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ath9k: content DMA start / stop through the PCU lock

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This helps align resets / RX enable & disable / TX stop / start.
Locking around the PCU is important to ensure the hardware doesn't
get stale data when working with DMA'able data.

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>
This commit is contained in:
Luis R. Rodriguez 2010-10-26 15:27:25 -07:00 committed by John W. Linville
parent 4bdd1e978e
commit 6a6733f256
2 changed files with 26 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
drivers/net/wireless/ath/ath9k/main.c
View File

@ -230,6 +230,8 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
ath9k_ps_wakeup(sc);
spin_lock_bh(&sc->sc_pcu_lock);
/*
* This is only performed if the channel settings have
* actually changed.
@ -242,8 +244,6 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
ath9k_hw_disable_interrupts(ah);
ath_drain_all_txq(sc, false);
spin_lock_bh(&sc->sc_pcu_lock);
stopped = ath_stoprecv(sc);
/* XXX: do not flush receive queue here. We don't want
@ -268,7 +268,6 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
"Unable to reset channel (%u MHz), "
"reset status %d\n",
channel->center_freq, r);
spin_unlock_bh(&sc->sc_pcu_lock);
goto ps_restore;
}
@ -276,12 +275,9 @@ 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->sc_pcu_lock);
goto ps_restore;
}
spin_unlock_bh(&sc->sc_pcu_lock);
ath_update_txpow(sc);
ath9k_hw_set_interrupts(ah, ah->imask);
@ -292,6 +288,8 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
}
ps_restore:
spin_unlock_bh(&sc->sc_pcu_lock);
ath9k_ps_restore(sc);
return r;
}
@ -605,6 +603,8 @@ void ath9k_tasklet(unsigned long data)
return;
}
spin_lock_bh(&sc->sc_pcu_lock);
if (!ath9k_hw_check_alive(ah))
ieee80211_queue_work(sc->hw, &sc->hw_check_work);
@ -615,15 +615,12 @@ void ath9k_tasklet(unsigned long data)
rxmask = (ATH9K_INT_RX | ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
if (status & rxmask) {
spin_lock_bh(&sc->sc_pcu_lock);
/* Check for high priority Rx first */
if ((ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) &&
(status & ATH9K_INT_RXHP))
ath_rx_tasklet(sc, 0, true);
ath_rx_tasklet(sc, 0, false);
spin_unlock_bh(&sc->sc_pcu_lock);
}
if (status & ATH9K_INT_TX) {
@ -649,6 +646,8 @@ void ath9k_tasklet(unsigned long data)
/* re-enable hardware interrupt */
ath9k_hw_enable_interrupts(ah);
spin_unlock_bh(&sc->sc_pcu_lock);
ath9k_ps_restore(sc);
}
@ -876,12 +875,13 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
int r;
ath9k_ps_wakeup(sc);
spin_lock_bh(&sc->sc_pcu_lock);
ath9k_hw_configpcipowersave(ah, 0, 0);
if (!ah->curchan)
ah->curchan = ath_get_curchannel(sc, sc->hw);
spin_lock_bh(&sc->sc_pcu_lock);
r = ath9k_hw_reset(ah, ah->curchan, ah->caldata, false);
if (r) {
ath_print(common, ATH_DBG_FATAL,
@ -897,8 +897,6 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
spin_unlock_bh(&sc->sc_pcu_lock);
return;
}
spin_unlock_bh(&sc->sc_pcu_lock);
if (sc->sc_flags & SC_OP_BEACONS)
ath_beacon_config(sc, NULL); /* restart beacons */
@ -911,6 +909,8 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
ath9k_hw_set_gpio(ah, ah->led_pin, 0);
ieee80211_wake_queues(hw);
spin_unlock_bh(&sc->sc_pcu_lock);
ath9k_ps_restore(sc);
}
@ -921,6 +921,8 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
int r;
ath9k_ps_wakeup(sc);
spin_lock_bh(&sc->sc_pcu_lock);
ieee80211_stop_queues(hw);
/*
@ -937,8 +939,6 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
ath_drain_all_txq(sc, false); /* clear pending tx frames */
spin_lock_bh(&sc->sc_pcu_lock);
ath_stoprecv(sc); /* turn off frame recv */
ath_flushrecv(sc); /* flush recv queue */
@ -955,10 +955,11 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
ath9k_hw_phy_disable(ah);
spin_unlock_bh(&sc->sc_pcu_lock);
ath9k_hw_configpcipowersave(ah, 1, 1);
spin_unlock_bh(&sc->sc_pcu_lock);
ath9k_ps_restore(sc);
ath9k_setpower(sc, ATH9K_PM_FULL_SLEEP);
}
@ -972,13 +973,13 @@ int ath_reset(struct ath_softc *sc, bool retry_tx)
/* Stop ANI */
del_timer_sync(&common->ani.timer);
spin_lock_bh(&sc->sc_pcu_lock);
ieee80211_stop_queues(hw);
ath9k_hw_disable_interrupts(ah);
ath_drain_all_txq(sc, retry_tx);
spin_lock_bh(&sc->sc_pcu_lock);
ath_stoprecv(sc);
ath_flushrecv(sc);
@ -991,8 +992,6 @@ 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->sc_pcu_lock);
/*
* We may be doing a reset in response to a request
* that changes the channel so update any state that
@ -1017,6 +1016,7 @@ int ath_reset(struct ath_softc *sc, bool retry_tx)
}
ieee80211_wake_queues(hw);
spin_unlock_bh(&sc->sc_pcu_lock);
/* Start ANI */
ath_start_ani(common);
@ -1381,25 +1381,25 @@ static void ath9k_stop(struct ieee80211_hw *hw)
ath9k_btcoex_timer_pause(sc);
}
spin_lock_bh(&sc->sc_pcu_lock);
/* make sure h/w will not generate any interrupt
* before setting the invalid flag. */
ath9k_hw_disable_interrupts(ah);
if (!(sc->sc_flags & SC_OP_INVALID)) {
ath_drain_all_txq(sc, false);
spin_lock_bh(&sc->sc_pcu_lock);
ath_stoprecv(sc);
ath9k_hw_phy_disable(ah);
spin_unlock_bh(&sc->sc_pcu_lock);
} else {
spin_lock_bh(&sc->sc_pcu_lock);
} else
sc->rx.rxlink = NULL;
spin_unlock_bh(&sc->sc_pcu_lock);
}
/* disable HAL and put h/w to sleep */
ath9k_hw_disable(ah);
ath9k_hw_configpcipowersave(ah, 1, 1);
spin_unlock_bh(&sc->sc_pcu_lock);
ath9k_ps_restore(sc);
/* Finally, put the chip in FULL SLEEP mode */

2
drivers/net/wireless/ath/ath9k/xmit.c
View File

@ -1148,13 +1148,11 @@ 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_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_pcu_lock);
}
for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {