diff options
Diffstat (limited to 'net/mac80211/agg-tx.c')
| -rw-r--r-- | net/mac80211/agg-tx.c | 77 |
1 files changed, 47 insertions, 30 deletions
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index 5a7ef51..7f2042d 100644 --- a/net/mac80211/agg-tx.c +++ b/net/mac80211/agg-tx.c @@ -220,6 +220,41 @@ static inline int ieee80211_ac_from_tid(int tid) return ieee802_1d_to_ac[tid & 7]; } +/* + * When multiple aggregation sessions on multiple stations + * are being created/destroyed simultaneously, we need to + * refcount the global queue stop caused by that in order + * to not get into a situation where one of the aggregation + * setup or teardown re-enables queues before the other is + * ready to handle that. + * + * These two functions take care of this issue by keeping + * a global "agg_queue_stop" refcount. + */ +static void __acquires(agg_queue) +ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid) +{ + int queue = ieee80211_ac_from_tid(tid); + + if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1) + ieee80211_stop_queue_by_reason( + &local->hw, queue, + IEEE80211_QUEUE_STOP_REASON_AGGREGATION); + __acquire(agg_queue); +} + +static void __releases(agg_queue) +ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid) +{ + int queue = ieee80211_ac_from_tid(tid); + + if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0) + ieee80211_wake_queue_by_reason( + &local->hw, queue, + IEEE80211_QUEUE_STOP_REASON_AGGREGATION); + __release(agg_queue); +} + int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) { struct sta_info *sta = container_of(pubsta, struct sta_info, sta); @@ -263,7 +298,6 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) } spin_lock_bh(&sta->lock); - spin_lock(&local->ampdu_lock); /* we have tried too many times, receiver does not want A-MPDU */ if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { @@ -289,9 +323,7 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) * which would require us to put them to the AC pending * afterwards which just makes the code more complex. */ - ieee80211_stop_queue_by_reason( - &local->hw, ieee80211_ac_from_tid(tid), - IEEE80211_QUEUE_STOP_REASON_AGGREGATION); + ieee80211_stop_queue_agg(local, tid); /* prepare A-MPDU MLME for Tx aggregation */ tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); @@ -327,11 +359,7 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); /* Driver vetoed or OKed, but we can take packets again now */ - ieee80211_wake_queue_by_reason( - &local->hw, ieee80211_ac_from_tid(tid), - IEEE80211_QUEUE_STOP_REASON_AGGREGATION); - - spin_unlock(&local->ampdu_lock); + ieee80211_wake_queue_agg(local, tid); /* activate the timer for the recipient's addBA response */ tid_tx->addba_resp_timer.expires = jiffies + ADDBA_RESP_INTERVAL; @@ -358,11 +386,8 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) err_free: kfree(tid_tx); err_wake_queue: - ieee80211_wake_queue_by_reason( - &local->hw, ieee80211_ac_from_tid(tid), - IEEE80211_QUEUE_STOP_REASON_AGGREGATION); + ieee80211_wake_queue_agg(local, tid); err_unlock_sta: - spin_unlock(&local->ampdu_lock); spin_unlock_bh(&sta->lock); return ret; } @@ -370,19 +395,16 @@ 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 and holding - * local->ampdu_lock across both calls. + * requires a call to ieee80211_agg_splice_finish later */ -static void ieee80211_agg_splice_packets(struct ieee80211_local *local, - struct tid_ampdu_tx *tid_tx, - u16 tid) +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; - u16 queue = ieee80211_ac_from_tid(tid); - ieee80211_stop_queue_by_reason( - &local->hw, queue, - IEEE80211_QUEUE_STOP_REASON_AGGREGATION); + ieee80211_stop_queue_agg(local, tid); if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates" " from the pending queue\n", tid)) @@ -397,11 +419,10 @@ static void ieee80211_agg_splice_packets(struct ieee80211_local *local, } } -static void ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid) +static void __releases(agg_queue) +ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid) { - ieee80211_wake_queue_by_reason( - &local->hw, ieee80211_ac_from_tid(tid), - IEEE80211_QUEUE_STOP_REASON_AGGREGATION); + ieee80211_wake_queue_agg(local, tid); } /* caller must hold sta->lock */ @@ -414,7 +435,6 @@ static void ieee80211_agg_tx_operational(struct ieee80211_local *local, printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid); #endif - spin_lock(&local->ampdu_lock); ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid); /* * Now mark as operational. This will be visible @@ -423,7 +443,6 @@ static void ieee80211_agg_tx_operational(struct ieee80211_local *local, */ set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state); ieee80211_agg_splice_finish(local, tid); - spin_unlock(&local->ampdu_lock); drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_TX_OPERATIONAL, @@ -604,7 +623,6 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) * more. */ - spin_lock(&local->ampdu_lock); ieee80211_agg_splice_packets(local, tid_tx, tid); /* future packets must not find the tid_tx struct any more */ @@ -613,7 +631,6 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) ieee80211_agg_splice_finish(local, tid); call_rcu(&tid_tx->rcu_head, kfree_tid_tx); - spin_unlock(&local->ampdu_lock); spin_unlock_bh(&sta->lock); rcu_read_unlock(); |