Re: OHCI/usb pass through

[Gerd Hoffmann]

  Hi,

> > > We can get the endpoint from a packet and from ohci so
> > > I wonder if we can get the active packet from ep->queue (and how to do 
> > > that)
> > 
> > I think ohci never looks beyond the active td so there should never be
> > more than one packet on the list.
> 
> OK, how to get the packet from that QTAILQ list? If there are multiple
> packets is the active one first or last? How to get that? I could try to
> find the answers in the code but I realy did not want to spend much time
> with it just trying to help Howard so I'd like to ask for some help with
> this.

See include/qemu/queue.h, QTAILQ_FIRST() is what you need.  Returns NULL
when the queue is empty.  There is also a separate QLIST_EMPTY() helper.

grepping in hw/usb/*.c should find you code examples in other host
adapters code.

take care,
  Gerd