Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[karo-tx-linux.git] / net / mac80211 / agg-tx.c

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index b3f65520e7a716312adc51d48d8fa9d8e2993c3d..b064e4df12c6d03a0534f5a8b026b9785befc190 100644 (file)
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -161,6 +161,12 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
                return -ENOENT;
        }
 
+       /* if we're already stopping ignore any new requests to stop */
+       if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+               spin_unlock_bh(&sta->lock);
+               return -EALREADY;
+       }
+
        if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
                /* not even started yet! */
                ieee80211_assign_tid_tx(sta, tid, NULL);
@@ -169,6 +175,8 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
                return 0;
        }
 
+       set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
+
        spin_unlock_bh(&sta->lock);
 
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -176,8 +184,6 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
               sta->sta.addr, tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
 
-       set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
-
        del_timer_sync(&tid_tx->addba_resp_timer);
 
        /*
@@ -187,6 +193,20 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
         */
        clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 
+       /*
+        * There might be a few packets being processed right now (on
+        * another CPU) that have already gotten past the aggregation
+        * check when it was still OPERATIONAL and consequently have
+        * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
+        * call into the driver at the same time or even before the
+        * TX paths calls into it, which could confuse the driver.
+        *
+        * Wait for all currently running TX paths to finish before
+        * telling the driver. New packets will not go through since
+        * the aggregation session is no longer OPERATIONAL.
+        */
+       synchronize_net();
+
        tid_tx->stop_initiator = initiator;
        tid_tx->tx_stop = tx;
 
@@ -757,11 +777,27 @@ void ieee80211_process_addba_resp(struct ieee80211_local *local,
                goto out;
        }
 
-       del_timer(&tid_tx->addba_resp_timer);
+       del_timer_sync(&tid_tx->addba_resp_timer);
 
 #ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 #endif
+
+       /*
+        * addba_resp_timer may have fired before we got here, and
+        * caused WANT_STOP to be set. If the stop then was already
+        * processed further, STOPPING might be set.
+        */
+       if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
+           test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+               printk(KERN_DEBUG
+                      "got addBA resp for tid %d but we already gave up\n",
+                      tid);
+#endif
+               goto out;
+       }
+
        /*
         * IEEE 802.11-2007 7.3.1.14:
         * In an ADDBA Response frame, when the Status Code field