Last updated 09/13/2016
Some notes on running Debian sid on a Dell XPS15 9550 with a 4K UHD HDPI touch panel. Specifically, running KDE/plasma 5.7 on kernel 4.7.0.
There are lots of other resources out there. Lots of resources will be shitty and for older models or outdated OS versions, and lots of Ubuntu forums. Oh the Ubuntu forums. In any case, here are the few things I found worth bookmarking:
I used the Debian/stretch "testing" installer on a USB stick in text mode in order to install from the network, and it worked reasonably well. First quirk is with microscopic text during install. I just squinted and dealt with it.
Another quirk here with the broadcom firmware -- the installer will complain about some missing firmware (.txt file) which isn't actually required. Just skip that part and the installer will happily continue and install from the net even without the magical missing file.
EFI is kinda new to me, so I wasn't even sure if I'd be able to use it. I just used a little care in order to not delete the factory EFI partition during install and the EFI situation continued to work. That is, the bios/config app is still around and I can see the volume after booting into sid.
I was pretty impressed when this just worked out of the box. I'm not sure how much I'll actually be touching my screen, but it is sometimes convenient and I was kinda shocked and surprised when it worked without any additional effort.
This effort most definitely is not painless. There are various quirks and roadblocks on the path to nirvana.
Pd is microscopic. I'm sure other apps are as well. Haven't yet found a convenient workaround, in spite of the "zoom" feature in Pd (very lacking!).
Even though there are pretty good instructions around xrandr here, I had a very hard time getting things to just work and appear as expected. Lots of randomness here.
The mouse pointer in KDE/plasma consistently flickers at an annoying interval/rate when the external monitor is attached/enabled.
The UI is pretty small. Some text is microscopic. No obvious/trivial way to fix it.