From a35e27802291a8119c2b12532fb5f3c1b3e565a2 Mon Sep 17 00:00:00 2001 From: Rajkumar Manoharan Date: Sat, 20 Aug 2011 17:22:10 +0530 Subject: [PATCH] ath9k: Change rate control to use legacy rate as last MRR In congested network, having all rate reties at MCS rates is failing to transmit the frame offenly. By the time reaching the success rate set, the application gets timed out. One such scenario is that authentication time out during 4-Way handshake. This patch uses a legacy rate as last retry sequnce for unaggregated frames or if the first selected rate's PER is ~80% of max limit. And also observed from the tx status that the frame was trasmitted successfully by using legacy rates. Signed-off-by: Rajkumar Manoharan Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath9k/rc.c | 34 +++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c index 9e3649a3d5ca..4f1301881137 100644 --- a/drivers/net/wireless/ath/ath9k/rc.c +++ b/drivers/net/wireless/ath/ath9k/rc.c @@ -603,7 +603,8 @@ static u8 ath_rc_setvalid_htrates(struct ath_rate_priv *ath_rc_priv, static u8 ath_rc_get_highest_rix(struct ath_softc *sc, struct ath_rate_priv *ath_rc_priv, const struct ath_rate_table *rate_table, - int *is_probing) + int *is_probing, + bool legacy) { u32 best_thruput, this_thruput, now_msec; u8 rate, next_rate, best_rate, maxindex, minindex; @@ -624,6 +625,8 @@ static u8 ath_rc_get_highest_rix(struct ath_softc *sc, u8 per_thres; rate = ath_rc_priv->valid_rate_index[index]; + if (legacy && !(rate_table->info[rate].rate_flags & RC_LEGACY)) + continue; if (rate > ath_rc_priv->rate_max_phy) continue; @@ -767,7 +770,7 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, struct ieee80211_tx_rate *rates = tx_info->control.rates; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; __le16 fc = hdr->frame_control; - u8 try_per_rate, i = 0, rix; + u8 try_per_rate, i = 0, rix, high_rix; int is_probe = 0; if (rate_control_send_low(sta, priv_sta, txrc)) @@ -786,7 +789,9 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, try_per_rate = 4; rate_table = ath_rc_priv->rate_table; - rix = ath_rc_get_highest_rix(sc, ath_rc_priv, rate_table, &is_probe); + rix = ath_rc_get_highest_rix(sc, ath_rc_priv, rate_table, + &is_probe, false); + high_rix = rix; /* * If we're in HT mode and both us and our peer supports LDPC. @@ -822,10 +827,7 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, } /* Fill in the other rates for multirate retry */ - for ( ; i < 4; i++) { - /* Use twice the number of tries for the last MRR segment. */ - if (i + 1 == 4) - try_per_rate = 8; + for ( ; i < 3; i++) { ath_rc_get_lower_rix(rate_table, ath_rc_priv, rix, &rix); /* All other rates in the series have RTS enabled */ @@ -833,6 +835,24 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, try_per_rate, rix, 1); } + /* Use twice the number of tries for the last MRR segment. */ + try_per_rate = 8; + + /* + * Use a legacy rate as last retry to ensure that the frame + * is tried in both MCS and legacy rates. + */ + if ((rates[2].flags & IEEE80211_TX_RC_MCS) && + (!(tx_info->flags & IEEE80211_TX_CTL_AMPDU) || + (ath_rc_priv->per[high_rix] > 45))) + rix = ath_rc_get_highest_rix(sc, ath_rc_priv, rate_table, + &is_probe, true); + else + ath_rc_get_lower_rix(rate_table, ath_rc_priv, rix, &rix); + + /* All other rates in the series have RTS enabled */ + ath_rc_rate_set_series(rate_table, &rates[i], txrc, + try_per_rate, rix, 1); /* * NB:Change rate series to enable aggregation when operating * at lower MCS rates. When first rate in series is MCS2 -- 2.34.1