It sounds like this bug didn't exists in Ubuntu 3.13.0-8. That kernel was based off of upstream 3.13.2. That may indicate that this bug was introduced by upstream stable 3.13.3 or 3.13.4. If you have time, can you also test the following two kernels:
If 3.13.3 has the bug, there is no need to test 3.13.4. However, the priority should be on the reverse bisect, so we can identify what fixes this in 3.14.
It sounds like this bug didn't exists in Ubuntu 3.13.0-8. That kernel was based off of upstream 3.13.2. That may indicate that this bug was introduced by upstream stable 3.13.3 or 3.13.4. If you have time, can you also test the following two kernels:
3.13.3: http:// kernel. ubuntu. com/~kernel- ppa/mainline/ v3.13.3- trusty/ kernel. ubuntu. com/~kernel- ppa/mainline/ v3.13.4- trusty/
3.13.4: http://
If 3.13.3 has the bug, there is no need to test 3.13.4. However, the priority should be on the reverse bisect, so we can identify what fixes this in 3.14.