From 904e385eba8241f7a9ec53f7851db3020407d51d Mon Sep 17 00:00:00 2001 From: Adrian Chadd Date: Mon, 3 Jun 2013 19:39:37 +0000 Subject: [PATCH] Fix the order of TX shutdown and reset. * Grab the reset lock first, so any subsequent interrupt, TX, RX work will fail * Then shut down interrupts * Then wait for TX/RX to finish running At this point no further work will be running, so it's safe to do the reset path code. PR: kern/179232 --- sys/dev/ath/if_ath.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/sys/dev/ath/if_ath.c b/sys/dev/ath/if_ath.c index ec96063d4f3c..ecd5ca124681 100644 --- a/sys/dev/ath/if_ath.c +++ b/sys/dev/ath/if_ath.c @@ -2328,12 +2328,27 @@ ath_reset(struct ifnet *ifp, ATH_RESET_TYPE reset_type) taskqueue_block(sc->sc_tq); ATH_PCU_LOCK(sc); - ath_hal_intrset(ah, 0); /* disable interrupts */ - ath_txrx_stop_locked(sc); /* Ensure TX/RX is stopped */ + + /* + * Grab the reset lock before TX/RX is stopped. + * + * This is needed to ensure that when the TX/RX actually does finish, + * no further TX/RX/reset runs in parallel with this. + */ if (ath_reset_grablock(sc, 1) == 0) { device_printf(sc->sc_dev, "%s: concurrent reset! Danger!\n", __func__); } + + /* disable interrupts */ + ath_hal_intrset(ah, 0); + + /* + * Now, ensure that any in progress TX/RX completes before we + * continue. + */ + ath_txrx_stop_locked(sc); + ATH_PCU_UNLOCK(sc); /* @@ -4871,12 +4886,18 @@ ath_chan_set(struct ath_softc *sc, struct ieee80211_channel *chan) taskqueue_block(sc->sc_tq); ATH_PCU_LOCK(sc); - ath_hal_intrset(ah, 0); /* Stop new RX/TX completion */ - ath_txrx_stop_locked(sc); /* Stop pending RX/TX completion */ + + /* Stop new RX/TX/interrupt completion */ if (ath_reset_grablock(sc, 1) == 0) { device_printf(sc->sc_dev, "%s: concurrent reset! Danger!\n", __func__); } + + ath_hal_intrset(ah, 0); + + /* Stop pending RX/TX completion */ + ath_txrx_stop_locked(sc); + ATH_PCU_UNLOCK(sc); DPRINTF(sc, ATH_DEBUG_RESET, "%s: %u (%u MHz, flags 0x%x)\n",