mac80211: fix time-is-after bug in mlme

The incorrect timeout check caused probing to happen when it did
not need to happen.  This in turn caused tx performance drop
for around 5 seconds in ath10k-ct driver.  Possibly that tx drop
is due to a secondary issue, but fixing the probe to not happen
when traffic is running fixes the symptom.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Fixes: 9abf4e49830d ("mac80211: optimize station connection monitor")
Acked-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210330230749.14097-1-greearb@candelatech.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ce4e3855fec18b801febaa0b23bf233397569196..96f487fc0071353573c44db20642ca39813437fc 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -4707,7 +4707,10 @@ static void ieee80211_sta_conn_mon_timer(struct timer_list *t)
                timeout = sta->rx_stats.last_rx;
        timeout += IEEE80211_CONNECTION_IDLE_TIME;
 
-       if (time_is_before_jiffies(timeout)) {
+       /* If timeout is after now, then update timer to fire at
+        * the later date, but do not actually probe at this time.
+        */
+       if (time_is_after_jiffies(timeout)) {
                mod_timer(&ifmgd->conn_mon_timer, round_jiffies_up(timeout));
                return;
        }