iwlwifi: mvm: disconnect in case of bad channel switch parameters

In case we receive channel switch announcement with immediate
quiet and unknown switching time, we will switch when FW identifies
AP left channel. However, if AP remains on channel, we will
eventually get TX queue hang. Init a work to disconnect if
switch doesn't occur within 1500 milliseconds. Do it also
for a too long channel switch.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 99 insertions, 72 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 5d56c6008787..af71e58bdd24 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -1500,6 +1500,91 @@ static int iwl_mvm_set_tx_power(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 	return iwl_mvm_send_cmd_pdu(mvm, REDUCE_TX_POWER_CMD, 0, len, &cmd);
 }
 
+static int iwl_mvm_post_channel_switch(struct ieee80211_hw *hw,
+				       struct ieee80211_vif *vif)
+{
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
+	int ret;
+
+	mutex_lock(&mvm->mutex);
+
+	if (mvmvif->csa_failed) {
+		mvmvif->csa_failed = false;
+		ret = -EIO;
+		goto out_unlock;
+	}
+
+	if (vif->type == NL80211_IFTYPE_STATION) {
+		struct iwl_mvm_sta *mvmsta;
+
+		mvmvif->csa_bcn_pending = false;
+		mvmsta = iwl_mvm_sta_from_staid_protected(mvm,
+							  mvmvif->ap_sta_id);
+
+		if (WARN_ON(!mvmsta)) {
+			ret = -EIO;
+			goto out_unlock;
+		}
+
+		iwl_mvm_sta_modify_disable_tx(mvm, mvmsta, false);
+
+		iwl_mvm_mac_ctxt_changed(mvm, vif, false, NULL);
+
+		ret = iwl_mvm_enable_beacon_filter(mvm, vif, 0);
+		if (ret)
+			goto out_unlock;
+
+		iwl_mvm_stop_session_protection(mvm, vif);
+	}
+
+	mvmvif->ps_disabled = false;
+
+	ret = iwl_mvm_power_update_ps(mvm);
+
+out_unlock:
+	mutex_unlock(&mvm->mutex);
+
+	return ret;
+}
+
+static void iwl_mvm_abort_channel_switch(struct ieee80211_hw *hw,
+					 struct ieee80211_vif *vif)
+{
+	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	struct iwl_chan_switch_te_cmd cmd = {
+		.mac_id = cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id,
+							  mvmvif->color)),
+		.action = cpu_to_le32(FW_CTXT_ACTION_REMOVE),
+	};
+
+	IWL_DEBUG_MAC80211(mvm, "Abort CSA on mac %d\n", mvmvif->id);
+
+	mutex_lock(&mvm->mutex);
+	WARN_ON(iwl_mvm_send_cmd_pdu(mvm,
+				     WIDE_ID(MAC_CONF_GROUP,
+					     CHANNEL_SWITCH_TIME_EVENT_CMD),
+				     0, sizeof(cmd), &cmd));
+	mutex_unlock(&mvm->mutex);
+
+	WARN_ON(iwl_mvm_post_channel_switch(hw, vif));
+}
+
+static void iwl_mvm_channel_switch_disconnect_wk(struct work_struct *wk)
+{
+	struct iwl_mvm *mvm;
+	struct iwl_mvm_vif *mvmvif;
+	struct ieee80211_vif *vif;
+
+	mvmvif = container_of(wk, struct iwl_mvm_vif, csa_work.work);
+	vif = container_of((void *)mvmvif, struct ieee80211_vif, drv_priv);
+	mvm = mvmvif->mvm;
+
+	iwl_mvm_abort_channel_switch(mvm->hw, vif);
+	ieee80211_chswitch_done(vif, false);
+}
+
 static int iwl_mvm_mac_add_interface(struct ieee80211_hw *hw,
 				     struct ieee80211_vif *vif)
 {
@@ -1626,6 +1711,8 @@ static int iwl_mvm_mac_add_interface(struct ieee80211_hw *hw,
 	}
 
 	iwl_mvm_tcm_add_vif(mvm, vif);
+	INIT_DELAYED_WORK(&mvmvif->csa_work,
+			  iwl_mvm_channel_switch_disconnect_wk);
 
 	if (vif->type == NL80211_IFTYPE_MONITOR)
 		mvm->monitor_on = true;
@@ -4484,6 +4571,7 @@ static int iwl_mvm_schedule_client_csa(struct iwl_mvm *mvm,
 				    0, sizeof(cmd), &cmd);
 }
 
+#define IWL_MAX_CSA_BLOCK_TX 1500
 static int iwl_mvm_pre_channel_switch(struct ieee80211_hw *hw,
 				      struct ieee80211_vif *vif,
 				      struct ieee80211_channel_switch *chsw)
@@ -4548,8 +4636,18 @@ static int iwl_mvm_pre_channel_switch(struct ieee80211_hw *hw,
 				((vif->bss_conf.beacon_int * (chsw->count - 1) -
 				  IWL_MVM_CHANNEL_SWITCH_TIME_CLIENT) * 1024);
 
-		if (chsw->block_tx)
+		if (chsw->block_tx) {
 			iwl_mvm_csa_client_absent(mvm, vif);
+			/*
+			 * In case of undetermined / long time with immediate
+			 * quiet monitor status to gracefully disconnect
+			 */
+			if (!chsw->count ||
+			    chsw->count * vif->bss_conf.beacon_int >
+			    IWL_MAX_CSA_BLOCK_TX)
+				schedule_delayed_work(&mvmvif->csa_work,
+						      msecs_to_jiffies(IWL_MAX_CSA_BLOCK_TX));
+		}
 
 		if (mvmvif->bf_data.bf_enabled) {
 			ret = iwl_mvm_disable_beacon_filter(mvm, vif, 0);
@@ -4584,54 +4682,6 @@ out_unlock:
 	return ret;
 }
 
-static int iwl_mvm_post_channel_switch(struct ieee80211_hw *hw,
-				       struct ieee80211_vif *vif)
-{
-	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
-	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
-	int ret;
-
-	mutex_lock(&mvm->mutex);
-
-	if (mvmvif->csa_failed) {
-		mvmvif->csa_failed = false;
-		ret = -EIO;
-		goto out_unlock;
-	}
-
-	if (vif->type == NL80211_IFTYPE_STATION) {
-		struct iwl_mvm_sta *mvmsta;
-
-		mvmvif->csa_bcn_pending = false;
-		mvmsta = iwl_mvm_sta_from_staid_protected(mvm,
-							  mvmvif->ap_sta_id);
-
-		if (WARN_ON(!mvmsta)) {
-			ret = -EIO;
-			goto out_unlock;
-		}
-
-		iwl_mvm_sta_modify_disable_tx(mvm, mvmsta, false);
-
-		iwl_mvm_mac_ctxt_changed(mvm, vif, false, NULL);
-
-		ret = iwl_mvm_enable_beacon_filter(mvm, vif, 0);
-		if (ret)
-			goto out_unlock;
-
-		iwl_mvm_stop_session_protection(mvm, vif);
-	}
-
-	mvmvif->ps_disabled = false;
-
-	ret = iwl_mvm_power_update_ps(mvm);
-
-out_unlock:
-	mutex_unlock(&mvm->mutex);
-
-	return ret;
-}
-
 static void iwl_mvm_channel_switch_rx_beacon(struct ieee80211_hw *hw,
 					     struct ieee80211_vif *vif,
 					     struct ieee80211_channel_switch *chsw)
@@ -4658,29 +4708,6 @@ static void iwl_mvm_channel_switch_rx_beacon(struct ieee80211_hw *hw,
 				     CMD_ASYNC, sizeof(cmd), &cmd));
 }
 
-static void iwl_mvm_abort_channel_switch(struct ieee80211_hw *hw,
-					 struct ieee80211_vif *vif)
-{
-	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
-	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
-	struct iwl_chan_switch_te_cmd cmd = {
-		.mac_id = cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id,
-							  mvmvif->color)),
-		.action = cpu_to_le32(FW_CTXT_ACTION_REMOVE),
-	};
-
-	IWL_DEBUG_MAC80211(mvm, "Abort CSA on mac %d\n", mvmvif->id);
-
-	mutex_lock(&mvm->mutex);
-	WARN_ON(iwl_mvm_send_cmd_pdu(mvm,
-				     WIDE_ID(MAC_CONF_GROUP,
-					     CHANNEL_SWITCH_TIME_EVENT_CMD),
-				     0, sizeof(cmd), &cmd));
-	mutex_unlock(&mvm->mutex);
-
-	WARN_ON(iwl_mvm_post_channel_switch(hw, vif));
-}
-
 static void iwl_mvm_flush_no_vif(struct iwl_mvm *mvm, u32 queues, bool drop)
 {
 	int i;