Hi all, I am currently working on an XHCI platform device simulation model. I noticed that the Linux driver (Linux 6.5.6 xhci-hcd) stops working when I configure the model without any USB2 ports. During an interrupt (TRB_PORT_STATUS), I only get "xhci-hcd 12100000.usb: ignore port event for removed USB3 hcd." During xhci_irq, in handle_port_status, xhci->shared_hcd is NULL [1], so the interrupt gets ignored. However, shared_hcd would only ever be allocated during xhci_plat_probe [2], if the device has both USB2 and USB3 ports, i.e. xhci_has_one_roothub returns false [3]. Without any USB2 ports, a shared_hcd will never be allocated in the first place, and handle_port_status will always exit early. I am new to the USB driver framework, so it's quite likely I am just overlooking something; but to me it seems that the driver cannot work unless I have an XHCI device that has at least one USB2 and one USB3 port. But during boot, I only get "USB2 root hub has no ports", which is not fatal. Best regards Jan [1] https://elixir.bootlin.com/linux/v6.5.6/source/drivers/usb/host/xhci-ring.c#L1895 [2] https://elixir.bootlin.com/linux/v6.5.6/source/drivers/usb/host/xhci-plat.c#L282 [3] https://elixir.bootlin.com/linux/v6.5.6/source/drivers/usb/host/xhci.h#L2001 -- Dr.-Ing. Jan Henrik Weinstock Managing Director MachineWare GmbH | www.machineware.de Hühnermarkt 19, 52062 Aachen, Germany Amtsgericht Aachen HRB25734 Geschäftsführung Lukas Jünger Dr.-Ing. Jan Henrik Weinstock
