up-to-date SteamOS debian beta with custom vanilla linux 4.11.6 with GCN1 support enabled in amdgpu.
dota2 -vulkan hangs once it has finished loading and it's in the dashboard. I still can move the cursor though.
I did built a fresh gnu/linux custom distro with git mesa, linux4.12.4, git gcc, git glibc, recent vulkan icd: the hang is exactly the same.
Ive got also a Tahiti (Radeon HD 7970), I had exactly the same issue with Dota2 and Vulkan like mentioned in this bug report. But things are working for me after:
The only difference is, Im using latest linux-amd-staging-4.11 maybe you could try this?
Yope, it did the trick for me. Each time I come reporting bugs there, some magic fixes it a little time right after my report without me knowing :)
Thanks for the tip!