[ofa-general] Re: [PATCH] IB/ipoib: Do not turn on carrier to a non active port

[Moni Shoua]

Roland Dreier wrote:
> And by the way, this current patch has a deadlock I think:
> 
>  > @@ -724,6 +724,8 @@ int ipoib_ib_dev_down(struct net_device *dev, int flush)
>  >  	ipoib_dbg(priv, "downing ib_dev\n");
>  >  
>  >  	clear_bit(IPOIB_FLAG_OPER_UP, &priv->flags);
>  > +	cancel_delayed_work(&priv->carrier_on_task);
> 
> ipoib_ib_dev_down() is called with rtnl held but carrier_on_task() does
> rtn_lock().  So if carrier_on_task() is running but about to take the
> rtnl when we try to do cancel_delayed_work() here, then it will wait
> forever.
> 
> I think using lockdep on a new enough kernel (2.6.30 or maybe 2.6.31)
> will report workqueue / timer vs. lock deadlocks.
> 
>  - R.
I may miss this but I don't  see how ipoib_ib_dev_down() is called with rtnl held.
Anyway, the new patch doesn't use delayed work.