drm/amdgpu: double fence slot

we introduced vmid fence, so one hw submission could produce two fences.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -352,9 +352,9 @@ int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
 	setup_timer(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback,
 		    (unsigned long)ring);
 
-	ring->fence_drv.num_fences_mask = num_hw_submission - 1;
+	ring->fence_drv.num_fences_mask = num_hw_submission * 2 - 1;
 	spin_lock_init(&ring->fence_drv.lock);
-	ring->fence_drv.fences = kcalloc(num_hw_submission, sizeof(void *),
+	ring->fence_drv.fences = kcalloc(num_hw_submission * 2, sizeof(void *),
 					 GFP_KERNEL);
 	if (!ring->fence_drv.fences)
 		return -ENOMEM;