2 files changed, 24 insertions, 1 deletions

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index e92f98d32746..76be61744198 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -392,6 +392,7 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 #endif
 
         spin_lock_bh(&sta->lock);
+        sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
         sta->ampdu_mlme.addba_req_num[tid]++;
         spin_unlock_bh(&sta->lock);
 
@@ -492,6 +493,24 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
                 goto err_unlock_sta;
         }
 
+        /*
+         * if we have tried more than HT_AGG_BURST_RETRIES times we
+         * will spread our requests in time to avoid stalling connection
+         * for too long
+         */
+        if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
+            time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
+                        HT_AGG_RETRIES_PERIOD)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "BA request denied - "
+                       "waiting a grace period after %d failed requests "
+                       "on tid %u\n",
+                       sta->ampdu_mlme.addba_req_num[tid], tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+                ret = -EBUSY;
+                goto err_unlock_sta;
+        }
+
         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
         /* check if the TID is not in aggregation flow already */
         if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 15b3bb7d8629..dee284290464 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -83,7 +83,9 @@ enum ieee80211_sta_state {
 
 #define STA_TID_NUM 16
 #define ADDBA_RESP_INTERVAL HZ
-#define HT_AGG_MAX_RETRIES              0x3
+#define HT_AGG_MAX_RETRIES              15
+#define HT_AGG_BURST_RETRIES            3
+#define HT_AGG_RETRIES_PERIOD           (15 * HZ)
 
 #define HT_AGG_STATE_DRV_READY          0
 #define HT_AGG_STATE_RESPONSE_RECEIVED  1
@@ -179,6 +181,7 @@ struct tid_ampdu_rx {
  * @tid_tx: aggregation info for Tx per TID
  * @tid_start_tx: sessions where start was requested
  * @addba_req_num: number of times addBA request has been sent.
+ * @last_addba_req_time: timestamp of the last addBA request.
  * @dialog_token_allocator: dialog token enumerator for each new session;
  * @work: work struct for starting/stopping aggregation
  * @tid_rx_timer_expired: bitmap indicating on which TIDs the
@@ -198,6 +201,7 @@ struct sta_ampdu_mlme {
         struct work_struct work;
         struct tid_ampdu_tx __rcu *tid_tx[STA_TID_NUM];
         struct tid_ampdu_tx *tid_start_tx[STA_TID_NUM];
+        unsigned long last_addba_req_time[STA_TID_NUM];
         u8 addba_req_num[STA_TID_NUM];
         u8 dialog_token_allocator;
 };