mac80211/minstrel: use the new rate control API
authorFelix Fietkau <nbd@openwrt.org>
Mon, 22 Apr 2013 14:14:43 +0000 (16:14 +0200)
committerJohannes Berg <johannes.berg@intel.com>
Mon, 22 Apr 2013 14:16:41 +0000 (16:16 +0200)
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>
net/mac80211/rc80211_minstrel.c
net/mac80211/rc80211_minstrel.h

index eda290fb8bd2145260f5f312d7cc40675761e2b0..ac7ef5414bdede030d289a81946eaabc7b5d7a88 100644 (file)
@@ -83,6 +83,50 @@ minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list)
                tp_list[j] = i;
 }
 
+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)
 {
@@ -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 *
index b9f8535fa15c51c59d8a8abff373c5344694dbb5..f4301f4b2e418f1e325ccd78c4c2a6986303ca36 100644 (file)
@@ -63,6 +63,8 @@ struct minstrel_rate {
 };
 
 struct minstrel_sta_info {
+       struct ieee80211_sta *sta;
+
        unsigned long stats_update;
        unsigned int sp_ack_dur;
        unsigned int rate_avg;