diff options
author | sam <sam@FreeBSD.org> | 2006-02-24 23:10:08 +0000 |
---|---|---|
committer | sam <sam@FreeBSD.org> | 2006-02-24 23:10:08 +0000 |
commit | b77a1092875ef1bea1aeed19238f7e92d88fd34d (patch) | |
tree | f4761c27bda775fad03c60c0946fd3d17c6bcc96 /sys | |
parent | 2c3357a0a6aa69c1b9e08ef6a1fd02ac37e41217 (diff) | |
download | FreeBSD-src-b77a1092875ef1bea1aeed19238f7e92d88fd34d.zip FreeBSD-src-b77a1092875ef1bea1aeed19238f7e92d88fd34d.tar.gz |
fix a race whereby a tx descriptor might get reused before the hardware
is finished with it; this may only occur when the tx queue is setup as
dba-gated but since the fix is cheap apply it to all queues
while here make the queue depth signed for use in assertions
Reviewed by: apatti
MFC after: 2 weeks
Diffstat (limited to 'sys')
-rw-r--r-- | sys/dev/ath/if_ath.c | 53 | ||||
-rw-r--r-- | sys/dev/ath/if_athvar.h | 7 |
2 files changed, 42 insertions, 18 deletions
diff --git a/sys/dev/ath/if_ath.c b/sys/dev/ath/if_ath.c index e264c6f..30a9391 100644 --- a/sys/dev/ath/if_ath.c +++ b/sys/dev/ath/if_ath.c @@ -1155,12 +1155,16 @@ ath_start(struct ifnet *ifp) */ ATH_TXBUF_LOCK(sc); bf = STAILQ_FIRST(&sc->sc_txbuf); - if (bf != NULL) - STAILQ_REMOVE_HEAD(&sc->sc_txbuf, bf_list); + if (bf != NULL) { + if (bf->bf_flags & ATH_FLAG_BUSY) + bf = NULL; + else + STAILQ_REMOVE_HEAD(&sc->sc_txbuf, bf_list); + } ATH_TXBUF_UNLOCK(sc); if (bf == NULL) { - DPRINTF(sc, ATH_DEBUG_XMIT, "%s: out of xmit buffers\n", - __func__); + DPRINTF(sc, ATH_DEBUG_XMIT, + "%s: no available xmit buffers\n", __func__); sc->sc_stats.ast_tx_qstop++; ifp->if_drv_flags |= IFF_DRV_OACTIVE; break; @@ -1181,14 +1185,14 @@ ath_start(struct ifnet *ifp) ieee80211_state_name[ic->ic_state]); sc->sc_stats.ast_tx_discard++; ATH_TXBUF_LOCK(sc); - STAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list); + STAILQ_INSERT_HEAD(&sc->sc_txbuf, bf, bf_list); ATH_TXBUF_UNLOCK(sc); break; } IFQ_DRV_DEQUEUE(&ifp->if_snd, m); /* XXX: LOCK */ if (m == NULL) { ATH_TXBUF_LOCK(sc); - STAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list); + STAILQ_INSERT_HEAD(&sc->sc_txbuf, bf, bf_list); ATH_TXBUF_UNLOCK(sc); break; } @@ -1275,7 +1279,7 @@ ath_start(struct ifnet *ifp) ifp->if_oerrors++; reclaim: ATH_TXBUF_LOCK(sc); - STAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list); + STAILQ_INSERT_HEAD(&sc->sc_txbuf, bf, bf_list); ATH_TXBUF_UNLOCK(sc); if (ni != NULL) ieee80211_free_node(ni); @@ -2411,7 +2415,7 @@ ath_descdma_setup(struct ath_softc *sc, __func__, dd->dd_name, ds, (u_long) dd->dd_desc_len, (caddr_t) dd->dd_desc_paddr, /*XXX*/ (u_long) dd->dd_desc_len); - /* allocate rx buffers */ + /* allocate buffers */ bsize = sizeof(struct ath_buf) * nbuf; bf = malloc(bsize, M_ATHDEV, M_NOWAIT | M_ZERO); if (bf == NULL) { @@ -3687,7 +3691,7 @@ ath_tx_start(struct ath_softc *sc, struct ieee80211_node *ni, struct ath_buf *bf , ctsrate /* rts/cts rate */ , ctsduration /* rts/cts duration */ ); - bf->bf_flags = flags; + bf->bf_txflags = flags; /* * Setup the multi-rate retry state only when we're * going to use it. This assumes ath_hal_setuptxdesc @@ -3758,7 +3762,7 @@ ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq) { struct ath_hal *ah = sc->sc_ah; struct ieee80211com *ic = &sc->sc_ic; - struct ath_buf *bf; + struct ath_buf *bf, *last; struct ath_desc *ds, *ds0; struct ieee80211_node *ni; struct ath_node *an; @@ -3790,7 +3794,14 @@ ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq) break; } ATH_TXQ_REMOVE_HEAD(txq, bf_list); - if (txq->axq_depth == 0) + if (txq->axq_depth > 0) { + /* + * More frames follow. Mark the buffer busy + * so it's not re-used while the hardware may + * still re-read the link field. + */ + bf->bf_flags |= ATH_FLAG_BUSY; + } else txq->axq_link = NULL; ATH_TXQ_UNLOCK(txq); @@ -3827,7 +3838,7 @@ ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq) * Hand the descriptor to the rate control algorithm. */ if ((ds->ds_txstat.ts_status & HAL_TXERR_FILT) == 0 && - (bf->bf_flags & HAL_TXDESC_NOACK) == 0) { + (bf->bf_txflags & HAL_TXDESC_NOACK) == 0) { /* * If frame was ack'd update the last rx time * used to workaround phantom bmiss interrupts. @@ -3853,6 +3864,9 @@ ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq) bf->bf_node = NULL; ATH_TXBUF_LOCK(sc); + last = STAILQ_LAST(&sc->sc_txbuf, ath_buf, bf_list); + if (last != NULL) + last->bf_flags &= ~ATH_FLAG_BUSY; STAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list); ATH_TXBUF_UNLOCK(sc); } @@ -3968,17 +3982,18 @@ ath_tx_draintxq(struct ath_softc *sc, struct ath_txq *txq) /* * NB: this assumes output has been stopped and - * we do not need to block ath_tx_tasklet + * we do not need to block ath_tx_proc */ for (ix = 0;; ix++) { ATH_TXQ_LOCK(txq); bf = STAILQ_FIRST(&txq->axq_q); if (bf == NULL) { - txq->axq_link = NULL; ATH_TXQ_UNLOCK(txq); break; } ATH_TXQ_REMOVE_HEAD(txq, bf_list); + if (txq->axq_depth == 0) + txq->axq_link = NULL; ATH_TXQ_UNLOCK(txq); #ifdef AR_DEBUG if (sc->sc_debug & ATH_DEBUG_RESET) @@ -3996,10 +4011,16 @@ ath_tx_draintxq(struct ath_softc *sc, struct ath_txq *txq) */ ieee80211_free_node(ni); } + bf->bf_flags &= ~ATH_FLAG_BUSY; ATH_TXBUF_LOCK(sc); STAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list); ATH_TXBUF_UNLOCK(sc); } + ATH_TXBUF_LOCK(sc); + bf = STAILQ_FIRST(&sc->sc_txbuf); + if (bf != NULL) + bf->bf_flags &= ~ATH_FLAG_BUSY; + ATH_TXBUF_UNLOCK(sc); } static void @@ -4877,10 +4898,10 @@ ath_printtxbuf(struct ath_buf *bf, u_int qnum, u_int ix, int done) printf("Q%u[%3u]", qnum, ix); for (i = 0, ds = bf->bf_desc; i < bf->bf_nseg; i++, ds++) { - printf(" (DS.V:%p DS.P:%p) L:%08x D:%08x F:04%x%s\n" + printf(" (DS.V:%p DS.P:%p) L:%08x D:%08x F:%x TF:%04x%s\n" " %08x %08x %08x %08x %08x %08x\n", ds, (struct ath_desc *)bf->bf_daddr + i, - ds->ds_link, ds->ds_data, bf->bf_flags, + ds->ds_link, ds->ds_data, bf->bf_flags, bf->bf_txflags, !done ? "" : (ds->ds_txstat.ts_status == 0) ? " *" : " !", ds->ds_ctl0, ds->ds_ctl1, ds->ds_hw[0], ds->ds_hw[1], ds->ds_hw[2], ds->ds_hw[3]); diff --git a/sys/dev/ath/if_athvar.h b/sys/dev/ath/if_athvar.h index cb9e95c..cef45f4 100644 --- a/sys/dev/ath/if_athvar.h +++ b/sys/dev/ath/if_athvar.h @@ -100,7 +100,8 @@ struct ath_node { struct ath_buf { STAILQ_ENTRY(ath_buf) bf_list; int bf_nseg; - int bf_flags; /* tx descriptor flags */ + u_int16_t bf_txflags; /* tx descriptor flags */ + u_int16_t bf_flags; /* see below */ struct ath_desc *bf_desc; /* virtual addr of desc */ bus_addr_t bf_daddr; /* physical addr of desc */ bus_dmamap_t bf_dmamap; /* DMA map for mbuf chain */ @@ -112,6 +113,8 @@ struct ath_buf { }; typedef STAILQ_HEAD(, ath_buf) ath_bufhead; +#define ATH_FLAG_BUSY 0x0001 /* tx descriptor owned by h/w */ + /* * DMA state for tx/rx descriptors. */ @@ -137,7 +140,7 @@ struct ath_descdma { */ struct ath_txq { u_int axq_qnum; /* hardware q number */ - u_int axq_depth; /* queue depth (stat only) */ + int axq_depth; /* queue depth (stat only) */ u_int axq_intrcnt; /* interrupt count */ u_int32_t *axq_link; /* link ptr in last TX desc */ STAILQ_HEAD(, ath_buf) axq_q; /* transmit queue */ |