From f2e5212624567973232a5a618335b62f7fd013da Mon Sep 17 00:00:00 2001 From: stsp Date: Sat, 27 Nov 2021 11:22:26 +0000 Subject: [PATCH] Let iwm(4) use per-Tx-queue interface timers to ensure that the interface watchdog will trigger a device timeout if a particular Tx queue gets stuck while other Tx queues keep working. The Linux driver is using a similar workaround for "stuck queues". I have only observed this problem on iwx(4) hardware but it won't hurt to add this workaround to iwm(4) as well. --- sys/dev/pci/if_iwm.c | 53 +++++++++++++++++++++++++---------------- sys/dev/pci/if_iwmvar.h | 4 ++-- 2 files changed, 34 insertions(+), 23 deletions(-) diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c index d3e9a6ee21b..7418b39b5c1 100644 --- a/sys/dev/pci/if_iwm.c +++ b/sys/dev/pci/if_iwm.c @@ -1,4 +1,4 @@ -/* $OpenBSD: if_iwm.c,v 1.382 2021/11/22 11:00:50 stsp Exp $ */ +/* $OpenBSD: if_iwm.c,v 1.383 2021/11/27 11:22:26 stsp Exp $ */ /* * Copyright (c) 2014, 2016 genua gmbh @@ -5569,8 +5569,6 @@ iwm_ampdu_tx_done(struct iwm_softc *sc, struct iwm_cmd_header *cmd_hdr, status != IWM_TX_STATUS_DIRECT_DONE); uint16_t seq; - sc->sc_tx_timer = 0; - if (ic->ic_state != IEEE80211_S_RUN) return; @@ -5670,17 +5668,19 @@ iwm_rx_tx_cmd(struct iwm_softc *sc, struct iwm_rx_packet *pkt, bus_dmamap_sync(sc->sc_dmat, data->map, 0, IWM_RBUF_SIZE, BUS_DMASYNC_POSTREAD); - sc->sc_tx_timer = 0; - /* Sanity checks. */ if (sizeof(*tx_resp) > len) return; if (qid < IWM_FIRST_AGG_TX_QUEUE && tx_resp->frame_count > 1) return; + if (qid > IWM_LAST_AGG_TX_QUEUE) + return; if (sizeof(*tx_resp) + sizeof(ssn) + tx_resp->frame_count * sizeof(tx_resp->status) > len) return; + sc->sc_tx_timer[qid] = 0; + txd = &ring->data[idx]; if (txd->m == NULL) return; @@ -5790,7 +5790,7 @@ iwm_rx_compressed_ba(struct iwm_softc *sc, struct iwm_rx_packet *pkt, if (qid != IWM_FIRST_AGG_TX_QUEUE + ban->tid) return; - sc->sc_tx_timer = 0; + sc->sc_tx_timer[qid] = 0; ba = &ni->ni_tx_ba[ban->tid]; if (ba->ba_state != IEEE80211_BA_AGREED) @@ -6733,6 +6733,9 @@ iwm_tx(struct iwm_softc *sc, struct mbuf *m, struct ieee80211_node *ni, int ac) sc->qfullmsk |= 1 << ring->qid; } + if (ic->ic_if.if_flags & IFF_UP) + sc->sc_tx_timer[ring->qid] = 15; + return 0; } @@ -10011,10 +10014,8 @@ iwm_start(struct ifnet *ifp) continue; } - if (ifp->if_flags & IFF_UP) { - sc->sc_tx_timer = 15; + if (ifp->if_flags & IFF_UP) ifp->if_timer = 1; - } } return; @@ -10084,7 +10085,8 @@ iwm_stop(struct ifnet *ifp) iwm_clear_reorder_buffer(sc, rxba); } iwm_led_blink_stop(sc); - ifp->if_timer = sc->sc_tx_timer = 0; + memset(sc->sc_tx_timer, 0, sizeof(sc->sc_tx_timer)); + ifp->if_timer = 0; splx(s); } @@ -10093,21 +10095,30 @@ void iwm_watchdog(struct ifnet *ifp) { struct iwm_softc *sc = ifp->if_softc; + int i; ifp->if_timer = 0; - if (sc->sc_tx_timer > 0) { - if (--sc->sc_tx_timer == 0) { - printf("%s: device timeout\n", DEVNAME(sc)); - if (ifp->if_flags & IFF_DEBUG) { - iwm_nic_error(sc); - iwm_dump_driver_status(sc); + + /* + * We maintain a separate timer for each Tx queue because + * Tx aggregation queues can get "stuck" while other queues + * keep working. The Linux driver uses a similar workaround. + */ + for (i = 0; i < nitems(sc->sc_tx_timer); i++) { + if (sc->sc_tx_timer[i] > 0) { + if (--sc->sc_tx_timer[i] == 0) { + printf("%s: device timeout\n", DEVNAME(sc)); + if (ifp->if_flags & IFF_DEBUG) { + iwm_nic_error(sc); + iwm_dump_driver_status(sc); + } + if ((sc->sc_flags & IWM_FLAG_SHUTDOWN) == 0) + task_add(systq, &sc->init_task); + ifp->if_oerrors++; + return; } - if ((sc->sc_flags & IWM_FLAG_SHUTDOWN) == 0) - task_add(systq, &sc->init_task); - ifp->if_oerrors++; - return; + ifp->if_timer = 1; } - ifp->if_timer = 1; } ieee80211_watchdog(ifp); diff --git a/sys/dev/pci/if_iwmvar.h b/sys/dev/pci/if_iwmvar.h index fe8490a324c..8ff9f922c33 100644 --- a/sys/dev/pci/if_iwmvar.h +++ b/sys/dev/pci/if_iwmvar.h @@ -1,4 +1,4 @@ -/* $OpenBSD: if_iwmvar.h,v 1.71 2021/10/11 09:03:22 stsp Exp $ */ +/* $OpenBSD: if_iwmvar.h,v 1.72 2021/11/27 11:22:26 stsp Exp $ */ /* * Copyright (c) 2014 genua mbh @@ -588,7 +588,7 @@ struct iwm_softc { struct iwm_bf_data sc_bf; - int sc_tx_timer; + int sc_tx_timer[IWM_MAX_QUEUES]; int sc_rx_ba_sessions; int tx_ba_queue_mask; -- 2.20.1