Re: USB3?

[Michal Suchanek <hramrach%centrum.cz@localhost>]

On 31 August 2011 13:16, Greg Troxel <gdt%ir.bbn.com@localhost> wrote:
>
> (Sorry if this is an already-answered question - searching and looking
> in sources didn't turn up much.)
>
> What's the state of USB3?  It seems there is a new controller type
> 'xhci'.
>
> Specifically:
>
>  any plans/status for a USB3 controller driver?  It seems FreeBSD got
>  this late 2010 but I don't know how well it works.
>
>  Do machines with usb2 and usb3 both tend to have a ehci chip for usb2,
>  plus an xhci for some usb3 ports?  (In other words, is NetBSD likely
>  to work on the usb2 ports and ignore the usb3 ports?)
>
>  Will our ehci driver work on the xhci chip in usb2 compat mode?

All I can say is that USB3 chips vary.

On an Intel Atom based board with one USB3 controller there were only
4 ports and they worked fine as USB1/2 without the xhci driver.

On another board with different USB3 controller based on AMD Zacate
chipset there were numerous ports and the two that were supposed to be
USB3 did not work at all without a xhci driver.

For compatibility reasons board makers are likely not going to make a
board only with ports working as xhci only but ymmv.

Thanks

Michal