Re: [PATCH v8 10/18] docs/system/devices/usb: Note the automatic hub change

[Junjie Cao <junjie.cao@xxxxxxxxx>]

Hi Jamin,

On Mon, Nov 02, 2026 at 09:22:17AM +0000, Jamin Lin wrote:
> +A machine type older than 11.2 plugs a virtual USB hub into the last
> +free port, so that more devices fit. A newer one does not, and a
> +device that finds no free port fails.

With the series going into 12.0 this becomes "older than 12.0".

It would also help to say how to get a hub back. piix3-usb-uhci has two
ports, so -usb with usb-kbd, usb-mouse and usb-tablet already fails on
the newest machine type (pc-i440fx-11.2 on v8). Either of these fixes
it here:

  -device usb-hub                     (ahead of the other devices)
  -global piix3-usb-uhci.auto-hub=on

Junjie