wifi: iwlwifi: mvm: exit EMLSR upon missed beacon

In case of more than 6 missed beacons on one of the links,
exit EMLSR by deactivating that link.
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240416134215.f9111c79cb53.Ie95ea60149a9bc4367f6b338b37c8635051351ba@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/constants.h

 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
 /*
  * Copyright (C) 2013-2015 Intel Mobile Communications GmbH
- * Copyright (C) 2013-2014, 2018-2023 Intel Corporation
+ * Copyright (C) 2013-2014, 2018-2024 Intel Corporation
  * Copyright (C) 2015 Intel Deutschland GmbH
  */
 #ifndef __MVM_CONSTANTS_H
@@ -123,5 +123,6 @@
 #define IWL_MVM_6GHZ_PASSIVE_SCAN_TIMEOUT       3000 /* in seconds */
 #define IWL_MVM_6GHZ_PASSIVE_SCAN_ASSOC_TIMEOUT 60   /* in seconds */
 #define IWL_MVM_AUTO_EML_ENABLE                 true
+#define IWL_MVM_MISSED_BEACONS_EXIT_ESR_THRESH	7
 
 #endif /* __MVM_CONSTANTS_H */

drivers/net/wireless/intel/iwlwifi/mvm/link.c

@@ -527,6 +527,7 @@ u8 iwl_mvm_set_link_selection_data(struct ieee80211_vif *vif,
 	u16 max_grade = 0;
 	unsigned long link_id;
 
+	/* TODO: don't select links that weren't discovered in the last scan */
 	for_each_set_bit(link_id, &usable_links, IEEE80211_MLD_MAX_NUM_LINKS) {
 		struct ieee80211_bss_conf *link_conf =
 			link_conf_dereference_protected(vif, link_id);
@@ -692,6 +693,25 @@ u8 iwl_mvm_get_primary_link(struct ieee80211_vif *vif)
 	return __ffs(vif->active_links);
 }
 
+/*
+ * For non-MLO/single link, this will return the deflink/single active link,
+ * respectively
+ */
+u8 iwl_mvm_get_other_link(struct ieee80211_vif *vif, u8 link_id)
+{
+	switch (hweight16(vif->active_links)) {
+	case 0:
+		return 0;
+	default:
+		WARN_ON(1);
+		fallthrough;
+	case 1:
+		return __ffs(vif->active_links);
+	case 2:
+		return __ffs(vif->active_links & ~BIT(link_id));
+	}
+}
+
 /* API to exit eSR mode */
 void iwl_mvm_exit_esr(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 		      enum iwl_mvm_esr_state reason,
@@ -720,8 +740,6 @@ void iwl_mvm_exit_esr(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 	ieee80211_set_active_links_async(vif, new_active_links);
 }
 
-#define IWL_MVM_BLOCK_ESR_REASONS IWL_MVM_ESR_BLOCKED_COEX
-
 void iwl_mvm_block_esr(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 		       enum iwl_mvm_esr_state reason,
 		       u8 link_to_keep)

drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c

@@ -1591,23 +1591,23 @@ void iwl_mvm_rx_missed_beacons_notif(struct iwl_mvm *mvm,
 	u32 id = le32_to_cpu(mb->link_id);
 	union iwl_dbg_tlv_tp_data tp_data = { .fw_pkt = pkt };
 	u32 mac_type;
+	int link_id = -1;
 	u8 notif_ver = iwl_fw_lookup_notif_ver(mvm->fw, LEGACY_GROUP,
 					       MISSED_BEACONS_NOTIFICATION,
 					       0);
 
-	rcu_read_lock();
-
 	/* before version four the ID in the notification refers to mac ID */
 	if (notif_ver < 4) {
-		vif = iwl_mvm_rcu_dereference_vif_id(mvm, id, true);
+		vif = iwl_mvm_rcu_dereference_vif_id(mvm, id, false);
 	} else {
 		struct ieee80211_bss_conf *bss_conf =
-			iwl_mvm_rcu_fw_link_id_to_link_conf(mvm, id, true);
+			iwl_mvm_rcu_fw_link_id_to_link_conf(mvm, id, false);
 
 		if (!bss_conf)
-			goto out;
+			return;
 
 		vif = bss_conf->vif;
+		link_id = bss_conf->link_id;
 	}
 
 	IWL_DEBUG_INFO(mvm,
@@ -1620,7 +1620,7 @@ void iwl_mvm_rx_missed_beacons_notif(struct iwl_mvm *mvm,
 		       le32_to_cpu(mb->num_expected_beacons));
 
 	if (!vif)
-		goto out;
+		return;
 
 	mac_type = iwl_mvm_get_mac_type(vif);
 
@@ -1647,6 +1647,10 @@ void iwl_mvm_rx_missed_beacons_notif(struct iwl_mvm *mvm,
 				 "missed_beacons:%d, missed_beacons_since_rx:%d\n",
 				 rx_missed_bcon, rx_missed_bcon_since_rx);
 		}
+	} else if (rx_missed_bcon >= IWL_MVM_MISSED_BEACONS_EXIT_ESR_THRESH &&
+		   link_id >= 0 && hweight16(vif->active_links) > 1) {
+		iwl_mvm_exit_esr(mvm, vif, IWL_MVM_ESR_EXIT_MISSED_BEACON,
+				 iwl_mvm_get_other_link(vif, link_id));
 	} else if (rx_missed_bcon_since_rx > IWL_MVM_MISSED_BEACONS_THRESHOLD) {
 		if (!iwl_mvm_has_new_tx_api(mvm))
 			ieee80211_beacon_loss(vif);
@@ -1660,7 +1664,7 @@ void iwl_mvm_rx_missed_beacons_notif(struct iwl_mvm *mvm,
 	trigger = iwl_fw_dbg_trigger_on(&mvm->fwrt, ieee80211_vif_to_wdev(vif),
 					FW_DBG_TRIGGER_MISSED_BEACONS);
 	if (!trigger)
-		goto out;
+		return;
 
 	bcon_trig = (void *)trigger->data;
 	stop_trig_missed_bcon = le32_to_cpu(bcon_trig->stop_consec_missed_bcon);
@@ -1672,9 +1676,6 @@ void iwl_mvm_rx_missed_beacons_notif(struct iwl_mvm *mvm,
 	if (rx_missed_bcon_since_rx >= stop_trig_missed_bcon_since_rx ||
 	    rx_missed_bcon >= stop_trig_missed_bcon)
 		iwl_fw_dbg_collect_trig(&mvm->fwrt, trigger, NULL);
-
-out:
-	rcu_read_unlock();
 }
 
 void iwl_mvm_rx_stored_beacon_notif(struct iwl_mvm *mvm,

drivers/net/wireless/intel/iwlwifi/mvm/mvm.h

@@ -354,11 +354,15 @@ struct iwl_mvm_vif_link_info {
  * reasons - use iwl_mvm_exit_esr().
  *
  * @IWL_MVM_ESR_BLOCKED_COEX: COEX is preventing the enablement of EMLSR
+ * @IWL_MVM_ESR_EXIT_MISSED_BEACON: exited EMLSR due to missed beacons
  */
 enum iwl_mvm_esr_state {
 	IWL_MVM_ESR_BLOCKED_COEX	= 0x1,
+	IWL_MVM_ESR_EXIT_MISSED_BEACON	= 0x10000,
 };
 
+#define IWL_MVM_BLOCK_ESR_REASONS 0xffff
+
 /**
  * struct iwl_mvm_vif - data per Virtual Interface, it is a MAC context
  * @mvm: pointer back to the mvm struct
@@ -1963,6 +1967,7 @@ int iwl_mvm_disable_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 
 void iwl_mvm_select_links(struct iwl_mvm *mvm, struct ieee80211_vif *vif);
 u8 iwl_mvm_get_primary_link(struct ieee80211_vif *vif);
+u8 iwl_mvm_get_other_link(struct ieee80211_vif *vif, u8 link_id);
 
 #if IS_ENABLED(CONFIG_IWLWIFI_KUNIT_TESTS)
 unsigned int iwl_mvm_get_link_grade(struct ieee80211_bss_conf *link_conf);

drivers/net/wireless/intel/iwlwifi/mvm/ops.c

@@ -372,7 +372,8 @@ static const struct iwl_rx_handlers iwl_mvm_rx_handlers[] = {
 		   struct iwl_umac_scan_iter_complete_notif),
 
 	RX_HANDLER(MISSED_BEACONS_NOTIFICATION, iwl_mvm_rx_missed_beacons_notif,
-		   RX_HANDLER_SYNC, struct iwl_missed_beacons_notif),
+		   RX_HANDLER_ASYNC_LOCKED_WIPHY,
+		   struct iwl_missed_beacons_notif),
 
 	RX_HANDLER(REPLY_ERROR, iwl_mvm_rx_fw_error, RX_HANDLER_SYNC,
 		   struct iwl_error_resp),