[patch 12/31] 8139too: RTNL and flush_scheduled_work deadlock

Greg KH
2007-04-11T23:04:31Z

[-- Attachment #1: 8139too-rtnl-and-flush_scheduled_work-deadlock.patch --]
[-- Type: text/plain, Size: 2811 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
From: Francois Romieu <romieu@fr.zoreil.com>

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@fr.zoreil.com>
Cc: Ben Greear <greearb@candelatech.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/8139too.c | 40 +++++++++++++++++-----------------------
1 file changed, 17 insertions(+), 23 deletions(-)

--- a/drivers/net/8139too.c
+++ b/drivers/net/8139too.c
@@ -1109,6 +1109,8 @@ static void __devexit rtl8139_remove_one

assert (dev != NULL);

+ flush_scheduled_work();
+
unregister_netdev (dev);

__rtl8139_cleanup_dev (dev);
@@ -1603,18 +1605,21 @@ static void rtl8139_thread (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
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 n
{
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_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));

--