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authorWey-Yi Guy <wey-yi.w.guy@intel.com>2010-03-05 00:38:59 +0300
committerReinette Chatre <reinette.chatre@intel.com>2010-03-19 23:41:26 +0300
commitd5a0ffa3eaf9e898f25a925813f1a723be7808f8 (patch)
tree37610c33a6802b6eac524cc2cd298705059cf18d /drivers/net/wireless/iwlwifi/iwl-rx.c
parentbeac5498b792ed8420885ee23e8d4f2885ee2d13 (diff)
downloadlinux-d5a0ffa3eaf9e898f25a925813f1a723be7808f8.tar.xz
iwlwifi: Recover TX flow failure
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 BA_TIMEOUT_MAX, no tx packets can be delivered. Reloading the uCode and bring the system back to normal operational state. Signed-off-by: Trieu 'Andrew' Nguyen <trieux.t.nguyen@intel.com> Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Diffstat (limited to 'drivers/net/wireless/iwlwifi/iwl-rx.c')
-rw-r--r--drivers/net/wireless/iwlwifi/iwl-rx.c50
1 files changed, 49 insertions, 1 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index d368b8df8d87..7aef285d2818 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -616,9 +616,18 @@ 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"
/*
- * This function checks for plcp error.
+ * This function checks for plcp error, ACK count ratios, aggregated BA
+ * timeout retries.
+ * - When the ACK count ratio is 0 and aggregated BA timeout retries is
+ * exceeding the BA_TIMEOUT_MAX, it will recover the failure by resetting
+ * the firmware.
* - When the plcp error is exceeding the thresholds, it will reset the radio
* to improve the throughput.
*/
@@ -628,6 +637,45 @@ void iwl_recover_from_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;
+
+ 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->_agn.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);
+ }
+ }
/*
* check for plcp_err and trigger radio reset if it exceeds