- /* 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--;