Re: mac80211 deadlock detection triggering with rt61pci

[Ivo van Doorn <ivdoorn@gmail.com>]

On Friday 18 July 2008, Ivo van Doorn wrote:
> Hi,
> 
> > I'm not sure whether this still happens in current versions or not, but
> > kerneloops is reporting a number of mac80211 warnings due to the TX
> > deadlock detection:
> > http://www.kerneloops.org/searchweek.php?search=ieee80211_master_start_xmit
> > 
> > The rt2x00 mac code seems fine, did it change recently which could
> > explain this warning triggering?
> 
> Interesting, the TX code did change for 2.6.27 recently with the DMA changes
> by GertJan, I think the Fedora kernels which are showing the above panics already
> contain those patches,
> 
> John, Does Fedora kernel 2.6.25.10-86.fc9.x86_64 contain rt2x00 2.1.8?
> 
> I also have some reports about a queue corruption in rt61pci and although I haven't
> figured out how that corruption is caused, I do think the above panics might somehow
> be related.

It might be me, but looking at those traces, aren't they triggered by:

static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb)
{
...
		if (WARN_ON(queue >= ieee80211_num_regular_queues(&local->hw)))
			goto drop;
...
}

Which would suggest that when MAC80211_QOS is disabled, the skb_queue_mapping
still returns something higher then 1.

Ivo