Sync files can go either to or from userspace. When a sync_file is sent from
the driver to userspace we call the fences it contains 'out-fences'. They are
related to a buffer that the driver is processing or is going to process, so
Sync files can go either to or from userspace. When a sync_file is sent from
the driver to userspace we call the fences it contains 'out-fences'. They are
related to a buffer that the driver is processing or is going to process, so