It will work as soon as the patch reaches the stable Ubuntu kernels.
The current patch probably will not work with 3.19.
The easiest way is to upgrade the kernel in 14.04.3 by
sudo apt-get install linux-generic-lts-wily
This kernel will be default in 14.04.4 that will come out this month.
If it is a serious problem to use 4.2, I can build a module for 3.19 as well.
But I do not really think it is necessary.
Regarding Ubuntu 14.04.3 with 3.19 kernel.
It will work as soon as the patch reaches the stable Ubuntu kernels.
The current patch probably will not work with 3.19.
The easiest way is to upgrade the kernel in 14.04.3 by
sudo apt-get install linux-generic- lts-wily
This kernel will be default in 14.04.4 that will come out this month.
If it is a serious problem to use 4.2, I can build a module for 3.19 as well.
But I do not really think it is necessary.