Re: Null Pointer BUG in uhci_hcd

Alan Stern
2009-07-08T21:02:59Z

On Wed, 8 Jul 2009, Michael S. Zick wrote:

> > Like I've been telling you all along, the hardware isn't working.
> >
>
> That sounds very fragile.

I'm not sure how to interpret that sentence. If you mean that your
system's hardware design isn't good, I agree. If you mean that the
kernel shouldn't produce a lot of output when faced with broken
hardware, that's not so clear. What else should it do (bearing in mind
that the kernel can't tell the hardware is broken)?

> > I suspect it's worse than a simple interrupt-routing mistake.
> >
>
> I would not object to your removing that one mistake - that is one less
> to contend with.

I didn't say there was an interrupt-routing mistake; I said it was
_worse_ than an interrupt-routing mistake.

> > > > > For more information enable CONFIG_USB_DEBUG and CONFIG_DEBUG_FS, then
> > > > > see what's sitting in the usb/uhci/* files in debugfs.
> > > > >
> > >
>
> Fours up-time - nothing written to dmesg since boot -
> Just the usual hard-lockup.
>
> Also - something in the combined fix/diagnostic patch
> disable any sensing of external usb events.
> So I couldn't very well poke devices at it. ;)

You should take out those BUG statements. If they ever trigger, they
will certainly lock up your system.

Alan Stern