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

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

On Wed, 8 Oct 2025 11:02:43 +0200, Arisa Snowbell wrote:
> Morning,
> 
> > 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?  
> 
> By testing a little bit more now in the morning I found new information.
> If I replug in the USB 2.0 port, no, it doesn't work. Only if I plug
> it into the 3.0 port.

Interesting, the patch was tested by people who reported the original
problem (empty USB3 root hubs on USB2-only controllers).

Please do this:

0. figure out PCI address of the USB2-only controller, possibly use
   a good kernel if necessary (but PCI addresses sometimes change)

1. boot with some device on a USB2-only port
2. echo 'module xhci_hcd +p' >/proc/dynamic_debug/control
3. disconnect and connect the device to the same port
4. do the unbind/bind thing on the USB2-only controller
5. echo 'module xhci_hcd -p' >/proc/dynamic_debug/control

Then upload dmesg.