From: Felix Fietkau Date: Sat, 6 Feb 2021 16:08:01 +0100 Subject: [PATCH] mac80211: minstrel_ht: reduce fluctuations in rate probability stats In some scenarios when there is a lot of fluctuation in packet error rates, rate switching can be amplified when the statistics get skewed by time slots with very few tries. Make the input data to the moving average more smooth by adding the success/attempts count from the last stats window as well. This has the advantage of smoothing the data without introducing any extra lag to sampling rates. This significantly improves rate stability on a strong test link subjected to periodic noise bursts generated with a SDR Signed-off-by: Felix Fietkau --- --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -769,7 +769,8 @@ minstrel_ht_calc_rate_stats(struct minst unsigned int cur_prob; if (unlikely(mrs->attempts > 0)) { - cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); + cur_prob = MINSTREL_FRAC(mrs->success + mrs->last_success, + mrs->attempts + mrs->last_attempts); minstrel_filter_avg_add(&mrs->prob_avg, &mrs->prob_avg_1, cur_prob); mrs->att_hist += mrs->attempts;