From 0bb5d39b7adab53ca35d9c44fdf0200e3377f72d Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Wed, 11 Nov 2020 19:49:54 +0100 Subject: [PATCH] mac80211: add minstrel fixes that fix mt76 issues in legacy mode Remove deferred sampling code which does not work well with rate tables + probing. Fix tx status handling if the first invalid rate idx is not set to -1 Signed-off-by: Felix Fietkau --- ...nstrel-remove-deferred-sampling-code.patch | 96 +++++++++++++++++++ ...l-fix-tx-status-processing-corner-ca.patch | 26 +++++ 2 files changed, 122 insertions(+) create mode 100644 package/kernel/mac80211/patches/subsys/334-mac80211-minstrel-remove-deferred-sampling-code.patch create mode 100644 package/kernel/mac80211/patches/subsys/335-mac80211-minstrel-fix-tx-status-processing-corner-ca.patch diff --git a/package/kernel/mac80211/patches/subsys/334-mac80211-minstrel-remove-deferred-sampling-code.patch b/package/kernel/mac80211/patches/subsys/334-mac80211-minstrel-remove-deferred-sampling-code.patch new file mode 100644 index 0000000000..e3a877fb94 --- /dev/null +++ b/package/kernel/mac80211/patches/subsys/334-mac80211-minstrel-remove-deferred-sampling-code.patch @@ -0,0 +1,96 @@ +From: Felix Fietkau +Date: Wed, 11 Nov 2020 19:17:44 +0100 +Subject: [PATCH] mac80211: minstrel: remove deferred sampling code + +Deferring sampling attempts to the second stage has some bad interactions +with drivers that process the rate table in hardware and use the probe flag +to indicate probing packets (e.g. most mt76 drivers). On affected drivers +it can lead to probing not working at all. + +If the link conditions turn worse, it might not be such a good idea to +do a lot of sampling for lower rates in this case. + +Fix this by simply skipping the sample attempt instead of deferring it, +but keep the checks that would allow it to be sampled if it was skipped +too often, but only if it has less than 95% success probability. + +Also ensure that IEEE80211_TX_CTL_RATE_CTRL_PROBE is set for all probing +packets. + +Cc: stable@vger.kernel.org +Fixes: cccf129f820e ("mac80211: add the 'minstrel' rate control algorithm") +Signed-off-by: Felix Fietkau +--- + +--- a/net/mac80211/rc80211_minstrel.c ++++ b/net/mac80211/rc80211_minstrel.c +@@ -287,12 +287,6 @@ minstrel_tx_status(void *priv, struct ie + mi->r[ndx].stats.success += success; + } + +- if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) +- mi->sample_packets++; +- +- if (mi->sample_deferred > 0) +- mi->sample_deferred--; +- + if (time_after(jiffies, mi->last_stats_update + + mp->update_interval / (mp->new_avg ? 2 : 1))) + minstrel_update_stats(mp, mi); +@@ -367,7 +361,7 @@ minstrel_get_rate(void *priv, struct iee + return; + + delta = (mi->total_packets * sampling_ratio / 100) - +- (mi->sample_packets + mi->sample_deferred / 2); ++ mi->sample_packets; + + /* delta < 0: no sampling required */ + prev_sample = mi->prev_sample; +@@ -376,7 +370,6 @@ minstrel_get_rate(void *priv, struct iee + return; + + if (mi->total_packets >= 10000) { +- mi->sample_deferred = 0; + mi->sample_packets = 0; + mi->total_packets = 0; + } else if (delta > mi->n_rates * 2) { +@@ -401,19 +394,8 @@ minstrel_get_rate(void *priv, struct iee + * rate sampling method should be used. + * Respect such rates that are not sampled for 20 interations. + */ +- if (mrr_capable && +- msr->perfect_tx_time > mr->perfect_tx_time && +- msr->stats.sample_skipped < 20) { +- /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark +- * packets that have the sampling rate deferred to the +- * second MRR stage. Increase the sample counter only +- * if the deferred sample rate was actually used. +- * Use the sample_deferred counter to make sure that +- * the sampling is not done in large bursts */ +- info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; +- rate++; +- mi->sample_deferred++; +- } else { ++ if (msr->perfect_tx_time < mr->perfect_tx_time || ++ msr->stats.sample_skipped >= 20) { + if (!msr->sample_limit) + return; + +@@ -433,6 +415,7 @@ minstrel_get_rate(void *priv, struct iee + + rate->idx = mi->r[ndx].rix; + rate->count = minstrel_get_retry_count(&mi->r[ndx], info); ++ info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; + } + + +--- a/net/mac80211/rc80211_minstrel.h ++++ b/net/mac80211/rc80211_minstrel.h +@@ -126,7 +126,6 @@ struct minstrel_sta_info { + u8 max_prob_rate; + unsigned int total_packets; + unsigned int sample_packets; +- int sample_deferred; + + unsigned int sample_row; + unsigned int sample_column; diff --git a/package/kernel/mac80211/patches/subsys/335-mac80211-minstrel-fix-tx-status-processing-corner-ca.patch b/package/kernel/mac80211/patches/subsys/335-mac80211-minstrel-fix-tx-status-processing-corner-ca.patch new file mode 100644 index 0000000000..b1c339a1e6 --- /dev/null +++ b/package/kernel/mac80211/patches/subsys/335-mac80211-minstrel-fix-tx-status-processing-corner-ca.patch @@ -0,0 +1,26 @@ +From: Felix Fietkau +Date: Wed, 11 Nov 2020 19:25:39 +0100 +Subject: [PATCH] mac80211: minstrel: fix tx status processing corner case + +Some drivers fill the status rate list without setting the rate index after +the final rate to -1. minstrel_ht already deals with this, but minstrel +doesn't, which causes it to get stuck at the lowest rate on these drivers. + +Fix this by checking the count as well. + +Cc: stable@vger.kernel.org +Fixes: cccf129f820e ("mac80211: add the 'minstrel' rate control algorithm") +Signed-off-by: Felix Fietkau +--- + +--- a/net/mac80211/rc80211_minstrel.c ++++ b/net/mac80211/rc80211_minstrel.c +@@ -274,7 +274,7 @@ minstrel_tx_status(void *priv, struct ie + success = !!(info->flags & IEEE80211_TX_STAT_ACK); + + for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { +- if (ar[i].idx < 0) ++ if (ar[i].idx < 0 || !ar[i].count) + break; + + ndx = rix_to_ndx(mi, ar[i].idx); -- 2.30.2