14.04 3.19.0-58 broke USB/HDMI/touchpad

I'm a little out of my depth, so I'll try to be concise.

Up to keel 3.19.0-56 my Aspire v15 (vn7-591g) works fine.

Under 3.19.0-58 none of my USB devices work, touchpad doesn't work and though the 2nd display (HDMI) is working, it's stuck in mirrored mode and I can't find the HDMI in xrandr/the Display menu to change anything.
The USB devices (keyboard for instance) work in Grub, but by the time I reach the login screen, it's dead.

xrandr on 3.19.0-56:

Screen 0: minimum 8 x 8, current 4480 x 1440, maximum 32767 x 32767
eDP1 coected primary 1920x1080+2560+0 (normal left inverted right x axis y axis) 345mm x 194mm
   1920x1080      60.0*+   59.9  
<<SNIP>>
VGA1 discoected (normal left inverted right x axis y axis)
HDMI1 coected 2560x1440+0+0 (normal left inverted right x axis y axis) 621mm x 341mm
   3840x2160      30.0 +   30.0     25.0     24.0     24.0  
   2560x1440      60.0* 
<<SNIP>>
VIRTUAL1 discoected (normal left inverted right x axis y axis)

Failed to get size of gamma for output default
Screen 0: minimum 1600 x 1080, current 1600 x 1080, maximum 1600 x 1080
default coected primary 1600x1080+0+0 0mm x 0mm
1600x1080      77.0*

One thing that is "out of the ordinary" is that I use backport drivers to deal with the Qualcomm Atheros wireless card [168c:003e] (rev 32). I found the solution in another bug report, but I think this is related https://bugs.launchpad.net/ubuntu/+s...e/+bug/1520343
I generally just do the following after a keel up
cd ~/Downloads/backports-4.2.6-1/
make defconfig-ath10k
make
sudo make install

That's the only thing I can think of. Could this cause the issue?

I'm considering just backing up what I need and going to 15.10. If I can't track the problem, maybe a clean-slate and newer release will help.