I have a customized Linux distro (created via buildroot) running on an embedded platform. The system consists in a processing module (Based on Samsung Exynos 4412 microprocessor) with a base board for peripherals (such as RS232, Ethernet, USB ports, etc). It connects to the Internet via Ethernet cable or Wi-Fi, and that is set during boot.
Recently, a module was added on the kernel to enable the connection of a new device, which appears as
/dev/ttyACM0. Other peripherals have been used before, such as a serial printer (
/dev/ttyUSB0) and no problems were observed.
On this case though, there's a strange behaviour. Nothing wrong happens when the system boots set to Wi-Fi, no matter the number of peripherals connected. Also, if it boots set to Ethernet and the
ttyACM0 device is connected afterwards, it functions normally. The problem happens when the system is booted set to Ethernet while the device is connected. On this case, shortly after a connection has been made (I'm able to access it and see that the device is listed on
/dev) it loses the connection to the Internet.
Network interfaces don't have anything to do with
/dev, right? They're listed elsewhere, not having any references in
/dev. I don't see how one could possibly impact the other. Is there any reason why this could be happening?