diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/mac80211/ieee80211_i.h | 1 | ||||
| -rw-r--r-- | net/mac80211/scan.c | 71 |
2 files changed, 66 insertions, 6 deletions
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 241533e1bc03..b84126491ab1 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -745,6 +745,7 @@ struct ieee80211_local { int scan_channel_idx; int scan_ies_len; + unsigned long leave_oper_channel_time; enum mac80211_scan_state next_scan_state; struct delayed_work scan_work; struct ieee80211_sub_if_data *scan_sdata; diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index b822dce97867..75a85978c3b3 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -14,6 +14,8 @@ #include <linux/if_arp.h> #include <linux/rtnetlink.h> +#include <linux/pm_qos_params.h> +#include <net/sch_generic.h> #include <net/mac80211.h> #include "ieee80211_i.h" @@ -321,6 +323,7 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local) ieee80211_offchannel_stop_beaconing(local); + local->leave_oper_channel_time = 0; local->next_scan_state = SCAN_DECISION; local->scan_channel_idx = 0; @@ -425,11 +428,28 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, return rc; } +static unsigned long +ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) +{ + /* + * TODO: channel switching also consumes quite some time, + * add that delay as well to get a better estimation + */ + if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) + return IEEE80211_PASSIVE_CHANNEL_TIME; + return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; +} + static int ieee80211_scan_state_decision(struct ieee80211_local *local, unsigned long *next_delay) { bool associated = false; + bool tx_empty = true; + bool bad_latency; + bool listen_int_exceeded; + unsigned long min_beacon_int = 0; struct ieee80211_sub_if_data *sdata; + struct ieee80211_channel *next_chan; /* if no more bands/channels left, complete scan and advance to the idle state */ if (local->scan_channel_idx >= local->scan_req->n_channels) { @@ -437,7 +457,11 @@ static int ieee80211_scan_state_decision(struct ieee80211_local *local, return 1; } - /* check if at least one STA interface is associated */ + /* + * check if at least one STA interface is associated, + * check if at least one STA interface has pending tx frames + * and grab the lowest used beacon interval + */ mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { if (!ieee80211_sdata_running(sdata)) @@ -446,7 +470,16 @@ static int ieee80211_scan_state_decision(struct ieee80211_local *local, if (sdata->vif.type == NL80211_IFTYPE_STATION) { if (sdata->u.mgd.associated) { associated = true; - break; + + if (sdata->vif.bss_conf.beacon_int < + min_beacon_int || min_beacon_int == 0) + min_beacon_int = + sdata->vif.bss_conf.beacon_int; + + if (!qdisc_all_tx_empty(sdata->dev)) { + tx_empty = false; + break; + } } } } @@ -455,11 +488,34 @@ static int ieee80211_scan_state_decision(struct ieee80211_local *local, if (local->scan_channel) { /* * we're currently scanning a different channel, let's - * switch back to the operating channel now if at least - * one interface is associated. Otherwise just scan the - * next channel + * see if we can scan another channel without interfering + * with the current traffic situation. + * + * Since we don't know if the AP has pending frames for us + * we can only check for our tx queues and use the current + * pm_qos requirements for rx. Hence, if no tx traffic occurs + * at all we will scan as many channels in a row as the pm_qos + * latency allows us to. Additionally we also check for the + * currently negotiated listen interval to prevent losing + * frames unnecessarily. + * + * Otherwise switch back to the operating channel. */ - if (associated) + next_chan = local->scan_req->channels[local->scan_channel_idx]; + + bad_latency = time_after(jiffies + + ieee80211_scan_get_channel_time(next_chan), + local->leave_oper_channel_time + + usecs_to_jiffies(pm_qos_requirement(PM_QOS_NETWORK_LATENCY))); + + listen_int_exceeded = time_after(jiffies + + ieee80211_scan_get_channel_time(next_chan), + local->leave_oper_channel_time + + usecs_to_jiffies(min_beacon_int * 1024) * + local->hw.conf.listen_interval); + + if (associated && ( !tx_empty || bad_latency || + listen_int_exceeded)) local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; else local->next_scan_state = SCAN_SET_CHANNEL; @@ -491,6 +547,9 @@ static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *loca else *next_delay = HZ / 10; + /* remember when we left the operating channel */ + local->leave_oper_channel_time = jiffies; + /* advance to the next channel to be scanned */ local->next_scan_state = SCAN_SET_CHANNEL; } |