mac80211: minstrel: fix sampling/reporting of CCK rates in HT mode

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>
This commit is contained in:
Felix Fietkau 2018-10-06 19:35:05 +02:00 committed by Johannes Berg
parent 80df9be67c
commit 972b66b86f

View File

@ -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;