const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
+static const u8 minstrel_sample_seq[] = {
+ MINSTREL_SAMPLE_TYPE_INC,
+ MINSTREL_SAMPLE_TYPE_JUMP,
+ MINSTREL_SAMPLE_TYPE_INC,
+ MINSTREL_SAMPLE_TYPE_JUMP,
+ MINSTREL_SAMPLE_TYPE_INC,
+ MINSTREL_SAMPLE_TYPE_SLOW,
+};
static void
minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
}
}
-static bool
-minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group,
- int tp_idx, const struct mcs_group *group)
-{
- if (group->bw < tp_group->bw)
- return false;
-
- if (group->streams == tp_group->streams)
- return true;
-
- if (tp_idx < 4 && group->streams == tp_group->streams - 1)
- return true;
-
- return group->streams == tp_group->streams + 1;
-}
-
-static void
-minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates,
- bool faster_rate)
+static u16
+__minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi,
+ enum minstrel_sample_type type)
{
- const struct mcs_group *group, *tp_group;
- int i, g, max_dur;
- int tp_idx;
-
- tp_group = &minstrel_mcs_groups[MI_RATE_GROUP(mi->max_tp_rate[0])];
- tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]);
-
- max_dur = minstrel_get_duration(mi->max_tp_rate[0]);
- if (faster_rate)
- max_dur -= max_dur / 16;
-
- for (g = 0; g < MINSTREL_GROUPS_NB; g++) {
- u16 supported = mi->supported[g];
-
- if (!supported)
- continue;
+ u16 *rates = mi->sample[type].sample_rates;
+ u16 cur;
+ int i;
- group = &minstrel_mcs_groups[g];
- if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group))
+ for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
+ if (!rates[i])
continue;
- for (i = 0; supported; supported >>= 1, i++) {
- int idx;
-
- if (!(supported & 1))
- continue;
-
- if ((group->duration[i] << group->shift) > max_dur)
- continue;
-
- idx = MI_RATE(g, i);
- if (idx == mi->max_tp_rate[0])
- continue;
-
- rates[(*n_rates)++] = idx;
- break;
- }
+ cur = rates[i];
+ rates[i] = 0;
+ return cur;
}
+
+ return 0;
}
static void
minstrel_ht_rate_sample_switch(struct minstrel_priv *mp,
struct minstrel_ht_sta *mi)
{
- struct minstrel_rate_stats *mrs;
- u16 rates[MINSTREL_GROUPS_NB];
- int n_rates = 0;
- int probe_rate = 0;
- bool faster_rate;
- int i;
- u8 random;
+ u16 rate;
/*
* Use rate switching instead of probing packets for devices with
if (mp->hw->max_rates > 1)
return;
- /*
- * If the current EWMA prob is >75%, look for a rate that's 6.25%
- * faster than the max tp rate.
- * If that fails, look again for a rate that is at least as fast
- */
- mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
- faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100);
- minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate);
- if (!n_rates && faster_rate)
- minstrel_ht_find_probe_rates(mi, rates, &n_rates, false);
-
- /* If no suitable rate was found, try to pick the next one in the group */
- if (!n_rates) {
- int g_idx = MI_RATE_GROUP(mi->max_tp_rate[0]);
- u16 supported = mi->supported[g_idx];
-
- supported >>= MI_RATE_IDX(mi->max_tp_rate[0]);
- for (i = 0; supported; supported >>= 1, i++) {
- if (!(supported & 1))
- continue;
-
- probe_rate = mi->max_tp_rate[0] + i;
- goto out;
- }
-
+ rate = __minstrel_ht_get_sample_rate(mi, MINSTREL_SAMPLE_TYPE_INC);
+ if (!rate)
return;
- }
- i = 0;
- if (n_rates > 1) {
- random = prandom_u32();
- i = random % n_rates;
- }
- probe_rate = rates[i];
-
-out:
- mi->sample_rate = probe_rate;
+ mi->sample_rate = rate;
mi->sample_mode = MINSTREL_SAMPLE_ACTIVE;
}
mrs->attempts = 0;
}
+static bool
+minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx)
+{
+ int i;
+
+ for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
+ u16 cur = mi->sample[type].sample_rates[i];
+
+ if (cur == idx)
+ return true;
+
+ if (!cur)
+ break;
+ }
+
+ return false;
+}
+
+static int
+minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type,
+ u32 fast_rate_dur, u32 slow_rate_dur)
+{
+ u16 *rates = mi->sample[type].sample_rates;
+ int i, j;
+
+ for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) {
+ u32 duration;
+ bool valid = false;
+ u16 cur;
+
+ cur = rates[i];
+ if (!cur)
+ continue;
+
+ duration = minstrel_get_duration(cur);
+ switch (type) {
+ case MINSTREL_SAMPLE_TYPE_SLOW:
+ valid = duration > fast_rate_dur &&
+ duration < slow_rate_dur;
+ break;
+ case MINSTREL_SAMPLE_TYPE_INC:
+ case MINSTREL_SAMPLE_TYPE_JUMP:
+ valid = duration < fast_rate_dur;
+ break;
+ default:
+ valid = false;
+ break;
+ }
+
+ if (!valid) {
+ rates[i] = 0;
+ continue;
+ }
+
+ if (i == j)
+ continue;
+
+ rates[j++] = cur;
+ rates[i] = 0;
+ }
+
+ return j;
+}
+
+static int
+minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group,
+ u32 max_duration)
+{
+ u16 supported = mi->supported[group];
+ int i;
+
+ for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) {
+ if (!(supported & BIT(0)))
+ continue;
+
+ if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration)
+ continue;
+
+ return i;
+ }
+
+ return -1;
+}
+
+/*
+ * Incremental update rates:
+ * Flip through groups and pick the first group rate that is faster than the
+ * highest currently selected rate
+ */
+static u16
+minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur)
+{
+ struct minstrel_mcs_group_data *mg;
+ u8 type = MINSTREL_SAMPLE_TYPE_INC;
+ int i, index = 0;
+ u8 group;
+
+ group = mi->sample[type].sample_group;
+ for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
+ group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
+ mg = &mi->groups[group];
+
+ index = minstrel_ht_group_min_rate_offset(mi, group,
+ fast_rate_dur);
+ if (index < 0)
+ continue;
+
+ index = MI_RATE(group, index & 0xf);
+ if (!minstrel_ht_find_sample_rate(mi, type, index))
+ goto out;
+ }
+ index = 0;
+
+out:
+ mi->sample[type].sample_group = group;
+
+ return index;
+}
+
+static int
+minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group,
+ u16 supported, int offset)
+{
+ struct minstrel_mcs_group_data *mg = &mi->groups[group];
+ u16 idx;
+ int i;
+
+ for (i = 0; i < MCS_GROUP_RATES; i++) {
+ idx = sample_table[mg->column][mg->index];
+ if (++mg->index >= MCS_GROUP_RATES) {
+ mg->index = 0;
+ if (++mg->column >= ARRAY_SIZE(sample_table))
+ mg->column = 0;
+ }
+
+ if (idx < offset)
+ continue;
+
+ if (!(supported & BIT(idx)))
+ continue;
+
+ return MI_RATE(group, idx);
+ }
+
+ return -1;
+}
+
+/*
+ * Jump rates:
+ * Sample random rates, use those that are faster than the highest
+ * currently selected rate. Rates between the fastest and the slowest
+ * get sorted into the slow sample bucket, but only if it has room
+ */
+static u16
+minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur,
+ u32 slow_rate_dur, int *slow_rate_ofs)
+{
+ struct minstrel_mcs_group_data *mg;
+ struct minstrel_rate_stats *mrs;
+ u32 max_duration = slow_rate_dur;
+ int i, index, offset;
+ u16 *slow_rates;
+ u16 supported;
+ u32 duration;
+ u8 group;
+
+ if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
+ max_duration = fast_rate_dur;
+
+ slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates;
+ group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group;
+ for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
+ u8 type;
+
+ group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
+ mg = &mi->groups[group];
+
+ supported = mi->supported[group];
+ if (!supported)
+ continue;
+
+ offset = minstrel_ht_group_min_rate_offset(mi, group,
+ max_duration);
+ if (offset < 0)
+ continue;
+
+ index = minstrel_ht_next_group_sample_rate(mi, group, supported,
+ offset);
+ if (index < 0)
+ continue;
+
+ duration = minstrel_get_duration(index);
+ if (duration < fast_rate_dur)
+ type = MINSTREL_SAMPLE_TYPE_JUMP;
+ else
+ type = MINSTREL_SAMPLE_TYPE_SLOW;
+
+ if (minstrel_ht_find_sample_rate(mi, type, index))
+ continue;
+
+ if (type == MINSTREL_SAMPLE_TYPE_JUMP)
+ goto found;
+
+ if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
+ continue;
+
+ if (duration >= slow_rate_dur)
+ continue;
+
+ /* skip slow rates with high success probability */
+ mrs = minstrel_get_ratestats(mi, index);
+ if (mrs->prob_avg > MINSTREL_FRAC(95, 100))
+ continue;
+
+ slow_rates[(*slow_rate_ofs)++] = index;
+ if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
+ max_duration = fast_rate_dur;
+ }
+ index = 0;
+
+found:
+ mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group;
+
+ return index;
+}
+
+static void
+minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi)
+{
+ u32 prob_dur = minstrel_get_duration(mi->max_prob_rate);
+ u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]);
+ u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]);
+ u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur);
+ u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur);
+ u16 *rates;
+ int i, j;
+
+ rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates;
+ i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC,
+ fast_rate_dur, slow_rate_dur);
+ while (i < MINSTREL_SAMPLE_RATES) {
+ rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur);
+ if (!rates[i])
+ break;
+
+ i++;
+ }
+
+ rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates;
+ i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP,
+ fast_rate_dur, slow_rate_dur);
+ j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW,
+ fast_rate_dur, slow_rate_dur);
+ while (i < MINSTREL_SAMPLE_RATES) {
+ rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur,
+ slow_rate_dur, &j);
+ if (!rates[i])
+ break;
+
+ i++;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(mi->sample); i++)
+ memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates,
+ sizeof(mi->sample[i].cur_sample_rates));
+}
+
+
/*
* Update rate statistics and select new primary rates
*
mi->ampdu_packets = 0;
}
- mi->sample_count = 0;
-
if (mi->supported[MINSTREL_CCK_GROUP])
group = MINSTREL_CCK_GROUP;
else if (mi->supported[MINSTREL_OFDM_GROUP])
if (!mi->supported[group])
continue;
- mi->sample_count++;
-
/* (re)Initialize group rate indexes */
for(j = 0; j < MAX_THR_RATES; j++)
tmp_group_tp_rate[j] = MI_RATE(group, 0);
/* Try to increase robustness of max_prob_rate*/
minstrel_ht_prob_rate_reduce_streams(mi);
-
- /* try to sample half of all available rates during each interval */
- mi->sample_count *= 4;
+ minstrel_ht_refill_sample_rates(mi);
if (sample)
minstrel_ht_rate_sample_switch(mp, mi);
/* Reset update timer */
mi->last_stats_update = jiffies;
+ mi->sample_time = jiffies;
}
static bool
return false;
}
-static void
-minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
-{
- struct minstrel_mcs_group_data *mg;
-
- for (;;) {
- mi->sample_group++;
- mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
- mg = &mi->groups[mi->sample_group];
-
- if (!mi->supported[mi->sample_group])
- continue;
-
- if (++mg->index >= MCS_GROUP_RATES) {
- mg->index = 0;
- if (++mg->column >= ARRAY_SIZE(sample_table))
- mg->column = 0;
- }
- break;
- }
-}
-
static void
minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
{
mi->ampdu_packets++;
mi->ampdu_len += info->status.ampdu_len;
- if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
- int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
-
- mi->sample_wait = 16 + 2 * avg_ampdu_len;
- mi->sample_tries = 1;
- mi->sample_count--;
- }
-
if (mi->sample_mode != MINSTREL_SAMPLE_IDLE)
rate_sample = minstrel_get_ratestats(mi, mi->sample_rate);
rate_control_set_rates(mp->hw, mi->sta, rates);
}
-static int
-minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
+static u16
+minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
{
- struct minstrel_rate_stats *mrs;
- struct minstrel_mcs_group_data *mg;
- unsigned int sample_dur, sample_group, cur_max_tp_streams;
- int tp_rate1, tp_rate2;
- int sample_idx = 0;
-
- if (mp->hw->max_rates == 1 && mp->sample_switch &&
- (mi->total_packets_cur >= SAMPLE_SWITCH_THR ||
- mp->sample_switch == 1))
- return -1;
+ u8 seq;
- if (mi->sample_wait > 0) {
- mi->sample_wait--;
- return -1;
- }
-
- if (!mi->sample_tries)
- return -1;
-
- sample_group = mi->sample_group;
- mg = &mi->groups[sample_group];
- sample_idx = sample_table[mg->column][mg->index];
- minstrel_set_next_sample_idx(mi);
-
- if (!(mi->supported[sample_group] & BIT(sample_idx)))
- return -1;
-
- mrs = &mg->rates[sample_idx];
- sample_idx += MI_RATE(sample_group, 0);
-
- tp_rate1 = mi->max_tp_rate[0];
-
- /* Set tp_rate2 to the second highest max_tp_rate */
- if (minstrel_get_duration(mi->max_tp_rate[0]) >
- minstrel_get_duration(mi->max_tp_rate[1])) {
- tp_rate2 = mi->max_tp_rate[0];
+ if (mp->hw->max_rates > 1) {
+ seq = mi->sample_seq;
+ mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq);
+ seq = minstrel_sample_seq[seq];
} else {
- tp_rate2 = mi->max_tp_rate[1];
+ seq = MINSTREL_SAMPLE_TYPE_INC;
}
- /*
- * Sampling might add some overhead (RTS, no aggregation)
- * to the frame. Hence, don't use sampling for the highest currently
- * used highest throughput or probability rate.
- */
- if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
- return -1;
-
- /*
- * Do not sample if the probability is already higher than 95%,
- * or if the rate is 3 times slower than the current max probability
- * rate, to avoid wasting airtime.
- */
- sample_dur = minstrel_get_duration(sample_idx);
- if (mrs->prob_avg > MINSTREL_FRAC(95, 100) ||
- minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
- return -1;
-
-
- /*
- * For devices with no configurable multi-rate retry, skip sampling
- * below the per-group max throughput rate, and only use one sampling
- * attempt per rate
- */
- if (mp->hw->max_rates == 1 &&
- (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur ||
- mrs->attempts))
- return -1;
-
- /* Skip already sampled slow rates */
- if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts)
- return -1;
-
- /*
- * Make sure that lower rates get sampled only occasionally,
- * if the link is working perfectly.
- */
-
- cur_max_tp_streams = minstrel_mcs_groups[MI_RATE_GROUP(tp_rate1)].streams;
- if (sample_dur >= minstrel_get_duration(tp_rate2) &&
- (cur_max_tp_streams - 1 <
- minstrel_mcs_groups[sample_group].streams ||
- sample_dur >= minstrel_get_duration(mi->max_prob_rate)))
- return -1;
-
- mi->sample_tries--;
-
- return sample_idx;
+ return __minstrel_ht_get_sample_rate(mi, seq);
}
static void
struct ieee80211_tx_rate *rate = &info->status.rates[0];
struct minstrel_ht_sta *mi = priv_sta;
struct minstrel_priv *mp = priv;
- int sample_idx;
+ u16 sample_idx;
if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
!minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_prob_rate)))
/* Don't use EAPOL frames for sampling on non-mrr hw */
if (mp->hw->max_rates == 1 &&
(info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
- sample_idx = -1;
- else
- sample_idx = minstrel_get_sample_rate(mp, mi);
+ return;
+
+ if (mp->hw->max_rates == 1 && mp->sample_switch &&
+ (mi->total_packets_cur >= SAMPLE_SWITCH_THR ||
+ mp->sample_switch == 1))
+ return;
+
+ if (time_is_before_jiffies(mi->sample_time))
+ return;
- if (sample_idx < 0)
+ mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;
+ sample_idx = minstrel_ht_get_sample_rate(mp, mi);
+ if (!sample_idx)
return;
sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)];
mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
- /* When using MRR, sample more on the first attempt, without delay */
- if (mp->has_mrr) {
- mi->sample_count = 16;
- mi->sample_wait = 0;
- } else {
- mi->sample_count = 8;
- mi->sample_wait = 8;
- }
- mi->sample_tries = 4;
-
if (!use_vht) {
stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
IEEE80211_HT_CAP_RX_STBC_SHIFT;
projects / kernel.git / commitdiff