From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: NETDEV WATCHDOG: eth0 (atl1c): transmit queue 0 timed out Date: Fri, 24 Feb 2012 20:20:29 +0100 Message-ID: <1330111229.15610.50.camel@edumazet-laptop> References: <1329063403.1449.14.camel@localhost.localdomain> <1329204997.24837.15.camel@edumazet-laptop> <1329366846.5646.1.camel@edumazet-laptop> <1329847015.5133.4.camel@localhost.localdomain> <1329848093.18384.35.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Linux Kernel Mailing List , jcliburn@gmail.com, chris.snook@gmail.com, netdev , Josh Boyer To: Thomas Meyer Return-path: In-Reply-To: <1329848093.18384.35.camel@edumazet-laptop> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le mardi 21 f=C3=A9vrier 2012 =C3=A0 19:14 +0100, Eric Dumazet a =C3=A9= crit : > Le mardi 21 f=C3=A9vrier 2012 =C3=A0 18:56 +0100, Thomas Meyer a =C3=A9= crit : >=20 > > Bad news. Just did hit the issue again, with above patch applied. > >=20 > > abrt_version: 2.0.7 > > cmdline: BOOT_IMAGE=3D/vmlinuz-3.2.6 root=3D/dev/sda2 rootfs= type=3Dext4 rootflags=3Ddata=3Dwriteback ro quiet rhgb > > kernel: 3.2.6 > > reason: [177799.342250] WARNING: at net/sched/sch_generic.c= :255 dev_watchdog+0x1e7/0x1f0() > > time: Di 21 Feb 2012 18:09:16 CET > >=20 > > backtrace: > > :[177799.342250] WARNING: at net/sched/sch_generic.c:255 dev_watchd= og+0x1e7/0x1f0() > > :[177799.342254] Hardware name: Aspire 1810T > > :[177799.342256] NETDEV WATCHDOG: eth0 (atl1c): transmit queue 0 ti= med out > > :[177799.342259] Modules linked in: vfat fat fuse bluetooth nf_conn= track_ipv6 nf_defrag_ipv6 ip6t_REJECT ip6table_filter ip6_tables snd_hd= a_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwde= p snd_seq arc4 snd_seq_device snd_pcm iwlwifi uvcvideo mac80211 snd_tim= er videodev cfg80211 snd usb_storage v4l2_compat_ioctl32 atl1c acer_wmi= soundcore sparse_keymap snd_page_alloc rfkill wmi joydev acerhdf pcspk= r virtio_net virtio virtio_ring kvm_intel kvm uinput ipv6 [last unloade= d: scsi_wait_scan] > > :[177799.342303] Pid: 4980, comm: alsa-sink Not tainted 3.2.6 #7 > > :[177799.342306] Call Trace: > > :[177799.342309] [] warn_slowpath_common+= 0x7a/0xb0 > > :[177799.342320] [] warn_slowpath_fmt+0x41/0x50 > > :[177799.342325] [] ? do_IRQ+0x5b/0xd0 > > :[177799.342330] [] dev_watchdog+0x1e7/0x1f0 > > :[177799.342336] [] run_timer_softirq+0xef/0x210 > > :[177799.342341] [] ? qdisc_reset+0x50/0x50 > > :[177799.342345] [] __do_softirq+0x87/0x110 > > :[177799.342350] [] call_softirq+0x1a/0x30 > > :[177799.342354] [] do_softirq+0x4d/0x80 > > :[177799.342358] [] irq_exit+0x7e/0xa0 > > :[177799.342363] [] smp_apic_timer_interrupt+0x5= a/0x90 > > :[177799.342368] [] apic_timer_interrupt+0x69/0x= 70 > > :[177799.342371] [] ? sysenter_dispatch+0= x7/0x26 > >=20 > > END: > >=20 >=20 > Thanks >=20 > This driver xmit function is racy I suspect, and several patches will= be > needed to fix bugs. >=20 Here is a cumulative patch to hopefuly remove the races in this driver, could you please test it ? diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c.h b/drivers/net/e= thernet/atheros/atl1c/atl1c.h index ca70e16..3b2851b 100644 --- a/drivers/net/ethernet/atheros/atl1c/atl1c.h +++ b/drivers/net/ethernet/atheros/atl1c/atl1c.h @@ -576,7 +576,6 @@ struct atl1c_adapter { u16 link_duplex; =20 spinlock_t mdio_lock; - spinlock_t tx_lock; atomic_t irq_sem; =20 struct work_struct common_task; diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/= net/ethernet/atheros/atl1c/atl1c_main.c index 1ff3c6d..896eb20 100644 --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c @@ -784,7 +784,6 @@ static int __devinit atl1c_sw_init(struct atl1c_ada= pter *adapter) atl1c_set_rxbufsize(adapter, adapter->netdev); atomic_set(&adapter->irq_sem, 1); spin_lock_init(&adapter->mdio_lock); - spin_lock_init(&adapter->tx_lock); set_bit(__AT_DOWN, &adapter->flags); =20 return 0; @@ -1653,9 +1652,11 @@ static bool atl1c_clean_tx_irq(struct atl1c_adap= ter *adapter, atomic_set(&tpd_ring->next_to_clean, next_to_clean); } =20 - if (netif_queue_stopped(adapter->netdev) && - netif_carrier_ok(adapter->netdev)) { - netif_wake_queue(adapter->netdev); + if (netif_carrier_ok(adapter->netdev)) { + /* make sure atl1c_xmit_frame() see our changes */ + smp_mb(); + if (netif_queue_stopped(adapter->netdev)) + netif_wake_queue(adapter->netdev); } =20 return true; @@ -2228,7 +2229,6 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buf= f *skb, struct net_device *netdev) { struct atl1c_adapter *adapter =3D netdev_priv(netdev); - unsigned long flags; u16 tpd_req =3D 1; struct atl1c_tpd_desc *tpd; enum atl1c_trans_queue type =3D atl1c_trans_normal; @@ -2239,24 +2239,20 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_b= uff *skb, } =20 tpd_req =3D atl1c_cal_tpd_req(skb); - if (!spin_trylock_irqsave(&adapter->tx_lock, flags)) { - if (netif_msg_pktdata(adapter)) - dev_info(&adapter->pdev->dev, "tx locked\n"); - return NETDEV_TX_LOCKED; - } =20 if (atl1c_tpd_avail(adapter, type) < tpd_req) { /* no enough descriptor, just stop queue */ netif_stop_queue(netdev); - spin_unlock_irqrestore(&adapter->tx_lock, flags); - return NETDEV_TX_BUSY; + smp_mb(); + if (atl1c_tpd_avail(adapter, type) < tpd_req) + return NETDEV_TX_BUSY; + netif_wake_queue(netdev); } =20 tpd =3D atl1c_get_tpd(adapter, type); =20 /* do TSO and check sum */ if (atl1c_tso_csum(adapter, skb, &tpd, type) !=3D 0) { - spin_unlock_irqrestore(&adapter->tx_lock, flags); dev_kfree_skb_any(skb); return NETDEV_TX_OK; } @@ -2277,7 +2273,6 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buf= f *skb, atl1c_tx_map(adapter, skb, tpd, type); atl1c_tx_queue(adapter, skb, tpd, type); =20 - spin_unlock_irqrestore(&adapter->tx_lock, flags); return NETDEV_TX_OK; } =20