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 <mar.kolya@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index e92f98d..76be6174 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -392,6 +392,7 @@
#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 @@
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]) {