Environment: Pi 4, 2gig, Buster, updated.
We have a USB 3 WiFi adapter (blue plug), which is plugged into one of the blue USB3 slots. The device vid/pid is: 0bda:b812, Realtek. Rated 867Mbps for the 5 GHz band.
$ lsusb -t
shows the following output:
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/1p, 480M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M |__ Port 2: Dev 3, If 0, Class=Vendor Specific Class, Driver=rtl88x2bu, 480M |__ Port 3: Dev 4, If 0, Class=Hub, Driver=hub/3p, 12M |__ Port 1: Dev 5, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M |__ Port 2: Dev 6, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
If I'm reading this correctly, it's saying that the WiFi adapter, Device 3, is on Bus 01, and that its speed is limited to 480M. It also seems to say that nothing is connected to Bus 02, which is the super-speed USB3 bus. The problem is that the WiFi adapter is only functioning at a fraction of its stated speed, and while I can't be sure this is the problem, it doesn't make sense to me that this device, which is definitely plugged into a USB3 slot is showing up on what appears to me to be the USB2 bus.
I've tried swapping the device between the two blue 3.0 slots, and while the device number changes, it still shows up on Bus 01.
I've also tried completely disconnecting the low-speed devices (keyboard/mouse) from the USB2 slot, to see if they were causing some kind of misdirection, but that didn't seem to help either.
If I plug the WiFi adapter into a USB2 slot, it gets a new device number, but still shows up as being on Bus 01, Port 1, with a limit of 480M.
If I type the following:
$ dmesg -w
then unplug and re-plug the device, it shows:
usb 1-1.4: USB disconnect, device number 12 usb 1-1.1: new high-speed USB device number 13 using xhci_hcd ...
followed by other vendor-specific info that looks right. The key part being that it looks like it recognizes the device as "high-speed", not "super-speed".
How can I get this adapter on the USB3 bus? Or is it already, and I'm not understanding this output? The device is not running at the advertised speed.