[Qemu-devel] Re: [patch 2/2] support for UHCI suspend / remote wake up

[Gerd Hoffmann]

> I was seeing bus disconnects when not clearing port resume bit properly.
>
> > >               port->ctrl&= ~(val&   0x000a);
> > > +            port->ctrl&= ~(port->ctrl&   0x0040); /* clear port resume 
> > > detected */
> > >           }
> >
> > This chunk looks suspicious ...
> >
> > I suspect the port suspend/resume emulation isn't complete.

The bug is that the port resume bit is masked out from guest writes, so 
the guest hasn't a chance to clear it ...

cheers,
  Gerd

PS: http://cgit.freedesktop.org/spice/qemu/log/?h=usb.1