mac80211: treat minstrel success probabilities below 10% as implausible

Based on minstrel_ht this patch treats success probabilities below 10% as
implausible values for throughput calculation in minstrel's statistics.
Current throughput per rate with such a low success probability is reset
to 0 MBit/s.

Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 5c0f532..f8d99a5 100644 (file)
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -92,7 +92,6 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
                        mr->probability = minstrel_ewma(mr->probability,
                                                        mr->cur_prob,
                                                        EWMA_LEVEL);
-                       mr->cur_tp = mr->probability * (1000000 / usecs);
                } else
                        mr->sample_skipped++;
 
@@ -101,6 +100,12 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
                mr->success = 0;
                mr->attempts = 0;
 
+               /* Update throughput per rate, reset thr. below 10% success */
+               if (mr->probability < MINSTREL_FRAC(10, 100))
+                       mr->cur_tp = 0;
+               else
+                       mr->cur_tp = mr->probability * (1000000 / usecs);
+
                /* Sample less often below the 10% chance of success.
                 * Sample less often above the 95% chance of success. */
                if (mr->probability > MINSTREL_FRAC(95, 100) ||