1 files changed, 46 insertions, 45 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/tx.c b/drivers/net/wireless/iwlwifi/mvm/tx.c
index 90378c217bc7..76ee486039d7 100644
--- a/drivers/net/wireless/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/tx.c
@@ -659,8 +659,14 @@ static void iwl_mvm_rx_tx_cmd_single(struct iwl_mvm *mvm,
         rcu_read_lock();
 
         sta = rcu_dereference(mvm->fw_id_to_mac_id[sta_id]);
+        /*
+         * sta can't be NULL otherwise it'd mean that the sta has been freed in
+         * the firmware while we still have packets for it in the Tx queues.
+         */
+        if (WARN_ON_ONCE(!sta))
+                goto out;
 
-        if (!IS_ERR_OR_NULL(sta)) {
+        if (!IS_ERR(sta)) {
                 mvmsta = iwl_mvm_sta_from_mac80211(sta);
 
                 if (tid != IWL_TID_NON_QOS) {
@@ -675,7 +681,6 @@ static void iwl_mvm_rx_tx_cmd_single(struct iwl_mvm *mvm,
                         spin_unlock_bh(&mvmsta->lock);
                 }
         } else {
-                sta = NULL;
                 mvmsta = NULL;
         }
 
@@ -683,42 +688,38 @@ static void iwl_mvm_rx_tx_cmd_single(struct iwl_mvm *mvm,
          * If the txq is not an AMPDU queue, there is no chance we freed
          * several skbs. Check that out...
          */
-        if (txq_id < mvm->first_agg_queue && !WARN_ON(skb_freed > 1) &&
-            atomic_sub_and_test(skb_freed, &mvm->pending_frames[sta_id])) {
-                if (mvmsta) {
-                        /*
-                         * If there are no pending frames for this STA, notify
-                         * mac80211 that this station can go to sleep in its
-                         * STA table.
-                         */
-                        if (mvmsta->vif->type == NL80211_IFTYPE_AP)
-                                ieee80211_sta_block_awake(mvm->hw, sta, false);
-                        /*
-                         * We might very well have taken mvmsta pointer while
-                         * the station was being removed. The remove flow might
-                         * have seen a pending_frame (because we didn't take
-                         * the lock) even if now the queues are drained. So make
-                         * really sure now that this the station is not being
-                         * removed. If it is, run the drain worker to remove it.
-                         */
-                        spin_lock_bh(&mvmsta->lock);
-                        sta = rcu_dereference(mvm->fw_id_to_mac_id[sta_id]);
-                        if (!sta || PTR_ERR(sta) == -EBUSY) {
-                                /*
-                                 * Station disappeared in the meantime:
-                                 * so we are draining.
-                                 */
-                                set_bit(sta_id, mvm->sta_drained);
-                                schedule_work(&mvm->sta_drained_wk);
-                        }
-                        spin_unlock_bh(&mvmsta->lock);
-                } else if (!mvmsta && PTR_ERR(sta) == -EBUSY) {
-                        /* Tx response without STA, so we are draining */
-                        set_bit(sta_id, mvm->sta_drained);
-                        schedule_work(&mvm->sta_drained_wk);
-                }
+        if (txq_id >= mvm->first_agg_queue)
+                goto out;
+
+        /* We can't free more than one frame at once on a shared queue */
+        WARN_ON(skb_freed > 1);
+
+        /* If we have still frames from this STA nothing to do here */
+        if (!atomic_sub_and_test(skb_freed, &mvm->pending_frames[sta_id]))
+                goto out;
+
+        if (mvmsta && mvmsta->vif->type == NL80211_IFTYPE_AP) {
+                /*
+                 * If there are no pending frames for this STA, notify
+                 * mac80211 that this station can go to sleep in its
+                 * STA table.
+                 * If mvmsta is not NULL, sta is valid.
+                 */
+                ieee80211_sta_block_awake(mvm->hw, sta, false);
         }
 
+        if (PTR_ERR(sta) == -EBUSY || PTR_ERR(sta) == -ENOENT) {
+                /*
+                 * We are draining and this was the last packet - pre_rcu_remove
+                 * has been called already. We might be after the
+                 * synchronize_net already.
+                 * Don't rely on iwl_mvm_rm_sta to see the empty Tx queues.
+                 */
+                set_bit(sta_id, mvm->sta_drained);
+                schedule_work(&mvm->sta_drained_wk);
+        }
+
+out:
         rcu_read_unlock();
 }
 
@@ -821,16 +822,12 @@ int iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
         struct iwl_mvm_ba_notif *ba_notif = (void *)pkt->data;
         struct sk_buff_head reclaimed_skbs;
         struct iwl_mvm_tid_data *tid_data;
-        struct ieee80211_tx_info *info;
         struct ieee80211_sta *sta;
         struct iwl_mvm_sta *mvmsta;
-        struct ieee80211_hdr *hdr;
         struct sk_buff *skb;
         int sta_id, tid, freed;
-
         /* "flow" corresponds to Tx queue */
         u16 scd_flow = le16_to_cpu(ba_notif->scd_flow);
-
         /* "ssn" is start of block-ack Tx window, corresponds to index
          * (in Tx queue's circular buffer) of first TFD/frame in window */
         u16 ba_resp_scd_ssn = le16_to_cpu(ba_notif->scd_ssn);
@@ -887,22 +884,26 @@ int iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
         freed = 0;
 
         skb_queue_walk(&reclaimed_skbs, skb) {
-                hdr = (struct ieee80211_hdr *)skb->data;
+                struct ieee80211_hdr *hdr = (void *)skb->data;
+                struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 
                 if (ieee80211_is_data_qos(hdr->frame_control))
                         freed++;
                 else
                         WARN_ON_ONCE(1);
 
-                info = IEEE80211_SKB_CB(skb);
                 iwl_trans_free_tx_cmd(mvm->trans, info->driver_data[1]);
 
+                memset(&info->status, 0, sizeof(info->status));
+                /* Packet was transmitted successfully, failures come as single
+                 * frames because before failing a frame the firmware transmits
+                 * it without aggregation at least once.
+                 */
+                info->flags |= IEEE80211_TX_STAT_ACK;
+
                 if (freed == 1) {
                         /* this is the first skb we deliver in this batch */
                         /* put the rate scaling data there */
-                        info = IEEE80211_SKB_CB(skb);
-                        memset(&info->status, 0, sizeof(info->status));
-                        info->flags |= IEEE80211_TX_STAT_ACK;
                         info->flags |= IEEE80211_TX_STAT_AMPDU;
                         info->status.ampdu_ack_len = ba_notif->txed_2_done;
                         info->status.ampdu_len = ba_notif->txed;