iwlwifi: mvm: choose an initial tx rate based on rssi conditions
Improve the initial tx rate and antenna selection to be based on
the rssi of the last rx. This avoids starting at the lowest legacy
rate always and requiring more tx traffic to "climb" up the rates.
Since this option might cause trouble in certain setups, allow to
disable it by default.
Signed-off-by: Eyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/mvm/rs.c b/drivers/net/wireless/iwlwifi/mvm/rs.c
index f77dfe4..d179a8e 100644
--- a/drivers/net/wireless/iwlwifi/mvm/rs.c
+++ b/drivers/net/wireless/iwlwifi/mvm/rs.c
@@ -2288,6 +2288,110 @@
lq_sta->last_txrate_idx = index;
}
+struct rs_init_rate_info {
+ s8 rssi;
+ u8 rate_idx;
+};
+
+static const struct rs_init_rate_info rs_init_rates_24ghz[] = {
+ { -60, IWL_RATE_54M_INDEX },
+ { -64, IWL_RATE_48M_INDEX },
+ { -68, IWL_RATE_36M_INDEX },
+ { -80, IWL_RATE_24M_INDEX },
+ { -84, IWL_RATE_18M_INDEX },
+ { -85, IWL_RATE_12M_INDEX },
+ { -86, IWL_RATE_11M_INDEX },
+ { -88, IWL_RATE_5M_INDEX },
+ { -90, IWL_RATE_2M_INDEX },
+ { S8_MIN, IWL_RATE_1M_INDEX },
+};
+
+static const struct rs_init_rate_info rs_init_rates_5ghz[] = {
+ { -60, IWL_RATE_54M_INDEX },
+ { -64, IWL_RATE_48M_INDEX },
+ { -72, IWL_RATE_36M_INDEX },
+ { -80, IWL_RATE_24M_INDEX },
+ { -84, IWL_RATE_18M_INDEX },
+ { -85, IWL_RATE_12M_INDEX },
+ { -87, IWL_RATE_9M_INDEX },
+ { S8_MIN, IWL_RATE_6M_INDEX },
+};
+
+/* Choose an initial legacy rate and antenna to use based on the RSSI
+ * of last Rx
+ */
+static void rs_get_initial_rate(struct iwl_mvm *mvm,
+ struct iwl_lq_sta *lq_sta,
+ enum ieee80211_band band,
+ struct rs_rate *rate)
+{
+ int i, nentries;
+ s8 best_rssi = S8_MIN;
+ u8 best_ant = ANT_NONE;
+ u8 valid_tx_ant = mvm->fw->valid_tx_ant;
+ const struct rs_init_rate_info *initial_rates;
+
+ for (i = 0; i < ARRAY_SIZE(lq_sta->pers.chain_signal); i++) {
+ if (!(lq_sta->pers.chains & BIT(i)))
+ continue;
+
+ if (lq_sta->pers.chain_signal[i] > best_rssi) {
+ best_rssi = lq_sta->pers.chain_signal[i];
+ best_ant = BIT(i);
+ }
+ }
+
+ IWL_DEBUG_RATE(mvm, "Best ANT: %s Best RSSI: %d\n",
+ rs_pretty_ant(best_ant), best_rssi);
+
+ if (best_ant != ANT_A && best_ant != ANT_B)
+ rate->ant = first_antenna(valid_tx_ant);
+ else
+ rate->ant = best_ant;
+
+ rate->sgi = false;
+ rate->ldpc = false;
+ rate->bw = RATE_MCS_CHAN_WIDTH_20;
+
+ rate->index = find_first_bit(&lq_sta->active_legacy_rate,
+ BITS_PER_LONG);
+
+ if (band == IEEE80211_BAND_5GHZ) {
+ rate->type = LQ_LEGACY_A;
+ initial_rates = rs_init_rates_5ghz;
+ nentries = ARRAY_SIZE(rs_init_rates_5ghz);
+ } else {
+ rate->type = LQ_LEGACY_G;
+ initial_rates = rs_init_rates_24ghz;
+ nentries = ARRAY_SIZE(rs_init_rates_24ghz);
+ }
+
+ if (IWL_MVM_RS_RSSI_BASED_INIT_RATE) {
+ for (i = 0; i < nentries; i++) {
+ int rate_idx = initial_rates[i].rate_idx;
+ if ((best_rssi >= initial_rates[i].rssi) &&
+ (BIT(rate_idx) & lq_sta->active_legacy_rate)) {
+ rate->index = rate_idx;
+ break;
+ }
+ }
+ }
+
+ IWL_DEBUG_RATE(mvm, "rate_idx %d ANT %s\n", rate->index,
+ rs_pretty_ant(rate->ant));
+}
+
+/* Save info about RSSI of last Rx */
+void rs_update_last_rssi(struct iwl_mvm *mvm,
+ struct iwl_lq_sta *lq_sta,
+ struct ieee80211_rx_status *rx_status)
+{
+ lq_sta->pers.chains = rx_status->chains;
+ lq_sta->pers.chain_signal[0] = rx_status->chain_signal[0];
+ lq_sta->pers.chain_signal[1] = rx_status->chain_signal[1];
+ lq_sta->pers.chain_signal[2] = rx_status->chain_signal[2];
+}
+
/**
* rs_initialize_lq - Initialize a station's hardware rate table
*
@@ -2310,17 +2414,11 @@
{
struct iwl_scale_tbl_info *tbl;
struct rs_rate *rate;
- int i;
u8 active_tbl = 0;
- u8 valid_tx_ant;
if (!sta || !lq_sta)
return;
- i = lq_sta->last_txrate_idx;
-
- valid_tx_ant = mvm->fw->valid_tx_ant;
-
if (!lq_sta->search_better_tbl)
active_tbl = lq_sta->active_tbl;
else
@@ -2329,18 +2427,8 @@
tbl = &(lq_sta->lq_info[active_tbl]);
rate = &tbl->rate;
- if ((i < 0) || (i >= IWL_RATE_COUNT))
- i = 0;
-
- rate->index = i;
- rate->ant = first_antenna(valid_tx_ant);
- rate->sgi = false;
- rate->ldpc = false;
- rate->bw = RATE_MCS_CHAN_WIDTH_20;
- if (band == IEEE80211_BAND_5GHZ)
- rate->type = LQ_LEGACY_A;
- else
- rate->type = LQ_LEGACY_G;
+ rs_get_initial_rate(mvm, lq_sta, band, rate);
+ lq_sta->last_txrate_idx = rate->index;
WARN_ON_ONCE(rate->ant != ANT_A && rate->ant != ANT_B);
if (rate->ant == ANT_A)
@@ -2397,6 +2485,8 @@
lq_sta->pers.dbg_fixed_rate = 0;
lq_sta->pers.dbg_fixed_txp_reduction = TPC_INVALID;
#endif
+ lq_sta->pers.chains = 0;
+ memset(lq_sta->pers.chain_signal, 0, sizeof(lq_sta->pers.chain_signal));
return &sta_priv->lq_sta;
}
@@ -2630,11 +2720,6 @@
/* as default allow aggregation for all tids */
lq_sta->tx_agg_tid_en = IWL_AGG_ALL_TID;
-
- /* Set last_txrate_idx to lowest rate */
- lq_sta->last_txrate_idx = rate_lowest_index(sband, sta);
- if (sband->band == IEEE80211_BAND_5GHZ)
- lq_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
lq_sta->is_agg = 0;
#ifdef CONFIG_IWLWIFI_DEBUGFS
iwl_mvm_reset_frame_stats(mvm, &mvm->drv_rx_stats);