I some cases, when the device is USB-tethered to a host PC, and the device is sharing its mobile network connection with the host PC, if the user originates a call on the device, then the device's modem may reset and cause the phone call to not succeed. This may block the user from dialing emergency services. This patch resolves the device's modem reset issue.
https://en-us.support.motorola.com/app/answers/detail/a_id/175354