upowerd consuming 100% cpu

Do you have an iphone connected to the computer? This happens to me whenever I connect my iphone to it.

Linux arjun-thinkpad 4.4.7-1-lts #1 SMP Thu Apr 14 17:26:39 CEST 2016 x86_64 GNU/Linux

After discovering this page I did some experimentation; connecting and disconnecting my iPhone 4 (ios 7.1.2) with up-to-date Ubuntu 16.10 using Unity running on a MacBookPro7,1

I found that just confirming Trust on the iPhone had no effect; { in fact I am asked repetitively to allow trust on this system unless I indicate 'Don't Trust', but that is another matter }

I also found that usbmuxd is playing a big part in this problem, so forcing usbmuxd to exit is a quick and dirty fix.

/usr/sbin/usbmuxd -X

After NOT Trusting and running the command I can charge the phone, and connect to it as a wireless or bluetooth hotspot without the cpu time consumption. { the phone also stops asking whether to trust the computer or not, and usbmuxd stops restarting }