After GPU reset amdgpu_vm_clear_bo triggers VM flush
but job->vm_pd_addr is not set causing SDMA TO.
v2:
Per advise by Christian König avoid flushing VM for jobs where
job->vm_pd_addr wasn't explicitly set.
v3:
Shortcut vm_flush_needed early.
Fixes 
cbd5285 drm/amdgpu: move setting the GART addr into TTM.
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
        amdgpu_sync_create(&(*job)->sync);
        amdgpu_sync_create(&(*job)->sched_sync);
        (*job)->vram_lost_counter = atomic_read(&adev->vram_lost_counter);
+       (*job)->vm_pd_addr = AMDGPU_BO_INVALID_OFFSET;
 
        return 0;
 }
 
        }
 
        gds_switch_needed &= !!ring->funcs->emit_gds_switch;
-       vm_flush_needed &= !!ring->funcs->emit_vm_flush;
+       vm_flush_needed &= !!ring->funcs->emit_vm_flush  &&
+                       job->vm_pd_addr != AMDGPU_BO_INVALID_OFFSET;
        pasid_mapping_needed &= adev->gmc.gmc_funcs->emit_pasid_mapping &&
                ring->funcs->emit_wreg;