Re: [RFC PATCH] usb/acpi: Add support usb port power off mechanism for device fixed on the motherboard

Alan Stern
2012-05-12T13:54:44Z

On Fri, 11 May 2012, Greg KH wrote:

> On Fri, May 11, 2012 at 04:59:22PM -0700, Sarah Sharp wrote:
> > > > Only the xHCI host controller will have the port power off mechanism.
> > >
> > > You're only talking about the upcoming Intel implementation, right?
> >
> > Yes. The port power off mechanism is an Intel specific ACPI call.
> > AFAIK, there isn't anyone else who is going to have this mechanism.
>
> That's not fair, you don't know what other vendors are going to do in
> their controllers, or their system firmware, to be able to accurately say
> this.

Right. Even if other vendors don't use this ACPI mechanism, some of
them may very well implement the native USB port power control
mechanism. If we add port power support to our drivers, we should
certainly include native support.

Alan Stern