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mac80211: calculate beacon loss time accurately

Instead of using a fixed 2 second timeout, calculate beacon loss interval
from the advertised beacon interval and a frame count.  With this beacon
loss happens after N (default 7) consecutive frames are missed which
for a typical setup (100TU beacon interval) is ~700ms (or ~1/3 previous).

Signed-off-by: Sam Leffler <sleffler@chromium.org>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
wifi-calibration
Felix Fietkau 2010-11-19 22:55:38 +01:00 committed by John W. Linville
parent c8a7972c3b
commit 7ccc8bd759
2 changed files with 13 additions and 4 deletions

View File

@ -349,6 +349,7 @@ struct ieee80211_if_managed {
struct work_struct chswitch_work;
struct work_struct beacon_connection_loss_work;
unsigned long beacon_timeout;
unsigned long probe_timeout;
int probe_send_count;

View File

@ -31,10 +31,15 @@
#define IEEE80211_MAX_PROBE_TRIES 5
/*
* beacon loss detection timeout
* XXX: should depend on beacon interval
* Beacon loss timeout is calculated as N frames times the
* advertised beacon interval. This may need to be somewhat
* higher than what hardware might detect to account for
* delays in the host processing frames. But since we also
* probe on beacon miss before declaring the connection lost
* default to what we want.
*/
#define IEEE80211_BEACON_LOSS_TIME (2 * HZ)
#define IEEE80211_BEACON_LOSS_COUNT 7
/*
* Time the connection can be idle before we probe
* it to see if we can still talk to the AP.
@ -121,7 +126,7 @@ void ieee80211_sta_reset_beacon_monitor(struct ieee80211_sub_if_data *sdata)
return;
mod_timer(&sdata->u.mgd.bcn_mon_timer,
round_jiffies_up(jiffies + IEEE80211_BEACON_LOSS_TIME));
round_jiffies_up(jiffies + sdata->u.mgd.beacon_timeout));
}
void ieee80211_sta_reset_conn_monitor(struct ieee80211_sub_if_data *sdata)
@ -871,6 +876,9 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
bss_info_changed |= ieee80211_handle_bss_capability(sdata,
cbss->capability, bss->has_erp_value, bss->erp_value);
sdata->u.mgd.beacon_timeout = usecs_to_jiffies(ieee80211_tu_to_usec(
IEEE80211_BEACON_LOSS_COUNT * bss_conf->beacon_int));
sdata->u.mgd.associated = cbss;
memcpy(sdata->u.mgd.bssid, cbss->bssid, ETH_ALEN);