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);
return 0;
}
+ set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
+
spin_unlock_bh(&sta->lock);
#ifdef CONFIG_MAC80211_HT_DEBUG
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);
/*
*/
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;
__release(agg_queue);
}
+/*
+ * splice packets from the STA's pending to the local pending,
+ * requires a call to ieee80211_agg_splice_finish later
+ */
+static void __acquires(agg_queue)
+ieee80211_agg_splice_packets(struct ieee80211_local *local,
+ struct tid_ampdu_tx *tid_tx, u16 tid)
+{
+ int queue = ieee80211_ac_from_tid(tid);
+ unsigned long flags;
+
+ ieee80211_stop_queue_agg(local, tid);
+
+ if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
+ " from the pending queue\n", tid))
+ return;
+
+ if (!skb_queue_empty(&tid_tx->pending)) {
+ spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
+ /* copy over remaining packets */
+ skb_queue_splice_tail_init(&tid_tx->pending,
+ &local->pending[queue]);
+ spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
+ }
+}
+
+static void __releases(agg_queue)
+ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
+{
+ ieee80211_wake_queue_agg(local, tid);
+}
+
void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
{
struct tid_ampdu_tx *tid_tx;
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
/*
- * While we're asking the driver about the aggregation,
- * stop the AC queue so that we don't have to worry
- * about frames that came in while we were doing that,
- * which would require us to put them to the AC pending
- * afterwards which just makes the code more complex.
+ * Start queuing up packets for this aggregation session.
+ * We're going to release them once the driver is OK with
+ * that.
*/
- ieee80211_stop_queue_agg(local, tid);
-
clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
/*
- * make sure no packets are being processed to get
- * valid starting sequence number
+ * Make sure no packets are being processed. This ensures that
+ * we have a valid starting sequence number and that in-flight
+ * packets have been flushed out and no packets for this TID
+ * will go into the driver during the ampdu_action call.
*/
synchronize_net();
" tid %d\n", tid);
#endif
spin_lock_bh(&sta->lock);
+ ieee80211_agg_splice_packets(local, tid_tx, tid);
ieee80211_assign_tid_tx(sta, tid, NULL);
+ ieee80211_agg_splice_finish(local, tid);
spin_unlock_bh(&sta->lock);
- ieee80211_wake_queue_agg(local, tid);
kfree_rcu(tid_tx, rcu_head);
return;
}
- /* we can take packets again now */
- ieee80211_wake_queue_agg(local, tid);
-
/* activate the timer for the recipient's addBA response */
mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
#ifdef CONFIG_MAC80211_HT_DEBUG
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
-/*
- * splice packets from the STA's pending to the local pending,
- * requires a call to ieee80211_agg_splice_finish later
- */
-static void __acquires(agg_queue)
-ieee80211_agg_splice_packets(struct ieee80211_local *local,
- struct tid_ampdu_tx *tid_tx, u16 tid)
-{
- int queue = ieee80211_ac_from_tid(tid);
- unsigned long flags;
-
- ieee80211_stop_queue_agg(local, tid);
-
- if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
- " from the pending queue\n", tid))
- return;
-
- if (!skb_queue_empty(&tid_tx->pending)) {
- spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
- /* copy over remaining packets */
- skb_queue_splice_tail_init(&tid_tx->pending,
- &local->pending[queue]);
- spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
- }
-}
-
-static void __releases(agg_queue)
-ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
-{
- ieee80211_wake_queue_agg(local, tid);
-}
-
static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
struct sta_info *sta, u16 tid)
{
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
git.openpandora.org / pandora-kernel.git / blobdiff