I thought I had the Mayflash Gamecube to USB adapter which has a config file here : https://github.com/libretro/retroarch-joypad-autoconfig/blob/master/udev/Mayflash_GameCube_to_USB_Adapter.cfg But it seems I don’t as it is not working out-of-the-box neither in PC mode (however I see a « mayflash… not configured » message on screen once Lakka is started) nor in Wii U/NS (Nintendo Switch) mode. Mayflash has at least two models (2 ports-model, 4 ports-model) so perhaps I just don’t have the right model.
However I used udevadm info command (from another OS on same device - RPi3) and I see for my adapter 0079 as vendor id and 1844 as model id (hex numbers), far from what I see in the .cfg file (6708 for vendor, whereas I would expect 121 - decimal equivalent of 0079). I do see 121 in some others Mayflash*.cfg and 3727 in others. What’s wrong ?