iwlwifi: mvm: reconfigure qos seq on D0i3 exit

In order to restore the qos seq number on d0i3 exit,
we need to read it from the wowlan status.

However, in order to make sure we use correct seq num
for tx frames, we need to defer any outgoing frames,
and re-enqueue them only after the seq num is configured
correctly.

Sync new Tx aggregations with D0i3 so that the correct
seq num is used for them. Wait synchronously for D0i3
exit before starting a new Tx agg.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index 66760e0..48a8e67 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -424,6 +424,47 @@ int iwl_mvm_mac_setup_register(struct iwl_mvm *mvm)
 	return ret;
 }
 
+static bool iwl_mvm_defer_tx(struct iwl_mvm *mvm,
+			     struct ieee80211_sta *sta,
+			     struct sk_buff *skb)
+{
+	struct iwl_mvm_sta *mvmsta;
+	bool defer = false;
+
+	/*
+	 * double check the IN_D0I3 flag both before and after
+	 * taking the spinlock, in order to prevent taking
+	 * the spinlock when not needed.
+	 */
+	if (likely(!test_bit(IWL_MVM_STATUS_IN_D0I3, &mvm->status)))
+		return false;
+
+	spin_lock(&mvm->d0i3_tx_lock);
+	/*
+	 * testing the flag again ensures the skb dequeue
+	 * loop (on d0i3 exit) hasn't run yet.
+	 */
+	if (!test_bit(IWL_MVM_STATUS_IN_D0I3, &mvm->status))
+		goto out;
+
+	mvmsta = iwl_mvm_sta_from_mac80211(sta);
+	if (mvmsta->sta_id == IWL_MVM_STATION_COUNT ||
+	    mvmsta->sta_id != mvm->d0i3_ap_sta_id)
+		goto out;
+
+	__skb_queue_tail(&mvm->d0i3_tx, skb);
+	ieee80211_stop_queues(mvm->hw);
+
+	/* trigger wakeup */
+	iwl_mvm_ref(mvm, IWL_MVM_REF_TX);
+	iwl_mvm_unref(mvm, IWL_MVM_REF_TX);
+
+	defer = true;
+out:
+	spin_unlock(&mvm->d0i3_tx_lock);
+	return defer;
+}
+
 static void iwl_mvm_mac_tx(struct ieee80211_hw *hw,
 			   struct ieee80211_tx_control *control,
 			   struct sk_buff *skb)
@@ -451,6 +492,8 @@ static void iwl_mvm_mac_tx(struct ieee80211_hw *hw,
 		sta = NULL;
 
 	if (sta) {
+		if (iwl_mvm_defer_tx(mvm, sta, skb))
+			return;
 		if (iwl_mvm_tx_skb(mvm, skb, sta))
 			goto drop;
 		return;
@@ -471,6 +514,7 @@ static int iwl_mvm_mac_ampdu_action(struct ieee80211_hw *hw,
 {
 	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
 	int ret;
+	bool tx_agg_ref = false;
 
 	IWL_DEBUG_HT(mvm, "A-MPDU action on addr %pM tid %d: action %d\n",
 		     sta->addr, tid, action);
@@ -478,6 +522,23 @@ static int iwl_mvm_mac_ampdu_action(struct ieee80211_hw *hw,
 	if (!(mvm->nvm_data->sku_cap_11n_enable))
 		return -EACCES;
 
+	/* return from D0i3 before starting a new Tx aggregation */
+	if (action == IEEE80211_AMPDU_TX_START) {
+		iwl_mvm_ref(mvm, IWL_MVM_REF_TX_AGG);
+		tx_agg_ref = true;
+
+		/*
+		 * wait synchronously until D0i3 exit to get the correct
+		 * sequence number for the tid
+		 */
+		if (!wait_event_timeout(mvm->d0i3_exit_waitq,
+			  !test_bit(IWL_MVM_STATUS_IN_D0I3, &mvm->status), HZ)) {
+			WARN_ON_ONCE(1);
+			iwl_mvm_unref(mvm, IWL_MVM_REF_TX_AGG);
+			return -EIO;
+		}
+	}
+
 	mutex_lock(&mvm->mutex);
 
 	switch (action) {
@@ -515,6 +576,13 @@ static int iwl_mvm_mac_ampdu_action(struct ieee80211_hw *hw,
 	}
 	mutex_unlock(&mvm->mutex);
 
+	/*
+	 * If the tid is marked as started, we won't use it for offloaded
+	 * traffic on the next D0i3 entry. It's safe to unref.
+	 */
+	if (tx_agg_ref)
+		iwl_mvm_unref(mvm, IWL_MVM_REF_TX_AGG);
+
 	return ret;
 }
 
@@ -592,6 +660,7 @@ static void iwl_mvm_mac_restart_complete(struct ieee80211_hw *hw)
 	mutex_lock(&mvm->mutex);
 
 	clear_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status);
+	iwl_mvm_d0i3_enable_tx(mvm, NULL);
 	ret = iwl_mvm_update_quotas(mvm, NULL);
 	if (ret)
 		IWL_ERR(mvm, "Failed to update quotas after restart (%d)\n",