4.10.0-28-generic
[AMD/ATI] Tahiti LE [Radeon HD 7870 XT]

I have the same problem with this card. 

On amdgpu I got black screen. But monitor remains on. I can log in via ssh and
all.

On radeon first I get screen full of colourful pixels, then black screen, then
monitor says no-signal and goes stand-by. And then pc hangs and I can no longer
log in via ssh.

On radeon there are a lot of 
radeon 0000:01:00.0: ring 3 stalled for more than 10036msec
kinda logs in dmesg. But on amdgpu there is nothing interesting really. It
seems like it almost works, except for the black screen ;)

I think I'm gonna try fresh kernel from padoka ppa next. When I have some free
time.