There were a few issues that were slowing down the process of finding the optimal rate, especially on devices with multi-rate retry limitations:
When max_tp_rate[0] was slower than max_tp_rate[1], the code did not sample max_tp_rate[1], which would often allow it to switch places with max_tp_rate[0] (e.g. if only the first sampling attempts were bad, but the rate is otherwise good). Also, sample attempts of rates between max_tp_rate[0] and [1] were being ignored in this case, because the code only checked if the rate was slower than [1]. Fix this by checking against the fastest / second fastest max_tp_rate instead of assuming a specific order between the two. In my tests this patch significantly reduces the time until minstrel_ht finds the optimal rate right after assoc Signed-off-by: Felix Fietkau <[email protected]> --- net/mac80211/rc80211_minstrel_ht.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 3928dbd..9197191 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -923,6 +923,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) struct minstrel_rate_stats *mrs; struct minstrel_mcs_group_data *mg; unsigned int sample_dur, sample_group, cur_max_tp_streams; + int tp_rate1, tp_rate2; int sample_idx = 0; if (mi->sample_wait > 0) { @@ -944,14 +945,22 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) mrs = &mg->rates[sample_idx]; sample_idx += sample_group * MCS_GROUP_RATES; + /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ + if (minstrel_get_duration(mi->max_tp_rate[0]) > + minstrel_get_duration(mi->max_tp_rate[1])) { + tp_rate1 = mi->max_tp_rate[1]; + tp_rate2 = mi->max_tp_rate[0]; + } else { + tp_rate1 = mi->max_tp_rate[0]; + tp_rate2 = mi->max_tp_rate[1]; + } + /* * Sampling might add some overhead (RTS, no aggregation) - * to the frame. Hence, don't use sampling for the currently - * used rates. + * to the frame. Hence, don't use sampling for the highest currently + * used highest throughput or probability rate. */ - if (sample_idx == mi->max_tp_rate[0] || - sample_idx == mi->max_tp_rate[1] || - sample_idx == mi->max_prob_rate) + if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) return -1; /* @@ -966,10 +975,10 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) * if the link is working perfectly. */ - cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / + cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / MCS_GROUP_RATES].streams; sample_dur = minstrel_get_duration(sample_idx); - if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) && + if (sample_dur >= minstrel_get_duration(tp_rate2) && (cur_max_tp_streams - 1 < minstrel_mcs_groups[sample_group].streams || sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
