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iwlwifi: Monitor and recover the aggregation TX flow failure

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This change monitors the tx statistics to detect the drop in throughput.
When the throughput drops, the ratio of the actual_ack_count and the expected_
ack_count also drops.  At the same time, the aggregated ba_timeout (the number
of ba timeout retries) also rises.  If the actual_ack_count/expected_ack_count
ratio is 0 and the number of ba timeout retries rises to 16, no tx packets
(tcp, udp, or ping - icmp) can be delivered.  The driver recovers from this
situation by reseting the uCode firmware.  If the actual_ack_count/expected_
ack_count ratio drops below 50% (but not 0) and the aggregated ba_timeout
retries just exceed 5 (but not 16), then the driver can reset the radio to
bring the throughput up.

Signed-off-by: Trieu 'Andrew' Nguyen <trieux.t.nguyen@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
This commit is contained in:
Trieu 'Andrew' Nguyen 2010-02-10 10:27:34 -08:00 committed by Reinette Chatre
parent a9e10fb9b1
commit 1db5950f1d
3 changed files with 62 additions and 1 deletions
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14
drivers/net/wireless/iwlwifi/iwl-agn.c
View file

@ -2941,10 +2941,21 @@ static int iwl_mac_ampdu_action(struct ieee80211_hw *hw,
return ret;
case IEEE80211_AMPDU_TX_START:
IWL_DEBUG_HT(priv, "start Tx\n");
return iwl_tx_agg_start(priv, sta->addr, tid, ssn);
ret = iwl_tx_agg_start(priv, sta->addr, tid, ssn);
if (ret == 0) {
priv->agg_tids_count++;
IWL_DEBUG_HT(priv, "priv->agg_tids_count = %u\n",
priv->agg_tids_count);
}
return ret;
case IEEE80211_AMPDU_TX_STOP:
IWL_DEBUG_HT(priv, "stop Tx\n");
ret = iwl_tx_agg_stop(priv, sta->addr, tid);
if ((ret == 0) && (priv->agg_tids_count > 0)) {
priv->agg_tids_count--;
IWL_DEBUG_HT(priv, "priv->agg_tids_count = %u\n",
priv->agg_tids_count);
}
if (test_bit(STATUS_EXIT_PENDING, &priv->status))
return 0;
else
@ -3364,6 +3375,7 @@ static int iwl_init_drv(struct iwl_priv *priv)
priv->iw_mode = NL80211_IFTYPE_STATION;
priv->current_ht_config.smps = IEEE80211_SMPS_STATIC;
priv->missed_beacon_threshold = IWL_MISSED_BEACON_THRESHOLD_DEF;
priv->agg_tids_count = 0;
/* Choose which receivers/antennas to use */
if (priv->cfg->ops->hcmd->set_rxon_chain)

3
drivers/net/wireless/iwlwifi/iwl-dev.h
View file

@ -1072,6 +1072,9 @@ struct iwl_priv {
/* storing the jiffies when the plcp error rate is received */
unsigned long plcp_jiffies;
/* reporting the number of tids has AGG on. 0 means no AGGREGATION */
u8 agg_tids_count;
/* force reset */
unsigned long last_force_reset_jiffies;

46
drivers/net/wireless/iwlwifi/iwl-rx.c
View file

@ -616,6 +616,11 @@ static void iwl_accumulative_statistics(struct iwl_priv *priv,
#define REG_RECALIB_PERIOD (60)
/* the threshold ratio of actual_ack_cnt to expected_ack_cnt in percent */
#define ACK_CNT_RATIO (50)
#define BA_TIMEOUT_CNT (5)
#define BA_TIMEOUT_MAX (16)
#define PLCP_MSG "plcp_err exceeded %u, %u, %u, %u, %u, %d, %u mSecs\n"
void iwl_rx_statistics(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
@ -625,6 +630,9 @@ void iwl_rx_statistics(struct iwl_priv *priv,
int combined_plcp_delta;
unsigned int plcp_msec;
unsigned long plcp_received_jiffies;
int actual_ack_cnt_delta;
int expected_ack_cnt_delta;
int ba_timeout_delta;
IWL_DEBUG_RX(priv, "Statistics notification received (%d vs %d).\n",
(int)sizeof(priv->statistics),
@ -639,6 +647,44 @@ void iwl_rx_statistics(struct iwl_priv *priv,
#ifdef CONFIG_IWLWIFI_DEBUG
iwl_accumulative_statistics(priv, (__le32 *)&pkt->u.stats);
#endif
actual_ack_cnt_delta = le32_to_cpu(pkt->u.stats.tx.actual_ack_cnt) -
le32_to_cpu(priv->statistics.tx.actual_ack_cnt);
expected_ack_cnt_delta = le32_to_cpu(
pkt->u.stats.tx.expected_ack_cnt) -
le32_to_cpu(priv->statistics.tx.expected_ack_cnt);
ba_timeout_delta = le32_to_cpu(
pkt->u.stats.tx.agg.ba_timeout) -
le32_to_cpu(priv->statistics.tx.agg.ba_timeout);
if ((priv->agg_tids_count > 0) &&
(expected_ack_cnt_delta > 0) &&
(((actual_ack_cnt_delta * 100) / expected_ack_cnt_delta) <
ACK_CNT_RATIO) &&
(ba_timeout_delta > BA_TIMEOUT_CNT)) {
IWL_DEBUG_RADIO(priv,
"actual_ack_cnt delta = %d, expected_ack_cnt = %d\n",
actual_ack_cnt_delta, expected_ack_cnt_delta);
#ifdef CONFIG_IWLWIFI_DEBUG
IWL_DEBUG_RADIO(priv, "rx_detected_cnt delta = %d\n",
priv->delta_statistics.tx.rx_detected_cnt);
IWL_DEBUG_RADIO(priv,
"ack_or_ba_timeout_collision delta = %d\n",
priv->delta_statistics.tx.ack_or_ba_timeout_collision);
#endif
IWL_DEBUG_RADIO(priv, "agg ba_timeout delta = %d\n",
ba_timeout_delta);
if ((actual_ack_cnt_delta == 0) &&
(ba_timeout_delta >=
BA_TIMEOUT_MAX)) {
IWL_DEBUG_RADIO(priv,
"call iwl_force_reset(IWL_FW_RESET)\n");
iwl_force_reset(priv, IWL_FW_RESET);
} else {
IWL_DEBUG_RADIO(priv,
"call iwl_force_reset(IWL_RF_RESET)\n");
iwl_force_reset(priv, IWL_RF_RESET);
}
}
/*
* check for plcp_err and trigger radio reset if it exceeds
* the plcp error threshold plcp_delta.