net: Eliminate flush_scheduled_work() calls while RTNL is held.

If the RTNL is held when we invoke flush_scheduled_work() we could
deadlock.  One such case is linkwatch, it is a work struct which tries
to grab the RTNL semaphore.

The most common case are net driver ->stop() methods.  The
simplest conversion is to instead use cancel_{delayed_}work_sync()
explicitly on the various work struct the driver uses.

This is an OK transformation because these work structs are doing
things like resetting the chip, restarting link negotiation, and so
forth.  And if we're bringing down the device, we're about to turn the
chip off and reset it anways.  So if we cancel a pending work event,
that's fine here.

Some drivers were working around this deadlock by using a msleep()
polling loop of some sort, and those cases are converted to instead
use cancel_{delayed_}work_sync() as well.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index 1eaf5bb3d9c2..2377cc13bf61 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -6656,7 +6656,6 @@ struct bnx2 {
         int                     current_interval;
         struct                  timer_list timer;
         struct work_struct      reset_task;
-        int                     in_reset_task;
 
         /* Used to synchronize phy accesses. */
         spinlock_t              phy_lock;