I have a USB Dongle That I communicate with it using UART commands.
So if I connect my dongle after starting the system I can send commands and I'm able to receive info, But if I leave the dongle connected to my card and I reboot I receive nothing after command sent and the dongle blocked.
1 Example (works):
Start the system
connect the dongle after system started
send UART command (info\n\r for example)
I receive my info correctly
Bus 001 Device 006: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
2 Example (issue):
I leave my dongle connected to my Raspberry
I send UART command
Nothing happened and the dongle still blocked I can do nothing
Bus 001 Device 004: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC