mac80211/minstrel: use the new rate control API

Pass the rate selection table to mac80211 from minstrel_update_stats.
Only rates for sample attempts are set in info->control.rates, with deferred
sampling, only the second slot gets changed.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 109 insertions, 91 deletions

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index eda290fb8bd2..ac7ef5414bde 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -84,6 +84,50 @@ minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list)
 }
 
 static void
+minstrel_set_rate(struct minstrel_sta_info *mi, struct ieee80211_sta_rates *ratetbl,
+                  int offset, int idx)
+{
+        struct minstrel_rate *r = &mi->r[idx];
+
+        ratetbl->rate[offset].idx = r->rix;
+        ratetbl->rate[offset].count = r->adjusted_retry_count;
+        ratetbl->rate[offset].count_cts = r->retry_count_cts;
+        ratetbl->rate[offset].count_rts = r->retry_count_rtscts;
+}
+
+static void
+minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
+{
+        struct ieee80211_sta_rates *ratetbl;
+        int i = 0;
+
+        ratetbl = kzalloc(sizeof(*ratetbl), GFP_ATOMIC);
+        if (!ratetbl)
+                return;
+
+        /* Start with max_tp_rate */
+        minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[0]);
+
+        if (mp->hw->max_rates >= 3) {
+                /* At least 3 tx rates supported, use max_tp_rate2 next */
+                minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[1]);
+        }
+
+        if (mp->hw->max_rates >= 2) {
+                /* At least 2 tx rates supported, use max_prob_rate next */
+                minstrel_set_rate(mi, ratetbl, i++, mi->max_prob_rate);
+        }
+
+        /* Use lowest rate last */
+        ratetbl->rate[i].idx = mi->lowest_rix;
+        ratetbl->rate[i].count = mp->max_retry;
+        ratetbl->rate[i].count_cts = mp->max_retry;
+        ratetbl->rate[i].count_rts = mp->max_retry;
+
+        rate_control_set_rates(mp->hw, mi->sta, ratetbl);
+}
+
+static void
 minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 {
         u8 tmp_tp_rate[MAX_THR_RATES];
@@ -161,6 +205,8 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 
         /* Reset update timer */
         mi->stats_update = jiffies;
+
+        minstrel_update_rates(mp, mi);
 }
 
 static void
@@ -240,13 +286,12 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
         struct minstrel_sta_info *mi = priv_sta;
         struct minstrel_priv *mp = priv;
-        struct ieee80211_tx_rate *ar = info->control.rates;
-        unsigned int ndx, sample_ndx = 0;
+        struct ieee80211_tx_rate *rate = &info->control.rates[0];
+        struct minstrel_rate *msr, *mr;
+        unsigned int ndx;
         bool mrr_capable;
-        bool indirect_rate_sampling = false;
-        bool rate_sampling = false;
-        int i, delta;
-        int mrr_ndx[3];
+        bool prev_sample = mi->prev_sample;
+        int delta;
         int sampling_ratio;
 
         /* management/no-ack frames do not use rate control */
@@ -262,107 +307,75 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
         else
                 sampling_ratio = mp->lookaround_rate;
 
-        /* init rateindex [ndx] with max throughput rate */
-        ndx = mi->max_tp_rate[0];
-
         /* increase sum packet counter */
         mi->packet_count++;
 
         delta = (mi->packet_count * sampling_ratio / 100) -
                         (mi->sample_count + mi->sample_deferred / 2);
 
-        /* delta > 0: sampling required */
-        if ((delta > 0) && (mrr_capable || !mi->prev_sample)) {
-                struct minstrel_rate *msr;
-                if (mi->packet_count >= 10000) {
-                        mi->sample_deferred = 0;
-                        mi->sample_count = 0;
-                        mi->packet_count = 0;
-                } else if (delta > mi->n_rates * 2) {
-                        /* With multi-rate retry, not every planned sample
-                         * attempt actually gets used, due to the way the retry
-                         * chain is set up - [max_tp,sample,prob,lowest] for
-                         * sample_rate < max_tp.
-                         *
-                         * If there's too much sampling backlog and the link
-                         * starts getting worse, minstrel would start bursting
-                         * out lots of sampling frames, which would result
-                         * in a large throughput loss. */
-                        mi->sample_count += (delta - mi->n_rates * 2);
-                }
+        /* delta < 0: no sampling required */
+        mi->prev_sample = false;
+        if (delta < 0 || (!mrr_capable && prev_sample))
+                return;
 
-                /* get next random rate sample */
-                sample_ndx = minstrel_get_next_sample(mi);
-                msr = &mi->r[sample_ndx];
-                rate_sampling = true;
-
-                /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage)
-                 * rate sampling method should be used.
-                 * Respect such rates that are not sampled for 20 interations.
-                 */
-                if (mrr_capable &&
-                    msr->perfect_tx_time > mi->r[ndx].perfect_tx_time &&
-                    msr->sample_skipped < 20)
-                                indirect_rate_sampling = true;
-
-                if (!indirect_rate_sampling) {
-                        if (msr->sample_limit != 0) {
-                                ndx = sample_ndx;
-                                mi->sample_count++;
-                                if (msr->sample_limit > 0)
-                                        msr->sample_limit--;
-                        } else
-                                rate_sampling = false;
-                } else {
-                        /* 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;
-                        mi->sample_deferred++;
-                }
+        if (mi->packet_count >= 10000) {
+                mi->sample_deferred = 0;
+                mi->sample_count = 0;
+                mi->packet_count = 0;
+        } else if (delta > mi->n_rates * 2) {
+                /* With multi-rate retry, not every planned sample
+                 * attempt actually gets used, due to the way the retry
+                 * chain is set up - [max_tp,sample,prob,lowest] for
+                 * sample_rate < max_tp.
+                 *
+                 * If there's too much sampling backlog and the link
+                 * starts getting worse, minstrel would start bursting
+                 * out lots of sampling frames, which would result
+                 * in a large throughput loss. */
+                mi->sample_count += (delta - mi->n_rates * 2);
+        }
+
+        /* get next random rate sample */
+        ndx = minstrel_get_next_sample(mi);
+        msr = &mi->r[ndx];
+        mr = &mi->r[mi->max_tp_rate[0]];
+
+        /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage)
+         * 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->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->sample_limit != 0)
+                        return;
+
+                mi->sample_count++;
+                if (msr->sample_limit > 0)
+                        msr->sample_limit--;
         }
-        mi->prev_sample = rate_sampling;
 
         /* If we're not using MRR and the sampling rate already
          * has a probability of >95%, we shouldn't be attempting
          * to use it, as this only wastes precious airtime */
-        if (!mrr_capable && rate_sampling &&
+        if (!mrr_capable &&
            (mi->r[ndx].probability > MINSTREL_FRAC(95, 100)))
-                ndx = mi->max_tp_rate[0];
-
-        /* mrr setup for 1st stage */
-        ar[0].idx = mi->r[ndx].rix;
-        ar[0].count = minstrel_get_retry_count(&mi->r[ndx], info);
-
-        /* non mrr setup for 2nd stage */
-        if (!mrr_capable) {
-                if (!rate_sampling)
-                        ar[0].count = mp->max_retry;
-                ar[1].idx = mi->lowest_rix;
-                ar[1].count = mp->max_retry;
                 return;
-        }
 
-        /* mrr setup for 2nd stage */
-        if (rate_sampling) {
-                if (indirect_rate_sampling)
-                        mrr_ndx[0] = sample_ndx;
-                else
-                        mrr_ndx[0] = mi->max_tp_rate[0];
-        } else {
-                mrr_ndx[0] = mi->max_tp_rate[1];
-        }
+        mi->prev_sample = true;
 
-        /* mrr setup for 3rd & 4th stage */
-        mrr_ndx[1] = mi->max_prob_rate;
-        mrr_ndx[2] = 0;
-        for (i = 1; i < 4; i++) {
-                ar[i].idx = mi->r[mrr_ndx[i - 1]].rix;
-                ar[i].count = mi->r[mrr_ndx[i - 1]].adjusted_retry_count;
-        }
+        rate->idx = mi->r[ndx].rix;
+        rate->count = minstrel_get_retry_count(&mi->r[ndx], info);
 }
 
 
@@ -412,12 +425,16 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
         unsigned int i, n = 0;
         unsigned int t_slot = 9; /* FIXME: get real slot time */
 
+        mi->sta = sta;
         mi->lowest_rix = rate_lowest_index(sband, sta);
         ctl_rate = &sband->bitrates[mi->lowest_rix];
         mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10,
                                 ctl_rate->bitrate,
                                 !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1);
 
+        memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate));
+        mi->max_prob_rate = 0;
+
         for (i = 0; i < sband->n_bitrates; i++) {
                 struct minstrel_rate *mr = &mi->r[n];
                 unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0;
@@ -473,6 +490,7 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
         mi->stats_update = jiffies;
 
         init_sample_table(mi);
+        minstrel_update_rates(mp, mi);
 }
 
 static void *