mac80211: add beacon filtering support
Add IEEE80211_HW_BEACON_FILTERING flag so that driver inform that it supports
beacon filtering. Drivers need to call the new function
ieee80211_beacon_loss() to notify about beacon loss.
Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/Documentation/DocBook/mac80211.tmpl b/Documentation/DocBook/mac80211.tmpl
index 8af6d96..fbeaffc 100644
--- a/Documentation/DocBook/mac80211.tmpl
+++ b/Documentation/DocBook/mac80211.tmpl
@@ -227,6 +227,12 @@
!Pinclude/net/mac80211.h Powersave support
</chapter>
+ <chapter id="beacon-filter">
+ <title>Beacon filter support</title>
+!Pinclude/net/mac80211.h Beacon filter support
+!Finclude/net/mac80211.h ieee80211_beacon_loss
+ </chapter>
+
<chapter id="qos">
<title>Multiple queues and QoS support</title>
<para>TBD</para>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 174dc1d..d881ed8 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -882,6 +882,10 @@
*
* @IEEE80211_HW_MFP_CAPABLE:
* Hardware supports management frame protection (MFP, IEEE 802.11w).
+ *
+ * @IEEE80211_HW_BEACON_FILTER:
+ * Hardware supports dropping of irrelevant beacon frames to
+ * avoid waking up cpu.
*/
enum ieee80211_hw_flags {
IEEE80211_HW_RX_INCLUDES_FCS = 1<<1,
@@ -897,6 +901,7 @@
IEEE80211_HW_PS_NULLFUNC_STACK = 1<<11,
IEEE80211_HW_SUPPORTS_DYNAMIC_PS = 1<<12,
IEEE80211_HW_MFP_CAPABLE = 1<<13,
+ IEEE80211_HW_BEACON_FILTER = 1<<14,
};
/**
@@ -1121,6 +1126,24 @@
*/
/**
+ * DOC: Beacon filter support
+ *
+ * Some hardware have beacon filter support to reduce host cpu wakeups
+ * which will reduce system power consumption. It usuallly works so that
+ * the firmware creates a checksum of the beacon but omits all constantly
+ * changing elements (TSF, TIM etc). Whenever the checksum changes the
+ * beacon is forwarded to the host, otherwise it will be just dropped. That
+ * way the host will only receive beacons where some relevant information
+ * (for example ERP protection or WMM settings) have changed.
+ *
+ * Beacon filter support is informed with %IEEE80211_HW_BEACON_FILTER flag.
+ * The driver needs to enable beacon filter support whenever power save is
+ * enabled, that is %IEEE80211_CONF_PS is set. When power save is enabled,
+ * the stack will not check for beacon miss at all and the driver needs to
+ * notify about complete loss of beacons with ieee80211_beacon_loss().
+ */
+
+/**
* DOC: Frame filtering
*
* mac80211 requires to see many management frames for proper
@@ -1970,6 +1993,16 @@
struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_hw *hw,
const u8 *addr);
+/**
+ * ieee80211_beacon_loss - inform hardware does not receive beacons
+ *
+ * @vif: &struct ieee80211_vif pointer from &struct ieee80211_if_init_conf.
+ *
+ * When beacon filtering is enabled with IEEE80211_HW_BEACON_FILTERING and
+ * IEEE80211_CONF_PS is set, the driver needs to inform whenever the
+ * hardware is not receiving beacons with this function.
+ */
+void ieee80211_beacon_loss(struct ieee80211_vif *vif);
/* Rate control API */
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8a617a7..acba78e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -275,6 +275,7 @@
struct timer_list chswitch_timer;
struct work_struct work;
struct work_struct chswitch_work;
+ struct work_struct beacon_loss_work;
u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
@@ -1086,6 +1087,7 @@
int powersave);
void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
struct ieee80211_hdr *hdr);
+void ieee80211_beacon_loss_work(struct work_struct *work);
void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
enum queue_stop_reason reason);
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index dd2a276f..91e8e1b 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -477,6 +477,9 @@
*/
cancel_work_sync(&sdata->u.mgd.work);
cancel_work_sync(&sdata->u.mgd.chswitch_work);
+
+ cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
+
/*
* When we get here, the interface is marked down.
* Call synchronize_rcu() to wait for the RX path
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 8f30f4d..7ecda9d 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -610,6 +610,8 @@
bss_info_changed |= ieee80211_handle_bss_capability(sdata,
bss->cbss.capability, bss->has_erp_value, bss->erp_value);
+ cfg80211_hold_bss(&bss->cbss);
+
ieee80211_rx_bss_put(local, bss);
}
@@ -751,6 +753,8 @@
{
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
struct ieee80211_local *local = sdata->local;
+ struct ieee80211_conf *conf = &local_to_hw(local)->conf;
+ struct ieee80211_bss *bss;
struct sta_info *sta;
u32 changed = 0, config_changed = 0;
@@ -774,6 +778,15 @@
ieee80211_sta_tear_down_BA_sessions(sta);
+ bss = ieee80211_rx_bss_get(local, ifmgd->bssid,
+ conf->channel->center_freq,
+ ifmgd->ssid, ifmgd->ssid_len);
+
+ if (bss) {
+ cfg80211_unhold_bss(&bss->cbss);
+ ieee80211_rx_bss_put(local, bss);
+ }
+
if (self_disconnected) {
if (deauth)
ieee80211_send_deauth_disassoc(sdata,
@@ -925,6 +938,33 @@
jiffies + IEEE80211_MONITORING_INTERVAL);
}
+void ieee80211_beacon_loss_work(struct work_struct *work)
+{
+ struct ieee80211_sub_if_data *sdata =
+ container_of(work, struct ieee80211_sub_if_data,
+ u.mgd.beacon_loss_work);
+ struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+
+ printk(KERN_DEBUG "%s: driver reports beacon loss from AP %pM "
+ "- sending probe request\n", sdata->dev->name,
+ sdata->u.mgd.bssid);
+
+ ifmgd->flags |= IEEE80211_STA_PROBEREQ_POLL;
+ ieee80211_send_probe_req(sdata, ifmgd->bssid, ifmgd->ssid,
+ ifmgd->ssid_len, NULL, 0);
+
+ mod_timer(&ifmgd->timer, jiffies + IEEE80211_MONITORING_INTERVAL);
+}
+
+void ieee80211_beacon_loss(struct ieee80211_vif *vif)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+ queue_work(sdata->local->hw.workqueue,
+ &sdata->u.mgd.beacon_loss_work);
+}
+EXPORT_SYMBOL(ieee80211_beacon_loss);
+
static void ieee80211_associated(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
@@ -959,7 +999,13 @@
goto unlock;
}
- if (time_after(jiffies,
+ /*
+ * Beacon filtering is only enabled with power save and then the
+ * stack should not check for beacon loss.
+ */
+ if (!((local->hw.flags & IEEE80211_HW_BEACON_FILTER) &&
+ (local->hw.conf.flags & IEEE80211_CONF_PS)) &&
+ time_after(jiffies,
ifmgd->last_beacon + IEEE80211_MONITORING_INTERVAL)) {
printk(KERN_DEBUG "%s: beacon loss from AP %pM "
"- sending probe request\n",
@@ -1869,6 +1915,7 @@
ifmgd = &sdata->u.mgd;
INIT_WORK(&ifmgd->work, ieee80211_sta_work);
INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
+ INIT_WORK(&ifmgd->beacon_loss_work, ieee80211_beacon_loss_work);
setup_timer(&ifmgd->timer, ieee80211_sta_timer,
(unsigned long) sdata);
setup_timer(&ifmgd->chswitch_timer, ieee80211_chswitch_timer,