This is a bug related to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1210858. Its fix was supposed to be released
in 3.11.0-7.13, but I can confirm that it is still present in 3.11.0-13 and in 3.12 (I used mainline kernel to check it).
The effect is that the USB 2.0 port in my laptop doesn't detects any device when plugged.
This is a bug related to https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1210858. Its fix was supposed to be released
in 3.11.0-7.13, but I can confirm that it is still present in 3.11.0-13 and in 3.12 (I used mainline kernel to check it).
The effect is that the USB 2.0 port in my laptop doesn't detects any device when plugged.