ath9k: Fix IBSS joiner mode

On joining an existing IBSS network, beaconing has to start
only after a TSF sync has happened by receiving a beacon from
the BSS. In creator mode, beaconing can start immediately after
a HW reset has been done.

Now that mac80211 notifies the driver of the mode type (creator/joiner)
via ieee80211_bss_conf->ibss_creator, make use of it to properly setup
the HW beacon timers.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 97c90b2..a56b241 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -389,6 +389,7 @@ struct ath_beacon_config {
        u16 bmiss_timeout;
        u8 dtim_count;
        bool enable_beacon;
+       bool ibss_creator;
 };
 
 struct ath_beacon {

diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index dd37719..5f05c26 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -407,12 +407,17 @@ void ath9k_beacon_tasklet(unsigned long data)
        }
 }
 
-static void ath9k_beacon_init(struct ath_softc *sc, u32 nexttbtt, u32 intval)
+/*
+ * Both nexttbtt and intval have to be in usecs.
+ */
+static void ath9k_beacon_init(struct ath_softc *sc, u32 nexttbtt,
+                             u32 intval, bool reset_tsf)
 {
        struct ath_hw *ah = sc->sc_ah;
 
        ath9k_hw_disable_interrupts(ah);
-       ath9k_hw_reset_tsf(ah);
+       if (reset_tsf)
+               ath9k_hw_reset_tsf(ah);
        ath9k_beaconq_config(sc);
        ath9k_hw_beaconinit(ah, nexttbtt, intval);
        sc->beacon.bmisscnt = 0;
@@ -442,10 +447,12 @@ static void ath9k_beacon_config_ap(struct ath_softc *sc,
        else
                ah->imask &= ~ATH9K_INT_SWBA;
 
-       ath_dbg(common, BEACON, "AP nexttbtt: %u intval: %u conf_intval: %u\n",
+       ath_dbg(common, BEACON,
+               "AP (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
+               (conf->enable_beacon) ? "Enable" : "Disable",
                nexttbtt, intval, conf->beacon_interval);
 
-       ath9k_beacon_init(sc, nexttbtt, intval);
+       ath9k_beacon_init(sc, nexttbtt, intval, true);
 }
 
 /*
@@ -586,17 +593,45 @@ static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
        ath9k_reset_beacon_status(sc);
 
        intval = TU_TO_USEC(conf->beacon_interval);
-       nexttbtt = intval;
+
+       if (conf->ibss_creator) {
+               nexttbtt = intval;
+       } else {
+               u32 tbtt, offset, tsftu;
+               u64 tsf;
+
+               /*
+                * Pull nexttbtt forward to reflect the current
+                * sync'd TSF.
+                */
+               tsf = ath9k_hw_gettsf64(ah);
+               tsftu = TSF_TO_TU(tsf >> 32, tsf) + FUDGE;
+               offset = tsftu % conf->beacon_interval;
+               tbtt = tsftu - offset;
+               if (offset)
+                       tbtt += conf->beacon_interval;
+
+               nexttbtt = TU_TO_USEC(tbtt);
+       }
 
        if (conf->enable_beacon)
                ah->imask |= ATH9K_INT_SWBA;
        else
                ah->imask &= ~ATH9K_INT_SWBA;
 
-       ath_dbg(common, BEACON, "IBSS nexttbtt: %u intval: %u conf_intval: %u\n",
+       ath_dbg(common, BEACON,
+               "IBSS (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
+               (conf->enable_beacon) ? "Enable" : "Disable",
                nexttbtt, intval, conf->beacon_interval);
 
-       ath9k_beacon_init(sc, nexttbtt, intval);
+       ath9k_beacon_init(sc, nexttbtt, intval, conf->ibss_creator);
+
+       /*
+        * Set the global 'beacon has been configured' flag for the
+        * joiner case in IBSS mode.
+        */
+       if (!conf->ibss_creator && conf->enable_beacon)
+               set_bit(SC_OP_BEACONS, &sc->sc_flags);
 }
 
 bool ath9k_allow_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif)
@@ -639,6 +674,7 @@ static void ath9k_cache_beacon_config(struct ath_softc *sc,
        cur_conf->dtim_period = bss_conf->dtim_period;
        cur_conf->listen_interval = 1;
        cur_conf->dtim_count = 1;
+       cur_conf->ibss_creator = bss_conf->ibss_creator;
        cur_conf->bmiss_timeout =
                ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;
 
@@ -666,34 +702,59 @@ void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
 {
        struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
        struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
+       unsigned long flags;
+       bool skip_beacon = false;
 
        if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
                ath9k_cache_beacon_config(sc, bss_conf);
                ath9k_set_beacon(sc);
                set_bit(SC_OP_BEACONS, &sc->sc_flags);
-       } else {
-               /*
-                * Take care of multiple interfaces when
-                * enabling/disabling SWBA.
-                */
-               if (changed & BSS_CHANGED_BEACON_ENABLED) {
-                       if (!bss_conf->enable_beacon &&
-                           (sc->nbcnvifs <= 1)) {
-                               cur_conf->enable_beacon = false;
-                       } else if (bss_conf->enable_beacon) {
-                               cur_conf->enable_beacon = true;
-                               ath9k_cache_beacon_config(sc, bss_conf);
-                       }
+               return;
+
+       }
+
+       /*
+        * Take care of multiple interfaces when
+        * enabling/disabling SWBA.
+        */
+       if (changed & BSS_CHANGED_BEACON_ENABLED) {
+               if (!bss_conf->enable_beacon &&
+                   (sc->nbcnvifs <= 1)) {
+                       cur_conf->enable_beacon = false;
+               } else if (bss_conf->enable_beacon) {
+                       cur_conf->enable_beacon = true;
+                       ath9k_cache_beacon_config(sc, bss_conf);
                }
+       }
 
-               if (cur_conf->beacon_interval) {
+       /*
+        * Configure the HW beacon registers only when we have a valid
+        * beacon interval.
+        */
+       if (cur_conf->beacon_interval) {
+               /*
+                * If we are joining an existing IBSS network, start beaconing
+                * only after a TSF-sync has taken place. Ensure that this
+                * happens by setting the appropriate flags.
+                */
+               if ((changed & BSS_CHANGED_IBSS) && !bss_conf->ibss_creator &&
+                   bss_conf->enable_beacon) {
+                       spin_lock_irqsave(&sc->sc_pm_lock, flags);
+                       sc->ps_flags |= PS_BEACON_SYNC | PS_WAIT_FOR_BEACON;
+                       spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
+                       skip_beacon = true;
+               } else {
                        ath9k_set_beacon(sc);
-
-                       if (cur_conf->enable_beacon)
-                               set_bit(SC_OP_BEACONS, &sc->sc_flags);
-                       else
-                               clear_bit(SC_OP_BEACONS, &sc->sc_flags);
                }
+
+               /*
+                * Do not set the SC_OP_BEACONS flag for IBSS joiner mode
+                * here, it is done in ath9k_beacon_config_adhoc().
+                */
+               if (cur_conf->enable_beacon && !skip_beacon)
+                       set_bit(SC_OP_BEACONS, &sc->sc_flags);
+               else
+                       clear_bit(SC_OP_BEACONS, &sc->sc_flags);
        }
 }
 

diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 2d0fd17..ee156e5 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -533,7 +533,7 @@ static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
        if (sc->ps_flags & PS_BEACON_SYNC) {
                sc->ps_flags &= ~PS_BEACON_SYNC;
                ath_dbg(common, PS,
-                       "Reconfigure Beacon timers based on timestamp from the AP\n");
+                       "Reconfigure beacon timers based on synchronized timestamp\n");
                ath9k_set_beacon(sc);
        }