From 371e8bc2af11b0571982390932bc07b5ffed9aba Mon Sep 17 00:00:00 2001 From: Francois Romieu Date: Tue, 31 Jan 2006 01:04:33 +0100 Subject: [PATCH] 8139too: fix a TX timeout watchdog thread against NAPI softirq race Ingo's stealth lock validator detected that both thread acquire dev->xmit_lock and tp->rx_lock in reverse order. Signed-off-by: Francois Romieu --- drivers/net/8139too.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c index adfba44dac5..2beac55b57d 100644 --- a/drivers/net/8139too.c +++ b/drivers/net/8139too.c @@ -586,6 +586,7 @@ struct rtl8139_private { dma_addr_t tx_bufs_dma; signed char phys[4]; /* MII device addresses. */ char twistie, twist_row, twist_col; /* Twister tune state. */ + unsigned int watchdog_fired : 1; unsigned int default_port : 4; /* Last dev->if_port value. */ unsigned int have_thread : 1; spinlock_t lock; @@ -638,6 +639,7 @@ static void rtl8139_set_rx_mode (struct net_device *dev); static void __set_rx_mode (struct net_device *dev); static void rtl8139_hw_start (struct net_device *dev); static void rtl8139_thread (void *_data); +static void rtl8139_tx_timeout_task(void *_data); static struct ethtool_ops rtl8139_ethtool_ops; /* write MMIO register, with flush */ @@ -1598,13 +1600,14 @@ static void rtl8139_thread (void *_data) { struct net_device *dev = _data; struct rtl8139_private *tp = netdev_priv(dev); - unsigned long thr_delay; + unsigned long thr_delay = next_tick; - if (rtnl_shlock_nowait() == 0) { + if (tp->watchdog_fired) { + tp->watchdog_fired = 0; + rtl8139_tx_timeout_task(_data); + } else if (rtnl_shlock_nowait() == 0) { rtl8139_thread_iter (dev, tp, tp->mmio_addr); rtnl_unlock (); - - thr_delay = next_tick; } else { /* unlikely race. mitigate with fast poll. */ thr_delay = HZ / 2; @@ -1631,7 +1634,8 @@ static void rtl8139_stop_thread(struct rtl8139_private *tp) if (tp->have_thread) { cancel_rearming_delayed_work(&tp->thread); tp->have_thread = 0; - } + } else + flush_scheduled_work(); } static inline void rtl8139_tx_clear (struct rtl8139_private *tp) @@ -1642,14 +1646,13 @@ static inline void rtl8139_tx_clear (struct rtl8139_private *tp) /* XXX account for unsent Tx packets in tp->stats.tx_dropped */ } - -static void rtl8139_tx_timeout (struct net_device *dev) +static void rtl8139_tx_timeout_task (void *_data) { + struct net_device *dev = _data; struct rtl8139_private *tp = netdev_priv(dev); void __iomem *ioaddr = tp->mmio_addr; int i; u8 tmp8; - unsigned long flags; printk (KERN_DEBUG "%s: Transmit timeout, status %2.2x %4.4x %4.4x " "media %2.2x.\n", dev->name, RTL_R8 (ChipCmd), @@ -1670,23 +1673,34 @@ static void rtl8139_tx_timeout (struct net_device *dev) if (tmp8 & CmdTxEnb) RTL_W8 (ChipCmd, CmdRxEnb); - spin_lock(&tp->rx_lock); + spin_lock_bh(&tp->rx_lock); /* Disable interrupts by clearing the interrupt mask. */ RTL_W16 (IntrMask, 0x0000); /* Stop a shared interrupt from scavenging while we are. */ - spin_lock_irqsave (&tp->lock, flags); + spin_lock_irq(&tp->lock); rtl8139_tx_clear (tp); - spin_unlock_irqrestore (&tp->lock, flags); + spin_unlock_irq(&tp->lock); /* ...and finally, reset everything */ if (netif_running(dev)) { rtl8139_hw_start (dev); netif_wake_queue (dev); } - spin_unlock(&tp->rx_lock); + spin_unlock_bh(&tp->rx_lock); } +static void rtl8139_tx_timeout (struct net_device *dev) +{ + struct rtl8139_private *tp = netdev_priv(dev); + + if (!tp->have_thread) { + INIT_WORK(&tp->thread, rtl8139_tx_timeout_task, dev); + schedule_delayed_work(&tp->thread, next_tick); + } else + tp->watchdog_fired = 1; + +} static int rtl8139_start_xmit (struct sk_buff *skb, struct net_device *dev) { -- 2.41.1