ath10k: add hw connection monitor support

Some firmware revisions (e.g. qca6174 with fw73)
don't deliver beacons to host reliably. This
causes random disconnects even in perfect
conditions. This is most visible with
multi-channel operation.

All available firmware revisions seem to support
beacon miss offloading so there shouldn't be any
problems.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/core.h

@@ -43,6 +43,7 @@
 #define ATH10K_SCAN_ID 0
 #define WMI_READY_TIMEOUT (5 * HZ)
 #define ATH10K_FLUSH_TIMEOUT_HZ (5*HZ)
+#define ATH10K_CONNECTION_LOSS_HZ (3*HZ)
 #define ATH10K_NUM_CHANS 38
 
 /* Antenna noise floor */
@@ -342,6 +343,7 @@ struct ath10k_vif {
 	int txpower;
 	struct wmi_wmm_params_all_arg wmm_params;
 	struct work_struct ap_csa_work;
+	struct delayed_work connection_loss_work;
 };
 
 struct ath10k_vif_iter {

drivers/net/wireless/ath/ath10k/mac.c

@@ -1509,6 +1509,75 @@ static void ath10k_mac_vif_ap_csa_work(struct work_struct *work)
 	mutex_unlock(&ar->conf_mutex);
 }
 
+static void ath10k_mac_handle_beacon_iter(void *data, u8 *mac,
+					  struct ieee80211_vif *vif)
+{
+	struct sk_buff *skb = data;
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	struct ath10k_vif *arvif = ath10k_vif_to_arvif(vif);
+
+	if (vif->type != NL80211_IFTYPE_STATION)
+		return;
+
+	if (!ether_addr_equal(mgmt->bssid, vif->bss_conf.bssid))
+		return;
+
+	cancel_delayed_work(&arvif->connection_loss_work);
+}
+
+void ath10k_mac_handle_beacon(struct ath10k *ar, struct sk_buff *skb)
+{
+	ieee80211_iterate_active_interfaces_atomic(ar->hw,
+						   IEEE80211_IFACE_ITER_NORMAL,
+						   ath10k_mac_handle_beacon_iter,
+						   skb);
+}
+
+static void ath10k_mac_handle_beacon_miss_iter(void *data, u8 *mac,
+					       struct ieee80211_vif *vif)
+{
+	u32 *vdev_id = data;
+	struct ath10k_vif *arvif = ath10k_vif_to_arvif(vif);
+	struct ath10k *ar = arvif->ar;
+	struct ieee80211_hw *hw = ar->hw;
+
+	if (arvif->vdev_id != *vdev_id)
+		return;
+
+	if (!arvif->is_up)
+		return;
+
+	ieee80211_beacon_loss(vif);
+
+	/* Firmware doesn't report beacon loss events repeatedly. If AP probe
+	 * (done by mac80211) succeeds but beacons do not resume then it
+	 * doesn't make sense to continue operation. Queue connection loss work
+	 * which can be cancelled when beacon is received.
+	 */
+	ieee80211_queue_delayed_work(hw, &arvif->connection_loss_work,
+				     ATH10K_CONNECTION_LOSS_HZ);
+}
+
+void ath10k_mac_handle_beacon_miss(struct ath10k *ar, u32 vdev_id)
+{
+	ieee80211_iterate_active_interfaces_atomic(ar->hw,
+						   IEEE80211_IFACE_ITER_NORMAL,
+						   ath10k_mac_handle_beacon_miss_iter,
+						   &vdev_id);
+}
+
+static void ath10k_mac_vif_sta_connection_loss_work(struct work_struct *work)
+{
+	struct ath10k_vif *arvif = container_of(work, struct ath10k_vif,
+						connection_loss_work.work);
+	struct ieee80211_vif *vif = arvif->vif;
+
+	if (!arvif->is_up)
+		return;
+
+	ieee80211_connection_loss(vif);
+}
+
 /**********************/
 /* Station management */
 /**********************/
@@ -2140,6 +2209,8 @@ static void ath10k_bss_disassoc(struct ieee80211_hw *hw,
 	}
 
 	arvif->is_up = false;
+
+	cancel_delayed_work_sync(&arvif->connection_loss_work);
 }
 
 static int ath10k_station_assoc(struct ath10k *ar,
@@ -3378,6 +3449,8 @@ static int ath10k_add_interface(struct ieee80211_hw *hw,
 
 	INIT_LIST_HEAD(&arvif->list);
 	INIT_WORK(&arvif->ap_csa_work, ath10k_mac_vif_ap_csa_work);
+	INIT_DELAYED_WORK(&arvif->connection_loss_work,
+			  ath10k_mac_vif_sta_connection_loss_work);
 
 	if (ar->free_vdev_map == 0) {
 		ath10k_warn(ar, "Free vdev map is empty, no more interfaces allowed.\n");
@@ -3596,6 +3669,7 @@ static void ath10k_remove_interface(struct ieee80211_hw *hw,
 	int ret;
 
 	cancel_work_sync(&arvif->ap_csa_work);
+	cancel_delayed_work_sync(&arvif->connection_loss_work);
 
 	mutex_lock(&ar->conf_mutex);
 
@@ -5727,7 +5801,8 @@ int ath10k_mac_register(struct ath10k *ar)
 			IEEE80211_HW_HAS_RATE_CONTROL |
 			IEEE80211_HW_AP_LINK_PS |
 			IEEE80211_HW_SPECTRUM_MGMT |
-			IEEE80211_HW_SW_CRYPTO_CONTROL;
+			IEEE80211_HW_SW_CRYPTO_CONTROL |
+			IEEE80211_HW_CONNECTION_MONITOR;
 
 	ar->hw->wiphy->features |= NL80211_FEATURE_STATIC_SMPS;
 

drivers/net/wireless/ath/ath10k/mac.h

@@ -45,6 +45,8 @@ void ath10k_mac_vif_beacon_free(struct ath10k_vif *arvif);
 void ath10k_drain_tx(struct ath10k *ar);
 bool ath10k_mac_is_peer_wep_key_set(struct ath10k *ar, const u8 *addr,
 				    u8 keyidx);
+void ath10k_mac_handle_beacon(struct ath10k *ar, struct sk_buff *skb);
+void ath10k_mac_handle_beacon_miss(struct ath10k *ar, u32 vdev_id);
 
 static inline struct ath10k_vif *ath10k_vif_to_arvif(struct ieee80211_vif *vif)
 {

drivers/net/wireless/ath/ath10k/wmi.c

@@ -1586,6 +1586,9 @@ int ath10k_wmi_event_mgmt_rx(struct ath10k *ar, struct sk_buff *skb)
 		}
 	}
 
+	if (ieee80211_is_beacon(hdr->frame_control))
+		ath10k_mac_handle_beacon(ar, skb);
+
 	ath10k_dbg(ar, ATH10K_DBG_MGMT,
 		   "event mgmt rx skb %p len %d ftype %02x stype %02x\n",
 		   skb, skb->len,
@@ -2815,8 +2818,10 @@ void ath10k_wmi_event_roam(struct ath10k *ar, struct sk_buff *skb)
 			    reason, vdev_id);
 
 	switch (reason) {
-	case WMI_ROAM_REASON_BETTER_AP:
 	case WMI_ROAM_REASON_BEACON_MISS:
+		ath10k_mac_handle_beacon_miss(ar, vdev_id);
+		break;
+	case WMI_ROAM_REASON_BETTER_AP:
 	case WMI_ROAM_REASON_LOW_RSSI:
 	case WMI_ROAM_REASON_SUITABLE_AP_FOUND:
 	case WMI_ROAM_REASON_HO_FAILED: