Re: Bad interaction between uhci_hcd and de2104x

From: Martin Michlmayr
Date: Sat Feb 04 2006 - 06:13:52 EST


* Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> [2006-02-03 22:30]:
> > When I unload de2104x and uhci_hcd and load only de2104x again
> > then Ethernet works. Similarly, when I completely blacklist the
> > uhci_hcd module the de2104x driver works without any problems.
>
> And presumably, if you blacklist the de2104x driver then your USB
> controller works without any problems.
...
> For some reason, the de2104x driver isn't listed as a handler for
> IRQ 10. That's probably the cause of the problem. Did you have any
> full- or low-speed USB devices plugged in at the time this occurred?
> If you didn't then the UHCI hardware would not have generated any
> interrupt requests.

No, I don't think I ever used USB on this machine. I did some more
tests based on what you said and have the following data points:
- Having a USB device (USB stick) plugged in when booting doesn't
make a difference.
- When I load the de2104x driver _before_ uhci_hcd, both USB and
Ethernet work fine.
- Both modules load fine. USB also works. The problem only occurs
when I actually try to use the Ethernet device (i.e. run DHCP).
Then I get that traceback, and USB also stops working.

--
Martin Michlmayr
http://www.cyrius.com/
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