FTDI D2XX - FT_Open not working on WSL2

[ThierryCam]

Windows Version

Microsoft Windows [Version 10.0.19045.2965]

WSL Version

1.2.5.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

5.15.90.1

Distro Version

Ubuntu 20.04

Other Software

FTDI D2XX - Linux X64 - library version 1.4.27 (https://ftdichip.com/drivers/d2xx-drivers/)
USBIPD - 3.0.0+361.Branch.master.Sha.89d4b327c99a4eecc9b583e1843a428aae3c9270

Repro Steps

Not sure if it's a bug or a missing feature.

• I try to use FTDI library within WSL2.
• I use usbipd wsl attach to attach my USB device (ID 0403:6010) to WSL2 Distro
• I can see /dev/ttyUSB0 & /dev/ttyUSB1 ($ ls /dev/ttyUSB*)
  the

Expected Behavior

On calling the FTDI library API, I expected the FT_Open() method to succeed (return 0)
See https://ftdichip.com/wp-content/uploads/2020/08/D2XX_Programmers_GuideFT_000071.pdf

My goal is to be able to use the FTDI driver within WSL2, if it's possible.

Actual Behavior

Calling FT_Open return FT_DEVICE_NOT_OPENED

Diagnostic Logs

• Following FTDI installation guide (https://ftdichip.com/wp-content/uploads/2020/08/AN_220_FTDI_Drivers_Installation_Guide_for_Linux-1.pdf)
• In Linux, the VCP driver and D2XX driver are incompatible with each other. When a FTDI device is plugged in, the VCP driver must be unloaded before a D2XX application can be run. Use the remove module (rmmod) command to do this:
  $ sudo rmmod ftdi_sio
  But this command doesn't work.
• I also tried to add this udev rules, which didn't work either:
  ACTION=="add",ATTRS{idVendor}=="0403",ATTRS{idProduct}=="6010",MODE="0666",RUN+="/sbin/rmmod ftdi_sio",OPTIONS="last_rule"

[elsaco]

@ThierryCam the USB FTDI serial driver is built into the kernel, see details at:

https://github.com/microsoft/WSL2-Linux-Kernel/blob/4aeb7776ebf6d022dfe49fc8abf4ece02d523e84/Microsoft/config-wsl#L2761

Build a custom kernel with ftdi_sio as a module.

[ThierryCam]

The issue I have (I guess), is not about ftdi_sio, which giving correctly a Virtual Com Port (VCP) on my setup.
What I cannot do is to disable this udev service for a specific device, to use D2XX API instead.
I tried to add this udev rules, but it seems not to be possible to do it on WSL:
ACTION=="add",ATTRS{idVendor}=="0403",ATTRS{idProduct}=="6010",MODE="0666",RUN+="/sbin/rmmod ftdi_sio",OPTIONS="last_rule"
FT_Open (FTDI API) is still returning FT_DEVICE_NOT_OPENED, and not sure there's a way to make it work on WSL.

[OneBlue]

Thanks for reporting this @ThierryCam. WSL doesn't directly manage USB devices so this issue should be opened on usbpid