Abstract out the ampdu TX pps initialisation code so it can be reused

in the superg fast-frames code.

This harks back to an earlier commit (r280349) where I found that
initialising the pps code with ticks=0 would cause hilariously bad
hz ticks wraparound failures, leading to never actually aggregating
traffic.  This is still true for the superg path and so I have to
do the same thing there.

This is a big no-op; a subsequent commit will flip this on so it
works with the fast-frames transmit path.

Tested:

* AR9170, otus(4) - STA mode, 11bg operation
* AR9331, AP mode

2 files changed, 15 insertions, 4 deletions

diff --git a/sys/net80211/ieee80211_ht.c b/sys/net80211/ieee80211_ht.c
index b43bc07..a850a33 100644
--- a/sys/net80211/ieee80211_ht.c
+++ b/sys/net80211/ieee80211_ht.c
@@ -1081,7 +1081,7 @@ ieee80211_ht_node_init(struct ieee80211_node *ni)
 		tap = &ni->ni_tx_ampdu[tid];
 		tap->txa_tid = tid;
 		tap->txa_ni = ni;
-		tap->txa_lastsample = ticks;
+		ieee80211_txampdu_init_pps(tap);
 		/* NB: further initialization deferred */
 	}
 	ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
@@ -1251,7 +1251,7 @@ ieee80211_ht_wds_init(struct ieee80211_node *ni)
 	for (tid = 0; tid < WME_NUM_TID; tid++) {
 		tap = &ni->ni_tx_ampdu[tid];
 		tap->txa_tid = tid;
-		tap->txa_lastsample = ticks;
+		ieee80211_txampdu_init_pps(tap);
 	}
 	/* NB: AMPDU tx/rx governed by IEEE80211_FHT_AMPDU_{TX,RX} */
 	ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
@@ -1752,8 +1752,7 @@ ampdu_tx_stop(struct ieee80211_tx_ampdu *tap)
 	/*
 	 * Reset packet estimate.
 	 */
-	tap->txa_lastsample = ticks;
-	tap->txa_avgpps = 0;
+	ieee80211_txampdu_init_pps(tap);
 
 	/* NB: clearing NAK means we may re-send ADDBA */ 
 	tap->txa_flags &= ~(IEEE80211_AGGR_SETUP | IEEE80211_AGGR_NAK);
diff --git a/sys/net80211/ieee80211_ht.h b/sys/net80211/ieee80211_ht.h
index f099ffe..e2b3318 100644
--- a/sys/net80211/ieee80211_ht.h
+++ b/sys/net80211/ieee80211_ht.h
@@ -84,8 +84,19 @@ struct ieee80211_tx_ampdu {
  */
 
 static __inline void
+ieee80211_txampdu_init_pps(struct ieee80211_tx_ampdu *tap)
+{
+	/*
+	 * Reset packet estimate.
+	 */
+	tap->txa_lastsample = ticks;
+	tap->txa_avgpps = 0;
+}
+
+static __inline void
 ieee80211_txampdu_update_pps(struct ieee80211_tx_ampdu *tap)
 {
+
 	/* NB: scale factor of 2 was picked heuristically */
 	tap->txa_avgpps = ((tap->txa_avgpps << 2) -
 	     tap->txa_avgpps + tap->txa_pkts) >> 2;
@@ -97,6 +108,7 @@ ieee80211_txampdu_update_pps(struct ieee80211_tx_ampdu *tap)
 static __inline void
 ieee80211_txampdu_count_packet(struct ieee80211_tx_ampdu *tap)
 {
+
 	/* XXX bound loop/do more crude estimate? */
 	while (ticks - tap->txa_lastsample >= hz) {
 		ieee80211_txampdu_update_pps(tap);