps_mode);
+			/* fall through */
+		case IEEE80211_SMPS_OFF:
+			needed_static = sdata->needed_rx_chains;
+			needed_dynamic = sdata->needed_rx_chains;
+			break;
+		case IEEE80211_SMPS_DYNAMIC:
+			needed_static = 1;
+			needed_dynamic = sdata->needed_rx_chains;
+			break;
+		case IEEE80211_SMPS_STATIC:
+			needed_static = 1;
+			needed_dynamic = 1;
+			break;
+		}
+
+		rx_chains_static = max(rx_chains_static, needed_static);
+		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
+	}
+	rcu_read_unlock();
+
+	if (!local->use_chanctx) {
+		if (rx_chains_static > 1)
+			local->smps_mode = IEEE80211_SMPS_OFF;
+		else if (rx_chains_dynamic > 1)
+			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
+		else
+			local->smps_mode = IEEE80211_SMPS_STATIC;
+		ieee80211_hw_config(local, 0);
+	}
+
+	if (rx_chains_static == chanctx->conf.rx_chains_static &&
+	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
+		return;
+
+	chanctx->conf.rx_chains_static = rx_chains_static;
+	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
+	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
+}
+
 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 			      struct ieee80211_channel *channel,
 			      enum nl80211_channel_type channel_type,
@@ -278,6 +365,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 		goto out;
 	}
 
+	ieee80211_recalc_smps_chanctx(local, ctx);
  out:
 	mutex_unlock(&local->chanctx_mtx);
 	return ret;
diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index 6d5aec9418ee..34e173976573 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -217,7 +217,7 @@ static ssize_t ieee80211_if_fmt_smps(const struct ieee80211_sub_if_data *sdata,
 
 	return snprintf(buf, buflen, "request: %s\nused: %s\n",
 			smps_modes[sdata->u.mgd.req_smps],
-			smps_modes[sdata->u.mgd.ap_smps]);
+			smps_modes[sdata->smps_mode]);
 }
 
 static ssize_t ieee80211_if_parse_smps(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 34d9235117d9..291c9e07f1bd 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -1132,6 +1132,9 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 	changed |= BSS_CHANGED_HT;
 	ieee80211_bss_info_change_notify(sdata, changed);
 
+	sdata->smps_mode = IEEE80211_SMPS_OFF;
+	sdata->needed_rx_chains = sdata->local->rx_chains;
+
 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 
 	return 0;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 6660118b46b3..132577d22928 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -433,7 +433,6 @@ struct ieee80211_if_managed {
 	bool powersave; /* powersave requested for this iface */
 	bool broken_ap; /* AP is broken -- turn off powersave */
 	enum ieee80211_smps_mode req_smps, /* requested smps mode */
-				 ap_smps, /* smps mode AP thinks we're in */
 				 driver_smps_mode; /* smps mode request */
 
 	struct work_struct request_smps_work;
@@ -728,11 +727,17 @@ struct ieee80211_sub_if_data {
 
 	struct ieee80211_tx_queue_params tx_conf[IEEE80211_NUM_ACS];
 
+	/* used to reconfigure hardware SM PS */
+	struct work_struct recalc_smps;
+
 	struct work_struct work;
 	struct sk_buff_head skb_queue;
 
 	bool arp_filter_state;
 
+	u8 needed_rx_chains;
+	enum ieee80211_smps_mode smps_mode;
+
 	/*
 	 * AP this belongs to: self in AP mode and
 	 * corresponding AP in VLAN mode, NULL for
@@ -905,9 +910,6 @@ struct ieee80211_local {
 	/* used for uploading changed mc list */
 	struct work_struct reconfig_filter;
 
-	/* used to reconfigure hardware SM PS */
-	struct work_struct recalc_smps;
-
 	/* aggregated multicast list */
 	struct netdev_hw_addr_list mc_list;
 
@@ -944,6 +946,9 @@ struct ieee80211_local {
 	/* wowlan is enabled -- don't reconfig on resume */
 	bool wowlan;
 
+	/* number of RX chains the hardware has */
+	u8 rx_chains;
+
 	int tx_headroom; /* required headroom for hardware/radiotap */
 
 	/* Tasklet and skb queue to process calls from IRQ mode. All frames
@@ -1408,6 +1413,8 @@ void ieee80211_ba_session_work(struct work_struct *work);
 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid);
 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid);
 
+u8 ieee80211_mcs_to_chains(const struct ieee80211_mcs_info *mcs);
+
 /* Spectrum management */
 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 				       struct ieee80211_mgmt *mgmt,
@@ -1554,7 +1561,7 @@ u32 ieee80211_sta_get_rates(struct ieee80211_local *local,
 			    enum ieee80211_band band, u32 *basic_rates);
 int __ieee80211_request_smps(struct ieee80211_sub_if_data *sdata,
 			     enum ieee80211_smps_mode smps_mode);
-void ieee80211_recalc_smps(struct ieee80211_local *local);
+void ieee80211_recalc_smps(struct ieee80211_sub_if_data *sdata);
 
 size_t ieee80211_ie_split(const u8 *ies, size_t ielen,
 			  const u8 *ids, int n_ids, size_t offset);
@@ -1585,6 +1592,9 @@ ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 			  enum ieee80211_chanctx_mode mode);
 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata);
 
+void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
+				   struct ieee80211_chanctx *chanctx);
+
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
 #else
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 7cb8382b19e5..99f2b19c8f0d 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -739,6 +739,8 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 	del_timer_sync(&local->dynamic_ps_timer);
 	cancel_work_sync(&local->dynamic_ps_enable_work);
 
+	cancel_work_sync(&sdata->recalc_smps);
+
 	/* APs need special treatment */
 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
 		struct ieee80211_sub_if_data *vlan, *tmpsdata;
@@ -1125,6 +1127,13 @@ static void ieee80211_iface_work(struct work_struct *work)
 	}
 }
 
+static void ieee80211_recalc_smps_work(struct work_struct *work)
+{
+	struct ieee80211_sub_if_data *sdata =
+		container_of(work, struct ieee80211_sub_if_data, recalc_smps);
+
+	ieee80211_recalc_smps(sdata);
+}
 
 /*
  * Helper function to initialise an interface to a specific type.
@@ -1153,6 +1162,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 
 	skb_queue_head_init(&sdata->skb_queue);
 	INIT_WORK(&sdata->work, ieee80211_iface_work);
+	INIT_WORK(&sdata->recalc_smps, ieee80211_recalc_smps_work);
 
 	switch (type) {
 	case NL80211_IFTYPE_P2P_GO:
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 9cb6280aa2f2..2c8969b67851 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -372,14 +372,6 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw)
 }
 EXPORT_SYMBOL(ieee80211_restart_hw);
 
-static void ieee80211_recalc_smps_work(struct work_struct *work)
-{
-	struct ieee80211_local *local =
-		container_of(work, struct ieee80211_local, recalc_smps);
-
-	ieee80211_recalc_smps(local);
-}
-
 #ifdef CONFIG_INET
 static int ieee80211_ifa_changed(struct notifier_block *nb,
 				 unsigned long data, void *arg)
@@ -667,7 +659,6 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 	INIT_WORK(&local->restart_work, ieee80211_restart_work);
 
 	INIT_WORK(&local->reconfig_filter, ieee80211_reconfig_filter);
-	INIT_WORK(&local->recalc_smps, ieee80211_recalc_smps_work);
 	local->smps_mode = IEEE80211_SMPS_OFF;
 
 	INIT_WORK(&local->dynamic_ps_enable_work,
@@ -773,6 +764,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	if (hw->max_report_rates == 0)
 		hw->max_report_rates = hw->max_rates;
 
+	local->rx_chains = 1;
+
 	/*
 	 * generic code guarantees at least one band,
 	 * set this very early because much code assumes
@@ -804,6 +797,13 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 			max_bitrates = sband->n_bitrates;
 		supp_ht = supp_ht || sband->ht_cap.ht_supported;
 		supp_vht = supp_vht || sband->vht_cap.vht_supported;
+
+		if (sband->ht_cap.ht_supported)
+			local->rx_chains =
+				max(ieee80211_mcs_to_chains(&sband->ht_cap.mcs),
+				    local->rx_chains);
+
+		/* TODO: consider VHT for RX chains, hopefully it's the same */
 	}
 
 	local->int_scan_req = kzalloc(sizeof(*local->int_scan_req) +
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 4add50063161..f3f338541b01 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -543,7 +543,7 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 
 	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
 		ieee80211_add_ht_ie(sdata, skb, assoc_data->ap_ht_param,
-				    sband, chan, ifmgd->ap_smps);
+				    sband, chan, sdata->smps_mode);
 
 	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
 		ieee80211_add_vht_ie(sdata, skb, sband);
@@ -1392,7 +1392,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 	ieee80211_recalc_ps(local, -1);
 	mutex_unlock(&local->iflist_mtx);
 
-	ieee80211_recalc_smps(local);
+	ieee80211_recalc_smps(sdata);
 	ieee80211_recalc_ps_vif(sdata);
 
 	netif_tx_start_all_queues(sdata->dev);
@@ -3157,6 +3157,10 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 	}
 
 	if (ht_oper) {
+		const u8 *ht_cap_ie;
+		const struct ieee80211_ht_cap *ht_cap;
+		u8 chains = 1;
+
 		channel_type = NL80211_CHAN_HT20;
 
 		if (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) {
@@ -3170,8 +3174,22 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 				break;
 			}
 		}
+
+		ht_cap_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY,
+					     cbss->information_elements,
+					     cbss->len_information_elements);
+		if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap)) {
+			ht_cap = (void *)(ht_cap_ie + 2);
+			chains = ieee80211_mcs_to_chains(&ht_cap->mcs);
+		}
+		sdata->needed_rx_chains = min(chains, local->rx_chains);
+	} else {
+		sdata->needed_rx_chains = 1;
 	}
 
+	/* will change later if needed */
+	sdata->smps_mode = IEEE80211_SMPS_OFF;
+
 	ieee80211_vif_release_channel(sdata);
 	return ieee80211_vif_use_channel(sdata, cbss->channel, channel_type,
 					 IEEE80211_CHANCTX_SHARED);
@@ -3485,11 +3503,11 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 
 	if (ifmgd->req_smps == IEEE80211_SMPS_AUTOMATIC) {
 		if (ifmgd->powersave)
-			ifmgd->ap_smps = IEEE80211_SMPS_DYNAMIC;
+			sdata->smps_mode = IEEE80211_SMPS_DYNAMIC;
 		else
-			ifmgd->ap_smps = IEEE80211_SMPS_OFF;
+			sdata->smps_mode = IEEE80211_SMPS_OFF;
 	} else
-		ifmgd->ap_smps = ifmgd->req_smps;
+		sdata->smps_mode = ifmgd->req_smps;
 
 	assoc_data->capability = req->bss->capability;
 	assoc_data->wmm = bss->wmm_used &&
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 3af0cc4130f1..21fa5c72ea14 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -189,30 +189,31 @@ static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
 	}
 
 	if (ieee80211_is_action(mgmt->frame_control) &&
-	    sdata->vif.type == NL80211_IFTYPE_STATION &&
 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
-	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) {
+	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
+	    sdata->vif.type == NL80211_IFTYPE_STATION &&
+	    ieee80211_sdata_running(sdata)) {
 		/*
 		 * This update looks racy, but isn't -- if we come
 		 * here we've definitely got a station that we're
 		 * talking to, and on a managed interface that can
 		 * only be the AP. And the only other place updating
-		 * this variable is before we're associated.
+		 * this variable in managed mode is before association.
 		 */
 		switch (mgmt->u.action.u.ht_smps.smps_control) {
 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
-			sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC;
+			sdata->smps_mode = IEEE80211_SMPS_DYNAMIC;
 			break;
 		case WLAN_HT_SMPS_CONTROL_STATIC:
-			sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC;
+			sdata->smps_mode = IEEE80211_SMPS_STATIC;
 			break;
 		case WLAN_HT_SMPS_CONTROL_DISABLED:
 		default: /* shouldn't happen since we don't send that */
-			sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF;
+			sdata->smps_mode = IEEE80211_SMPS_OFF;
 			break;
 		}
 
-		ieee80211_queue_work(&local->hw, &local->recalc_smps);
+		ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
 	}
 }
 
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index a3f5fe2a84a8..629364705f7b 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -29,11 +29,16 @@
 #define VIF_PR_ARG	__get_str(vif_name), __entry->vif_type, __entry->p2p ? "/p2p" : ""
 
 #define CHANCTX_ENTRY	__field(int, freq)					\
-			__field(int, chantype)
+			__field(int, chantype)					\
+			__field(u8, rx_chains_static)				\
+			__field(u8, rx_chains_dynamic)
 #define CHANCTX_ASSIGN	__entry->freq = ctx->conf.channel->center_freq;		\
-			__entry->chantype = ctx->conf.channel_type
-#define CHANCTX_PR_FMT	" freq:%d MHz chantype:%d"
-#define CHANCTX_PR_ARG	__entry->freq, __entry->chantype
+			__entry->chantype = ctx->conf.channel_type;		\
+			__entry->rx_chains_static = ctx->conf.rx_chains_static;	\
+			__entry->rx_chains_dynamic = ctx->conf.rx_chains_dynamic
+#define CHANCTX_PR_FMT	" freq:%d MHz chantype:%d chains:%d/%d"
+#define CHANCTX_PR_ARG	__entry->freq, __entry->chantype,			\
+			__entry->rx_chains_static, __entry->rx_chains_dynamic
 
 
 
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 7d737071dedb..b732e219b107 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1618,68 +1618,24 @@ void ieee80211_resume_disconnect(struct ieee80211_vif *vif)
 }
 EXPORT_SYMBOL_GPL(ieee80211_resume_disconnect);
 
-static int check_mgd_smps(struct ieee80211_if_managed *ifmgd,
-			  enum ieee80211_smps_mode *smps_mode)
+void ieee80211_recalc_smps(struct ieee80211_sub_if_data *sdata)
 {
-	if (ifmgd->associated) {
-		*smps_mode = ifmgd->ap_smps;
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_chanctx *chanctx;
 
-		if (*smps_mode == IEEE80211_SMPS_AUTOMATIC) {
-			if (ifmgd->powersave)
-				*smps_mode = IEEE80211_SMPS_DYNAMIC;
-			else
-				*smps_mode = IEEE80211_SMPS_OFF;
-		}
+	mutex_lock(&local->chanctx_mtx);
 
-		return 1;
-	}
+	chanctx_conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+					lockdep_is_held(&local->chanctx_mtx));
 
-	return 0;
-}
-
-void ieee80211_recalc_smps(struct ieee80211_local *local)
-{
-	struct ieee80211_sub_if_data *sdata;
-	enum ieee80211_smps_mode smps_mode = IEEE80211_SMPS_OFF;
-	int count = 0;
-
-	mutex_lock(&local->iflist_mtx);
-
-	/*
-	 * This function could be improved to handle multiple
-	 * interfaces better, but right now it makes any
-	 * non-station interfaces force SM PS to be turned
-	 * off. If there are multiple station interfaces it
-	 * could also use the best possible mode, e.g. if
-	 * one is in static and the other in dynamic then
-	 * dynamic is ok.
-	 */
-
-	list_for_each_entry(sdata, &local->interfaces, list) {
-		if (!ieee80211_sdata_running(sdata))
-			continue;
-		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
-			continue;
-		if (sdata->vif.type != NL80211_IFTYPE_STATION)
-			goto set;
-
-		count += check_mgd_smps(&sdata->u.mgd, &smps_mode);
-
-		if (count > 1) {
-			smps_mode = IEEE80211_SMPS_OFF;
-			break;
-		}
-	}
-
-	if (smps_mode == local->smps_mode)
+	if (WARN_ON_ONCE(!chanctx_conf))
 		goto unlock;
 
- set:
-	local->smps_mode = smps_mode;
-	/* changed flag is auto-detected for this */
-	ieee80211_hw_config(local, 0);
+	chanctx = container_of(chanctx_conf, struct ieee80211_chanctx, conf);
+	ieee80211_recalc_smps_chanctx(local, chanctx);
  unlock:
-	mutex_unlock(&local->iflist_mtx);
+	mutex_unlock(&local->chanctx_mtx);
 }
 
 static bool ieee80211_id_in_list(const u8 *ids, int n_ids, u8 id)
@@ -1978,3 +1934,19 @@ int ieee80211_ave_rssi(struct ieee80211_vif *vif)
 	return ifmgd->ave_beacon_signal;
 }
 EXPORT_SYMBOL_GPL(ieee80211_ave_rssi);
+
+u8 ieee80211_mcs_to_chains(const struct ieee80211_mcs_info *mcs)
+{
+	if (!mcs)
+		return 1;
+
+	/* TODO: consider rx_highest */
+
+	if (mcs->rx_mask[3])
+		return 4;
+	if (mcs->rx_mask[2])
+		return 3;
+	if (mcs->rx_mask[1])
+		return 2;
+	return 1;
+}