On Thu, Jul 19, 2012 at 09:27:55PM +0200, Oliver Neukum wrote:
> On Thursday 19 July 2012 10:42:23 Alan Stern wrote:
> > > 
> > > 1) remote wakeup is requested
> > > 2) user space has blocked it via the new sysfs attribute
> > > 3) USB_QUIRK_RESET_MORPHS is set
> > 
> > The same is true for external ports if they are marked as 
> > non-removable.  For example, consider a compound keyboard/mouse device 
> > with a built-in hub.  The connections from the keyboard and the mouse 
> > to the hub are internal and not removable.
> 
> True. So the decisive factor is not just being internal.

Sure, we can tell whether an external device is removable by looking at
the hub "DeviceRemovable" bit for each port.  However, the port power
off mechanism will only work for roothub ports on the Intel system.  I
suppose external USB 2.0 or USB 3.0 hubs might actually be able to power
off ports as well.

Sarah Sharp
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