ath9k: reduce false positives in the baseband hang check

SVN-Revision: 25359

diff --git a/package/mac80211/patches/570-ath9k_bb_hang_check_fix.patch b/package/mac80211/patches/570-ath9k_bb_hang_check_fix.patch
new file mode 100644 (file)
index 0000000..5314883
--- /dev/null
+++ b/package/mac80211/patches/570-ath9k_bb_hang_check_fix.patch
@@ -0,0 +1,109 @@
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -177,7 +177,12 @@ static void ath_update_survey_nf(struct 
+       }
+ }
+ 
+-static void ath_update_survey_stats(struct ath_softc *sc)
++/*
++ * Updates the survey statistics and returns the busy time since last
++ * update in %, if the measurement duration was long enough for the
++ * result to be useful, -1 otherwise.
++ */
++static int ath_update_survey_stats(struct ath_softc *sc)
+ {
+       struct ath_hw *ah = sc->sc_ah;
+       struct ath_common *common = ath9k_hw_common(ah);
+@@ -185,9 +190,10 @@ static void ath_update_survey_stats(stru
+       struct survey_info *survey = &sc->survey[pos];
+       struct ath_cycle_counters *cc = &common->cc_survey;
+       unsigned int div = common->clockrate * 1000;
++      int ret = 0;
+ 
+       if (!ah->curchan)
+-              return;
++              return -1;
+ 
+       if (ah->power_mode == ATH9K_PM_AWAKE)
+               ath_hw_cycle_counters_update(common);
+@@ -202,9 +208,18 @@ static void ath_update_survey_stats(stru
+               survey->channel_time_rx += cc->rx_frame / div;
+               survey->channel_time_tx += cc->tx_frame / div;
+       }
++
++      if (cc->cycles < div)
++              return -1;
++
++      if (cc->cycles > 0)
++              ret = cc->rx_busy * 100 / cc->cycles;
++
+       memset(cc, 0, sizeof(*cc));
+ 
+       ath_update_survey_nf(sc, pos);
++
++      return ret;
+ }
+ 
+ /*
+@@ -226,6 +241,8 @@ int ath_set_channel(struct ath_softc *sc
+       if (sc->sc_flags & SC_OP_INVALID)
+               return -EIO;
+ 
++      sc->hw_busy_count = 0;
++
+       del_timer_sync(&common->ani.timer);
+       cancel_work_sync(&sc->paprd_work);
+       cancel_work_sync(&sc->hw_check_work);
+@@ -584,17 +601,25 @@ static void ath_node_detach(struct ath_s
+ void ath_hw_check(struct work_struct *work)
+ {
+       struct ath_softc *sc = container_of(work, struct ath_softc, hw_check_work);
+-      int i;
++      struct ath_common *common = ath9k_hw_common(sc->sc_ah);
++      unsigned long flags;
++      int busy;
+ 
+       ath9k_ps_wakeup(sc);
++      if (ath9k_hw_check_alive(sc->sc_ah))
++              goto out;
+ 
+-      for (i = 0; i < 3; i++) {
+-              if (ath9k_hw_check_alive(sc->sc_ah))
+-                      goto out;
++      spin_lock_irqsave(&common->cc_lock, flags);
++      busy = ath_update_survey_stats(sc);
++      spin_unlock_irqrestore(&common->cc_lock, flags);
+ 
+-              msleep(1);
+-      }
+-      ath_reset(sc, true);
++      ath_dbg(common, ATH_DBG_RESET, "Possible baseband hang, "
++              "busy=%d (try %d)\n", busy, sc->hw_busy_count + 1);
++      if (busy >= 99) {
++              if (++sc->hw_busy_count >= 3)
++                      ath_reset(sc, true);
++      } else if (busy >= 0)
++              sc->hw_busy_count = 0;
+ 
+ out:
+       ath9k_ps_restore(sc);
+@@ -988,6 +1013,8 @@ int ath_reset(struct ath_softc *sc, bool
+       struct ieee80211_hw *hw = sc->hw;
+       int r;
+ 
++      sc->hw_busy_count = 0;
++
+       /* Stop ANI */
+       del_timer_sync(&common->ani.timer);
+ 
+--- a/drivers/net/wireless/ath/ath9k/ath9k.h
++++ b/drivers/net/wireless/ath/ath9k/ath9k.h
+@@ -598,6 +598,8 @@ struct ath_softc {
+       struct completion paprd_complete;
+       bool paprd_pending;
+ 
++      unsigned int hw_busy_count;
++
+       u32 intrstatus;
+       u32 sc_flags; /* SC_OP_* */
+       u16 ps_flags; /* PS_* */