mac80211: introduce beacon-only timing data
In order to be able to predict the next DTIM TBTT
in the driver, add the ability to use timing data
from beacons only with the new hardware flag
IEEE80211_HW_TIMING_BEACON_ONLY and the BSS info
value sync_dtim_count which is only valid if the
timing data came from a beacon. The data can only
come from a beacon, and if no beacon was received
before association it is updated later together
with the DTIM count notification.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 46e08ba..b9e0246 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -277,9 +277,16 @@
* valid in station mode only if after the driver was notified
* with the %BSS_CHANGED_DTIM_PERIOD flag, will be non-zero then.
* @sync_tsf: last beacon's/probe response's TSF timestamp (could be old
- * as it may have been received during scanning long ago)
+ * as it may have been received during scanning long ago). If the
+ * HW flag %IEEE80211_HW_TIMING_BEACON_ONLY is set, then this can
+ * only come from a beacon, but might not become valid until after
+ * association when a beacon is received (which is notified with the
+ * %BSS_CHANGED_DTIM flag.)
* @sync_device_ts: the device timestamp corresponding to the sync_tsf,
* the driver/device can use this to calculate synchronisation
+ * (see @sync_tsf)
+ * @sync_dtim_count: Only valid when %IEEE80211_HW_TIMING_BEACON_ONLY
+ * is requested, see @sync_tsf/@sync_device_ts.
* @beacon_int: beacon interval
* @assoc_capability: capabilities taken from assoc resp
* @basic_rates: bitmap of basic rates, each bit stands for an
@@ -331,6 +338,7 @@
u16 assoc_capability;
u64 sync_tsf;
u32 sync_device_ts;
+ u8 sync_dtim_count;
u32 basic_rates;
int mcast_rate[IEEE80211_NUM_BANDS];
u16 ht_operation_mode;
@@ -1371,6 +1379,9 @@
* @IEEE80211_HW_P2P_DEV_ADDR_FOR_INTF: Use the P2P Device address for any
* P2P Interface. This will be honoured even if more than one interface
* is supported.
+ *
+ * @IEEE80211_HW_TIMING_BEACON_ONLY: Use sync timing from beacon frames
+ * only, to allow getting TBTT of a DTIM beacon.
*/
enum ieee80211_hw_flags {
IEEE80211_HW_HAS_RATE_CONTROL = 1<<0,
@@ -1399,6 +1410,7 @@
IEEE80211_HW_TX_AMPDU_SETUP_IN_HW = 1<<23,
IEEE80211_HW_SCAN_WHILE_IDLE = 1<<24,
IEEE80211_HW_P2P_DEV_ADDR_FOR_INTF = 1<<25,
+ IEEE80211_HW_TIMING_BEACON_ONLY = 1<<26,
};
/**
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8e884fc..d794856 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -86,7 +86,7 @@
struct ieee80211_bss {
- u32 device_ts;
+ u32 device_ts_beacon, device_ts_presp;
bool wmm_used;
bool uapsd_supported;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 51eca5a..a29d09c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2567,6 +2567,17 @@
ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
ifmgd->assoc_data->have_beacon = true;
ifmgd->assoc_data->need_beacon = false;
+ if (local->hw.flags & IEEE80211_HW_TIMING_BEACON_ONLY) {
+ sdata->vif.bss_conf.sync_tsf =
+ le64_to_cpu(mgmt->u.beacon.timestamp);
+ sdata->vif.bss_conf.sync_device_ts =
+ rx_status->device_timestamp;
+ if (elems.tim)
+ sdata->vif.bss_conf.sync_dtim_count =
+ elems.tim->dtim_count;
+ else
+ sdata->vif.bss_conf.sync_dtim_count = 0;
+ }
/* continue assoc process */
ifmgd->assoc_data->timeout = jiffies;
run_again(ifmgd, ifmgd->assoc_data->timeout);
@@ -2725,7 +2736,7 @@
/*
* If we haven't had a beacon before, tell the driver about the
- * DTIM period now.
+ * DTIM period (and beacon timing if desired) now.
*/
if (!bss_conf->dtim_period) {
/* a few bogus AP send dtim_period = 0 or no TIM IE */
@@ -2733,6 +2744,19 @@
bss_conf->dtim_period = elems.tim->dtim_period ?: 1;
else
bss_conf->dtim_period = 1;
+
+ if (local->hw.flags & IEEE80211_HW_TIMING_BEACON_ONLY) {
+ sdata->vif.bss_conf.sync_tsf =
+ le64_to_cpu(mgmt->u.beacon.timestamp);
+ sdata->vif.bss_conf.sync_device_ts =
+ rx_status->device_timestamp;
+ if (elems.tim)
+ sdata->vif.bss_conf.sync_dtim_count =
+ elems.tim->dtim_count;
+ else
+ sdata->vif.bss_conf.sync_dtim_count = 0;
+ }
+
changed |= BSS_CHANGED_DTIM_PERIOD;
}
@@ -3712,10 +3736,33 @@
/* set timing information */
sdata->vif.bss_conf.beacon_int = cbss->beacon_interval;
rcu_read_lock();
- ies = rcu_dereference(cbss->ies);
- sdata->vif.bss_conf.sync_tsf = ies->tsf;
+ ies = rcu_dereference(cbss->beacon_ies);
+ if (ies) {
+ const u8 *tim_ie;
+
+ sdata->vif.bss_conf.sync_tsf = ies->tsf;
+ sdata->vif.bss_conf.sync_device_ts =
+ bss->device_ts_beacon;
+ tim_ie = cfg80211_find_ie(WLAN_EID_TIM,
+ ies->data, ies->len);
+ if (tim_ie && tim_ie[1] >= 2)
+ sdata->vif.bss_conf.sync_dtim_count = tim_ie[2];
+ else
+ sdata->vif.bss_conf.sync_dtim_count = 0;
+ } else if (!(local->hw.flags &
+ IEEE80211_HW_TIMING_BEACON_ONLY)) {
+ ies = rcu_dereference(cbss->proberesp_ies);
+ /* must be non-NULL since beacon IEs were NULL */
+ sdata->vif.bss_conf.sync_tsf = ies->tsf;
+ sdata->vif.bss_conf.sync_device_ts =
+ bss->device_ts_presp;
+ sdata->vif.bss_conf.sync_dtim_count = 0;
+ } else {
+ sdata->vif.bss_conf.sync_tsf = 0;
+ sdata->vif.bss_conf.sync_device_ts = 0;
+ sdata->vif.bss_conf.sync_dtim_count = 0;
+ }
rcu_read_unlock();
- sdata->vif.bss_conf.sync_device_ts = bss->device_ts;
/* tell driver about BSSID, basic rates and timing */
ieee80211_bss_info_change_notify(sdata,
@@ -4041,13 +4088,23 @@
const u8 *tim_ie = cfg80211_find_ie(WLAN_EID_TIM,
beacon_ies->data,
beacon_ies->len);
+ u8 dtim_count = 0;
+
if (tim_ie && tim_ie[1] >= sizeof(struct ieee80211_tim_ie)) {
const struct ieee80211_tim_ie *tim;
tim = (void *)(tim_ie + 2);
ifmgd->dtim_period = tim->dtim_period;
+ dtim_count = tim->dtim_count;
}
assoc_data->have_beacon = true;
assoc_data->timeout = jiffies;
+
+ if (local->hw.flags & IEEE80211_HW_TIMING_BEACON_ONLY) {
+ sdata->vif.bss_conf.sync_tsf = beacon_ies->tsf;
+ sdata->vif.bss_conf.sync_device_ts =
+ bss->device_ts_beacon;
+ sdata->vif.bss_conf.sync_dtim_count = dtim_count;
+ }
} else {
assoc_data->timeout = jiffies;
}
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 400153f..edd47d9 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -80,7 +80,10 @@
bss = (void *)cbss->priv;
- bss->device_ts = rx_status->device_timestamp;
+ if (beacon)
+ bss->device_ts_beacon = rx_status->device_timestamp;
+ else
+ bss->device_ts_presp = rx_status->device_timestamp;
if (elems->parse_error) {
if (beacon)
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index a2ca72c..0bdd7ae 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -340,6 +340,7 @@
__field(u16, assoc_cap)
__field(u64, sync_tsf)
__field(u32, sync_device_ts)
+ __field(u8, sync_dtim_count)
__field(u32, basic_rates)
__array(int, mcast_rate, IEEE80211_NUM_BANDS)
__field(u16, ht_operation_mode)
@@ -379,6 +380,7 @@
__entry->assoc_cap = info->assoc_capability;
__entry->sync_tsf = info->sync_tsf;
__entry->sync_device_ts = info->sync_device_ts;
+ __entry->sync_dtim_count = info->sync_dtim_count;
__entry->basic_rates = info->basic_rates;
memcpy(__entry->mcast_rate, info->mcast_rate,
sizeof(__entry->mcast_rate));