Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 371e8bc2 authored by Francois Romieu's avatar Francois Romieu Committed by Francois Romieu
Browse files

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: default avatarFrancois Romieu <romieu@fr.zoreil.com>
parent 8351538d

drivers/net/8139too.c

+26 −12
Original line number Diff line number Diff line
@@ -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)

{