What is the deal with usbserial kernel module in current Ubuntu version? I cannot install any drivers, which depend on usbserial.ko.

How I got to this:
When I connect CP2102 Virtual COM Port (VCP) adapter to USB I get this output:

[ 1893.942663] usb 1- new full-speed USB device number 12 using ehci-pci
[ 1894.052823] usb 1- New USB device found, idVendor=10c4, idProduct=ea60
[ 1894.052826] usb 1- New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1894.052828] usb 1- Product: CP2102 USB to UART Bridge Controller
[ 1894.052829] usb 1- Manufacturer: Silicon Labs
[ 1894.052831] usb 1- SerialNumber: 0001
[ 1895.067552] cp210x: Unknown symbol usb_serial_generic_open (err 0)
[ 1895.067565] cp210x: Unknown symbol usb_serial_generic_close (err 0)
[ 1895.067579] cp210x: Unknown symbol usb_serial_deregister_drivers (err 0)
[ 1895.067595] cp210x: Unknown symbol usb_serial_register_drivers (err 0)

$ lsmod | grep 210x and $ lsmod | grep usbserial outputs nothing

Then I tried to rebuild the driver. Downloaded new CP210x driver form http://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers

$ make
$ cp ./cp210x.ko /lib/modules/4.8.0-58-generic/kernel/drivers/usb/serial/cp210x.ko
$ insmod /lib/modules/4.8.0-58-generic/kernel/drivers/usb/serial/cp210x.ko 
insmod: ERROR: could not insert module /lib/modules/4.8.0-58-generic/kernel/drivers/usb/serial/cp210x.ko: Unknown symbol in module

Also $ modinfo usbserial outputs

filename:       /lib/modules/4.8.0-58-generic/kernel/drivers/usb/serial/usbserial.ko
modinfo: ERROR: could not get modinfo from 'usbserial': No such file or directory

My system info: 4.8.0-58-generic #63~16.04.1-Ubuntu SMP Mon Jun 26 18:08:51 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux What is going on here and how to fix it? And how to get drivers up and running?

Thank you in advance!!

2 Answers 2


I had exactly the same problem you mention with my SiLabs CP2102-based ESP32-DevKitC board from Espressif. You don't mention the environment you're using, but I was running Ubuntu as a VirtualBox VM, which turned out to be the source of my problem.

The problem is that USB Serial drivers aren't installed by default in Ubuntu images designed for VM and cloud use.

To resolve the issue, install the linux-image-extra-virtual package by running:

sudo apt-get install linux-image-extra-virtual

Once I installed that package, I got a /dev/ttyUSB0 serial device shortly after connecting my USB device to my (host) Mac.


I had the same problem. You just need to install linux-modules-extra which contains the driver for your kernel.

With the following command:

sudo apt install linux-modules-extra-$(uname -r)

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