After some investigation I've found that fix of this bug introduced new problem - https://bugs.launchpad.net/ubuntu/+source/linux-lts-vivid/+bug/1527599. More specially problem appears after http://kernel.ubuntu.com/git/ubuntu/ubuntu-vivid.git/commit/?id=06ec92f3bac598a7a9b9ecf451ab1915929a5980 commit.
After some investigation I've found that fix of this bug introduced new problem - https:/ /bugs.launchpad .net/ubuntu/ +source/ linux-lts- vivid/+ bug/1527599. kernel. ubuntu. com/git/ ubuntu/ ubuntu- vivid.git/ commit/ ?id=06ec92f3bac 598a7a9b9ecf451 ab1915929a5980 commit.
More specially problem appears after http://