Re: [REGRESSION] USB-A devices not working on boot after recent USB merge

[Michal Pecio <michal.pecio@gmail.com>]

On Wed, 8 Oct 2025 03:15:31 +0200, Arisa Snowbell wrote:
> The first bad commit seems to be
> [719de070f764e079cdcb4ddeeb5b19b3ddddf9c1] usb: xhci-pci: add support
> for hosts with zero USB3 ports. All USB-A devices stop being
> visible/detected.

Hmm, OK. Copying xHCI people.

So the issue is that there are some USB ports on the motherboard where
devices work when they are hotplugged, but nothing is enumerated during
boot, correct?

Are all USB-A ports affected or only those limited to USB 2.0 speed?

If you look at hotplug notifications like
[    4.612030] usb 18-2: new high-speed USB device number 2 using xhci_hcd

the first number (18) is the USB bus number. You can then find the PCI
address of the xHCI controller by looking at the root hub (device 1):

$ lsusb -vs 18:1 |grep iSerial
  iSerial                 1 0000:0c:00.0


Can you reproduce the bug without rebooting by connecting some device
and then reloading the xhci driver on this particular controller?

echo 0000:0c:00.0 |tee /sys/bus/pci/drivers/xhci_hcd/unbind /sys/bus/pci/drivers/xhci_hcd/bind

Regards,
Michal