wifi: iwlwifi: mvm: don't add default link in fw restart flow

When we add the vif (and its default link) in fw restart we may
override the link that already exists. We take care of this but if
link 0 is a valid MLO link, then we will re-create a default link on
mvmvif->link[0] and we'll loose the real link we had there.

In non-MLO, we need to re-create the default link upon the interface
creation, this is fine. In MLO, we'll just wait for change_vif_links()
to re-build the links.

Fixes: bf976c8 ("wifi: iwlwifi: mvm: implement link change ops")
Signed-off-by: Emmanuel Grumbach <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://patch.msgid.link/20241010140328.385bfea1b2e9.I4a127312285ccb529cc95cc4edf6fbe1e0a136ad@changeid
Signed-off-by: Johannes Berg <[email protected]>

Author: egrumbach

drivers/net/wireless/intel/iwlwifi/mvm/mld-mac80211.c

@@ -41,8 +41,6 @@ static int iwl_mvm_mld_mac_add_interface(struct ieee80211_hw *hw,
 	/* reset deflink MLO parameters */
 	mvmvif->deflink.fw_link_id = IWL_MVM_FW_LINK_ID_INVALID;
 	mvmvif->deflink.active = 0;
-	/* the first link always points to the default one */
-	mvmvif->link[0] = &mvmvif->deflink;
 
 	ret = iwl_mvm_mld_mac_ctxt_add(mvm, vif);
 	if (ret)
@@ -60,9 +58,19 @@ static int iwl_mvm_mld_mac_add_interface(struct ieee80211_hw *hw,
 				     IEEE80211_VIF_SUPPORTS_CQM_RSSI;
 	}
 
-	ret = iwl_mvm_add_link(mvm, vif, &vif->bss_conf);
-	if (ret)
-		goto out_free_bf;
+	/* We want link[0] to point to the default link, unless we have MLO and
+	 * in this case this will be modified later by .change_vif_links()
+	 * If we are in the restart flow with an MLD connection, we will wait
+	 * to .change_vif_links() to setup the links.
+	 */
+	if (!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status) ||
+	    !ieee80211_vif_is_mld(vif)) {
+		mvmvif->link[0] = &mvmvif->deflink;
+
+		ret = iwl_mvm_add_link(mvm, vif, &vif->bss_conf);
+		if (ret)
+			goto out_free_bf;
+	}
 
 	/* Save a pointer to p2p device vif, so it can later be used to
 	 * update the p2p device MAC when a GO is started/stopped
@@ -1194,7 +1202,11 @@ iwl_mvm_mld_change_vif_links(struct ieee80211_hw *hw,
 
 	mutex_lock(&mvm->mutex);
 
-	if (old_links == 0) {
+	/* If we're in RESTART flow, the default link wasn't added in
+         * drv_add_interface(), and link[0] doesn't point to it.
+	 */
+	if (old_links == 0 && !test_bit(IWL_MVM_STATUS_IN_HW_RESTART,
+					&mvm->status)) {
 		err = iwl_mvm_disable_link(mvm, vif, &vif->bss_conf);
 		if (err)
 			goto out_err;