According to Apple's announcement, if there are repeated restarts on the iPhone, iPad or iPod touch of the iOS 11 operating system, follow these steps:
1. Click "Notifications" in the "Settings" menu.
2. Turn off the "Allow notifications" option in each App.
3. Update the device to the latest version of iOS 11.2.
4. And then follow the previous steps, each App "Allow Notification" option is turned on.
In case the above steps still can not be solved, go to Apple Store, Apple Reseller or Apple's official website "Apple Support." Currently there are users return iOS12.2 update has returned to normal and smooth, but the power consumption situation still seems to exist.
Apple's official website announced earlier: to solve the update black screen to close the application push notification.