drm/xe: Ensure LR engines are not persistent

With our ref counting scheme long running (LR) engines only close
properly if not persistent, ensure that LR engines are non-persistent.

v2: spell out LR
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_engine.c

@@ -599,7 +599,9 @@ int xe_engine_create_ioctl(struct drm_device *dev, void *data,
 			return -ENOENT;
 
 		e = xe_engine_create(xe, vm, logical_mask,
-				     args->width, hwe, ENGINE_FLAG_PERSISTENT);
+				     args->width, hwe,
+				     xe_vm_no_dma_fences(vm) ? 0 :
+				     ENGINE_FLAG_PERSISTENT);
 		xe_vm_put(vm);
 		if (IS_ERR(e))
 			return PTR_ERR(e);