Re: [linux-usb-devel] 2.6.18-rc6-mm1 (-mm2): ohci resume problem

Rafael J. Wysocki
2006-09-14T14:09:28Z

On Thursday, 14 September 2006 15:14, Rafael J. Wysocki wrote:
> On Wednesday, 13 September 2006 23:55, Alan Stern wrote:
> > On Wed, 13 Sep 2006, Rafael J. Wysocki wrote:
> >
> > > > Try this patch instead. It looks for problems occurring a little earlier
> > > > in the call chain.
> > >
> > > I've applied both patches at a time (I hope they don't conflict).
> > >
> > > The dmesg output is attached.
> >
> > The dmesg output shows the root-hub device state is set wrong.
> >
> > I have to leave now, so I can't give you another patch to try. You can
> > experiment as follows...
> >
> > Look in drivers/usb/host/ehci-pci.c, at ehci_pci_resume(). The part of
> > interest is everything following the "restart:" statement label.
> >
> > Try adding some ehci_dbg() lines in there (copy the form of the line just
> > after restart:). We want to follow the value of
> > hcd->self.root_hub->state. Initially it should be equal to
> > USB_STATE_SUSPENDED (= 8), and it shouldn't change. But somewhere it is
> > getting set to USB_STATE_CONFIGURED (= 7). I don't know where, but almost
> > certainly somewhere in this routine. If you can find out where that
> > happens, I'd appreciate it.
>
> Done, but it shows hcd->self.root_hub->state is already 7 right after restart.

BTW, all of the systems on which the problem shows up seem to be 64-bit.

If you can't reproduce it on a 32-bit system, some type casting may be wrong
somewhere.

Greetings,
Rafael

--
You never change things by fighting the existing reality.
R. Buckminster Fuller