From 84381b4ed58498e1e3d49a4a306fec9894b8e00c Mon Sep 17 00:00:00 2001 From: Nikolay Martynov Date: Sat, 17 Dec 2011 19:39:35 -0500 Subject: [PATCH] mac80211: split addba retries in time Currently code allows three (HT_AGG_MAX_RETRIES) unanswered addba requests. When this limit is reached aggregation is turned off for given TID permanently. This doesn't seem right: three requests is not that much, some 'blackout' can happen, but effect of it affects whole connection indefinitely. This patch increases number of retries to 15. Also, when there have been 3 or more retries it splits further retries apart by 15 seconds instead of sending them in very short period of time. Signed-off-by: Nikolay Martynov Signed-off-by: John W. Linville --- net/mac80211/agg-tx.c | 19 +++++++++++++++++++ net/mac80211/sta_info.h | 6 +++++- 2 files changed, 24 insertions(+), 1 deletion(-) 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; }; -- 2.34.1