From owner-freebsd-wireless@FreeBSD.ORG Mon Jun 3 19:40:01 2013 Return-Path: Delivered-To: freebsd-wireless@smarthost.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 72C304BD for ; Mon, 3 Jun 2013 19:40:01 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:1900:2254:206c::16:87]) by mx1.freebsd.org (Postfix) with ESMTP id 48CCE120C for ; Mon, 3 Jun 2013 19:40:01 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.7/8.14.7) with ESMTP id r53Je1YD020419 for ; Mon, 3 Jun 2013 19:40:01 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.7/8.14.7/Submit) id r53Je1JS020418; Mon, 3 Jun 2013 19:40:01 GMT (envelope-from gnats) Date: Mon, 3 Jun 2013 19:40:01 GMT Message-Id: <201306031940.r53Je1JS020418@freefall.freebsd.org> To: freebsd-wireless@FreeBSD.org Cc: From: dfilter@FreeBSD.ORG (dfilter service) Subject: Re: kern/179232: commit references a PR X-BeenThere: freebsd-wireless@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: dfilter service List-Id: "Discussions of 802.11 stack, tools device driver development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Jun 2013 19:40:01 -0000 The following reply was made to PR kern/179232; it has been noted by GNATS. From: dfilter@FreeBSD.ORG (dfilter service) To: bug-followup@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-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org"