Hi,
as stated in the title, we have a nrf52840 dongle (PCA10059) which does not come up normally on a Nvidia xavier devboard. Output of dmesg:
We tried different OS and SW (bootloader/softdevice/application) versions all with the same outcome.
After a lot of testing and tracing we found out, that when we pull out the usb-dongle ot of the usb-socket just that far that the power-pins are still connected and only the connection-pins are disconnected and then plug it back, the device will be detected just fine. Also when using a external usb-hub it will come up normally.
So it seems the problem comes from a timing issue between the xavier-usb (tegra-xusb) driver and the dongle. Probably the dongle delivers the usb-config too slow so that the kernel has no config to select the further loading of cdc_acm.
Is there anything we can do in the bootloader/softdevice/app to somehow fix this problem, so that no external usb-hub is needed?