From 972b66b86f85f4e8201db454f4c3e9d990cf9836 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Sat, 6 Oct 2018 19:35:05 +0200
Subject: [PATCH] mac80211: minstrel: fix sampling/reporting of CCK rates in HT mode
Git-commit: 972b66b86f85f4e8201db454f4c3e9d990cf9836
Patch-mainline: v4.20-rc1
References: bsc#1051510
Long/short preamble selection cannot be sampled separately, since it
depends on the BSS state. Because of that, sampling attempts to
currently not used preamble modes are not counted in the statistics,
which leads to CCK rates being sampled too often.
Fix statistics accounting for long/short preamble by increasing the
index where necessary.
Fix excessive CCK rate sampling by dropping unsupported sample attempts.
This improves throughput on 2.4 GHz channels
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/mac80211/rc80211_minstrel_ht.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 6cc28ca5d4a6..fdcb4e9b4560 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -281,7 +281,8 @@ minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
break;
/* short preamble */
- if (!(mi->supported[group] & BIT(idx)))
+ if ((mi->supported[group] & BIT(idx + 4)) &&
+ (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
idx += 4;
}
return &mi->groups[group].rates[idx];
@@ -1080,18 +1081,23 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
return;
sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
+ sample_idx %= MCS_GROUP_RATES;
+
+ if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
+ (sample_idx >= 4) != txrc->short_preamble)
+ return;
+
info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
rate->count = 1;
- if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
+ if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
rate->idx = mp->cck_rates[idx];
} else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
sample_group->streams);
} else {
- rate->idx = sample_idx % MCS_GROUP_RATES +
- (sample_group->streams - 1) * 8;
+ rate->idx = sample_idx + (sample_group->streams - 1) * 8;
}
rate->flags = sample_group->flags;
--
2.16.4