Please consider this for the 2.6.20 stable branch. This fixes a deadlock between the bridging code and the 8139too driver. I am not the author of this patch, but I have tested a slightly modified version (so that it works with the 2.6.18 kernel) extensively
and it solves the deadlock.  Mr. Romieu suggested I forward this to you...

Thanks,
Ben

-------- Original Message --------
Subject:        [PATCH 3/4] 8139too: RTNL and flush_scheduled_work deadlock
Date:   Thu, 15 Feb 2007 23:37:44 +0100
From:   Francois Romieu <[EMAIL PROTECTED]>
To:     [EMAIL PROTECTED]
CC: Stephen Hemminger <[EMAIL PROTECTED]>, [EMAIL PROTECTED], netdev@vger.kernel.org, Ben Greear <[EMAIL PROTECTED]>, Kyle Lucke <[EMAIL PROTECTED]>, Raghavendra Koushik <[EMAIL PROTECTED]>, Al Viro <[EMAIL PROTECTED]>



Your usual dont-flush_scheduled_work-with-RTNL-held stuff.

It is a bit different here since the thread runs permanently
or is only occasionally kicked for recovery depending on the
hardware revision.

Signed-off-by: Francois Romieu <[EMAIL PROTECTED]>
---
drivers/net/8139too.c |   40 +++++++++++++++++-----------------------
1 files changed, 17 insertions(+), 23 deletions(-)

diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c
index 35ad5cf..99304b2 100644
--- a/drivers/net/8139too.c
+++ b/drivers/net/8139too.c
@@ -1109,6 +1109,8 @@ static void __devexit rtl8139_remove_one (struct pci_dev 
*pdev)

        assert (dev != NULL);

+       flush_scheduled_work();
+
        unregister_netdev (dev);

        __rtl8139_cleanup_dev (dev);
@@ -1603,18 +1605,21 @@ static void rtl8139_thread (struct work_struct *work)
        struct net_device *dev = tp->mii.dev;
        unsigned long thr_delay = next_tick;

+       rtnl_lock();
+
+       if (!netif_running(dev))
+               goto out_unlock;
+
        if (tp->watchdog_fired) {
                tp->watchdog_fired = 0;
                rtl8139_tx_timeout_task(work);
-       } else if (rtnl_trylock()) {
-               rtl8139_thread_iter (dev, tp, tp->mmio_addr);
-               rtnl_unlock ();
-       } else {
-               /* unlikely race.  mitigate with fast poll. */
-               thr_delay = HZ / 2;
-       }
+       } else
+               rtl8139_thread_iter(dev, tp, tp->mmio_addr);

-       schedule_delayed_work(&tp->thread, thr_delay);
+       if (tp->have_thread)
+               schedule_delayed_work(&tp->thread, thr_delay);
+out_unlock:
+       rtnl_unlock ();
}

static void rtl8139_start_thread(struct rtl8139_private *tp)
@@ -1626,19 +1631,11 @@ static void rtl8139_start_thread(struct rtl8139_private 
*tp)
                return;

        tp->have_thread = 1;
+       tp->watchdog_fired = 0;

        schedule_delayed_work(&tp->thread, next_tick);
}

-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)
{
        tp->cur_tx = 0;
@@ -1696,12 +1693,11 @@ static void rtl8139_tx_timeout (struct net_device *dev)
{
        struct rtl8139_private *tp = netdev_priv(dev);

+       tp->watchdog_fired = 1;
        if (!tp->have_thread) {
-               INIT_DELAYED_WORK(&tp->thread, rtl8139_tx_timeout_task);
+               INIT_DELAYED_WORK(&tp->thread, rtl8139_thread);
                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)
@@ -2233,8 +2229,6 @@ static int rtl8139_close (struct net_device *dev)

        netif_stop_queue (dev);

-       rtl8139_stop_thread(tp);
-
        if (netif_msg_ifdown(tp))
                printk(KERN_DEBUG "%s: Shutting down ethercard, status was 
0x%4.4x.\n",
                        dev->name, RTL_R16 (IntrStatus));
--
1.4.4.4

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--
Ben Greear <[EMAIL PROTECTED]> Candela Technologies Inc http://www.candelatech.com


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