The core of hub support (docs/usb-hub.md): a device on a hub's
downstream port now reaches its class driver exactly like one on a root
port. The hub's interrupt status-change endpoint is armed with an
in-process subscription — completions set the hub's pending-port mask
instead of queuing a class-driver report — and setupHub seeds every
downstream port pending so a STATIC topology (a device present at
power-on) enumerates without waiting on the initial interrupt edge.
On the bus tick, each pending hub port is serviced: GET_STATUS + clear
the change bits, and on a connect reset the port, read the speed, then
enable a slot and Address Device with the composed route string
((parent_route<<4)|port), the inherited root port, and the parent hub's
slot/port as the TRANSACTION TRANSLATOR — so the controller routes a
full/low-speed device's split transactions through the hub's TT. The
device then enumerates and registers its interfaces through the normal
path (a compact topology-unique port key keeps the id tag within its
8-byte cap), recursing setupHub if it is itself a hub.
Verified in QEMU (a keyboard behind a USB2 hub on a second controller):
'hub slot 1 port 1 device vendor 0x0627 ... usb-hid-keyboard: ok
(device 35)'. Full suite 89/89. The user's SuperSpeed Genesys hub +
full-speed keyboard/mouse on its USB2 companion is the real-hardware
target, flagged separately.
Daniel Samson
9da1a9899c