From 47df8e059b49a80c179fae39256bcd7096810934 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 8 Aug 2020 19:25:42 +0200 Subject: mac80211: reduce packet loss event false positives When running a large number of packets per second with a high data rate and long A-MPDUs, the packet loss threshold can be reached very quickly when the link conditions change. This frequently shows up as spurious disconnects. Mitigate false positives by using a similar logic for regular stations as the one being used for TDLS, though with a more aggressive timeout. Packet loss events are only reported if no ACK was received for a second. Signed-off-by: Felix Fietkau Link: https://lore.kernel.org/r/20200808172542.41628-1-nbd@nbd.name Signed-off-by: Johannes Berg --- net/mac80211/sta_info.h | 4 ++-- net/mac80211/status.c | 31 +++++++++++++++---------------- 2 files changed, 17 insertions(+), 18 deletions(-) diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h index 8060d142e4f1..d5010116cf4d 100644 --- a/net/mac80211/sta_info.h +++ b/net/mac80211/sta_info.h @@ -524,7 +524,7 @@ struct ieee80211_sta_rx_stats { * @status_stats.retry_failed: # of frames that failed after retry * @status_stats.retry_count: # of retries attempted * @status_stats.lost_packets: # of lost packets - * @status_stats.last_tdls_pkt_time: timestamp of last TDLS packet + * @status_stats.last_pkt_time: timestamp of last ACKed packet * @status_stats.msdu_retries: # of MSDU retries * @status_stats.msdu_failed: # of failed MSDUs * @status_stats.last_ack: last ack timestamp (jiffies) @@ -597,7 +597,7 @@ struct sta_info { unsigned long filtered; unsigned long retry_failed, retry_count; unsigned int lost_packets; - unsigned long last_tdls_pkt_time; + unsigned long last_pkt_time; u64 msdu_retries[IEEE80211_NUM_TIDS + 1]; u64 msdu_failed[IEEE80211_NUM_TIDS + 1]; unsigned long last_ack; diff --git a/net/mac80211/status.c b/net/mac80211/status.c index 6de63f1d8c7b..0794396a7988 100644 --- a/net/mac80211/status.c +++ b/net/mac80211/status.c @@ -755,12 +755,16 @@ static void ieee80211_report_used_skb(struct ieee80211_local *local, * - current throughput (higher value for higher tpt)? */ #define STA_LOST_PKT_THRESHOLD 50 +#define STA_LOST_PKT_TIME HZ /* 1 sec since last ACK */ #define STA_LOST_TDLS_PKT_THRESHOLD 10 #define STA_LOST_TDLS_PKT_TIME (10*HZ) /* 10secs since last ACK */ static void ieee80211_lost_packet(struct sta_info *sta, struct ieee80211_tx_info *info) { + unsigned long pkt_time = STA_LOST_PKT_TIME; + unsigned int pkt_thr = STA_LOST_PKT_THRESHOLD; + /* If driver relies on its own algorithm for station kickout, skip * mac80211 packet loss mechanism. */ @@ -773,21 +777,20 @@ static void ieee80211_lost_packet(struct sta_info *sta, return; sta->status_stats.lost_packets++; - if (!sta->sta.tdls && - sta->status_stats.lost_packets < STA_LOST_PKT_THRESHOLD) - return; + if (sta->sta.tdls) { + pkt_time = STA_LOST_TDLS_PKT_TIME; + pkt_thr = STA_LOST_PKT_THRESHOLD; + } /* * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD * of the last packets were lost, and that no ACK was received in the * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss * mechanism. + * For non-TDLS, use STA_LOST_PKT_THRESHOLD and STA_LOST_PKT_TIME */ - if (sta->sta.tdls && - (sta->status_stats.lost_packets < STA_LOST_TDLS_PKT_THRESHOLD || - time_before(jiffies, - sta->status_stats.last_tdls_pkt_time + - STA_LOST_TDLS_PKT_TIME))) + if (sta->status_stats.lost_packets < pkt_thr || + !time_after(jiffies, sta->status_stats.last_pkt_time + pkt_time)) return; cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr, @@ -1033,9 +1036,7 @@ static void __ieee80211_tx_status(struct ieee80211_hw *hw, sta->status_stats.lost_packets = 0; /* Track when last TDLS packet was ACKed */ - if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) - sta->status_stats.last_tdls_pkt_time = - jiffies; + sta->status_stats.last_pkt_time = jiffies; } else if (noack_success) { /* nothing to do here, do not account as lost */ } else { @@ -1172,9 +1173,8 @@ void ieee80211_tx_status_ext(struct ieee80211_hw *hw, if (sta->status_stats.lost_packets) sta->status_stats.lost_packets = 0; - /* Track when last TDLS packet was ACKed */ - if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) - sta->status_stats.last_tdls_pkt_time = jiffies; + /* Track when last packet was ACKed */ + sta->status_stats.last_pkt_time = jiffies; } else if (test_sta_flag(sta, WLAN_STA_PS_STA)) { return; } else if (noack_success) { @@ -1263,8 +1263,7 @@ void ieee80211_tx_status_8023(struct ieee80211_hw *hw, if (sta->status_stats.lost_packets) sta->status_stats.lost_packets = 0; - if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) - sta->status_stats.last_tdls_pkt_time = jiffies; + sta->status_stats.last_pkt_time = jiffies; } else { ieee80211_lost_packet(sta, info); } -- cgit v1.2.3