I have this bug too.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1441104
and I found another similar:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1401980
I have this bug too.
https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1441104
and I found another similar:
https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1401980