Re: mac80211 truesize bugs

Johannes Berg
2008-05-01T09:35:24Z

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On Thu, 2008-05-01 at 11:32 +0200, Michael Buesch wrote:
> On Thursday 01 May 2008 11:08:06 Johannes Berg wrote:
> >
> > > Hm, unrelated to this...
> > > But I am wondering what happens if the driver adds a device header to the skb.
> > > Is that header then also passed up netif_rx()?
> > > This doesn't happen for b43, as we use the DMA fragmentation to transmit the header,
> > > but it might happen for zd1211rw and others.
> >
> > Hmm. I thought we said that it was supposed to be removed again by the
> > hardware before TX status reporting. That's what most drivers seem to do
> > anyway.
>
> Ok. I was not aware of that. Is that documented somewhere? I guess we can't WARN_ON()?

Not sure. We could try to analyse the packet header and see if it's
802.11, or put a length into skb->cb (after my rework to put things into
skb->cb we have a single byte free so we could check skb->len % 256)