ath9k: lock reset and PCU start/stopping

Apart from locking the start and stop PCU we need
to ensure we also content starting and stopping the PCU
between hardware resets.

This is part of a series that will help resolve the bug:

https://bugzilla.kernel.org/show_bug.cgi?id=14624

For more details about this issue refer to:

http://marc.info/?l=linux-wireless&m=128629803703756&w=2

Cc: stable@kernel.org
Cc: Ben Greear <greearb@candelatech.com>
Cc: Kyungwan Nam <kyungwan.nam@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 27 insertions, 2 deletions

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 47df22b14cf8..b52f1cf8a603 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -241,6 +241,9 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
          */
         ath9k_hw_set_interrupts(ah, 0);
         ath_drain_all_txq(sc, false);
+
+        spin_lock_bh(&sc->rx.pcu_lock);
+
         stopped = ath_stoprecv(sc);
 
         /* XXX: do not flush receive queue here. We don't want
@@ -268,6 +271,7 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
                           "reset status %d\n",
                           channel->center_freq, r);
                 spin_unlock_bh(&sc->sc_resetlock);
+                spin_unlock_bh(&sc->rx.pcu_lock);
                 goto ps_restore;
         }
         spin_unlock_bh(&sc->sc_resetlock);
@@ -276,9 +280,12 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
                 ath_print(common, ATH_DBG_FATAL,
                           "Unable to restart recv logic\n");
                 r = -EIO;
+                spin_unlock_bh(&sc->rx.pcu_lock);
                 goto ps_restore;
         }
 
+        spin_unlock_bh(&sc->rx.pcu_lock);
+
         ath_update_txpow(sc);
         ath9k_hw_set_interrupts(ah, ah->imask);
 
@@ -876,6 +883,7 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
         if (!ah->curchan)
                 ah->curchan = ath_get_curchannel(sc, sc->hw);
 
+        spin_lock_bh(&sc->rx.pcu_lock);
         spin_lock_bh(&sc->sc_resetlock);
         r = ath9k_hw_reset(ah, ah->curchan, ah->caldata, false);
         if (r) {
@@ -890,8 +898,10 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
         if (ath_startrecv(sc) != 0) {
                 ath_print(common, ATH_DBG_FATAL,
                           "Unable to restart recv logic\n");
+                spin_unlock_bh(&sc->rx.pcu_lock);
                 return;
         }
+        spin_unlock_bh(&sc->rx.pcu_lock);
 
         if (sc->sc_flags & SC_OP_BEACONS)
                 ath_beacon_config(sc, NULL);    /* restart beacons */
@@ -930,6 +940,9 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
         ath9k_hw_set_interrupts(ah, 0);
 
         ath_drain_all_txq(sc, false);   /* clear pending tx frames */
+
+        spin_lock_bh(&sc->rx.pcu_lock);
+
         ath_stoprecv(sc);               /* turn off frame recv */
         ath_flushrecv(sc);              /* flush recv queue */
 
@@ -947,6 +960,9 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
         spin_unlock_bh(&sc->sc_resetlock);
 
         ath9k_hw_phy_disable(ah);
+
+        spin_unlock_bh(&sc->rx.pcu_lock);
+
         ath9k_hw_configpcipowersave(ah, 1, 1);
         ath9k_ps_restore(sc);
         ath9k_setpower(sc, ATH9K_PM_FULL_SLEEP);
@@ -966,6 +982,9 @@ int ath_reset(struct ath_softc *sc, bool retry_tx)
 
         ath9k_hw_set_interrupts(ah, 0);
         ath_drain_all_txq(sc, retry_tx);
+
+        spin_lock_bh(&sc->rx.pcu_lock);
+
         ath_stoprecv(sc);
         ath_flushrecv(sc);
 
@@ -980,6 +999,8 @@ int ath_reset(struct ath_softc *sc, bool retry_tx)
                 ath_print(common, ATH_DBG_FATAL,
                           "Unable to start recv logic\n");
 
+        spin_unlock_bh(&sc->rx.pcu_lock);
+
         /*
          * We may be doing a reset in response to a request
          * that changes the channel so update any state that
@@ -1142,6 +1163,7 @@ static int ath9k_start(struct ieee80211_hw *hw)
          * be followed by initialization of the appropriate bits
          * and then setup of the interrupt mask.
          */
+        spin_lock_bh(&sc->rx.pcu_lock);
         spin_lock_bh(&sc->sc_resetlock);
         r = ath9k_hw_reset(ah, init_channel, ah->caldata, false);
         if (r) {
@@ -1150,6 +1172,7 @@ static int ath9k_start(struct ieee80211_hw *hw)
                           "(freq %u MHz)\n", r,
                           curchan->center_freq);
                 spin_unlock_bh(&sc->sc_resetlock);
+                spin_unlock_bh(&sc->rx.pcu_lock);
                 goto mutex_unlock;
         }
         spin_unlock_bh(&sc->sc_resetlock);
@@ -1171,8 +1194,10 @@ static int ath9k_start(struct ieee80211_hw *hw)
                 ath_print(common, ATH_DBG_FATAL,
                           "Unable to start recv logic\n");
                 r = -EIO;
+                spin_unlock_bh(&sc->rx.pcu_lock);
                 goto mutex_unlock;
         }
+        spin_unlock_bh(&sc->rx.pcu_lock);
 
         /* Setup our intr mask. */
         ah->imask = ATH9K_INT_TX | ATH9K_INT_RXEOL |
@@ -1371,12 +1396,14 @@ static void ath9k_stop(struct ieee80211_hw *hw)
          * before setting the invalid flag. */
         ath9k_hw_set_interrupts(ah, 0);
 
+        spin_lock_bh(&sc->rx.pcu_lock);
         if (!(sc->sc_flags & SC_OP_INVALID)) {
                 ath_drain_all_txq(sc, false);
                 ath_stoprecv(sc);
                 ath9k_hw_phy_disable(ah);
         } else
                 sc->rx.rxlink = NULL;
+        spin_unlock_bh(&sc->rx.pcu_lock);
 
         /* disable HAL and put h/w to sleep */
         ath9k_hw_disable(ah);
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 67fe1f8a6439..fddb0129bb57 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -533,13 +533,11 @@ bool ath_stoprecv(struct ath_softc *sc)
 
 void ath_flushrecv(struct ath_softc *sc)
 {
-        spin_lock_bh(&sc->rx.pcu_lock);
         sc->sc_flags |= SC_OP_RXFLUSH;
         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
                 ath_rx_tasklet(sc, 1, true);
         ath_rx_tasklet(sc, 1, false);
         sc->sc_flags &= ~SC_OP_RXFLUSH;
-        spin_unlock_bh(&sc->rx.pcu_lock);
 }
 
 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)