From: Andy Lutomirski <luto@mit.edu>
To: "reinette chatre" <reinette.chatre@intel.com>
Cc: linville@tuxdriver.com, linux-wireless@vger.kernel.org,
ipw3943-devel@lists.sourceforge.net,
Trieu 'Andrew' Nguyen <trieux.t.nguyen@intel.com>
Subject: Re: [PATCH 12/12] iwlwifi: Monitor and recover the aggregation TX flow failure
Date: Fri, 12 Feb 2010 08:53:15 -0500 [thread overview]
Message-ID: <4B755D4B.8060005@mit.edu> (raw)
In-Reply-To: <1265913725-4279-13-git-send-email-reinette.chatre@intel.com>
Reinette Chatre wrote:
> From: Trieu 'Andrew' Nguyen <trieux.t.nguyen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>
> 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.
Any chance this fixes big 2120? Maybe I'm too optimistic, but I'll try
to test it this afternoon.
http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2120
--Andy
>
> Signed-off-by: Trieu 'Andrew' Nguyen <trieux.t.nguyen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Reinette Chatre <reinette.chatre-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
> drivers/net/wireless/iwlwifi/iwl-agn.c | 14 +++++++++-
> drivers/net/wireless/iwlwifi/iwl-dev.h | 3 ++
> drivers/net/wireless/iwlwifi/iwl-rx.c | 46 ++++++++++++++++++++++++++++++++
> 3 files changed, 62 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
> index 31b156d..4157c6c 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-agn.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
> @@ -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)
> diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
> index 71cf155..f81317d 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-dev.h
> +++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
> @@ -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;
>
> diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
> index aba8f4c..fed554a 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-rx.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
> @@ -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.
prev parent reply other threads:[~2010-02-12 14:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-11 18:41 [PATCH 00/12] iwlwifi updates for 2.6.34 Reinette Chatre
2010-02-11 18:41 ` [PATCH 01/12] iwlwifi: clear all tx queues when firmware ready Reinette Chatre
2010-02-11 18:41 ` [PATCH 02/12] iwlwifi: multiple force reset mode Reinette Chatre
2010-02-11 18:41 ` [PATCH 03/12] iwlwifi: add debug function to reset/reload radio/firmware Reinette Chatre
2010-02-11 18:41 ` [PATCH 04/12] iwlwifi: check for aggregation frame and queue Reinette Chatre
2010-02-11 18:41 ` [PATCH 05/12] iwlwifi: remove unused op-code in PHY Calibration command Reinette Chatre
2010-02-11 20:17 ` [ipw3945-devel] " Cahill, Ben M
2010-02-11 20:22 ` Guy, Wey-Yi
2010-02-11 21:23 ` Cahill, Ben M
2010-02-11 18:41 ` [PATCH 06/12] iwlwifi: cleanup return values Reinette Chatre
2010-02-11 18:42 ` [PATCH 07/12] iwlwifi: fix scan race Reinette Chatre
2010-02-11 18:42 ` [PATCH 08/12] iwlwifi: reset card during probe Reinette Chatre
2010-02-11 18:42 ` [PATCH 09/12] iwlwifi: Adjusting PLCP error threshold for 1000 NIC Reinette Chatre
2010-02-11 18:42 ` [PATCH 10/12] iwlwifi: use dma_alloc_coherent Reinette Chatre
2010-02-11 18:42 ` [PATCH 11/12] iwlwifi: clear all the stop_queue flag after load firmware Reinette Chatre
2010-02-11 18:42 ` [PATCH 12/12] iwlwifi: Monitor and recover the aggregation TX flow failure Reinette Chatre
2010-02-12 13:53 ` Andy Lutomirski [this message]
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