Having Ubuntu 15.04 running on a Surface Pro 3 is pretty awesome. However, for it to work you need to compile your own patched kernel. That being said, I did the annoying work for you and have a provided a link to a patched kernel below.
- power button
- volume buttons
- front/rear cam
- all known type covers
- finnicky touch screen
- finnicky pen
Here is the link to the kernel files for download:
To install just extract the tarball and run:
sudo dpkg -i linux-headers* linux-image*
If you want to build your own kernel you can follow a great guide here:
One thing to note is that you will also want to use a patch I created to make sure your keyboard works:
Type Cover 3 Patch
The reason is that there are 5 different Type Covers with different hard-coded product ids. The current 15.04 kernel only supports 1 out of the 5 known type covers. This patch will make sure that your type cover will work no matter what region or model.
Good luck and let me know if you have questions.