Need info about ATCoP

[ghost]

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• I have searched the open Issues and made sure I am not filing a duplicate.
• I have read the notes on debugging and will properly maintain this Issue.

SDM660 (modem- MSM4114), Mi A2, Android One 9(stock), 2 sim

I founded two devices(not symlinks), that can recieve at commands and answer them. Its /dev/smd8 and smd11. Smd7 is owned by root:root, smd11 - radio:radio.
Both of the devices output same IMEI, is it normal behavior?

What are /dev/at_mdm0 and at_usb0 devices for?