diff options
Diffstat (limited to 'net/mac80211/agg-tx.c')
| -rw-r--r-- | net/mac80211/agg-tx.c | 128 |
1 files changed, 80 insertions, 48 deletions
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index b3f65520e7a7..2e4b961648d4 100644 --- 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; @@ -283,6 +303,38 @@ ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid) __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; @@ -294,19 +346,17 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 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(); @@ -320,17 +370,15 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) " 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 @@ -446,38 +494,6 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, } 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) { @@ -757,11 +773,27 @@ 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 |