[PATCH] mac80211: only schedule TXQ when reasonable airtime reporting

[Ryder Lee]

For some drivers and hardware may report faulty airtime, which ends up
with excessive hold time (~0.9s on mt7915 multiclent tests) impacting
system performance.

Although issue has been fixed in driver, but it make sense to select txqi
depends on a reasonable airtime reporting to prevent such a case from
happening again.

Tested-by: Jiao Bo <jiao.bao at mediatek.com>
Tested-by: Sujuan Chen <sujuan.chen at mediatek.com>
Signed-off-by: Ryder Lee <ryder.lee at mediatek.com>
---
 net/mac80211/tx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6422da6690f7..0b8a8c3600f4 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3770,6 +3770,10 @@ struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac)
 				sta->airtime_weight;
 
 		if (deficit < 0 || !aql_check) {
+			if (txqi->schedule_round == local->schedule_round[ac])
+				goto out;
+
+			txqi->schedule_round = local->schedule_round[ac];
 			list_move_tail(&txqi->schedule_order,
 				       &local->active_txqs[txqi->txq.ac]);
 			goto begin;
-- 
2.18.0