(In reply to Alex Deucher from comment #33)
> I think Sonny fixed this.  It was due to using the wrong firmware.
> [    1.827060] [drm] initializing kernel modesetting (HAINAN 0x1002:0x6665
> 0x1028:0x0844 0xC3).  This chip should be using radeon/banks_k_2_smc.bin smc
> firmware.  Is that available on the test system and kernel?
The firmware radeon/banks_k_2_smc.bin is on the test system.
With Ubuntu kernel 4.4.0-101-generic, I am not pretty sure the radeon driver is
using this firmware.
With Ubuntu kernel 4.13.0-16-generic, I tried both amdgpu and radeon drivers,
but the system hang. as soon as the system hang, the amdgpu_pm_info shows
'invalid dpm profile 15'.

(In reply to Alex Deucher from comment #34)
> The following commits are relevant:
> abb2e3c1ce64c8bba678973800c34ea1dc97c42c
> 6458bd4dfd9414cba5804eb9907fe2a824278c34
> ef736d394e85b1bf1fd65ba5e5257b85f6c82325
> 4e6e98b1e48c9474aed7ce03025ec319b941e26e
These commits would be already included in Ubuntu kernel 4.13.0-16-generic.

(In reply to Alex Deucher from comment #35)
> Does reverting a628392cf03e0eef21b345afbb192cbade041741 fix the issue?
Removing this commit does not fix the issue.

BTW, with 4.13.0-16-generic, I change the max_sclk in drm/radeon/si_dpm.c (what
we did with Ubuntu kernel 4.4.0-101-generic) from 75000 to 65000, but still met
the hang issue.