(In reply to jk from comment #0)
> Created attachment 120000 [details]
> Logfile
> 
> Switched from catalyst to amdgpu, Kernel 4.2 and Kernel 4.3 with powerplay
> fixes crash, wenn modesetting is enabled (which just has to be, to get
> everything working..) 
> When booting without modesetting no Kernel Panic occurs, but just nothing
> else works really good...
> 
> I'm using Archlinux with mesa/llvm etc build from git.
> Kernel 4.2 is Archlinux vanilla kernel, 4.3 is build from
> http://cgit.freedesktop.org/~agd5f/linux/?h=amdgpu-powerplay
> 
> Log files are attached.I've tried with disabled/enabled Iommu, it think this
> Log is with disabled Iommu.

jk, did situation improve with newer kernels?