Now I tested version 3.13.0-69.112~precise1 from https://launchpad.net/~canonical-kernel-team/+archive/ubuntu/ppa/+packages?field.name_filter=linux-lts-trusty&field.status_filter=&field.series_filter=precise and it has same problem as 3.13.0-71. So this bug was introduced somewhere between -68 and -69.
Now I tested version 3.13.0- 69.112~ precise1 from https:/ /launchpad. net/~canonical- kernel- team/+archive/ ubuntu/ ppa/+packages? field.name_ filter= linux-lts- trusty& field.status_ filter= &field. series_ filter= precise and it has same problem as 3.13.0-71. So this bug was introduced somewhere between -68 and -69.