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 <romieu@fr.zoreil.com>
diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c
index adfba44..2beac55 100644
--- a/drivers/net/8139too.c
+++ b/drivers/net/8139too.c
@@ -586,6 +586,7 @@
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 __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 @@
{
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 @@
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 @@
/* 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 @@
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)
{