With latest agd5f drm-fixes-4.8 / drm-next-4.9-wip + Linus master kernel:

Latest git mesa master with SDMA enabled on CIK patch:

1) AMDGPU DDX shows squared corruption, X locks up
2) Using vlc desktop recording / vokoscreen desktop recording get corrupted
video recording

Kernel spits out GPUVPM faults:

[ 6612.359198] amdgpu 0000:01:00.0: GPU fault detected: 146 0x0248770c
[ 6612.359199] amdgpu 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_ADDR  
0x0010C836
[ 6612.359199] amdgpu 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_STATUS
0x0807700C
[ 6612.359200] VM fault (0x0c, vmid 4) at page 1099830, read from 'SDM0'
(0x53444d30) (119)

  Revert "radeonsi: enable SDMA on CIK"

    This reverts commit 0241d8300f66ee2c6c2c55fe64ac88d76440c591.


When reverted problems go away.