ath9k: fix ad-hoc mode beacon selection

In ad-hoc mode, beacon timers are configured differently compared to AP
mode, and (depending on the scenario) can vary enough to make the beacon
tasklet not detect slot 0 based on the TSF.
Since staggered beacons are not (and cannot be) used in ad-hoc mode, it
makes more sense to just hardcode slot 0 here, avoiding unnecessary
TSF reads and calculations.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Reported-by: Rajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index 637dbc5f7b67478e975e81a33a33ab5785fc5d84..c7f46797c75c6e409fbb7240e25a9ae821e4a25b 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -351,9 +351,7 @@ void ath_beacon_tasklet(unsigned long data)
        struct ath_buf *bf = NULL;
        struct ieee80211_vif *vif;
        int slot;
-       u32 bfaddr, bc = 0, tsftu;
-       u64 tsf;
-       u16 intval;
+       u32 bfaddr, bc = 0;
 
        /*
         * Check if the previous beacon has gone out.  If
@@ -388,17 +386,27 @@ void ath_beacon_tasklet(unsigned long data)
         * on the tsf to safeguard against missing an swba.
         */
 
-       intval = cur_conf->beacon_interval ? : ATH_DEFAULT_BINTVAL;
 
-       tsf = ath9k_hw_gettsf64(ah);
-       tsf += TU_TO_USEC(ah->config.sw_beacon_response_time);
-       tsftu = TSF_TO_TU((tsf * ATH_BCBUF) >>32, tsf * ATH_BCBUF);
-       slot = (tsftu % (intval * ATH_BCBUF)) / intval;
-       vif = sc->beacon.bslot[slot];
+       if (ah->opmode == NL80211_IFTYPE_AP) {
+               u16 intval;
+               u32 tsftu;
+               u64 tsf;
+
+               intval = cur_conf->beacon_interval ? : ATH_DEFAULT_BINTVAL;
+               tsf = ath9k_hw_gettsf64(ah);
+               tsf += TU_TO_USEC(ah->config.sw_beacon_response_time);
+               tsftu = TSF_TO_TU((tsf * ATH_BCBUF) >>32, tsf * ATH_BCBUF);
+               slot = (tsftu % (intval * ATH_BCBUF)) / intval;
+               vif = sc->beacon.bslot[slot];
+
+               ath_dbg(common, ATH_DBG_BEACON,
+                       "slot %d [tsf %llu tsftu %u intval %u] vif %p\n",
+                       slot, tsf, tsftu / ATH_BCBUF, intval, vif);
+       } else {
+               slot = 0;
+               vif = sc->beacon.bslot[slot];
+       }
 
-       ath_dbg(common, ATH_DBG_BEACON,
-               "slot %d [tsf %llu tsftu %u intval %u] vif %p\n",
-               slot, tsf, tsftu / ATH_BCBUF, intval, vif);
 
        bfaddr = 0;
        if (vif) {