Arch Linux

shoelesshunter

Member

Registered: 2014-05-18

Posts: 116

lenovo ideapad L3400 usb issue

Just bought a Lenovo Ideapad L3400 Gaming laptop, and everything works out of the box flawlessly, but I noticed something strange.

The product is advertised as having 2 USB-A 3.0 ports and one Type-C (3.1). I am using KDE and kinforcenter shows this:

Manufacturer: Linux 5.10.16-arch1-1 xhci-hcd
Serial #: 0000:00:14.0


Class
9
(Hub)
Subclass
0
(Unused)
Protocol
0
(Full speed (or root) hub)
USB Version
2.00




Vendor ID
0x1d6b
(Linux Foundation)
Product ID
0x2
(2.0 root hub)
Revision
0.00




Speed
480 Mbit/s

Channels
16

Max. Packet Size
64Manufacturer: Linux 5.10.16-arch1-1 xhci-hcd
Serial #: 0000:00:14.0


Class
9
(Hub)
Subclass
0
(Unused)
Protocol
0
(Full speed (or root) hub)
USB Version
3.10




Vendor ID
0x1d6b
(Linux Foundation)
Product ID
0x3
(3.0 root hub)
Revision
0.00




Speed
10,000 Mbit/s

Channels
8

Meaning I have one 2.0 controlser and one 3.0 controller (I assume the type-C is type 3.0 here).
but

 lshw | grep USB 

shows this:

description: USB controller
             product: Cannon Lake PCH USB 3.1 xHCI Host Controller

Meaning I have just one 3.1 controller which is what I wanted to purchase.

Can someone help me make heads or tails of this?

Last edited by shoelesshunter (2021-02-21 17:34:29)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 12,211

Re: lenovo ideapad L3400 usb issue

What's the output of lsusb ? Many systems often have an internal USB bus that's not exposed to the outside for things like the touchpad and the keyboard which is likely the USB 2 controller you're seeing.

bjornp_

Member

Registered: 2020-12-31

Posts: 14

Re: lenovo ideapad L3400 usb issue

I also own the Lenovo L340. I specifically own the 81LK L340-15IRH variant.

My kinfocenter shows exactly the same thing. There's two xHCI Host Controllers in the left list, and clicking on them reveals one is USB 2 and one is USB 3.2. I do not know why it is showing this, as I'm 100% certain that all three USB ports this laptop has are USB 3. The devices connected to the USB "2" controller are in this case for me devices connected to the USB C port through a USB C → 7 port USB 3 hub. As such I am completely positive these devices are connected through USB 3 ports.

One hint might be that all the devices connected to the USB "2" controller are in fact USB 2 devices in my case. It might run in some kind of compatibility mode to ensure these devices work. I'm not familiar enough with the USB spec to say that for certain. The internal webcam is also connected to the USB 2 controller, so it might be used internally as well.

In any case, the external USB ports are all capable of USB 3, so I don't think there's anything to worry about.

---

Fun fact: I actually have no clue what I'm doing

shoelesshunter

Member

Registered: 2014-05-18

Posts: 116

Re: lenovo ideapad L3400 usb issue

What's the output of lsusb ? Many systems often have an internal USB bus that's not exposed to the outside for things like the touchpad and the keyboard which is likely the USB 2 controller you're seeing.

lsusb:

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 04ca:7070 Lite-On Technology Corp. Integrated Camera
Bus 001 Device 002: ID 25a7:fa23 Areson Technology Corp 2.4G Receiver
Bus 001 Device 004: ID 8087:0aaa Intel Corp. Bluetooth 9460/9560 Jefferson Peak (JfP)
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

The only external device plugged into the type-A port is my wireless mouse receiver.

shoelesshunter

Member

Registered: 2014-05-18

Posts: 116

Re: lenovo ideapad L3400 usb issue

I also own the Lenovo L340. I specifically own the 81LK L340-15IRH variant.

My kinfocenter shows exactly the same thing. There's two xHCI Host Controllers in the left list, and clicking on them reveals one is USB 2 and one is USB 3.2. I do not know why it is showing this, as I'm 100% certain that all three USB ports this laptop has are USB 3. The devices connected to the USB "2" controller are in this case for me devices connected to the USB C port through a USB C → 7 port USB 3 hub. As such I am completely positive these devices are connected through USB 3 ports.

One hint might be that all the devices connected to the USB "2" controller are in fact USB 2 devices in my case. It might run in some kind of compatibility mode to ensure these devices work. I'm not familiar enough with the USB spec to say that for certain. The internal webcam is also connected to the USB 2 controller, so it might be used internally as well.

In any case, the external USB ports are all capable of USB 3, so I don't think there's anything to worry about.

I have no experience with Type-C 3.1 (and this laptop is supposed to be Gen 2 10Gb/s). I am about to buy a HDD enclosure with a Type-C Gen 2 hookup. Will this work reliably with a multiplier hub?