ath9k: Fix MCC scanning

Scanning is curently broken when two channel contexts
are active. For example in a P2P-GO/STA setup, the
offchannel timer allows HZ / 10 to elapse before initiating
a switch to the next scan channel from the current operating
channel, which in this case would be the P2P-GO context.

But, the channel context timer might decide to switch
to the STA context when an SWBA comes early and a beacon
is sent out. Since pending offchannel requests are processed
in EVENT_BEACON_PREPARE, this causes inconsistent scanning.

Fix this by making sure that a context switch happens
before processing the pending offchannel request. This
also makes sure that active channel contexts will always
have higher priority than offchannel operations and the
scan sequence looks like this:

p2p-go, sta, p2p-go, offchannel, p2p-go, sta, p2p-go, offchannel,.....

The oper-channel is p2p-go, so the STA context has to
switch to p2p-go again before switching offchannel.

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 46a1d2e24dae5ce5967151c428cb4da4a4053ef5..0c071b094010c4932a595d2a313e9b6c28e4887d 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -378,6 +378,7 @@ enum ath_chanctx_state {
 struct ath_chanctx_sched {
        bool beacon_pending;
        bool offchannel_pending;
+       bool wait_switch;
        enum ath_chanctx_state state;
        u8 beacon_miss;
 

diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c
index a31f526ba852c1aa4c515509d24a39e32a8e8b25..522894ba727a9252ee544abb4f54210449645851 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/channel.c
+++ b/drivers/net/wireless/ath/ath9k/channel.c
@@ -333,7 +333,7 @@ void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
                        break;
                }
 
-               if (sc->sched.offchannel_pending) {
+               if (sc->sched.offchannel_pending && !sc->sched.wait_switch) {
                        sc->sched.offchannel_pending = false;
                        sc->next_chan = &sc->offchannel.chan;
                        sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
@@ -490,6 +490,7 @@ void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
                        "Move chanctx state to WAIT_FOR_TIMER (event SWITCH)\n");
 
                sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
+               sc->sched.wait_switch = false;
 
                tsf_time = TU_TO_USEC(cur_conf->beacon_interval) / 2;
                if (sc->sched.beacon_miss >= 2) {
@@ -588,6 +589,7 @@ static void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
        if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) &&
            (sc->cur_chan != ctx) && (ctx == &sc->offchannel.chan)) {
                sc->sched.offchannel_pending = true;
+               sc->sched.wait_switch = true;
                if (chandef)
                        ctx->chandef = *chandef;
                spin_unlock_bh(&sc->chan_lock);