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

Sarah Sharp
2012-05-15T01:47:39Z

On Fri, May 11, 2012 at 11:09:40PM +0200, Peter Stuge wrote:
> Sarah Sharp wrote:
> > Theoretically there's no maximum number for xHCI root ports
>
> Hm? Please clarify this?
>
> HCSPARAMS1 MaxPorts is 8 bits and "Valid values are in the range of
> 1h to FFh."

Sorry, yes, you're correct, the maximum number of ports for xHCI is 255.
I was just trying to point out that it's possible that xHCI hosts will
have a much larger number of USB ports than what we've previously seen
on EHCI host controllers.

Sarah Sharp