The following reply was made to PR kern/179232; it has been noted by GNATS.
From: dfil...@freebsd.org (dfilter service) To: bug-follo...@freebsd.org Cc: Subject: Re: kern/179232: commit references a PR Date: Mon, 3 Jun 2013 19:39:50 +0000 (UTC) Author: adrian Date: Mon Jun 3 19:39:37 2013 New Revision: 251342 URL: http://svnweb.freebsd.org/changeset/base/251342 Log: 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 Modified: head/sys/dev/ath/if_ath.c Modified: head/sys/dev/ath/if_ath.c ============================================================================== --- head/sys/dev/ath/if_ath.c Mon Jun 3 19:29:03 2013 (r251341) +++ head/sys/dev/ath/if_ath.c Mon Jun 3 19:39:37 2013 (r251342) @@ -2328,12 +2328,27 @@ ath_reset(struct ifnet *ifp, ATH_RESET_T 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, struc 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", _______________________________________________ svn-src-...@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org" _______________________________________________ freebsd-wireless@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-wireless To unsubscribe, send any mail to "freebsd-wireless-unsubscr...@freebsd.org"
