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Message-ID: <4615E00C.9070406@candelatech.com>
Date: Thu, 05 Apr 2007 22:52:12 -0700
From: Ben Greear <greearb@...delatech.com>
To: gregkh@...e.de, NetDev <netdev@...r.kernel.org>
Subject: [Fwd: [PATCH 3/4] 8139too: RTNL and flush_scheduled_work deadlock]
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 <romieu@...zoreil.com>
To: jeff@...zik.org
CC: Stephen Hemminger <shemminger@...ux-foundation.org>,
akpm@...ux-foundation.org, netdev@...r.kernel.org, Ben Greear
<greearb@...delatech.com>, Kyle Lucke <klucke@...ibm.com>, Raghavendra
Koushik <raghavendra.koushik@...erion.com>, Al Viro <viro@....linux.org.uk>
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 <romieu@...zoreil.com>
---
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 <greearb@...delatech.com>
Candela Technologies Inc http://www.candelatech.com
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