I have a imx6ul board, and a 2G modem connected to ttymxc4, also I use the ModemManager to manage it. The ModemManager would listen the udev event of ttymxc4 as the udev rules indict, once the udev has the add action, the ModemManger would talk with the modem.
And this works some times, but sometimes, the modemManger didn't get the udev event of probe of ttymxc4. So my question is:
1. How to simulator a udev event of the 'add' action of ttymxc4 device when the system is booted?
2. Or how can I defer probe the ttymxc4, so the probe uevent wouldn't lost?