Chunming Zhou afe1008149 drm/amdgpu: add check for callback
it is possible that the callback isn't defined sometimes.

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian K?nig <christian.koenig@amd.com>
2015-08-17 16:50:39 -04:00
..
2015-08-17 16:50:39 -04:00