drm/amdgpu: handle gang submit before VMID

Otherwise it can happen that not all gang members can get a VMID
assigned and we deadlock.

Signed-off-by: Christian König <[email protected]>
Tested-by: Timur Kristóf <[email protected]>
Acked-by: Timur Kristóf <[email protected]>
Fixes: 68ce8b2 ("drm/amdgpu: add gang submit backend v2")
Reviewed-by: Alex Deucher <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: ChristianKoenigAMD

drivers/gpu/drm/amd/amdgpu/amdgpu_job.c

@@ -254,6 +254,9 @@ static struct dma_fence *amdgpu_job_dependency(struct drm_sched_job *sched_job,
 			DRM_ERROR("Error adding fence (%d)\n", r);
 	}
 
+	if (!fence && job->gang_submit)
+		fence = amdgpu_device_switch_gang(ring->adev, job->gang_submit);
+
 	while (fence == NULL && vm && !job->vmid) {
 		r = amdgpu_vmid_grab(vm, ring, &job->sync,
 				     &job->base.s_fence->finished,
@@ -264,9 +267,6 @@ static struct dma_fence *amdgpu_job_dependency(struct drm_sched_job *sched_job,
 		fence = amdgpu_sync_get_fence(&job->sync);
 	}
 
-	if (!fence && job->gang_submit)
-		fence = amdgpu_device_switch_gang(ring->adev, job->gang_submit);
-
 	return fence;
 }