USB3 devices fall back to USB2

Help
1

Hello, I have recently needed to use a USB3 device at its full speed but then I noticed that it is connected using USB2.
The device of interest:

Bus 009 Device 003: ID 03e7:2485 Intel Movidius MyriadX

Running lsusb -t I can see that it is connected with the speed of 480M

/:  Bus 009.Port 001: Dev 001, Class=root_hub, Driver=xhci_hcd/2p, 480M
    |__ Port 001: Dev 002, If 0, Class=Video, Driver=uvcvideo, 480M
    |__ Port 001: Dev 002, If 1, Class=Video, Driver=uvcvideo, 480M
    |__ Port 001: Dev 002, If 2, Class=Video, Driver=uvcvideo, 480M
    |__ Port 001: Dev 002, If 3, Class=Audio, Driver=snd-usb-audio, 480M
    |__ Port 001: Dev 002, If 4, Class=Audio, Driver=snd-usb-audio, 480M
    |__ Port 002: Dev 003, If 0, Class=Vendor Specific Class, Driver=[none], 480M

Looking at dmesg I have bunch of buses inited as USB3, as well as USB2, but whenever I plug a device into a USB3 port it gets assigned to a USB2 bus.

...
[    1.608162] usb usb7: Product: xHCI Host Controller
[    1.608162] usb usb7: Manufacturer: Linux 6.12.74 xhci-hcd
[    1.609502] usb usb8: Product: xHCI Host Controller
[    1.609503] usb usb8: Manufacturer: Linux 6.12.74 xhci-hcd
[    1.611439] xhci_hcd 0000:76:00.4: xHCI Host Controller
[    1.611442] xhci_hcd 0000:76:00.4: new USB bus registered, assigned bus number 9
[    1.611788] xhci_hcd 0000:76:00.4: hcc params 0x0120ffc5 hci version 0x120 quirks 0x0000000200000010
[    1.612142] xhci_hcd 0000:76:00.4: xHCI Host Controller
[    1.612145] xhci_hcd 0000:76:00.4: new USB bus registered, assigned bus number 10
[    1.612147] xhci_hcd 0000:76:00.4: Host supports USB 3.1 Enhanced SuperSpeed
[    1.612173] usb usb9: Product: xHCI Host Controller
[    1.612174] usb usb9: Manufacturer: Linux 6.12.74 xhci-hcd
[    1.613633] usb usb10: Product: xHCI Host Controller
[    1.613634] usb usb10: Manufacturer: Linux 6.12.74 xhci-hcd
[    1.615244] xhci_hcd 0000:77:00.0: xHCI Host Controller
...

Any clue what might be up?

Host: Micro-Star International Co., Ltd. X870 GAMING PLUS WIFI 
Kernel: 6.12.74 
AMD Ryzen 9 7950X (32) @ 5.881GHz

Also notably I asked an LLM for what can I try to do, and it told me to try using those KernelParams, but they had no effect.

	boot.kernelParams = [
		"usbcore.quirks=07ca:e575:u"
	  	"usbcore.autosuspend=-1"
	  	"pcie_aspm=off"  
		"iommu=soft"
		"pci=realloc"
  		"usbcore.old_scheme_first=1"
	];
2
  1. Is the port marked as USB 2.0?
  2. Is the USB 3.0 device still operating on USB 2.0 when you plug it into a USB 3.0 port?

USB 3.0 requires additional 5 additional contacts which are not present in a USB 2.0 port.

3

Ya, sorry that was a typo, I’m plugging it into USB3 port. I tried 5G, 10G, and 40G USB ports, it still falls back to USB2. I also tried different cables as well.

4

Given that the 40G port is a type-C port and the 5G ports are type-A ports, how are you connecting the device to the ports?

5

I tried both. For 5G I did type-A to type-C, and for 40G I tried type-C to C