From 7ceb98a313b8a1a5d949f538f4bb5ead4fabad23 Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Mon, 28 Jul 2014 12:59:45 +0300 Subject: [PATCH] iwlwifi: mvm: reduce the AMPDU size in low latency mode This allows to leave a frame in the Tx Fifo which allows the firmware to try to enter burst mode. The end result of this is a better latency since the firmware utilises the TxOP better. Also limit the AMPDU size to the limit set in the ADDBA response. This doesn't change much since the AMPDU size was limited by the configuration of the hardware scheduler, but here we add a software limit by the mean of the link quality command. Reviewed-by: Johannes Berg Signed-off-by: Emmanuel Grumbach --- drivers/net/wireless/iwlwifi/mvm/rs.c | 56 ++++++++++++++++++--------- 1 file changed, 38 insertions(+), 18 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/mvm/rs.c b/drivers/net/wireless/iwlwifi/mvm/rs.c index c70e959bf0e3..51fa571d5c45 100644 --- a/drivers/net/wireless/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/iwlwifi/mvm/rs.c @@ -2678,6 +2678,7 @@ static void rs_build_rates_table_from_fixed(struct iwl_mvm *mvm, int i; int num_rates = ARRAY_SIZE(lq_cmd->rs_table); __le32 ucode_rate_le32 = cpu_to_le32(ucode_rate); + u8 ant = (ucode_rate & RATE_MCS_ANT_ABC_MSK) >> RATE_MCS_ANT_POS; for (i = 0; i < num_rates; i++) lq_cmd->rs_table[i] = ucode_rate_le32; @@ -2688,6 +2689,13 @@ static void rs_build_rates_table_from_fixed(struct iwl_mvm *mvm, lq_cmd->mimo_delim = num_rates - 1; else lq_cmd->mimo_delim = 0; + + lq_cmd->reduced_tpc = 0; + + if (num_of_ant(ant) == 1) + lq_cmd->single_stream_ant_msk = ant; + + lq_cmd->agg_frame_cnt_limit = LINK_QUAL_AGG_FRAME_LIMIT_DEF; } #endif /* CONFIG_MAC80211_DEBUGFS */ @@ -2811,31 +2819,46 @@ static void rs_fill_lq_cmd(struct iwl_mvm *mvm, const struct rs_rate *initial_rate) { struct iwl_lq_cmd *lq_cmd = &lq_sta->lq; - u8 ant = initial_rate->ant; + struct iwl_mvm_sta *mvmsta; + struct iwl_mvm_vif *mvmvif; + + lq_cmd->agg_disable_start_th = LINK_QUAL_AGG_DISABLE_START_DEF; + lq_cmd->agg_time_limit = + cpu_to_le16(LINK_QUAL_AGG_TIME_LIMIT_DEF); #ifdef CONFIG_MAC80211_DEBUGFS if (lq_sta->pers.dbg_fixed_rate) { rs_build_rates_table_from_fixed(mvm, lq_cmd, lq_sta->band, lq_sta->pers.dbg_fixed_rate); - lq_cmd->reduced_tpc = 0; - ant = (lq_sta->pers.dbg_fixed_rate & RATE_MCS_ANT_ABC_MSK) >> - RATE_MCS_ANT_POS; - } else + return; + } #endif - rs_build_rates_table(mvm, lq_sta, initial_rate); + if (WARN_ON_ONCE(!sta || !initial_rate)) + return; - if (num_of_ant(ant) == 1) - lq_cmd->single_stream_ant_msk = ant; + rs_build_rates_table(mvm, lq_sta, initial_rate); - lq_cmd->agg_frame_cnt_limit = LINK_QUAL_AGG_FRAME_LIMIT_DEF; - lq_cmd->agg_disable_start_th = LINK_QUAL_AGG_DISABLE_START_DEF; + if (num_of_ant(initial_rate->ant) == 1) + lq_cmd->single_stream_ant_msk = initial_rate->ant; - lq_cmd->agg_time_limit = - cpu_to_le16(LINK_QUAL_AGG_TIME_LIMIT_DEF); + mvmsta = iwl_mvm_sta_from_mac80211(sta); + mvmvif = iwl_mvm_vif_from_mac80211(mvmsta->vif); - if (sta) - lq_cmd->agg_time_limit = + if (num_of_ant(initial_rate->ant) == 1) + lq_cmd->single_stream_ant_msk = initial_rate->ant; + + lq_cmd->agg_frame_cnt_limit = mvmsta->max_agg_bufsize; + + /* + * In case of low latency, tell the firwmare to leave a frame in the + * Tx Fifo so that it can start a transaction in the same TxOP. This + * basically allows the firmware to send bursts. + */ + if (iwl_mvm_vif_low_latency(mvmvif)) + lq_cmd->agg_frame_cnt_limit--; + + lq_cmd->agg_time_limit = cpu_to_le16(iwl_mvm_coex_agg_time_limit(mvm, sta)); } @@ -2932,10 +2955,7 @@ static void rs_program_fix_rate(struct iwl_mvm *mvm, lq_sta->lq.sta_id, lq_sta->pers.dbg_fixed_rate); if (lq_sta->pers.dbg_fixed_rate) { - struct rs_rate rate; - rs_rate_from_ucode_rate(lq_sta->pers.dbg_fixed_rate, - lq_sta->band, &rate); - rs_fill_lq_cmd(mvm, NULL, lq_sta, &rate); + rs_fill_lq_cmd(mvm, NULL, lq_sta, NULL); iwl_mvm_send_lq_cmd(lq_sta->pers.drv, &lq_sta->lq, false); } } -- 2.39.2