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From: Miri Korenblit <miriam.rachel.korenblit@intel.com>
To: johannes@sipsolutions.net
Cc: linux-wireless@vger.kernel.org,
	Benjamin Berg <benjamin.berg@intel.com>
Subject: [PATCH 10/16] wifi: iwlwifi: mvm: remove stale STA link data during restart
Date: Sun, 12 May 2024 07:31:04 +0300
Message-Id: <20240512072733.12d9368a4f72.I840d4fdce5fd49fe69896d928b071067e3730259@changeid>
In-Reply-To: <20240512043110.3413383-1-miriam.rachel.korenblit@intel.com>
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From: Benjamin Berg <benjamin.berg@intel.com>

If pre-recovery mac80211 tried to disable a link but this disablement
failed, then there might be a mismatch between mac80211 assuming the
link has been disabled and the driver still having the data around.
During recover itself, that is not a problem, but should the link be
activated again at a later point, iwlwifi will refuse the activation as
it detects the inconsistent state.

Solve this corner-case by iterating the station in the restart cleanup
handler.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
---
 .../net/wireless/intel/iwlwifi/mvm/mac80211.c | 37 +++++++++++++++++++
 .../net/wireless/intel/iwlwifi/mvm/mld-sta.c  | 10 ++---
 drivers/net/wireless/intel/iwlwifi/mvm/sta.h  |  5 +++
 3 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 486a6b8f3c97..628b50ee0244 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -1128,6 +1128,39 @@ static void iwl_mvm_cleanup_iterator(void *data, u8 *mac,
 	RCU_INIT_POINTER(mvmvif->deflink.probe_resp_data, NULL);
 }
 
+static void iwl_mvm_cleanup_sta_iterator(void *data, struct ieee80211_sta *sta)
+{
+	struct iwl_mvm *mvm = data;
+	struct iwl_mvm_sta *mvm_sta;
+	struct ieee80211_vif *vif;
+	int link_id;
+
+	mvm_sta = iwl_mvm_sta_from_mac80211(sta);
+	vif = mvm_sta->vif;
+
+	if (!sta->valid_links)
+		return;
+
+	for (link_id = 0; link_id < ARRAY_SIZE((sta)->link); link_id++) {
+		struct iwl_mvm_link_sta *mvm_link_sta;
+
+		mvm_link_sta =
+			rcu_dereference_check(mvm_sta->link[link_id],
+					      lockdep_is_held(&mvm->mutex));
+		if (mvm_link_sta && !(vif->active_links & BIT(link_id))) {
+			/*
+			 * We have a link STA but the link is inactive in
+			 * mac80211. This will happen if we failed to
+			 * deactivate the link but mac80211 roll back the
+			 * deactivation of the link.
+			 * Delete the stale data to avoid issues later on.
+			 */
+			iwl_mvm_mld_free_sta_link(mvm, mvm_sta, mvm_link_sta,
+						  link_id, false);
+		}
+	}
+}
+
 static void iwl_mvm_restart_cleanup(struct iwl_mvm *mvm)
 {
 	iwl_mvm_stop_device(mvm);
@@ -1150,6 +1183,10 @@ static void iwl_mvm_restart_cleanup(struct iwl_mvm *mvm)
 	 */
 	ieee80211_iterate_interfaces(mvm->hw, 0, iwl_mvm_cleanup_iterator, mvm);
 
+	/* cleanup stations as links may be gone after restart */
+	ieee80211_iterate_stations_atomic(mvm->hw,
+					  iwl_mvm_cleanup_sta_iterator, mvm);
+
 	mvm->p2p_device_vif = NULL;
 
 	iwl_mvm_reset_phy_ctxts(mvm);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mld-sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/mld-sta.c
index 3b2875f2cab7..d20aa639eea5 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mld-sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mld-sta.c
@@ -515,11 +515,11 @@ static int iwl_mvm_mld_cfg_sta(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
 	return iwl_mvm_mld_send_sta_cmd(mvm, &cmd);
 }
 
-static void iwl_mvm_mld_free_sta_link(struct iwl_mvm *mvm,
-				      struct iwl_mvm_sta *mvm_sta,
-				      struct iwl_mvm_link_sta *mvm_sta_link,
-				      unsigned int link_id,
-				      bool is_in_fw)
+void iwl_mvm_mld_free_sta_link(struct iwl_mvm *mvm,
+			       struct iwl_mvm_sta *mvm_sta,
+			       struct iwl_mvm_link_sta *mvm_sta_link,
+			       unsigned int link_id,
+			       bool is_in_fw)
 {
 	RCU_INIT_POINTER(mvm->fw_id_to_mac_id[mvm_sta_link->sta_id],
 			 is_in_fw ? ERR_PTR(-EINVAL) : NULL);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.h b/drivers/net/wireless/intel/iwlwifi/mvm/sta.h
index 264f1f9394b6..754a05a8c189 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.h
@@ -662,6 +662,11 @@ int iwl_mvm_mld_update_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 			   struct ieee80211_sta *sta);
 int iwl_mvm_mld_rm_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 		       struct ieee80211_sta *sta);
+void iwl_mvm_mld_free_sta_link(struct iwl_mvm *mvm,
+			       struct iwl_mvm_sta *mvm_sta,
+			       struct iwl_mvm_link_sta *mvm_sta_link,
+			       unsigned int link_id,
+			       bool is_in_fw);
 int iwl_mvm_mld_rm_sta_id(struct iwl_mvm *mvm, u8 sta_id);
 int iwl_mvm_mld_update_sta_links(struct iwl_mvm *mvm,
 				 struct ieee80211_vif *vif,
-- 
2.34.1