Hey folks,
Mate has a Pi 4 + a case that has a few addons. The Pi 4 slots into circuitboard within the case, and rather than using GPIO pins, case comms are done through the USB C power port (having been set to otg_mode=1).
The USB C port is connected to a GL825G hub, which then splits out to some additional USB ports, as well as USB to Serial converter which uses CH341 kernel driver.
When enabling otg_mode=1, an lsusb will show:
- The hub
- The serial adapter
When comparing lsmod ch341 and lsusb, the ch341 driver contains matching ID, so it should be autoloaded ... but it isn't.
Manually running modprobe ch341 loads the driver, but /dev/ttyUSB0 is still not created. Is there something missing from LE udev implementation perhaps? Does a specific udev rules file need to be added?
Mate is using LE 9.x because he needs VNC support to remotely help older folks who are normally the users of the Pi, and dispman changes appear to break VNC plugin in later versions of LE.