ath9k: simplify hw reset locking

The new PCU lock is better placed so we can just contend
against that when trying to reset hardware.

This is part of a series of patches which fix stopping
TX DMA completley when requested on the driver.
For more details about this issue refer to this thread:

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

Tested-by:  Ben Greear <greearb@candelatech.com>
Cc: Kyungwan Nam <kyungwan.nam@atheros.com>
Cc: stable@kernel.org
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.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 81fed83..cb9194a 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -599,7 +599,6 @@ struct ath_softc {
        struct ath_hw *sc_ah;
        void __iomem *mem;
        int irq;
-       spinlock_t sc_resetlock;
        spinlock_t sc_serial_rw;
        spinlock_t sc_pm_lock;
        struct mutex mutex;

diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 1b72720..adff0da 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -580,7 +580,6 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc, u16 subsysid,
        spin_lock_init(&common->cc_lock);
 
        spin_lock_init(&sc->wiphy_lock);
-       spin_lock_init(&sc->sc_resetlock);
        spin_lock_init(&sc->sc_serial_rw);
        spin_lock_init(&sc->sc_pm_lock);
        mutex_init(&sc->mutex);

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 92ed5bb..341d587 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -262,19 +262,15 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
                  channel->center_freq, conf_is_ht40(conf),
                  fastcc);
 
-       spin_lock_bh(&sc->sc_resetlock);
-
        r = ath9k_hw_reset(ah, hchan, caldata, fastcc);
        if (r) {
                ath_print(common, ATH_DBG_FATAL,
                          "Unable to reset channel (%u MHz), "
                          "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);
 
        if (ath_startrecv(sc) != 0) {
                ath_print(common, ATH_DBG_FATAL,
@@ -886,7 +882,6 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
                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) {
                ath_print(common, ATH_DBG_FATAL,
@@ -894,7 +889,6 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
                          "reset status %d\n",
                          channel->center_freq, r);
        }
-       spin_unlock_bh(&sc->sc_resetlock);
 
        ath_update_txpow(sc);
        if (ath_startrecv(sc) != 0) {
@@ -951,7 +945,6 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
        if (!ah->curchan)
                ah->curchan = ath_get_curchannel(sc, hw);
 
-       spin_lock_bh(&sc->sc_resetlock);
        r = ath9k_hw_reset(ah, ah->curchan, ah->caldata, false);
        if (r) {
                ath_print(ath9k_hw_common(sc->sc_ah), ATH_DBG_FATAL,
@@ -959,7 +952,6 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
                          "reset status %d\n",
                          channel->center_freq, r);
        }
-       spin_unlock_bh(&sc->sc_resetlock);
 
        ath9k_hw_phy_disable(ah);
 
@@ -990,12 +982,10 @@ int ath_reset(struct ath_softc *sc, bool retry_tx)
        ath_stoprecv(sc);
        ath_flushrecv(sc);
 
-       spin_lock_bh(&sc->sc_resetlock);
        r = ath9k_hw_reset(ah, sc->sc_ah->curchan, ah->caldata, false);
        if (r)
                ath_print(common, ATH_DBG_FATAL,
                          "Unable to reset hardware; reset status %d\n", r);
-       spin_unlock_bh(&sc->sc_resetlock);
 
        if (ath_startrecv(sc) != 0)
                ath_print(common, ATH_DBG_FATAL,
@@ -1166,18 +1156,15 @@ static int ath9k_start(struct ieee80211_hw *hw)
         * 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) {
                ath_print(common, ATH_DBG_FATAL,
                          "Unable to reset hardware; reset status %d "
                          "(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);
 
        /*
         * This is needed only to setup initial state
@@ -1398,14 +1385,17 @@ static void ath9k_stop(struct ieee80211_hw *hw)
         * before setting the invalid flag. */
        ath9k_hw_disable_interrupts(ah);
 
-       spin_lock_bh(&sc->rx.pcu_lock);
        if (!(sc->sc_flags & SC_OP_INVALID)) {
                ath_drain_all_txq(sc, false);
+               spin_lock_bh(&sc->rx.pcu_lock);
                ath_stoprecv(sc);
                ath9k_hw_phy_disable(ah);
-       } else
+               spin_unlock_bh(&sc->rx.pcu_lock);
+       } else {
+               spin_lock_bh(&sc->rx.pcu_lock);
                sc->rx.rxlink = NULL;
-       spin_unlock_bh(&sc->rx.pcu_lock);
+               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/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index f2ade24..e662eca 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1148,13 +1148,13 @@ void ath_drain_all_txq(struct ath_softc *sc, bool retry_tx)
                ath_print(common, ATH_DBG_FATAL,
                          "Failed to stop TX DMA. Resetting hardware!\n");
 
-               spin_lock_bh(&sc->sc_resetlock);
+               spin_lock_bh(&sc->rx.pcu_lock);
                r = ath9k_hw_reset(ah, sc->sc_ah->curchan, ah->caldata, false);
                if (r)
                        ath_print(common, ATH_DBG_FATAL,
                                  "Unable to reset hardware; reset status %d\n",
                                  r);
-               spin_unlock_bh(&sc->sc_resetlock);
+               spin_unlock_bh(&sc->rx.pcu_lock);
        }
 
        for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {